2006 ENTOMOLOGY RESEARCH Annual... · 2008. 2. 1. · Dupont Crop Protection Seed Treatments,...

2006 ENTOMOLOGY

RESEARCH

Texas A & M University Agricultural Research and Extension Center

Beaumont, Texas

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Table of Contents

Rice

Rice water weevil (Lissorhoptrus oryzophilus) 1. Syngenta Crop Protection, Inc. Rice Seed Treatments for Rice Water Weevil Control. Beaumont, TX ................................. 1 2. Dupont Crop Protection Seed Treatments, Granulars, and Water Surface Applications for Rice Water Weevil Control. Beaumont, TX........................................................................................................... 3 3. Valent U.S.A. Corporation Seed Treatments for Rice Water Weevil Control. Beaumont, TX ......................................... 5 4. Valent U.S.A. Corporation V-10170 Formulations for Rice Water Weevil Control. Beaumont, TX................................ 7 5. Host Plant Resistance to Rice Water Weevil. Beaumont, TX ................................................ 9 6. Planting Date vs. Rice Water Weevil. Beaumont, TX.......................................................... 13 7. Interaction of Sheath Blight and Rice Water Weevil Activity. Beaumont, TX.................... 18 8. Effect of Conventional Tillage and a Stale Seedbed on Rice Water Weevil Activity and Control. Eagle Lake, TX....................................................................................................... 21 9. Landis International and Mitsui Chemicals, Inc. Efficacy of Etofenprox for Rice Water Weevil Control in a Commercial Field. Jefferson Co., TX................................................................................................................... 23 Rice stink bug (Oebalus pugnax) 10. FMC Corporation Residual Activity of Mustang Max and Orthene 90S in Combination with Gibberellic Acid for Rice Stink Bug Control. Beaumont, TX................................................................. 24 11. Valent U.S.A. Corporation Residual Activity of V-10170, Venom and Orthene for Rice Stink Bug Control. Beaumont, TX........................................................................................................................ 26 12. Syngenta Crop Protection, Inc. Residual activity of Centric and Karate Z for Rice Stink Bug Control. Beaumont, TX ...... 28 Note: Additional rice stink bug research conducted by Luis Espino can be found in his dissertation to be published in 2007. Stalk borers 13. Evaluation of Insecticides for Stem Borer Control. Ganado, TX......................................... 30 14. Host Plant Resistance to Stem Borers. Ganado, TX............................................................. 33 15. Effect of Planting Date on Stem Borer Activity in Rice. Eagle Lake, TX ........................... 37 16. Trapping for Mexican Rice Borer. Texas Rice Belt ............................................................. 41 Chinch bug (Blissus leucopterus leucopterus) 17. Dupont Crop Protection Efficacy of Seed Treatments for Chinch Bug Control. Beaumont, TX................................ 42

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Table of Contents (continued)

Soybeans

Stink Bugs 18. Red-banded Stink Bug and Flat Pod Syndrome. Beaumont, TX.......................................... 43 19. Efficacy of Selected Insecticides for Control of Stink Bugs in a MGIV Soybean. Beaumont, TX........................................................................................................................ 48 20. Makhteshim Agan of North America Novaluron Research On Stink Bug Control In Soybean. Beaumont, TX............................. 51 21. Hornbeck Seed Co., Inc. Soybean Yield Trials. Beaumont, TX................................................................................... 56 22. Cooperator: Jim Heitholt. Texas Agricultural Experiment Station. Dallas, TX Preliminary MGVI Soybean Yield Trial. Beaumont, TX..................................................... 61

Sugarcane 23. Sugarcane Research. Beaumont, TX .................................................................................... 63

Tomatoes 24. Insecticide Screening Research on Tomatoes. Beaumont, TX............................................. 64

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Syngenta Crop Protection, Inc. Rice Seed Treatments for Rice Water Weevil Control

Beaumont, TX 2006

Agronomic and Cultural Information

Planting: Drill-planted Cocodrie @ 90 lb/A into League soil (pH 5.5, sand 3.2%, silt 32.4%, clay 64.4%, and organic matter 3.8 - 4.8%) on Apr 7 Plot size = 7 rows, 7 in. row spacing, 18 ft long with metal barriers around each plot Experimental design: randomized complete block with 4 replications Emergence on Apr 15 Irrigation: Flushed block (temporary flood for 48 hours, then drain) on Apr 7 Note: Plots were flushed as needed from emergence to permanent flood Permanent flood on May 5 Fertilization: All fertilizer (urea) was distributed by hand. 56.7 lb N/acre (a of 170) on Apr 7 at planting 56.7 lb N/acre (a of 170) on May 5 at permanent flood 56.7 lb N/acre (a of 170) on May 22 at panicle differentiation 40 lb N/acre on Jun 12 at late boot/heading (Total season N/acre = 210 lb N/acre) Herbicide: Stam 80EDF @ 2.0 lb, Basagran @ 0.75 lb, Facet 75DF @ 0.25 lb and Ordram @ 2.0 lb (AI)/acre and Agri-Dex @ 1.0 pt/acre with a 2-person hand-held spray boom (13- 80015 nozzles, 50 mesh screens, 21 gpa final spray volume) for early season weed control Treatments: See Table 1 for treatment descriptions and rates. Treatments 1 – 7 (seed treatments) were applied on Mar 31. Treatment 8 (Karate Z) applied before flood (BF) as a foliar spray with a hand- held CO2-pressurized spray boom (3-800067 nozzles, 50 mesh screens, 20 psi, 24 gpa) on May 5 Sampling: Stand counts (4- 3 ft counts in rows 2, 3, 5 and 6 of each plot) on Apr 24 Adult RWW feeding scars from 5 random plants per plot recorded 7 days after flood (DAF) on May 12 Rice water weevil (RWW) cores (5 cores per plot, each core 4 in. diameter, 4 in. deep, containing at least one rice plant) collected on May 26 (3 wks after permanent flood) and Jun 7 (12 days following first cores). Cores were later washed through 40-mesh screen buckets and immature RWW counted. Note: Prior to analysis RWW core data transformed using 5.0+x Harvest: Harvested plots on Aug 2 Size harvested plot = 7 rows, 7 in. row spacing, 18 ft long Yields converted to lb/acre and adjusted to 12% moisture

1

Rice Seed Treatments for Rice Water Weevil Control

Discussion

Plots emerged to good, uniform stands (test mean of 17 plants per foot of row). There were no significant differences in stand establishment among treatments. Dramatically fewer adult rice water weevil (RWW) feeding scars were observed in plots treated before flood (BF) with a foliar spray of Karate Z (Trt. 8). Feeding scars were also reduced in seed treatments containing Cruiser 5FS regardless of the rate (Table 1). Immature RWW in untreated plots were well above threshold level (about 15 per 5 cores) at the first sampling date (May 26). The low, mid and high rates of Cruiser 5FS in combination with the low, mid and high rates of A14006 (Trts. 4, 5, and 6) performed equally as well as the Karate Z foliar spray (Trt. 8). A14006 and Cruiser 5FS, each alone at the high rate (Trts. 2 and 3) were less effective at controlling immature RWW. Karate Z applied as a seed treatment (Trt. 7) showed absolutely no immature RWW efficacy. A question arose as to the possibility that seed for this treatment were inadvertently not treated. At the second sampling date (Jun 7), immature RWW declined across all treatments, including the untreated. All seed treatments, excluding Karate Z (Trt. 7), resulted in good immature RWW control by the second sampling date (about 5 weeks after permanent flood). Despite the high number of immature RWW in untreated plots, there were no significant differences in yield among treatments (Table 1). Untreated plots, however, yielded the lowest. On average, seed treatments (excluding Karate Z, Trt. 7) yielded only 300 lb/acre more than untreated. The Karate Z foliar spray resulted in a 450 lb/acre increase over untreated. With the elimination of Icon 6.2FS as a viable rice seed treatment for RWW, it is extremely important to continue research to identify and approve suitable alternatives. Table 1. Syngenta rice seed treatments for rice water weevil (RWW) control. Beaumont, TX. 2006

No. immature RWW/5 coresTrt. no. Description

Rate [g(AI)/100kg

seed] Timing

Adult RWW feeding

scars/plant May 26 Jun 7 Yield

(lb/acre) 1 Untreated --- --- 51 a 99 a 59 a 8578 2 A14006 50 STa 53 a 35 b 6 cd 8788 3 Cruiser 5FS 80 ST 25 c 19 bc 14 c 8821

4 A14006 + Cruiser 5FS 25 + 40 ST 34 bc 13 cd 8 cd 8607

5 A14006 + Cruiser 5FS 37.5 + 60 ST 28 c 10 cd 5 de 8946

6 A14006 + Cruiser 5FS 50 + 80 ST 25 c 4 d 3 de 9206

7 Karate Z 2.08CS 80 ST 41 ab 126 a 41 b 8637 8 Karate Z 2.08CS 34 BFb 5 d 5 d 1 e 9029 NS

a ST = seed treatment b BF = immediately before flood (foliar spray) Means in a column followed by the same or no letter are not significantly different (NS) at the 5% level (ANOVA, LSD).

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Dupont Crop Protection Seed Treatments, Granulars, and Water Surface Applications for Rice Water

Weevil Control

Agronomic and Cultural Information Planting: Drill-planted Cocodrie @ 90 lb/A into League soil (pH 5.5, sand 3.2%, silt 32.4%, clay 64.4%, and organic matter 3.8 - 4.8%) on May 17 Experimental design: randomized complete block with 4 replications Plot size = 7 rows, 7 in. row spacing, 18 ft long with metal barriers surrounding each plot Emergence on May 24 Irrigation: Flushed blocks (temporary flood for 48 hours, then drain) on May 17 Note: Plots were flushed as needed from emergence to permanent flood Permanent flood on Jun 14 Fertilization: All fertilizer (urea) was distributed by hand. 113.3 lb N/acre (⅔ of 170) on May 17 at planting 56.7 lb N/acre (a of 170) on Jun 29 at panicle differentiation 40 lb N/acre on Jul 19 at late boot/heading (Total season N/acre = 210 lb N/acre) Herbicide: Stam 80EDF @ 2.0 lb, Basagran @ 0.75 lb, Facet 75DF @ 0.25 lb and Ordram @ 2.0 lb (AI)/acre and Agri-Dex @ 1.0 pt/acre with a 2-person hand-held spray boom (13- 80015 nozzles, 50 mesh screens, 21 gpa final spray volume) on Jun 12 for early season weed control Treatments: See Table 1 for treatment descriptions and rates. Treatments 2 – 8 are seed treatments. Treatments 9 through 14 are granular treatments broadcast by hand on Jun 17 [3 days after permanent flood (DAF)]. Treatment 15 (Karate Z) applied as a foliar spray with a hand-held CO2- pressurized spray boom (3-800067 nozzles, 50 mesh screens, 20 psi, 24 gpa) on Jun 17 (3 DAF) Sampling: Stand counts (4- 3 ft counts in rows 2, 3, 5, and 6 of each plot) on Jun 2 Rice water weevil (RWW) cores (5 cores per plot, each core 4 in. diameter, 4 in. deep containing at least one rice plant) collected on Jul 7 (23 DAF) and Jul 17 (10 days following first cores). Cores were later washed through 40- mesh screen buckets and immature RWW counted. Note: Prior to analysis RWW core data transformed using 5.0+x Harvest: Harvested plots on Sep 17 Size harvested plot = 7 rows, 7 in. row spacing, 18 ft long Yields converted to lb/acre and adjusted to 12% moisture

3

Seed Treatments, Granulars, and Water Surface Application for Rice Water Weevil Control

Discussion

Plots emerged to good, uniform stands. There were no visual differences among treatments in stand establishment. Plant stands ranged from 10 – 14 plants per foot of row. Phytotoxicity was not observed in any treatment. On Jul 7, about 3 weeks after permanent flood, immature RWW were well above threshold level (about 15 per 5 cores) in untreated plots (Table 1). All seed treatments (Trts. 2 – 8) provided excellent control of immature RWW. Also, the high rate of treatment 10, a post-flood granular, provided excellent control. Generally, the post-flood (PF) broadcast granulars (Trts. 9 – 14), with the exception of Trt. 10, did not adequately control immature RWW populations by the first sampling date (Jul 7). The Karate Z foliar spray applied PF (Trt. 15) provided good control of immature RWW. Excellent control of immature RWW was maintained through the second sampling date (Jul 17) in all seed treatments, the high rate of PF broadcast granular C (Trt. 10), and Karate Z foliar spray applied PF. With the exception of Trt. 10, seed-treated plots generally out-yielded plots treated PF (both broadcast granulars and Karate Z foliar spray). On average, seed-treated plots resulted in a 600 lb/acre yield increase over PF-treated plots (excluding Trt. 10). It is extremely important to continue research to identify and approve effective seed treatments for RWW control.

Table 1. Dupont seed treatments, granulars, and water surface applications for rice water weevil (RWW). Beaumont, TX. 2006

Immature RWW/5 cores Trt. no. Treatment Rate Timinga Jul 7 Jul 17

Yield (lb/acre)

1 Untreated --- --- 104 a 30 a 6932 de 2 Fipronil one rate ST 9 de 4 c 7554 ab 3 A low ST 2 ef 1 cde 7381 abc 4 A mid ST 0 f 0 de 7507 ab 5 A high ST 0 f 0 e 7670 a 6 B low ST 4 ef 1 de 7405 abc 7 B mid ST 2 ef 1 de 7169 bcd 8 B high ST 0 f 1 cde 7304 abcd 9 C low PF 20 cd 2 cd 7001 cde 10 C high PF 7 de 1 cde 7395 abc 11 D low PF 50 b 16 b 6688 e 12 D high PF 53 b 10 b 6705 e 13 E low PF 65 b 13 b 6666 e 14 E high PF 28 c 13 b 6929 de 15 Karate Z one rate PF 8 de 3 cd 6924 de

a Timing: ST = seed treatment, PF = post-flood Means in a column followed by the same letter are not significantly different at the 5% level (ANOVA, LSD).

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Valent U.S.A. Corporation Seed Treatments for Rice Water Weevil Control

Beaumont, TX 2006


Planting: Drill-planted Cocodrie @ 90 lb/A into League soil (pH 5.5, sand 3.2%, silt 32.4%, clay 64.4%, and organic matter 3.8 - 4.8%) on Mar 27 Experimental design: randomized complete block with 4 replications Plot size = 7 rows, 7 in. row spacing, 18 ft long with metal barriers Emergence on Apr 5 Irrigation: Flushed blocks (temporary flood for 48 hours, then drain) on Mar 27 Note: Plots were flushed as needed from emergence to permanent flood Permanent flood on Apr 27 Fertilization: All fertilizer (urea) was distributed by hand. 42.5 lb N/acre (25% of 170) on Mar 27 at planting 59.5 lb N/acre (35% of 170) on Apr 27 at permanent flood 68 lb N/acre (40% of 170) on May 11 at panicle differentiation 40 lb N/acre on Jun 2 at late boot/heading (Total season N/acre = 210 lb N/acre) Herbicide: Stam 80EDF @ 2.0 lb, Basagran @ 0.75 lb, Facet 75DF @ 0.25 lb and Ordram @ 2.0 lb (AI)/acre and Agri-Dex @ 1.0 pt/acre with a 2-person hand-held spray boom (13- 80015 nozzles, 50 mesh screens, 16 gpa final spray volume) on Apr 11 for early season weed control Treatments: Seed treatments were applied on Mar 8 Karate Z applied before flood (BF) with a hand-held CO2-pressurized spray boom on Apr 27 (3-800067 nozzles, 50 mesh screens, 20 psi, 24 gpa) Sampling: Stand counts (4- 3 ft counts in rows 2, 3, 5, and 6 of each plot) on Apr 7 No phytotoxicity or vigor differences noted on Apr 10 and May 4 Adult rice water weevil (RWW) feeding scars recorded from 5 plants per plot on May 4 (7 days after permanent flood) RWW cores (5 cores per plot, each core 4 in. diameter, 4 in. deep containing at least one rice plant) were collected on May 17 and May 31, later washed through 40-mesh buckets and immature RWW counted. Note: Prior to analysis RWW core data transformed using 5.0+x No differences in root damage were noted between treatments and/or rates in 2nd core plants, however, more damage was noted in untreated than treated Harvest: Harvested plots on Jul 31 Size harvested plot = 5 middle rows, 7 in. row spacing, 18 ft long Yields converted to lb/acre and adjusted to 12% moisture

5

Seed Treatments for Rice Water Weevil Control

Discussion

Plots for all treatments emerged to uniform good stands (test mean of 17 plants per foot of row). There were no statistical differences in plant stands among treatments. Adult rice water weevil (RWW) feeding scars were recorded 7 days after permanent flood. Scars were significantly highest in untreated plots (Table 1) which indicates seed treatments may affect adult RWW feeding activity. Immature RWW counts from core samples in untreated plots on both sampling dates were well above threshold levels (about 15 per 5 cores). Karate Z (foliar spray) and the high and low rates of both V-10170 and V-10194 seed treatments provided excellent control of RWW larvae (Table 1). This control persisted through the second sampling date on May 31. Both the high and low rates of V-10170 and V-10194 provided significant yield responses when compared to plots untreated for RWW. Seed treatments averaged 7970 lb/acre. Plots treated with Karate Z yielded 7593 lb/acre. On average, seed treatments resulted in a 1610 lb/acre yield advantage over untreated seed. With the elimination of Icon 6.2FS as a viable rice seed treatment for RWW, it is extremely important to continue research to identify and approve suitable alternatives.

Table 1. Valent seed treatments for rice water weevil (RWW) control. Beaumont, TX. 2006.

No. immature RWW/5 cores

Treatment Rate

[g (AI)/hkg] TimingRWW feeding

scars/plant May 17 May 31 Yield

(lb/acre) Untreated --- --- 18.7 a 90 a 65 a 6356 b

Karate Z 0.03 lb (AI)/acre BFa 6.0 bc 1 b 0 b 7593 a

V-10170 250 STb 4.2 bc 0 b 1 b 8112 a

V-10170 500 ST 2.9 c 0 b 1 b 7946 a

V-10194 250 ST 8.1 b 1 b 2 b 7800 a

V-10194 500 ST 2.9 c 0 b 1 b 8025 a a BF = immediately before flood b ST = seed treatment Means in a column followed by the same letter are not significantly different at the 5% level (ANOVA, LSD).

6

7

Valent U.S.A. Corporation V-10170 Formulations for Rice Water Weevil Control

Beaumont, TX 2006


Planting: Drill-planted Cocodrie @ 90 lb/A into League soil (pH 5.5, sand 3.2%, silt 32.4%, clay 64.4%, and organic matter 3.8 - 4.8%) on Apr 20 Randomized complete block with 4 replications Plot size = 7 rows, 7 in. row spacing, 18 ft long with metal barriers around plots Emergence on Apr 28 Irrigation: Flushed blocks (temporary flood for 48 hours, then drain) on Apr 20 Note: Plots were flushed as needed from emergence to permanent flood Permanent flood on May 19 (3 weeks after emergence) Fertilization: All fertilizer (urea) was distributed by hand. 56.7 lb N/acre (⅓ of 170) on Apr 20 at planting 56.7 lb N/acre (⅓ of 170) on May 19 at permanent flood 56.7 lb N/acre (⅓ of 170) on Jun 2 at panicle differentiation 40 lb N/acre on Jun 23 at late boot/heading (Total season N/acre = 210 lb N/acre) Herbicide: Stam 80EDF @ 2.0 lb, Basagran @ 0.75 lb, Facet 75DF @ 0.25 lb and Ordram @ 2.0 lb (AI)/acre and Agri-Dex @ 1.0 pt/acre with a 2-person hand-held spray boom (13- 80015 nozzles, 50 mesh screens, 16 gpa final spray volume) on May 12 for early season weed control Treatments: Karate Z and V-10170 50WDG were applied as a foliar spray with a hand-held CO2-pressurized spray boom (3-800067 nozzles, 50 mesh screens, 20 psi, 24 gpa). V-10170 GR (granular formulation) was distributed by hand. Before flood (BF) treatments applied on May 19 3 days after flood (DAF) treatments applied on May 22 12 DAF treatments applied on May 31 See Table 1 for treatment descriptions and rates. Sampling: Stand counts (4- 3 ft counts in rows 2, 3, 5 and 6 of each plot) on May 10 Rice water weevil (RWW) cores (5 cores per plot, each core 4 in. diameter, 4 in. deep, containing at least one rice plant) were collected on Jun 9 and 19, washed through 40-mesh screen buckets and immature RWW counted. Note: Prior to analysis RWW core data transformed using 5.0+x Harvest: Harvested plots on Aug 17 (time from emergence to harvest = 111 days) Size harvested plot = 7 rows, 7 in. row spacing, 18 ft long Yields converted to lb/acre and adjusted to 12% moisture

V-10170 Formulations for Rice Water Weevil Control

Discussion

Plots emerged to uniform, good stands. Three weeks after permanent flood, immature rice water weevil (RWW) were well above threshold levels (about 15 per 5 cores) in untreated plots. All treatments (Karate Z, V-10170 50WDG and V-10170 GR) provided good control of immature RWW at the first sampling date (Table 1). This control persisted through the second sampling date on Jun 19. Also, there was a natural decline in immature RWW populations as observed in untreated plots. The three days after flood (DAF) application of V-10170 GR (both the high and low rate) performed as well as in combination with the V-10170 50WDG foliar spray applied before flood (BF). As observed in previous research, timing of application was extremely important. BF and 3 DAF applications statistically outperformed 12 DAF applications. However, the 12 DAF applications of both the high and low rate of V-10170 GR still effectively controlled immature RWW. Due to variability in harvest data, there was not a statistical difference in yield among treatments. However, all treatments out-yielded untreated plots. On average, plots receiving a BF treatment resulted in a 570 lb/acre yield advantage over the untreated. Three and 12 DAF treatments, on average, provided only a 150 lb/acre increase over the untreated. The V10170 GR formulation applied BF and 3 DAF proved very effective at controlling immature RWW. The V-10170 50WDG formulation applied alone as a foliar spray has been tested in another experiment (See "Planting Date vs. Rice Water Weevil"). These data will help confirm the efficacy of this formulation.

Table 1. V-10170 formulations for rice water weevil (RWW) control. Beaumont, TX. 2006.


Treatment Rate

[lb (AI)/acre] Timing Jun 9 Jun 19 Yield

(lb/acre) Untreated --- --- 107 a 59 a 8631

Karate Z 0.03 BFa 1 c 1 bc 9085 V-10170 50WDG + V-10170 GR 1.5 oz prod + 0.187 BF + 3 DAF

b 0 c 1 bc 9351

V-10170 50WDG + V10170 GR 1.5 oz prod + 0.187 BF + 12 DAF 0 c 0 c 9164

V-10170 GR 0.187 3 DAF 1 c 1 bc 8775

V-10170 GR 0.187 12 DAF 7 b 2 bc 8792

V-10170 GR 0.094 3 DAF 0 c 4 b 8721

V-10170 GR 0.094 12 DAF 10 b 2 bc 8849

NS a BF = immediately before permanent flood b DAF = days after permanent flood Means in a column followed by the same or no letter are not significantly different (NS) at the5% level (ANOVA, LSD).

8

Host Plant Resistance to Rice Water Weevil Beaumont, TX

2006

Agronomic and Cultural Information Planting: Drill-planted test into League soil (pH 5.5, sand 3.2%, silt 32.4%, clay 64.4%, and organic matter 3.8 - 4.8%) on Mar 24 Experimental design: Split plot with 4 replications; main plot = genotype; sub plot = seed-treated or untreated for rice water weevil (RWW) with Icon 6.2FS at 0.05 lb (AI)/acre Plot size = 7 rows, 7 in. row spacing, 18 ft long (no barriers) Conventional cultivars are CL131, CL161, Cocodrie, Trenasse, Bengal and Jupiter seeded @ 90 lb/acre; hybrids are CL XL730, CL XP729, and XL723 seeded @ 35 lb/acre Emergence on Apr 10 Irrigation: Flushed blocks (temporary flood for 48 hours, then drain) on Mar 24 Note: Plots were flushed as needed from emergence to permanent flood Permanent flood on Apr 27 Fertilization: All fertilizer (urea) was distributed by hand. CL131, CL161, Cocodrie, Trenasse, and Jupiter: 42.5 lb N/acre (25% of 170) on Mar 24, 59.5 lb N/acre (35% of 170) on Apr 27 (preflood), 68.0 lb N/acre (40% of 170) on May 11 and 40.0 lb N/acre on Jun 2 (Total season nitrogen = 210 lb N/acre) Bengal: 37.5 lb N/acre (25% of 150) on Mar 24, 52.5 lb N/acre (35% of 150) on Apr 27 (preflood), 60.0 lb N/acre (40% of 150) on May 11, 40.0 lb N/acre on Jun 2 (Total season nitrogen = 190 lb N/acre) CL XL730, CL XP729, and XL723: 120.0 lb N/acre (67% of 180) on Apr 27 (preflood) and 60.0 lb N/acre (33% of 180) on Jun 22 (Total season nitrogen = 180 lb N/acre) Herbicide: Applied Stam 80EDF @ 2.0 lb, Basagran @ 0.75 lb, Facet 75DF @ 0.25 lb and Ordram 8E @ 2.0 lb (AI)/acre and Agri-Dex @ 1.0 pt/acre with a 2-person hand- held spray boom (13- 80015 nozzles, 50 mesh screens, 21 gpa final spray volume) on Apr 14 Treatments: Applied Icon 6.2FS @ 0.05 lb (AI)/acre on Mar 21 (CL XL730 and XL723) and Mar 22 (CL XP729, CL131, CL161, Cocodrie, Trenasse, Bengal, and Jupiter) to all seed to be planted in plots designated as treated (T) for RWW

9

Host Plant Resistance to Rice Water Weevil

Agronomic and Cultural Information (continued) Sampling: Stand counts (4- 3 ft counts in rows 2, 3, 5, and 6 of each plot) on Apr 10 RWW cores (5 cores per plot, each core 4 in. diameter, 4 in. deep containing at least one rice plant) collected on May 18 and May 31. Cores were placed in cold storage and later washed through 40-mesh buckets and immature RWW (larvae and pupae) counted. Note: Prior to analysis RWW core data were transformed using 5.0+x . Harvest: Harvested plots (CL131, CL161, Cocodrie, and Trenasse) on Aug 1 and (Bengal, Jupiter, CL XL730, CL XP729, and XL723) on Aug 8 Size harvested plot = 4 middle rows, 7 in. row spacing, 18 ft long (0.001 acres) Yields were converted to lb/acre and adjusted to 12% moisture. No lodging was observed in any plots.

Discussion

As expected, plants stands (plants/ft of row) were significantly lower for hybrids than the non-hybrids, but the hybrids out-yielded all other varieties in the experiment (Tables 1 and 2). Populations of rice water weevil (RWW) were high in all untreated plots on both sample dates (May 18 and 31), regardless of variety. Thus, none of the tested varieties exhibited antibiosis. Unfortunately, Icon 6.2FS seed treatments did not provide desired control in treated plots. Lack of desired efficacy was probably due to age of the Icon 6.2FS. We were unable to procure "fresh" stocks of Icon 6.2FS since it is no longer registered and available. Next year, we will apply a pyrethroid (preflood) to effectively control RWW. Across varieties, Icon 6.2FS gave only 71% control of RWW. In fact, treated plots of all tested varieties harbored RWW populations greater than the economic injury level of about 15 immatures per five cores. Across varieties the mean yield increase (from untreated to treated) was 404 lb/acre which showed the severity of RWW damage in untreated plots. Bengal and Cocodrie were affected most by RWW – more than 1000 lb/acre difference in yield between treated and untreated plots. CL XL730 and CL XP729 were affected least, so these hybrids exhibited tolerance to RWW attack. See Tables 1-2 below.

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Discussion (continued) Table 1. Host plant resistance to rice water weevil (RWW). Beaumont, TX. 2006


Genotype TreatmentaPlants/ft of row May 18 May 31

Yield (lb/acre)

T – U Yield

(lb/acre) Bengal T 11 35 54 7823 1054 U 11 82 82 6769

CL131 T 20 30 40 6080 523 U 19 88 74 5557 CL161 T 19 35 40 6720 380 U 19 77 62 6340 CL XL730 T 8 16 37 8991 -19 U 9 78 102 9010 CL XP729 T 8 22 40 8939 17 U 6 95 111 8922 Cocodrie T 17 21 35 7107 1020 U 17 79 63 6087

Jupiter T 14 23 29 8772 71 U 15 90 86 8701 Trenasse T 14 23 32 6670 90 U 14 91 80 6580 XL723 T 8 23 48 9929 501 U 8 94 89 9428 a T = seed-treated for RWW with Icon 6.2FS at 0.05 lb (AI)/acre, U = untreated

See Table 2 below.

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Discussion (continued)

Table 2. Statistical analysis of host plant resistance to rice water weevil (RWW). Beaumont, TX. 2006

No. Immature RWW/5 cores

Plants/ft of row May 18 May 31

Yield (lb/acre)

Main plot (variety): Bengal 11 d 59 68 7296 c CL131 19 a 59 57 5819 e CL161 19 a 56 51 6530 d CL XL730 9 e 47 70 9001 b CL XP729 7 f 59 76 8930 b Cocodrie 17 b 50 49 6597 d Jupiter 14 c 57 58 8736 b Trenasse 14 c 57 56 6625 d XL723 8 ef 59 69 9679 a NS NS Sub plot (treated or untreated for RWW): Treated 13 25 b 39 b 7892 a Untreated 13 86 a 83 a 7488 b NS Interaction: Main plot x sub plot NS NS NS NS Means in a column followed by the same or no letter are not significantly different (NS) at the 5% level (ANOVA, LSD).

12

Planting Date vs. Rice Water Weevil Beaumont, TX

2006

Introduction

This experiment is a continuation of a multi-year study to investigate the relationship between rice planting date and rice water weevil (RWW) activity. Determining yield response to RWW damage relative to planting date was the main objective of these experiments. Another objective was to evaluate the efficacy of labeled RWW insecticides in changing population densities observed across different planting dates. Five planting dates were conducted at the Beaumont Center. Cultural practices basically were the same for all planting dates (see below).


Planting dates: Drill-seeded Cocodrie @ 90 lb/acre into League soil (pH 5.5, sand 3.2%, silt

32.4%, clay 64.4% and organic matter 3.8-4.8%) Plot size = 7 rows, 7 in. row spacing, 18 ft long with metal barriers around plots Experimental design: randomized complete block with 4 replications Irrigation: Flushed plots after planting (temporary flood for 48 hours, then drain) Note: Plots were flushed as needed from emergence to permanent flood Permanent flood approximately 3 wk after emergence Herbicide: Stam 80EDF @ 2.0 lb, Basagran @ 0.75 lb, Facet 75DF @ 0.25 lb and Ordram @

2.0 lb (AI)/acre and Agri-Dex @ 1.0 pt/acre applied approximately 10-14 days after emergence for early season weed control

Fertilizer: Urea was applied by hand according to 2004 Rice Production Guidelines. All dates received 170 lb N/acre plus an additional 40 lb N/acre late season. Treatments: All treatments are foliar sprays applied with a hand-held spray boom (3- 800067

nozzles, 50 mesh screens, 25 gpa) See Table 1 for treatment descriptions, timing and rates. Sampling: RWW cores (5 cores per plot, each core 4 in. diameter, 4 in. deep, containing at

least one rice plant) were collected approximately 3 wk after permanent flood and 10-14 days following. Core samples were stored in a cold-room, later washed through 40 mesh screen buckets and immature RWW counted.

Note: Prior to analysis RWW counts transformed using square root (x + 0.5) Harvest: Entire plot harvested for yield Yields converted to lb/acre adjusted to 12% moisture

13

Planting Date vs. Rice Water Weevil

Discussion

In each planting date, all insecticide treatments controlled immature RWW except in the Jun 7 planting (Table 1). The before flood (BF) applications of Karate Z, Silencer and V10170 50WDG in the Jun 7 planting provided significant control of immature RWW. Best yield response to controlling RWW occurred in the earliest plantings (Mar 10 and 28). Yield response in later plantings was less pronounced. Heaviest RWW infestations occurred in the late March planting. Previous research indicates yield potential declines after an optimum planting window. In this experiment, yields declined significantly in the May 12 and Jun 7 plantings despite controlling immature RWW.

Table 1. Rice water weevil (RWW) and yield data. Beaumont, TX. 2006

No. immature RWW/5 cores Yield (lb/acre)

Description

Rate [lb

(AI)/acre] Timing 1st cores 2nd cores Main Ratoon Total Mar 10 planting date Untreated --- --- 40 a 112 a 7113 b 1905 9018 b Karate Z 0.0300 BFa 0 b 3 d 8212 a 2232 10444 a Karate Z 0.0300 3 DAFb 2 b 2 d 8405 a 2183 10588 a Mustang Max 0.0225 BF 1 b 9 bc 7776 ab 2065 9842 ab Mustang Max 0.0225 3 DAF 0 b 6 bcd 8252 a 2139 10390 a Prolex 0.01625 BF 0 b 3 d 8034 a 2189 10223 a Prolex 0.01625 3 DAF 1 b 4 cd 8250 a 2149 10400 a Dimilin 2L 0.1875 3 DAF 0 b 10 b 7856 a 2121 9978 a NS Mar 28 planting date Untreated --- --- 116 a 119 a 8832 1905 b 10737 Karate Z 0.0300 BF 2 bc 2 bc 9332 2696 a 12027 Karate Z 0.0300 3 DAF 2 bc 1 c 9413 2787 a 12200 Mustang Max 0.0225 BF 2 bc 4 b 9220 2673 a 11892 Mustang Max 0.0225 3 DAF 3 b 1 c 9406 2451 a 11857 Prolex 0.01625 BF 0 c 1 c 9370 2676 a 12045 Prolex 0.01625 3 DAF 2 bc 1 c 9605 2647 a 12251 Dimilin 2L 0.1875 3 DAF 5 b 2 bc 9098 2597 a 11695 NS NS a BF = immediately before permanent flood b DAF = days after flood Means in a column followed by the same or no letter are not significantly different (NS) at the 5% level (ANOVA, LSD).

Table 1 continued below

14


Table 1. Rice water weevil (RWW) and yield data (continued). Beaumont, TX. 2006

No. immature RWW/5 cores Yield (lb/acre) Description

Rate [lb (AI)/acre] Timing 1st cores 2nd cores Main Ratoon Total

Apr 14 planting date Untreated --- --- 61 a 83 a 9062 2675 11737 Karate Z 0.0300 BFa 1 cd 5 d 8866 2582 11448 Karate Z 0.0300 3 DAFb 2 bc 9 cd 9352 2558 11909 Mustang Max 0.0225 BF 0 d 19 bc 8645 2333 10978 Mustang Max 0.0225 3 DAF 1 cd 23 b 8575 2440 11015 Prolex 0.01625 BF 0 d 9 cd 9179 2702 11880 Prolex 0.01625 3 DAF 5 b 8 cd 8793 2324 11117 Dimilin 2L 0.1875 3 DAF 5 b 3 d 9184 2452 11635 NS NS NS May 12 planting date Untreated --- --- 59 a 34 a 7540 NA NA Karate Z 0.0300 BF 3 d 1 e 7716 NA NA Karate Z 0.0300 3 DAF 15 c 7 bcd 7542 NA NA Mustang Max 0.0225 BF 4 d 5 cd 7334 NA NA Mustang Max 0.0225 3 DAF 18 bc 11 bc 7567 NA NA Prolex 0.01625 BF 4 d 3 de 7599 NA NA Prolex 0.01625 3 DAF 19 bc 8 bc 7673 NA NA Dimilin 2L 0.1875 3 DAF 26 b 13 b 7810 NA NA NS Jun 7 planting date Untreated --- --- 75 a 37 a 5484 NA NA Karate Z 0.0300 BF 16 fg 9 b 5654 NA NA Karate Z 0.0300 3 DAF 50 bc 12 b 5523 NA NA Mustang Max 0.0225 BF 23 ef 17 b 5450 NA NA Mustang Max 0.0225 3 DAF 40 cd 15 b 5507 NA NA Prolex 0.01625 BF 28 de 16 b 5822 NA NA Prolex 0.01625 3 DAF 61 ab 16 b 5264 NA NA Dimilin 2L 0.1875 3 DAF 77 a 36 a 5497 NA NA Silencer 0.03 BF 13 fg 8 b 5911 NA NA V-10170 50WDG 1.5oz prod./acre BF 8 g 14 b 5909 NA NA V-10170 50WDG 1.5oz prod./acre 11 DAF 43 bcd 15 b 5725 NA NA NS a BF = immediately before permanent flood b DAF = days after flood Means in a column followed by the same or no letter are not significantly different (NS) at the 5% level (ANOVA, LSD).

15



Table 2 shows comparisons between untreated plots and the average of all insecticide treatments for each planting date. Previous research suggests controlling RWW in the main crop can contribute to ratoon yield. This is most evident in the Mar 28 planting where main crop treated rice ratooned over 700 lb/acre more than untreated rice. Table 3 examines the means of all treatments (including the untreated) within each planting date. Immature RWW data are less instructive in this analysis. However, yield data confirm earliest planting dates have the greatest yield potential. Early March plantings avoided heavier RWW infestations but suffered from colder temperatures at planting and emergence. Heaviest RWW pressure tended to coincide with optimum planting date (mid March to mid April), suggesting treatment for this pest continue to be an integral part of rice management.

Table 2. Comparison of treated and untreated plots for each planting date. Bmt., TX. 2006

No. immature RWW/5 cores Yield (lb/acre) Planting Date Treatmenta 1st cores 2nd cores Main Ratoon Total Mar 10 T 1 5 8112 2154 10266 U 40 112 7113 1905 9018 Mar 28 T 2 2 9349 2647 11996 U 116 119 8832 1905 10737 Apr 14 T 2 11 8942 2484 11426 U 61 83 9062 2675 11737 May 12 T 13 7 7606 NA 7606 U 59 34 7540 NA 7540 Jun 7 Tb 42 17 5531 NA 5531 U 75 37 5484 NA 5484 a T = treated for RWW, U = untreated b treated plots from Jun 7 planting date do not include Silencer and V-10170 50WDG treatments Table 3. Comparison of mean data for all treatmentsa within each planting date. Bmt., TX. 2006

No. immature RWW/5 cores Yield (lb/acre) Planting Date 1st cores 2nd cores Main Ratoon Total March 10 5 18 7987 2123 10110 March 28 16 16 9284 2554 11838 April 14 9 20 8957 2508 11465 May 12 18 10 7597 NA 7597 June 7 46 20 5525 NA 5525 a Mean data include untreated plots and does not include Silencer and V-10170 50WDG treatments

from June 7 planting date See economic analysis below.

16



Treating for RWW (especially on the Mar 10 and 28 plantings) provided a significant yield advantage (Table 4). Also, the economic advantage in $/acre was highest in these earliest planting dates (Table 5). Economic data are calculated using the following parameters concerning insecticide costs, aerial application charges and cwt price of rice: $6.90/cwt price of rice (ca. loan rate, does not include hauling and drying costs) Karate Z applied BF: $412.25/gal (no aerial charge if tank-mixed with pre-flood herbicides) Karate Z applied 3 DAF: $412.25/gal + $7.50/acre aerial charge Mustang Max applied BF: $227.76/gal (no aerial charge if tank-mixed with pre-flood herbicides) Mustang Max applied 3 DAF: $227.76/gal + $7.50/acre aerial charge Prolex applied BF: $395.00/gal (no aerial charge if tank-mixed with pre-flood herbicides) Prolex applied 3 DAF: $395.00/gal + $7.50/acre aerial charge Dimilin 2L applied 3 DAF: $186.75/gal + $7.50/acre aerial charge

Table 4. Yield advantage of RWW treatments across five planting dates. Beaumont, TX. 2006

Yield advantage [Treated – Untreated (lb/acre)] Treatment

Timing Mar 10 Mar 28 Apr 14 May 12 Jun 7

Meana (lb/acre)

Karate Z BF 1426 1290 -289 176 170 555 Karate Z 3 DAF 1570 1463 172 2 39 649 Mustang Max BF 824 1155 -759 -206 -34 196 Mustang Max 3 DAF 1372 1120 -722 27 23 364 Prolex BF 1205 1308 143 59 338 611 Prolex 3 DAF 1382 1514 -620 133 -220 438 Dimilin 2L 3 DAF 960 958 -102 270 13 420

Meanb advantage (lb/acre) 1248 1258 -311 66 47 a Mean yield advantage for each individual treatment across five planting dates b Mean yield advantage for each individual planting date across all treatments Table 5. Economic advantage of RWW treatments across five planting dates. Bmt., TX. 2006

Net return ($/acre) Treatment

Timing Mar 10 Mar 28 Apr 14 May 12 Jun 7

Meana ($/acre)

Karate Z BF 92.41 83.03 -25.92 6.16 5.75 32.29 Karate Z 3 DAF 94.85 87.47 -1.61 -13.34 -10.79 31.31 Mustang Max BF 50.45 73.72 -58.35 -20.19 -8.33 7.46 Mustang Max 3 DAF 88.69 71.30 -55.80 -4.12 -4.39 19.14 Prolex BF 78.02 85.12 4.74 -1.06 18.19 37.00 Prolex 3 DAF 82.73 91.84 -55.41 -3.45 -27.81 17.58 Dimilin 2L 3 DAF 41.07 40.93 -32.21 -6.54 -24.27 3.80

Meanb advantage ($/acre) 75.46 76.20 -32.08 -6.08 -7.38 a Mean $/acre advantage for each individual treatment across five planting dates b Mean $/acre advantage for each individual planting date across all treatments

17

Interaction of Sheath Blight and Rice Water Weevil Activity Beaumont, TX

2006

Agronomic and Cultural Information Planting: Drill-planted Cocodrie @ 80 lb/A and Jefferson @ 116 lb/A into League soil (pH 5.5, sand 3.2%, silt 32.4%, clay 64.4%, organic matter 3.8 - 4.8%) on Apr 12 Plot size = 7 rows, 7 in. row spacing, 18 ft long Experimental design: split-split plot with 6 replications; main plot = variety; sub plot = treated for (RWW) with Icon 6.2FS or untreated; sub-sub plot = inoculated with Rhizoctonia solani (SB) or not inoculated (NI) Cocodrie emerged on Apr 19 and Jefferson on Apr 20. Irrigation: Flushed blocks (temporary flood for 48 hours, then drain) on Apr 12 Note: Plots were flushed as needed from emergence to permanent flood Permanent flood on May 15 Fertilization: All fertilizer (urea) was distributed by hand. 56.7 lb N/acre (⅓ of 170) on Apr 12 at planting 56.7 lb N/acre (⅓ of 170) on May 15 at permanent flood 56.7 lb N/acre (⅓ of 170) on May 31 at panicle differentiation 40 lb N/acre on Jun 22 at late boot/heading (Total season N/acre = 210 lb N/acre) Herbicide: Stam 80EDF @ 2.0 lb, Basagran @ 0.75 lb, Facet 75DF @ 0.25 lb and Ordram @ 2.0 lb (AI)/acre and Agri-Dex @ 1.0 pt/acre with a 2-person hand-held spray boom (13- 80015 nozzles, 50 mesh screens, 16 gpa final spray volume) on May 12 Treatments: Treated ½ both varieties of seed with Icon 6.2FS @ 0.05 lb (AI)/acre on Apr 10 SB plots were inoculated by Don Groth with 150 ml of SB inoculum on Jun 14. Quadris was applied @ 10 oz/acre with a hand-held CO2-pressurized spray boom (33 gpa) on Jun 14 and 28 to all NI plots to control natural SB. Sampling: Stand counts (3- 3 ft counts in the middle rows of each plot) on Apr 27 SB ratings were recorded on Aug 9 (Don Groth). Ratings were atypically high for NI plots due to high rainfall in July and August. RWW cores (5 cores per plot, each core 4 in. diameter, 4 in. deep containing at least one rice plant) were collected on Jun 5 and 15. Cores were washed through 40-mesh screen buckets and immature RWW counted. Note: Prior to analysis RWW core data transformed using 5.0+x Harvest: Harvested plots on Aug 9 Size harvested plot = 7 rows, 7 in. row spacing, 18 ft long Yields converted to lb/acre and adjusted to 12% moisture

18

Interaction of Sheath Blight and Rice Water Weevil Activity

Discussion Cocodrie and Jefferson were planted at individual seeding rates in an attempt to achieve equal plant stands. Cocodrie emerged to a slightly higher plant population (15 plants/ft of row compared to 14 for Jefferson). In RWW-treated plots (T), Icon 6.2 FS was less than satisfactory at controlling RWW, but numbers were reduced enough to make comparisons (Table 1). SB ratings in non-inoculated (NI) plots were higher than desired and similar to artificially inoculated plots. This made interaction comparisons between RWW infestation and SB inconclusive. Jefferson, as observed in previous host plant resistance studies, was less infested with immature RWW than Cocodrie. NI plots of both varieties were equally affected by natural SB despite two applications of Quadris. In plots treated for RWW, Cocodrie was most affected by the artificial SB inoculation (about 520 lb/acre yield loss when compared to NI plots). As expected, a positive yield response occurred in varietal interaction with RWW treatment and varietal interaction with SB (Table 2). Although this experiment showed a significant interaction between RWW treatment and SB for the first RWW cores (Jun 5), data from previous years indicate that RWW infestations and resulting root damage are probably not a factor in the later-arriving SB organism and severity of the disease. Table 1. Interaction of sheath blight (SB) and rice water weevil (RWW) activity. Beaumont, TX. 2006

No. immature RWW/5 cores Variety RWWa SBb

SB ratingc Jun 5 Jun 15

Yield (lb/acre)

Cocodrie U NI 5 61 68 8328 Cocodrie U SB 8 53 58 7717 Cocodrie T NI 5 20 35 8270 Cocodrie T SB 7 19 40 7748 Jefferson U NI 5 46 39 5820 Jefferson U SB 7 36 36 5942 Jefferson T NI 5 9 30 6361 Jefferson T SB 7 14 25 6169 a RWW: T = seed-treated for RWW with Icon 6.2FS at 0.05 lb (AI)/acre, U = untreated b Sheath blight: SB = each plot inoculated with 150 ml SB inoculum, NI = not inoculated, sprayed with 2 applications of Quadris

c Sheath blight rating (0-9): 0 = no disease, 9 = dead and collapsed See Table 2 below.

19

Interaction of Sheath Blight and Rice Water Weevil Activity

Discussion (continued) Table 2. Statistical analysis of Table 1. Beaumont, TX. 2006

No. immature RWW/5 cores SB ratinga Jun 5 Jun 15

Yield (lb/acre)

Main plot (variety) effects: Cocodrie 6.3 a 38 a 50 a 8016 a Jefferson 6.0 a 26 b 33 b 6073 b Sub plot (T or U for RWW) effects: Treatedb 6.0 16 b 33 b 7137 a Untreated 6.5 49 a 50 a 6952 b Sub-sub plot (SB or NI) effects: SB-inoculatedc 7.3 a 31 40 6894 b Not inoculated 5.0 b 34 43 7195 a Interactions: Main plot x sub plot

NS

NS

SIG (P>0.0320)

SIG (P>0.0100)

Main plot x sub-sub plot

NS

NS

NS

SIG (P>0.0009)

Sub plot x sub-sub plot

NS

SIG (P>0.0301)

NS

NS

Main plot x sub plot x sub-sub plot

NS

NS

NS

NS

a Sheath blight rating (0-9): 0 = no disease, 9 = dead & collapsed b Treated = seed-treated for RWW with Icon 6.2FS at 0.0375 lb (AI)/acre c Each plot inoculated with 150 ml SB inoculum Means in a column followed by the same or no letter are not significantly different (NS) at the 5% level (ANOVA, LSD).

20

Effect of Conventional Tillage and a Stale Seedbed on Rice Water Weevil Activity and Control

Eagle Lake, TX 2006


Land preparation: Stale seedbed (SSB) area was worked in fall 2005 and sprayed with Roundup

several times prior to planting and sprayed with Command and Roundup before rice emergence (See Herbicide).

Conventional tillage (CONV) area was disked, worked with a roterra and leveled with a harrow just prior to planting.

Planting date: Cocodrie was drill-seeded into Nada soil (CONV and SSB) @ 90 lb/acre on

Mar 27 Plot size = 16 rows, 7.5 in. row spacing, 16 ft long Experimental design: split plot with 4 replications; main plot = tillage CONV

or SSB; sub plot = RWW treatment (Icon 6.2FS, Karate Z, or untreated) Barriers were erected around the 7 middle rows of Karate Z plots to prevent

interplot movement of insecticide when applied. Herbicide: Command @ 0.2 and Roundup @ 1.0 lb (AI)/acre on Mar 31 Command 3ME @ 0.3 and Propanil @ 2.0 lb (AI)/acre on Apr 19 Propanil @ 2.0 and Permit @ 0.06 lb (AI)/acre on May 2 Fertilizer: 45-45-45 (lbs N-P-K/acre) on Apr 12 (after emergence) 70 lb N/acre (urea) on May 3 (just prior to permanent flood) 70 lb N/acre (ammonium sulfate) on May 24 (PD) Total season nitrogen = 185 lb N/acre RWW treatments: Icon 6.2FS: seed treatment applied @ 0.0375 lb (AI)/acre on Mar 13 Karate Z: foliar spray applied @ 0.03 lb (AI)/acre immediately before

permanent flood with a hand-held CO2-pressurized spray boom (3- 800067 nozzles, 50 mesh screens, 25 psi, 26 gpa final spray volume) on May 4

RWW sampling: Rice water weevil (RWW) cores (5 cores per plot, each core 4 in. diameter, 4 in. deep, containing at least one rice plant) collected on May 26 (3 wks after permanent flood) and Jun 9 (14 days following first cores) Cores were later washed through 40-mesh screen buckets and immature RWW counted. Prior to analysis RWW counts were transformed using x + 05. . Harvest: Harvested plots on Aug 1 Size harvested plot = 6 middle rows, 7.5 in. row spacing, 16 ft long Yields were converted to lb/acre and adjusted to 12% moisture.

21

Effect of Conventional Tillage and a Stale Seedbed on Rice Water Weevil Activity and Control

Discussion

Immature RWW populations were similar in untreated plots of both the stale seedbed (SSB) and conventionally tilled (CONV) areas and well above threshold (about 15 per 5 cores). Tillage practice apparently did not affect adult RWW activity and subsequent larval infestation. Treatments for RWW (Icon 6.2FS and Karate Z) were generally more effective on SSB than CONV (Table 1). Icon 6.2FS, in contrast to Karate Z, did not control RWW as effectively as is normally observed (especially on CONV). Tillage practice may affect the efficacy of insecticides based on method of application (seed treatment vs. foliar spray), but results from this experiment are not conclusive. Although Karate Z controlled RWW, a positive yield response was not observed. Yields across all treatments in SSB and CONV were similar and not statistically different (Table 2). Table 1. Effect of conventional tillage and a stale seedbed on rice water weevil (RWW) activity and control. Eagle Lake, TX. 2006

No. immature RWW/5 cores Tillage Treatment Timing May 26 Jun 9

Yield (lb/acre)

Conventional Icon 6.2FS STa 28 28 8078 Karate Z BFb 6 5 8495 Untreated --- 66 56 7576 Stale seedbed Icon 6.2FS ST 12 15 8377 Karate Z BF 1 7 8365 Untreated --- 64 48 7784 a ST = seed treatment b BF = immediately before flood Table 2. Statistical analysis of Table 1. Eagle Lake, TX. 2006

No. immature RWW/5 cores May 26 Jun 9

Yield (lb/acre)

Main plot (tillage): Conventional 33 a 30 8050 Stale seedbed 26 b 23 8175 NS NS Sub plot (treated or untreated for RWW): Icon 6.2FS 20 b 22 b 8228 a Karate Z 4 c 6 c 8430 a Untreated 65 a 52 a 7680 b Interaction: Main plot x sub plot NS NS NS Means in a column followed by the same or no letter are not significantly different (NS) at the 5% level (ANOVA, LSD).

22

Landis International and Mitsui Chemicals, Inc. Efficacy of Etofenprox for Rice Water Weevil Control in a Commercial Field

Jefferson Co., TX 2006

Discussion

In cooperation with Bill Dishman, we utilized a commercial rice field to test etofenprox for rice water weevil (RWW) control. A 120 acre field planted with CL XL8 was divided into three sections: 114 acres were treated with Karate Z @ 0.03 lb(AI)/acre; 3 acres were treated with Trebon 0.9% (etofenprox) @ 21 lb/acre; 3 acres were left untreated. Pesticides were applied aerially by Twin County Air. RWW cores (20 cores/section, 4 in. diam., 4 in. deep containing at least one rice plant) were collected 3 wk after flood and again 10 days later. The cores were later washed through 40-mesh screen buckets and immature RWW counted. At maturity, samples were hand-harvested from each test area to determine yield. Yields were converted to lb/acre and adjusted to 12% moisture. Immature RWW numbers were relatively low in the untreated acres but were close to threshold. Although both etofenprox and Karate Z were effective at controlling RWW larvae, yields did not reflect expected results (Table 1). Etofenprox, however, out-yielded untreated plots. Etofenprox appears to be an effective RWW control and should be investigated more extensively in the future. The Entomology Project will submit a Section 18 for etofenprox in 2007. Table 1. Results of Etofenprox trial in a commercial rice field. Jefferson Co., TX. 2006

No. immature RWW/20 cores Treatment July 14 July 24 Yield (lb/acre) Etofenprox 1 0 7199 Karate Z 2 2 6916 Untreated 18 14 7026

23

FMC Corporation Residual Activity of Mustang Max and Orthene 90S in Combination

with Gibberellic Acid for Rice Stink Bug Control Beaumont, TX

2006

Agronomic and Cultural Information Planting: Drill-planted Cocodrie @ 90 lb/A into League soil (pH 5.5, sand 3.2%, silt 32.4%, clay 64.4%, and organic matter 3.8 - 4.8%) on May 17 Plot size = 7 rows, 7 in. row spacing, 18 ft long Experimental design: randomized complete block with 4 replications Emergence on May 24 Irrigation: Flushed block (temporary flood for 48 hours, then drain) on May 17 Note: Plots were flushed as needed from emergence to permanent flood Permanent flood on Jun 14 Fertilization: All fertilizer (urea) was distributed by hand. 113.3 lb N/acre (⅔ of 170) on May 17 at planting 56.7 lb N/acre (a of 170) on Jun 29 at panicle differentiation 40 lb N/acre on Jul 19 at late boot/heading (Total season N/acre = 210 lb N/acre) Herbicide: Applied Stam 80EDF @ 2.0 lb, Basagran @ 0.75 lb, Facet 75DF @ 0.25 lb and Ordram @ 2.0 lb (AI)/acre and Agri-Dex @ 1.0 pt/acre with a 2-person hand-held spray boom (13- 80015 nozzles, 50 mesh screens, 21 gpa final spray volume) on Jun 12 for early season weed control Treatments: All treatments included Latron AG-98 @ 0.5% v/v and were applied with a

hand-held CO2-pressurized spray boom (3-800067 nozzles, 50 mesh screens, 20 psi, 24 gpa) on Aug 23. Rice panicles were in soft dough stage.

Sampling: Four rice stalks with panicles attached were removed from each plot 1 day

after treatment (DAT) on Aug 24. The four stalks from each plot were inserted into sand-filled plastic cups (in a greenhouse) sitting in 1-2 in. of water to keep plant material moist. Each set of 4 rice stalks (with panicles attached) was then covered with a plastic tube and infested with 10 rice stink bug (RSB) adults. Number of dead RSB was recorded for each plot 24 and 48 hours after infestation. This procedure was repeated on Aug 28 (5 DAT) and Sep 1 (9 DAT).

Note: Number of dead RSB was transformed to percent mortality. Percent mortality was subjected to angular transformation to degrees and all data analyzed using ANOVA and LSD.

24

Residual Activity of Mustang Max and Orthene in Combination with GA for RSB Control

Discussion

The purpose of this experiment is to identify insecticides with residual activity for control of adult rice stink bug (RSB). A product which effectively controls RSB with immediate direct contact and also provides residual activity a few days or a week or more after treatment would be extremely valuable to the rice industry. Also, gibberellic acid (GA, a plant growth regulator sometimes used in rice) was tank-mixed with insecticides in this test to determine if GA interferes with insecticidal activity. The artificial environment inside the plastic tubes seemed acceptable for normal RSB activity. Very little to no mortality occurred throughout the experiment in tubes containing untreated panicles (Table 1). Orthene 90S provided 95% control of RSB at 1 day after treatment (DAT) and showed significant control 5 DAT. Mustang Max provided only minimal control of RSB at 1 and 5 DAT. All treatments showed no residual activity toward RSB by 9 DAT. GA had no apparent effect on the efficacy of Orthene 90S or Mustang Max. Also, GA did not exhibit any insecticidal activity. Table 1. Percent rice stink bug (RSB) mortality after 24 and 48 h exposure to treated or untreated rice panicles. Beaumont, TX. 2006

1 DATa 5 DAT 9 DAT Treatment

Rate [lb (AI)/acre] 24 hb 48 hb 24 h 48 h 24 h 48 h

Untreated --- 3 b 5 b 0 3 c 0 0 Mustang Max 0.025 3 b 20 b 3 15 b NA NA Orthene 90S 0.5 58 a 95 a 3 73 a 3 8 Gibberellic acid 0.009 3 b 5 b 0 8 bc NA NA Mustang Max + gibberellic acid 0.025 + 0.009 3 b 13 b 0 3 c NA NA Orthene 90S + gibberellic acid 0.5 + 0.009 73 a 90 a 3 60 a 3 13

NS NS NS a DAT = days after treatment b Percent RSB mortality after 24 and 48 hours exposure to rice panicles Means in a column followed by the same or no letter are not significantly different (NS) at the 5% level (ANOVA and LSD).

25

Valent U.S.A. Corporation Residual Activity of V-10170, Venom and Orthene for Rice Stink Bug Control

Beaumont, TX 2006


Experimental design: Complete randomized block with 4 replications This experiment was conducted late in the season on Jefferson rice which had previously been harvested and was making a ratoon crop. The treatments were applied on ratoon panicles. See "Interaction of Sheath Blight and Rice Water Weevil Activity" for agronomic and cultural information for the main crop. Treatments: All treatments were applied with a hand-held CO2-pressurized spray boom

(3-800067 nozzles, 50 mesh screens, 20 psi, 24 gpa) on Sep 26. Rice panicles were in soft dough stage. Sampling: Four rice stalks with panicles attached were removed from each plot 1 day

after treatment (DAT) on Sep 27. The four stalks from each plot were inserted into sand-filled plastic cups (in a greenhouse) sitting in 1-2 in. of water to keep plant material moist. Each set of 4 rice stalks (with panicles attached) was then covered with a plastic tube and infested with 10 rice stink bug (RSB) adults. Number of dead RSB was recorded for each plot 24 and 48 hours after infestation. This procedure was repeated on Oct 2 (6 DAT).


Discussion

This was the second of three experiments at the Beaumont Center to investigate residual activity of insecticides for RSB control. Minimal natural mortality occurred in tubes containing untreated panicles (Table 1). All three insecticides (V-10170, Venom and Orthene) showed promising results 1 DAT with 55, 65 and 75 percent mortality, respectively, after 48 hours exposure to treated panicles. At 6 DAT, however, residual activity of all treatments had declined significantly. Experiments on RSB mortality from direct contact with insecticides were not conducted this year. The insecticides in this experiment may provide control of RSB with direct contact and appear to have some residual activity for a short period following application. See Table 1 below.

26

Residual Activity of V-10170, Venom and Orthene for Rice Stink Bug Control

Discussion (continued) Table 1. Percent rice stink bug (RSB) mortality after 24 and 48 h exposure to treated or untreated rice panicles. Beaumont, TX. 2006

1 DATa 6 DAT Rate Treatment [lb (AI)/acre] 24 hb 48 hb 24 h 48 h Untreated --- 5 b 8 b 0 0 b V-10170 50WDG 0.06 40 a 55 a 10 23 a Venom 20SG 0.13 60 a 65 a 5 18 a Orthene 97SG 0.50 40 a 75 a 5 18 a NS a DAT = days after treatment b Percent RSB mortality after 24 and 48 hours exposure to treated or untreated panicles Means in a column followed by the same or no letter are not significantly different (NS) at the 5% level (ANOVA, LSD).

27

Syngenta Crop Protection, Inc. Residual activity of Centric and Karate Z for Rice Stink Bug Control

Beaumont, TX 2006


Planting: Drill-planted Cocodrie @ 90 lb/A into League soil (pH 5.5, sand 3.2%, silt 32.4%, clay 64.4%, and organic matter 3.8 - 4.8%) on Jun 8 Plot size = 7 rows, 7 in. row spacing, 18 ft long Experimental design: randomized complete block with 4 replications Emergence on Jun 14 Irrigation: Flushed blocks (temporary flood for 48 hours, then drain) on Jun 9 Note: Plots were flushed as needed from emergence to permanent flood Permanent flood on Jul 5 Fertilization: All fertilizer (urea) was distributed by hand. 113.3 lb N/acre (⅔ of 170) on Jun 9 at planting 56.7 lb N/acre (a of 170) on Jul 19 at panicle differentiation (Total season N/acre = 180 lb N/acre) Herbicide: Applied Stam 80EDF @ 2.0 lb, Basagran @ 0.75 lb, Facet 75DF @ 0.25 lb

and Ordram @ 2.0 lb (AI)/acre and Agri-Dex @ 1.0 pt/acre with a 2-person hand-held spray boom (13- 80015 nozzles, 50 mesh screens, 21 gpa final spray volume) on Jun 28 for early season weed control

Treatments: All treatments were applied with a hand-held CO2-pressurized spray boom

(3-800067 nozzles, 50 mesh screens, 20 psi, 24 gpa) on Sep 5. Rice panicles were in soft dough stage. Sampling: Four rice stalks with panicles attached were removed from each plot 1 day

after treatment (DAT) on Sep 6. The four stalks from each plot were inserted into sand-filled plastic cups (in a greenhouse) sitting in 1-2 in. of water to keep plant material moist. Each set of 4 rice stalks (with panicles attached) was then covered with a plastic tube and infested with 10 rice stink bug (RSB) adults. Number of dead RSB was recorded for each plot 24 and 48 hours after infestation. This procedure was repeated on Sep 11 (6 DAT).


28

Residual Activity of Centric and Karate Z for RSB Control

Discussion

This was the third of three experiments at the Beaumont Center to investigate residual activity of insecticides for rice stink bug (RSB) control. Adult RSB thrived well on untreated panicles with little to no mortality (Table 1). Centric 40WG provided some control at 1 day after treatment (DAT). Karate Z provided little to no control. The tank mix of Centric and Karate Z provided some control at 1 DAT but is most likely due to the activity of Centric. There was no residual activity in any treatment at 6 DAT. These insecticides may provide control of RSB with direct contact, but neither product produced a desirable level of residual RSB control. Table 1. Percent rice stink bug (RSB) mortality after 24 and 48 h exposure to treated or untreated rice panicles. Beaumont, TX. 2006

1 DATa 6 DAT Treatment

Rate [lb (AI)/acre] 24 hb 48 hb 24 h 48 h

Untreated --- 0 c 0 c 3 3 Centric 40WG 0.05 13 ab 23 ab 0 5 Karate Z 0.03 3 bc 10 bc 3 5 Centric 40WG + Karate Z 0.05 + 0.03 20 a 28 a 0 5 NS NS a DAT = days after treatment b Percent RSB mortality after 24 and 48 hours exposure to treated or untreated panicles Means in a column followed by the same or no letter are not significantly different (NS) at the 5%

level (ANOVA, LSD).

29

Evaluation of Insecticides for Stem Borer Control Ganado, TX

2006

Agronomic and Cultural Information Planting: Drill-planted Cocodrie @ 80 lb/acre into Edna fine sandy loam soil on Apr 18 Plot size = 9 rows, 7.5 in. row spacing, 16 ft long with metal barriers surrounding Treatment 6 plots (seed treatment) Experimental design: Randomized complete block with 4 replications Irrigation: Flushed blocks (temporary flood for 48 hours, then drain) on Apr 19 Additional flushes on Apr 17 and 30 Permanent flood on May 24 Fertilization: 45-45-45 (lbs N-P-K/acre) on May 16 after emergence 70 lb N/acre (urea) on May 23 before permanent flood (BF) 70 lb N/acre (ammonium sulfate) on Jun 13 at panicle differentiation (PD) Total season nitrogen = 185 lb N/acre Herbicide: Command 3ME applied @ 0.2 lb (AI)/acre on Apr 18 preemergence (PRE) Arrosolo @ 3.0, Facet @ 0.35, and Command @ 0.3 lb (AI)/acre on May 16 Propanil @ 3.0 and Permit @ 0.06 lb (AI)/acre applied BF on May 23 Treatments: See Table 1 for treatment description, rates and timing. Treatment 6 is a seed treatment under confidentiality. Treatments 4, 5, and 7 – 12 were applied at 1 – 2 in. panicle on Jun 21. Treatments 2, 3, 5, 9, 10 and 12 were applied at late boot/early heading on Jul 7. All treatments (except Trt. 6) were single application foliar sprays applied with a hand-held CO2-pressurized spray boom (3- 800067 nozzles, 50 mesh screens, 25 psi, 28 gpa application rate). Sampling: Whiteheads in main crop were observed and counts recorded from 4 middle rows in each plot on Aug 4. Individual yield components were determined from 10 panicles randomly selected from each plot. Whitehead panicles were excluded from this sampling. Filled and unfilled grains were separated, counted and weighed. Rice plants from border areas exhibiting borer damage were collected near main crop maturity and later dissected to assess stem borer species present. Specimens were 85% sugarcane borer (Diatraea saccharalis) and 15% Mexican rice borer (Eoreuma loftini). Note: Prior to analysis, whitehead counts were transformed using 5.0+x Harvest: Plots harvested on Aug 15 Size harvested plot = 7 middle rows, 7.5 in. row spacing, 16 ft long Yields were converted to lb/acre and adjusted to 12% moisture.

30

Evaluation of Insecticides for Stem Borer Control

Discussion

Previous research by the Entomology Project has shown that stem borers can cause significant yield loss in rice. In this experiment, stem borer pressure was not exceptionally heavy and a significant yield response among treatments did not occur (Table 1). However, plots with the highest numbers of whiteheads (Trts. 1, 4 and 6) yielded lowest (less than 7000 lb/acre). Plots with the least numbers of whiteheads (Trts. 3, 9, 10 and 12) yielded highest (over 7400 lb/acre). Generally, a dual application at 1 – 2" panicle (P) and late boot/early heading (LB/H) was most effective at controlling stem borers (both low and high rates of Mustang Max and Karate Z). A dual application of Orthene 90S, however, was not effective. A single application of insecticide at 1 -2" P proved to be less effective than the dual application. However, the single application of the high rate of the experimental compound at LB/H was very effective. The seed treatment (Trt. 6) was not effective at controlling stem borers. The individual yield component data suggest significant yield reductions occur due to unfilled grains even where insecticide treatments have adequately controlled whiteheads (Table 2). Further research may help clarify the role stem borers play in the production of unfilled grains. This experiment and previous research indicate that timing of insecticide application for stem borer control is most critical. Selection of an effective insecticide and rate are crucial.

Table 1. Evaluation of insecticides for stem borer control. Ganado, TX. 2006

Trt. no. Description Rate

[lb (AI)/acre] Timing No. WHsa

per 4 rows Yield

(lb/acre) 1 Untreated — — 26 a 6927 2 Experimental low LB/Hb 6 de 7393 3 Experimental high LB/H 2 g 7774 4 Orthene 90S 0.5 1-2" Pc 21 ab 6947 5 Orthene 90S 0.5 1-2" P + LB/H 15 bc 7229 6 Seed treatment — — 29 a 6803 7 Mustang Max 0.018 1-2" P 5 ef 7354 8 Mustang Max 0.025 1-2" P 13 bc 7172 9 Mustang Max 0.018 + 0.018 1-2" P + LB/H 2 fg 7670 10 Mustang Max 0.025 + 0.025 1-2" P + LB/H 1 g 7482 11 Karate Z 0.03 1-2" P 11 cd 7215 12 Karate Z 0.03 + 0.03 1-2" P + LB/H 1 g 7616 NS

a WHs = whiteheads b LB/H = late boot/early heading c 1-2" P = 1 - 2 in. panicle Means in a column followed by the same or no letter are not significantly different (NS) at the 5% level (ANOVA, LSD).

31

Evaluation of Insecticides for Stem Borer Control


Table 2. Analysis of individual yield components. Ganado, TX. 2006

No. grains per paniclea

Treatment Rate

[lb (AI)/acre] Timing

Panicles per ft of

row Filled Unfilled

Percent (%) unfilled

grains per paniclea

Weight (g) filled grains per paniclea

Untreated — — 28 101 21 b 18 bc 2.2 Experimental low LB/Ha 34 96 17 b 15 c 2.0 Experimental high LB/H 26 85 20 b 19 bc 1.9 Orthene 90S 0.5 1-2" Pb 26 98 19 b 16 c 2.2 Orthene 90S 0.5 1-2" P + LB/H 26 97 20 b 17 bc 2.2 Seed treatment — — 30 90 29 a 25 a 1.9 Mustang Max 0.018 1-2" P 25 93 22 b 19 bc 2.1 Mustang Max 0.025 1-2" P 26 80 22 b 21 ab 1.8 Mustang Max 0.018 + 0.018 1-2" P+LB/H 26 93 19 b 17 bc 2.1 Mustang Max 0.025 + 0.025 1-2" P+LB/H 27 91 22 b 19 bc 2.1 Karate Z 0.03 1-2" P 31 83 16 b 16 c 1.9 Karate Z

0.03 + 0.03

1-2" P+LB/H

30 NS

97 NS

17 b

15 c

2.2 NS

a Mean derived from 10 panicles per plot Means in a column followed by the same or no letter are not significantly different (NS) at the 5%

level (ANOVA, LSD).

32

Host Plant Resistance to Stem Borers Ganado, TX

2006

Agronomic and Cultural Information Planting: Drill-planted test into Edna fine sandy loam soil on Apr 6 Plot size = 9 rows, 7.5 in. row spacing, 16 ft long Conventional cultivars are Priscilla and Trenasse seeded @ 80 lb/acre; hybrids are XL723 and CL XL730 seeded @ 35 lb/acre, and CL XP729 seeded at 45 lb/acre due to lower germination Experimental design: Split plot with 4 replications; main plot = variety, sub plot = treated (T) or untreated (U) for stem borers Emergence on Apr 15 Irrigation: Flushed blocks (temporary flood for 48 hours, then drain) on Apr 8 Additional flushes on Apr 19 and 30 Permanent flood on May 17 Fertilization: 45-45-45 (lbs N-P-K/acre) on Apr 28 (after emergence) 70 lb N/acre (urea) on May 16 (just prior to permanent flood) 70 lb N/acre (ammonium sulfate) on Jun 7 at panicle differentiation (PD) (Total season nitrogen = 185 lb N/acre for all cultivars) Herbicide: Command 3ME applied @ 0.2 lb (AI)/acre on Apr 7 preemergence (PRE) Propanil @ 3.0, Ordram @ 3.0, Facet @ 0.35, Command @ 0.3, and Permit @ 0.06 lb (AI)/acre applied on Apr 28 Clincher applied @ 0.28 lb (AI)/acre on May 16 before permanent flood (BF) Treatments: Plots designated as (T) received foliar applications of Karate Z at 0.03 lb (AI)/acre on Jun 12 (plots at ¼ in. panicle) and Jun 27 (plots at late boot/early heading) with a hand-held CO2-pressurized spray boom (3- 800067 nozzles, 50 mesh screens, 25 psi, 21 gpa application rate) Sampling: Panicles/ft of row determined from 1- 1 ft count in each plot on Jul 20 Whiteheads counts in main and ratoon crops were recorded from 4 middle rows in each plot on Jul 20 and Oct 11, respectively. Individual yield components were determined from 10 panicles randomly selected from each plot. Whitehead panicles were excluded from this sampling. Filled and unfilled grains were separated, counted and weighed. Rice plants from border areas exhibiting borer damage were collected near main crop maturity and later dissected to assess stem borer species present. Species numbers were evenly distributed between Mexican rice borer and sugarcane borer. Note: Prior to analysis whitehead counts were transformed using 5.0+x

33

Host Plant Resistance to Stem Borers

Agronomic and Cultural Information (continued) Harvest: At harvest it was noted that CL XL730 treated and untreated plots were 60% lodged. Main crop harvested on Aug 14: Size harvested plot = 7 middle rows, 7.5 in. row spacing, 16 ft long Ratoon crop harvested on Oct. 1: Size harvested plot = 4 middle rows, 7.5 in. row spacing, 16 ft long Yields were converted to lb/acre and adjusted to 12% moisture.

Discussion

Although seeding rates varied relative to variety (lower for hybrids), panicle density was not significantly different across varieties or across treated or untreated plots (Tables 1 and 2). These data show that hybrids compensate for low seeding rates by producing more panicle-bearing tillers. The highest density of whiteheads was found in main crop untreated plots of Priscilla and Trenasse. The hybrid treated plots had the lowest number of whiteheads. These data confirm results from previous experiments. Across varieties, treated plots had virtually no whiteheads, which showed that two applications of Karate Z gave excellent control of stem borers. Across varieties, main crop-treated plots significantly out-yielded untreated plots 854 lb/acre. Across treated or untreated plots, highest total yields (main + ratoon crops) were produced by the hybrids, averaging over 14000 lb/acre. At harvest, CL XL730 (treated and untreated plots) were 60% lodged. Although this may have reduced harvest efficiency and/or affected ratoon development, CL XL730 yielded comparable to the other hybrids for both main and ratoon crops. Priscilla produced the greatest main crop yield difference between treated and untreated plots (T – U) with 1114 lb/acre. The least yield difference occurred in Trenasse which may exhibit a certain level of tolerance to stem borer damage. Although all hybrids exhibited relatively low densities of whiteheads, yield losses between treated and untreated plots ranged from 635 - 1262 lb/acre. This suggests stem borers cause damage other than whiteheads (e.g. partial filling of grains on panicles). Thus, for main crop rice, regardless of variety grown, farmers in stem borer-prone areas should treat for these serious pests (896 lb/acre yield advantage in treated versus untreated plots in this experiment). The ratoon crop, in general, suffered more whitehead damage than the main crop which shows the potential for increased stem borer damage in the ratoon crop. In our Mexican rice borer (MRB) pheromone trap collections, we typically catch the most moths during the fall, which coincides with ratoon crop development. Stem borer damage in the main crop may "carry over" to the ratoon crop. Although the ratoon crop was not treated for stem borers, significantly fewer whiteheads were observed in main crop-treated than untreated plots. Ratoon yields, however, were not significantly greater in main crop-treated than untreated plots. Highest ratoon yields were produced by XL723 and CL XP729 (greater than 4000 lb/acre for both varieties). Individual yield component data indicate plots untreated for stem borers experience a higher percentage of unfilled grains than treated plots (Table 3). Data from the small sample size (10 panicles) are not conclusive but further research may help clarify the role stem borers play in the production of unfilled grains.

See Tables 1-3 below.

34


35


Table 1. Host plant resistance to stem borers. Ganado, TX. 2006 No. whiteheads/4 rows Yield (lb/acre)

Variety Trt.aPanicles/ ft of row

Main crop

Ratoon crop

Main crop

Main crop (T – U)

Ratoon crop

Total

yieldb

Priscilla T 35 1 31 7544 1114 3796 11340 U 32 25 33 6430 3615 10045 Trenasse T 44 0 19 9347 414 3500 12847 U 44 9 29 8933 3186 12119 XL723 T 38 0 9 10593 635 4240 14833 U 39 6 11 9958 4152 14110 CL XL730 T 42 0 4 10102 1098 3855 13957

U 41 1 6 9004 3992 12996 CL XP729 T 38 0 9 10696 1262 3940 14636 U 42 5 10 9434 4596 14030 a Treatment: T = treated for stem borers, U = untreated b Total yield = main + ratoon crops

Table 2. Statistical analysis of Table 1. Ganado, TX. 2006

No. whiteheads/4 rows Yield (lb/acre) Panicles/

ft of row Main crop Ratoon

crop Main crop Ratoon crop Total yield Main plot (variety): Priscilla 33 13 a 32 a 6987 d 3705 bc 10692 d Trenasse 44 5 b 24 b 9140 c 3343 c 12483 c XL723 38 3 bc 10 c 10275 a 4196 a 14471 a CL XL730 41 1 c 5 d 9553 b 3923 ab 13476 b CL XP729 40 3 bc 10 c 10065 a 4268 a 14333 a

NS Sub plot (treatment): Treated 39 0 b 14 b 9568 a 3866 13434 a Untreated 40 9 a 18 a 8672 b 3908 12580 b

NS NS Interaction:

Main plot x sub plot

NS SIG P>0.0001

NS NS NS NS

Means in a column followed by the same or no letter are not significantly different (NS) at the 5% level (ANOVA, LSD).


36

Discussion (continued) Table 3. Analysis of yield components. Ganado, TX. 2006

No. grains/paniclea

Variety TreatmentbPanicles/ ft of row Filled Unfilled

Percent (%) unfilled grains per paniclea

Weight (g) filled grains per paniclea

CL XL730 T 42 131 23 15 3.3 U 41 114 25 18 2.9 CL XP729 T 38 136 30 18 3.5 U 42 119 27 19 3.1 XL723 T 38 123 36 23 3.2 U 39 125 39 24 3.3 Priscilla T 35 123 22 15 3.3 U 32 134 21 13 3.5 Trenasse T 44 101 22 18 2.5 U 44 94 24 21 2.4 Main plot (variety): CL XL730 41 122 a 24 bc 16 bc 3.1 a CL XP729 40 128 a 29 b 19 b 3.3 a XL723 38 124 a 37 a 23 a 3.3 a Priscilla 33 128 a 21 c 14 c 3.4 a Trenasse 44 98 b 23 bc 19 b 2.5 b NS Subplot (treatment): T 39 123 26 18 3.2 U 40 117 27 19 3.0 NS NS NS NS NS Interactions: Main plot x sub plot NS NS NS NS NS a Mean derived from 10 panicles per plot b T = Treated for stem borer, U = untreated Means in a column followed by the same or no letter are not significantly different (NS) at the 5% level (ANOVA, LSD).

Effect of Planting Date on Stem Borer Activity in Rice Eagle Lake, TX

2006

Agronomic and Cultural Information Planting: Three planting dates were drill-planted with Cocodrie and CL XL8 into Nada fine sandy loam soil. Date 1 = Mar 14, Date 2 = Apr 12, Date 3 = May 15 Experimental design: split plot with 3 replications; Main plot = planting date; sub plot = treated (T) or untreated (U) for stem borers Note: Data for CL XL8 are not included in this report. RiceTec requested all CL XL8 data be deleted due to possible off-type problems in CL XL8 seed lots distributed to researchers. Plot size = 9 rows, 7.5 in. row spacing, 16 ft long Planting dates 1-3 emerged on Mar 26, Apr 21 and May 23, respectively. Irrigation: Plots were flushed as needed from planting until permanent flood. Permanent floods on May 4, May 18, and Jun 15, respectively Fertilization: Date 1: 48-48-48 (N-P-K) on Mar14 preplant (PP), 70 N (urea) on May 3 at permanent flood (PF), and 70 N (ammonium sulfate) on May 24 at panicle differentiation (PD) Total season nitrogen = 188 lb N/acre Date 2: 45-45-45 (N-P-K) on Apr 12 (PP), 70 N (urea) on May 17 at PF, and 70 N (ammonium sulfate) on Jun 8 at PD Total season nitrogen = 185 lb N/acre Date 3: 45-45-45 (N-P-K) on May 18 preemergence (PRE), 70 N (urea) on Jun 14 at PF, and 70N (ammonium sulfate) on Jul 10 at PD Total season nitrogen = 185 lb N/acre Herbicide: Date 1: Command 3ME @ 0.2 lb (AI)/acre on Mar 15; Command 3ME @ 0.3 and Propanil @ 2.0 lb (AI)/acre on Apr 19; Propanil @ 2.0, Facet @ 0.35, and Permit @ 0.06 lb (AI)/acre on May 2 Date 2: Command 3ME @ 0.2 and Propanil @ 1.0 lb (AI)/acre on Apr 12; Propanil @ 2.0, Facet @ 0.35, and Permit @ 0.06 lb (AI)/acre on May 2 Date 3: Command 3ME @ 0.2 lb (AI)/acre on May 16; Command 3ME @ 0.3, Arosolo @ 3.0, and Permit @ 0.06 lb (AI)/acre on Jun 5 Treatments: Plots in all planting dates designated as (T) received foliar applications of Karate Z at 0.03 lb (AI)/acre near ½ in. panicle and at early boot/heading with a hand-held CO2-pressurized spray boom (3- 800067 nozzles, 50 mesh screens, 25 psi, 21 gpa application rate) Date 1: May 26 and Jun 9, Date 2: Jun 21 and Jun 27, Date 3: Jul 20 and Aug 4. Note: Date 2 received a third application on Jul 7 at heading.

37

Effect of Planting Date on Stem Borer Activity in Rice

Agronomic and Cultural Information (continued) Sampling: Panicles/ft of row determined from 3- 1 ft counts in each plot near maturity Whitehead counts in main and ratoon crops were collected from 4 middle rows in each plot near maturity. Individual yield components for main crop were determined from 10 panicles randomly selected from each plot. Whitehead panicles were excluded from this sampling. Filled and unfilled grains were separated, counted and weighed. As each main crop neared maturity, rice plants from border areas exhibiting borer damage were dissected to assess stem borer species present. In the first planting date (Mar 14) only Mexican rice borer (MRB) were found. In the second and third planting dates (Apr 12 and May15, respectively), species were fairly evenly distributed between MRB and sugarcane borer (SCB). There was not necessarily any stem borer preference for either Cocodrie or CL XL8. Stem borer larvae were found in both cultivars in all three planting dates in the main crop. Ratoon crop plants were not dissected to identify species present. Note: Prior to analysis whitehead counts were transformed using . 5.0+x Harvest: Main and ratoon crops were harvested on the following dates, respectively. Date 1: Jul 31 and Sep 16 Date 2: Aug 7 and Sep 23 Date 3: Sep 4 and ratoon crop not harvested Main crop size harvested plot = 7 middle rows, 7.5 in. row spacing, 16 ft long Ratoon crop size harvested plot = 4 middle rows, 7.5 in. row spacing, 16 ft long Yields were converted to lb/acre and adjusted to 12% moisture.

Discussion Untreated (U) plots in the first planting date (Mar 14) had the highest number of whiteheads compared to the second and third planting dates (Table 1). Applications of Karate Z effectively controlled whiteheads in treated (T) plots in all three planting dates. The second planting date (Apr 12) had significantly fewer whiteheads in the main crop. Although stem borer pressure appeared highest in the first planting, main crop yields in both T and U plots for both first (Mar 14) and second (Apr 12) planting dates were comparable. The third planting date (May 15) had a relatively high number of whiteheads in the main crop, and as might be expected due to the late planting, yielded much lower than the earlier planting dates (Table 1). Main crop yield loss in treated versus untreated plots across all three planting dates averaged 865 lb/acre. The Mar 14 planting, with the highest number of whiteheads in main crop, had the greatest yield loss (1043 lb/acre). Ratoon crops were not treated for stem borers and the May 15 planting date was not ratooned. Whitehead counts in the ratoon crop were noticeably higher than in the main crop. Ratoon crops from the Mar 14 and Apr 12 planting dates exhibited similar stem borer pressure. However, the Mar 14 planting date statistically out-yielded the Apr 12 planting date in both ratoon and total crop yield. Data show that stem borer damage did not affect panicle density (Table 2). The individual yield component data indicate a statistically higher percentage of unfilled grains per panicle in plots not treated for stem borers. Stem borers contribute to yield loss by causing whiteheads but may also play a role in panicles producing unfilled grains (another source of possibly significant yield

38


39

Discussion (continued) reduction). Further research may help clarify if stem borers are at least partially responsible for unfilled grains on an otherwise normal panicle. A specific planting date may coincide with higher stem borer pressure, necessitating treatment. In contrast, a given planting date also may avoid higher infestations of these pests. Regardless of stem borer pressure, planting date is a major factor in achieving greatest yield potential. In this experiment, the Mar 14 and Apr 12 planting dates produced comparable yields despite the presence of a higher number of whiteheads in the first planting date. The May 15 planting date produced very low yields but still benefited from stem borer control with an 824 lb/acre yield difference in treated versus untreated plots. In addition, data suggest that ratoon rice may benefit from stem borer control – application(s) of insecticide directly to the ratoon crop. Table 1. Response of rice and stem borer activity to planting date. Eagle Lake, TX. 2006

No. whiteheads in 4 middle rows Yield (lb/acre) Planting date Treatmenta

Panicles/ ft of row Main crop Ratoon crop Main Ratoon Total

Mar 14 T 37 8 40 8518 1799 10317 U 37 53 39 7475 1902 9377 Apr 12 T 33 2 31 8430 1573 10003 U 34 14 41 7721 1362 9083 May 15 T 25 4 NA 3866 NA NA U 25 30 NA 3024 NA NA

Statistical analysis: Main plot (planting date): Mar 14 37 a 31 a 40 7996 a 1851 a 9847 aApr 12 34 a 8 c 36 8075 a 1467 b 9543 bMay 15 25 b 17 b NA 3445 b NA NA

NS Sub plot (treatment): T 32 5 b 36 6938 a 1686 10160 aU 32 32 a 40 6073 b 1632 9230 b

NS NS NS Interactions: Main plot x sub plot NS SIG

P>0.0857 NS NS NS NS

a Treatment: T = treated for stem borers, U = untreated Means followed by the same or no letter are not significantly different (NS) at the 5% level

(ANOVA, LSD). Main plot ratoon yield is significant at the 10% level (P>0.0622).


40

Discussion (continued) Table 2. Analysis of individual yield components. Eagle Lake, TX. 2006

No. grains per paniclea

Planting Date TreatmentbPanicles

per ft of row Filled Unfilled

Percent (%) unfilled grains

per paniclea

Weight (g) filled grains per

paniclea

March 14 T 37 110 17 14 2.4 U 37 94 16 14 2.2 April 12 T 33 159 31 16 3.7 U 34 140 29 17 3.2 May 15 T 25 73 57 44 1.7 U 25 59 79 58 1.2

Statistical analysis: Main plot (planting date) effects: March 14 37 a 102 b 17 c 14 b 2.3 b April 12 34 a 150 a 30 b 17 b 3.4 a May 15 25 b 66 c 68 a 58 a 1.5 c

Subplot (T or U for stem borers) effects: T 32 114 a 35 25 b 2.6 a U 32 97 b 41 30 a 2.2 b

NS NS

Interactions: Main plot x sub plot NS

NS

SIG

P>0.0126 SIG

P>0.0498 NS

a Number of filled and unfilled grains derived from mean of 10 panicles per plot b Treatment: T = Treated for stem borer, U = untreated Means in a column followed by the same or no letter are not significantly different (NS) at the 5% level

(ANOVA, LSD).

41

Trapping for Mexican Rice Borer Texas Rice Belt

2006

MRB pheromone traps were set up in most counties of the Texas Rice Belt. Orange Co. remains the only county where adult MRB moths have not been detected. In 2005, we detected MRB in Jefferson Co., and in 2006, the moths were consistently present in the traps in low numbers. Because this exotic species continues to move east, the Louisiana sugarcane and rice industries are threatened. Table 1. Monthly totals of MRB adults from pheromone traps on the Texas Upper Gulf Coast in 2006 County Month Brazoria Chambers Colorado Galveston Jackson Jefferson Liberty Waller May NA 712 382 NA 1077 3 2291 NA Jun 1141 647 198 221 250 10 891 570 Jul 954 850 136 369 248 5 441 710 Aug 447 1102 148 817 210 22 242 808 Sep NA 1986 154 521 674 85 867 1732 Oct NA 1190 421 940 990 89 2875 2104 Nov NA 834 215 259 389 20 1065 395 Dec NA NA NA NA 60 5 NA 14 NA = traps not monitored during these months

42

Dupont Crop Protection Efficacy of Seed Treatments for Chinch Bug Control

Beaumont, TX 2006


Planting: The experiment was conducted in the greenhouse at the Beaumont Center. Cocodrie rice was previously seed-treated by Dupont. Hand-planted Cocodrie seed treatments @ 8 seeds per 6 in. diameter pots filled with League soil (pH 5.5, sand 3.2%, silt 32.4%, clay 64.4% and organic matter 3.8 – 4.8%) on Sep 21 Pots were arranged in a randomized complete block with 5 replications. Seedlings emerged on Sep 23 and 24. Infestation: Seedling height was measured on Sep 26. Average height for entire test was 33 mm. Plants in each pot were covered with a plastic tube and infested with 5 adult chinch bugs collected from untreated rice with a muslin sweep net on Sep 29. Rice seedlings were at 2-leaf stage. Number of dead chinch bugs was recorded 72 hours after infestation in Rep I, 96 hours in Reps II and III, and 120 hours in Reps IV and V. Note: Number of dead chinch bugs was transformed to percent mortality. Percent mortality was subjected to angular transformation to degrees and all data analyzed using ANOVA and LSD.

Discussion

Phytotoxicity was not observed in any treatment. Average percent mortality across all replications (72, 96 and 120 hours after infestation) is presented in Table 1. Seed treatments, regardless of formulation or rate, were ineffective at controlling adult chinch bugs. Across all treatments (a total of 125 adult chinch bugs), only one chinch bug did not survive. A seed treatment effective at controlling chinch bug would be very valuable to the rice industry and worthy of further research. Table 1. Efficacy of seed treatments for chinch bug control. Beaumont, TX. 2006

Treatment Rate Mortalitya

(%) Untreated --- 0

A low 0 A high 4 B low 0 B

high

0 NS

a Average of all 5 replications (72, 96 and 120 hours after infestation)

43

Red-banded Stink Bug and Flat Pod Syndrome Beaumont, TX

2006

Research Objective The objective of this research is to determine if red-banded stink bug (RBSB), Piezodorus guildinii, is associated with flat-pod syndrome in soybean. We also propose to determine if a substa

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