2003 ENTOMOLOGY RESEARCH. Texas AgriLife Research and Extension Center at Beaumont

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1 2003 ENTOMOLOGY RESEARCH Texas AgriLife Research and Exteion Center at Beaumont

2 OFFICE OF M. O. (Mo) Way, Professor of Entomology February 17, 2009 Dear stakeholder, cooperator and/or colleague: This report is a compilation of results of Entomology Project experiments conducted in Financial support for these experiments was provided by the Texas AgriLife Research, Texas Rice Research Foundation (rice check-off monies), Texas Soybean Board (soybean check-off monies) and various private agricultural companies. I thank these donors for their generous contributio. I am confident the results contained in this booklet will provide useful pest management information to my clientele. I also wish to thank my support staff for an outstanding, productive year in 2003: Mark Nunez... Research Associate Rebecca Pearson... Technician II Luis Espino... Graduate Student This annual report is also available online at the Beaumont Center website: If you have any questio or comments, please contact me. Sincerely, M.O. Way Professor Entomology Texas AgriLife Research and Exteion Center at Beaumont 1509 Aggie Drive Beaumont, Texas Tel , Exteion 2231 Cell Fax moway@aesrg.tamu.edu WWW

3 Table of Contents Rice Rice Water Weevil (Lissorhoptrus oryzophilus) Seed Treatments for Rice Water Weevil Control...1 Evaluation of Icon 6.2FS and Release Seed Treatments for Rice Water Weevil Control...3 Control of Rice Water Weevil with GF-317, Warrior, Karate Z and Dimilin 2L...5 Evaluation of BCS F for Control of Rice Water Weevil...7 Timing of Mustang Max for Control of Rice Water Weevil...9 Rice Water Weevil Control with Mustang Max Tank-Mixed with Selected Preflood Herbicides...11 Rice Water Weevil Populatio and Damage Relative to Planting Date...14 Does Rice Water Weevil Damage Predispose Rice to Increased Sheath Blight Severity?...21 Comparison of Rice Water Weevil Populatio and Damage in a Conventional and Stale Seedbed...24 Rice Water Weevil and Angoumois Grain Moth Control Following Fall/Winter Storage of Icon 6.2FS-Treated Cocodrie and XL8 Seed...29 Respoe of Rice and Rice Water Weevil to Propanil Following a Fipronil Seed Treatment...32 Phytotoxic Respoe of Rice to Propanil Following a Fipronil Seed Treatment...35 Rice Stink Bug (Oebalus pugnax) Evaluation of Selected Iecticides for Contact and Residual Activity Agait the Rice Stink Bug...38 Developing an Easy and Accurate Sampling Method for Rice Stink Bug...40 Stem Borers Evaluation of Timings of Karate Z for Control of Stem Borers...41 Evaluating Tragenic Rice for Activity Agait Stem Borers...43 Evaluating Selected Rice Varieties for Susceptibility to Stem Borers...45 Monitoring the Spread of the Mexican Rice Borer in the Texas Rice Belt...48 Soybea Evaluation of Soybean Iecticide Seed Treatments...49 Avoiding Soybean Iect Problems on the Upper Gulf Coast by Planting MGV and VI Soybea...51 Evaluation of Selected Iecticides for Control of Iect Pests of Soybea...75 Evaluation of Additional Selected Iecticides for Control of Iect Pests of MGVII Soybea...91 Evaluating Sugarcane Varieties in Southeast Texas Sugarcane Variety Trials at Beaumont i

4 Seed Treatments for Rice Water Weevil Control Beaumont, TX 2003 Introduction The objective of this experiment was to evaluate novel seed treatments for rice water weevil (RWW) control. Materials and Methods The experiment was conducted at the Texas A&M University Agricultural Research and Exteion Center at Beaumont in The experiment was designed as a RCB with eight treatments and four replicatio (see Tables for treatment descriptio). Plot size was 18 ft x 4 ft (seven rows, 7 inches apart). Each plot was surrounded by a metal barrier to prevent movement of fertilizer and pesticides among plots. All treatments were applied to Cocodrie rice seed. Seed treatments were prepared and supplied by Syngenta. On 24 Apr, plots were drill-planted at 90 lb/acre. The next day, all plots were hand-fertilized with urea at 56.7 lb N/acre followed by a flush (temporary flood for 48 hours then drain). On 3 May, rice emerged through League soil. From emergence of rice to application of the permanent flood, plots were flushed as needed. On 9 May, plots were sprayed with Arrosolo 3-3E at 2 qt/acre, Basagran at 1.5 pt/acre, Facet 75DF at 0.5 lb/acre and Latron CS-7 at 1 pt/acre. This herbicide tank mix was applied using a two-person CO 2 -powered spray rig equipped with 13 nozzles (80015 tip size) and 50 mesh scree. Swath width was 21.7 ft. Final spray volume was 11 gpa. On 12 May, rice plant stand counts were taken (number of rice plants in 3 ft of row in each plot). On 23 May (20 d after emergence of rice), plots were handfertilized with urea at 56.7 lb N/acre and the permanent flood was applied. On 6 Jun, plots were hand-fertilized with urea at 56.7 lb N/acre. On 14 and 27 Jun (22 and 35 d, respectively, after application of the permanent flood), five, 4 inch diam. by 4 inch deep mud cores (each core contained at least one rice plant) were removed from each plot. Rice roots from each core were thoroughly and gently washed with a water hose equipped with a spray nozzle. The mud surrounding the rice roots in each core was washed into a 40 mesh screen bucket which was gently agitated in a pan of clean water. The agitation caused the RWW larvae and pupae to float to the water surface where they were recovered and counted. On 8 Jul, plots were hand-fertilized with urea at 30 lb N/acre (a total of 200 lb N/acre applied to the main crop). On 10 Aug (99 d from rice emergence), plots were harvested with a small-plot combine. On 15 Aug, plots were raked to remove chaff and cut straw from main crop harvest, hand-fertilized with urea at 100 lb N/acre and flooded for ratoon crop production. On 21 October (67 d after flooding for ratoon crop production), plots were harvested with a small plot combine. Yields of both main and ratoon crops were adjusted to 12% moisture. RWW counts were traformed using x and all data analyzed by ANOVA and mea separated by LSD. Results Plant stands were similar among treatments (Table 1). Populatio of RWW were high in the untreated; the A14006B seed treatment provided excellent control of the RWW on both sample dates. On the first sample date, the Cruiser 5FS seed treatments gave better control than the Karate CS seed treatments. The low rates of Cruiser 5FS and Karate CS gave 90.2 and 76.7% control, respectively, 1

5 Seed Treatments for Rice Water Weevil Control compared to the untreated. Control with Cruiser 5FS and Karate CS treatments was not significantly rate respoive, so the lowest rates of both seed treatments performed as well as the highest rates. On the main crop, the A14006B treatment outyielded the untreated by 745 lb/acre. Average main crop yield increases over the untreated for the Cruiser 5FS and Karate CS treatments were 623 and 487 lb/acre, respectively. On the ratoon crop, Cruiser 5FS and Karate CS seed treatments outyielded the untreated an average of 352 and 260 lb/acre, respectively. The A14006B seed treatments outyielded the untreated an average of 357 lb/acre. These data suggest that controlling RWW on the main crop has a positive yield benefit on the ratoon crop (although ratoon crop yield differences among treatments were not significant). On the main plus ratoon crops, Cruiser 5FS and Karate CS seed treatments outyielded the untreated an average of 975 and 748 lb/acre, respectively. The A14006B seed treatment outyielded the untreated an average of 1102 lb/acre. Table 1. Seed treatments for rice water weevil (RWW) control. Beaumont, TX Rate g ai/100kg Plants/ft No RWW/5 cores Yield (lb/a) Treatment seed of row Jun 14 Jun 27 Main Ratoon Total Untreated a 12.8 a 8053 c c Cruiser 5FS c 5.8 b 8856 a a Cruiser 5FS cd 3.5 b 8604 ab ab Cruiser 5FS cd 2.8 b 8569 ab ab Karate CS b 5.3 b 8592 ab ab Karate CS b 4.3 b 8714 ab ab Karate CS b 3.3 b 8315 bc bc A14006B d 0 c 8798 a ab NS NS Mea in a column followed by the same or no letter are not significantly (NS) different (P = 0.05, ANOVA and LSD) 2

6 Evaluation of Icon 6.2FS and Release Seed Treatments for Rice Water Weevil Control Beaumont, TX 2003 Introduction The objective of this experiment was to identify and quantify possible interactio between Icon 6.2FS and Release seed treatments relative to rice water weevil (RWW) damage and control. Materials and Methods The experiment was conducted in 2003 at the Texas A&M University Agricultural Research and Exteion Center at Beaumont. The experimental design was a RCB with four treatments and four replicatio. Plot size was 18 ft x 4 ft (seven rows, 7 inches between rows) with each plot surrounded by a metal barrier to prevent interplot movement of fertilizer and pesticides. All seed treatments were provided by Bayer CropScience. On 24 Apr, plots were drill-planted with Cocodrie at 90 lb/acre. One day later, plots were hand-fertilized with urea at 56.7 lb N/acre and flushed (temporary flood for 48 h followed by drain). On 3 May, rice emerged through League soil. On 9 May, plots were sprayed with a tank mix of Arrosolo 3-3E at 2 qt/acre, Basagran at 1.5 pt/acre, Facet 75DF at 0.5 lb/acre and Latron CS-7 at 1 pt/acre. Herbicides were applied with a two-person, CO 2 - powered spray rig equipped with 13 nozzles (80015 tip size, 50 mesh scree). Spray width was 21.7 ft and final spray volume was 12.3 gpa. On 12 May, rice stand counts (three, 3 ft of row samples per plot) were taken. From rice emergence to application of the permanent flood, plots were flushed as needed. On 23 May (20 d after rice emergence), plots were hand-fertilized with urea at 56.7 lb N/acre and permanently flooded. On 6 Jun, plots were hand-fertilized with urea at 56.7 lb N/acre. On 14 and 27 Jun (22 and 35 d, respectively, after application of the permanent flood), five, 4 inch diam. by 4 inch deep mud cores (each core contained at least one rice plant) were removed from each plot. Cores were washed in a 40 mesh screen bucket and RWW larvae and pupae recovered and counted. On 8 Jul, plots were hand-fertilized with urea at 30 lb N/acre (total N/acre applied during growing season was 200 lb). On 10 Aug (99 d after rice emergence), plots were harvested with a small-plot combine. Yields were adjusted to 12% moisture. RWW data were traformed using x and all data analyzed by ANOVA and mea separated by LSD. Results Rice stands were highest in the Icon 6.2FS only treatment, and lowest in the Release only treatment (Table 1). However, the mean difference in rice stands between these treatments was only 2.1 plants per 1 ft of row. On the first RWW sample date, populatio were relatively high in the untreated (an average of almost 60 immatures per five cores which is well above the economic injury level of about 15 to 25). Surprisingly, RWW populatio in the Release only treatment were significantly less than the untreated. The Icon 6.2FS only treatment reduced populatio 77%, while the Icon 6.2FS + Release treatment reduced populatio 70%. Thus, the addition of Release to the Icon 6.2FS seed treatment did not significantly affect RWW control. On the second RWW sample date, RWW populatio were too low for a meaningful evaluation. The Icon 6.2FS only treatment outyielded the untreated 787 lb/acre. The Release only treatment outyielded the untreated 520 lb/acre 3

7 Icon 6.2FS and Release Seed Treatments for Rice Water Weevil Control which may be a reflection of reduced RWW populatio in this treatment relative to the untreated. The highest yield was produced by the Icon 6.2FS + Release treatment which outyielded the untreated 934 lb/acre. Table 1. Icon 6.2FS and Release seed treatments for rice water weevil (RWW) control. Beaumont, TX Rate Plants/ft of No. RWW/5 cores Yield Treatment fl oz/cwt row Jun 14 Jun 27 (lb/a) Untreated b 59.3 a b Icon 6.2FS a 13.5 c a Release 10 g/cwt 11.7 b 42.0 b ab Icon 6.2FS Release 10 g/cwt 12.4 b 18.0 c a NS Mea in a column followed by the same or no letter are not significantly (NS) different (P = 0.05, ANOVA and LSD) 4

8 Control of Rice Water Weevil with GF-317, Warrior, Karate Z and Dimilin 2L Beaumont, TX 2003 Introduction The objective of this experiment was to evaluate GF-317, Warrior, Karate Z and Dimilin 2L for control of rice water weevil (RWW). Materials and Methods The experiment was conducted in 2003 at the Texas A&M University Agricultural Research and Exteion Center at Beaumont. The experiment was designed as a RCB with seven treatments (see list of treatments in tables) and four replicatio. Plot size was 18 ft x 4 ft (seven rows, 7 inches between rows) and each plot was surrounded by a metal barrier to prevent interplot movement of pesticides and fertilizer. On 9 May, plots were drill-planted with Cocodrie at 90 lb/acre, handfertilized with urea at lb N/acre and flushed (48 h flood followed by drain). From emergence of rice to application of the permanent flood plots were flushed as needed. On 17 May, rice emerged through League soil. On 22 May, plots were sprayed with Arrosolo 3-3E at 2 qt/acre, Basagran at 1.5 pt/acre, Facet 75DF at 0.5 lb/acre, and Latron CS-7 at 1 pt/acre. This tank mix of herbicides was applied with a two person, CO 2 -powered (20-30 psi) spray rig equipped with 13 nozzles (80015 tip size, 50 mesh scree). Spray swath width was 21.7 ft and final spray volume was 12.3 gpa. On 6 Jun (20 d after rice emergence), selected treatments were applied with a hand-held, CO 2 -powered (20-30 psi) spray rig equipped with three nozzles (tip size , 50 mesh scree). Spray swath width was 4 ft and final spray volume was 28.8 gpa. Immediately following these treatment applicatio, plots were hand-fertilized with urea at 56.7 lb N/acre and permanently flooded (20 d after rice emergence). Three days after application of the permanent flood, selected treatments were applied using the same materials and methods as described previously. On 20 Jun, plots were handfertilized with urea at 56.7 lb N/acre. On 27 Jun and 11 Jul (21 and 35 d, respectively, after application of the permanent flood), five, 4 inch diam. by 4 inch deep (each core contained at least one rice plant) mud cores were removed from each plot. Cores were washed into a 40 mesh screen bucket and RWW larvae and pupae recovered and counted. On 8 Jul, plots were hand-fertilized with urea at 30 lb N/acre; thus, plots received a total of lb N/acre for the entire growing season. On 18 Sep (124 d after rice emergence, plots were harvested with a small plot combine. Yields were adjusted to 12% moisture. RWW counts were traformed using x and all data analyzed by ANOVA and mea separated by LSD. Results On the first sample date, all treatments significantly reduced immature RWW populatio relative to the untreated RWW populatio relative to the untreated (Table 1). However, on the second sample date, immature RWW populatio in all treatments were similar to the untreated. Highest yield was achieved by GF-317 applied 3 d after permanent flood (1567 lb/acre more than the untreated). Across all treatments, average yield increase over the untreated was 1227 lb/acre. 5

9 GF-317, Warrior, Karate Z and Dimilin 2L for Rice Water Weevil Control Table 1. Iecticides for rice water weevil (RWW) control. Beaumont, TX Rate No. RWW/5 cores Yield Treatment (fl oz/a) Timing a Jun 27 Jul 11 (lb/a) GF BF 9.3 a ab Warrior 3.84 BF 12.0 a b GF DAF 5.8 a a Warrior DAF 10.8 a ab Karate Z 0.03 lb ai/a 3 DAF 7.0 a ab Dimilin 2L lb ai/a 3 DAF 7.3 a ab Untreated b c NS a BF = immediately before permanent flood; DAF = days after permanent flood Mea in a column followed by the same or no letter are significantly (NS) different (P = 0.05, ANOVA and LSD) 6

10 Evaluation of BCS F for Control of Rice Water Weevil Beaumont, TX 2003 Introduction The objective of this experiment was to evaluate BCS F applied as a broadcast spray and impregnated on urea for control of rice water weevil (RWW), Lissorhoptrus oryzophilus. Materials and Methods The experiment was conducted in 2003 at the Texas A&M University Agricultural Research and Exteion Center at Beaumont. The experiment was designed as a randomized complete block with nine treatments (see description of treatments, including rates and timings, in the table) and four replicatio. Plot size was 18 ft x 7 ft rows (7 inches between rows) of drill-planted Cocodrie rice seed. Each plot was surrounded by a metal barrier to prevent interplot movement of pesticides and fertilizer. On 7 May, plots were planted at 90 lb seed/acre. Selected plots were planted with Icon 6.2FS - treated seed. This seed treatment was applied using the ALe Sak@ method. Broadcast spray applicatio of BCS F and Mustang MAX were applied with a hand-held, three nozzle (tip size = , 50 mesh screen) spray rig pressurized with CO 2 (20-30 psi). Spray width was 4 ft and final spray volume was 28.8 gpa. BCS F was impregnated on urea using a syringe to dribble the proper amount of product on the proper amount of urea. The impregnated urea was allowed to dry then broken up. A minimum amount of water was used to dilute the iecticide. This helped prevent the impregnated urea from becoming too wet and clump excessively. The fertility program for all the plots was: 1) urea at lb N/acre applied 1 day after planting (this urea was lightly incorporated with a rake), 2) urea at 50 lb N/acre 1 day before application of the permanent flood, 3) urea at 50 lb N/acre applied 2 days after application of the permanent flood, and 4) urea at 50 lb N/acre applied 14 days after application of the permanent flood (this timing was about 1 week before panicle differentiation). Thus, all plots received the same amount of urea at the same time. Total urea applied during the entire growing season was lb N/acre. All urea was applied by hand. The weed control program was a tank-mix of Arrosolo 3-3E at 2 qt/acre, Basagran at 1.5 pt/acre, Facet 75DF at 0.5 lb/acre and CS-7 at 1pt/acre applied 4 days after rice emergence. Herbicides were applied with a 13 nozzle (80015 tip size, 50 mesh screen), two-person spray rig pressurized with CO 2 (20-30 psi). Spray width was 21.7 ft and final spray volume was 12.3 gpa. The irrigation program was: 1) flush (48 hour flood followed by drain) 9 May after planting and, 2) repeated flushes as necessary until application of the permanent flood on 10 Jun (22 days after rice emergence through League soil. On 1 and 15 Jul (21 and 35 days, respectively, after application of the permanent flood), five, 4 inch diameter by 4 inch deep mud cores (each core contained at least one rice plant) were removed from each plot. Rice plants in cores were thoroughly washed into a 40 mesh screen bucket. The contents of the bucket were carefully ipected and RWW larvae and pupae recovered and counted. On 18 Sep (123 days after rice emergence), plots were harvested with a small plot combine. Yields were adjusted to 12% moisture. RWW counts were traformed using x and all data analyzed by ANOVA and LSD. 7

11 Evaluation of BCS F for Rice Water Weevil Control Results None of the BCS F treatments provided effective control of RWW (Table 1). The Icon 6.2FS and Mustang MAX treatments provided adequate control which resulted in yield increases over the untreated of 716 and 637 lb/acre for the Icon 6.2FS and Mustang MAX treatments, respectively. Table 1. Results of evaluation of BCS F for rice water weevil (RWW) control. Beaumont, TX Rate No. RWW/5 cores Yield Treatment (lb ai/a) Timing a 1 Jul 15 Jul (lb/acre) Untreated a 16.0 bc 8223 c BCS F 1.5 PPI 32.3 ab 10.0 cd 8166 c BCS F 1.5 1DBF 40.5 a 23.0 ab 8090 c BCS F 1.5 b 1DBF 25.8 bc 15.0 bcd 8465 bc BCS F 1.5 2DAF 34.5 ab 10.0 cd 8412 c BCS F 1.5 b 2DAF 30.5 ab 12.0 bcd 8031 c BCS F 1.5 b 14DAF 32.5 ab 10.0 cd 8074 c Mustang MAX DAF 11.3 d 32.0 a 8860 ab Icon 6.2FS ST 15.8 cd 7.0 d 8939 a a PPI = preplant incorporated; DBF = days before flood; DAF = days after flood; ST = seed treatment b impregnated on urea Mea in a column followed by the same letter are not significantly (NS) different (P = 0.05, ANOVA and LSD) 8

12 Timing of Mustang Max for Control of Rice Water Weevil Beaumont, TX 2003 Introduction The objective of this experiment was to determine the best time to apply Mustang Max for control of rice water weevil (RWW). Materials and Methods The experiment was conducted at the Texas A&M University Agricultural Research and Exteion Center at Beaumont in The experiment was designed as a RCB with 10 treatments (see Tables for treatment descriptio) and four replicatio. Plot size was 18 ft x 4 ft (seven rows, 7 inches apart) and each plot was surrounded by a metal barrier to prevent movement of fertilizer and pesticides among plots. On 22 Mar, plots were drill-planted with Cocodrie at 90 lb/acre. Treatments were applied at the times indicated in the Tables with a hand-held, CO 2 -powered (20-30 psi) spray rig equipped with three nozzles ( tip size, 50 mesh scree). Final spray volume was 28.8 gpa. On 24 Mar, the pre-emergence treatment was lightly incorporated into the soil with a rake. All other treatments were not incorporated. On the same date, plots were hand-fertilized with urea at 42.5 lb N/acre and flushed (temporary flood for 48 h followed by drain). On 7 Apr, rice emerged through League soil. On 14 Apr, plots were sprayed with a tank mix of Arrosolo 3-3E at 2 qt/acre, Basagran at 1.5 pt/acre, Facet 75DF at 0.5 lb/acre, and Latron CS-7 at 1 pt/acre. Herbicides were applied with a two-person, CO 2 -powered spray rig equipped with 13 nozzles (80015 tip size, 50 mesh scree). Spray width was 21.7 ft and final spray volume was 12.3 gpa. From rice emergence to application of the permanent flood, plots were flushed as needed. On 28 Apr (21 d after rice emergence), plots were hand-fertilized with urea at 59.5 lb N/acre and permanently flooded. On 13 May, plots were handfertilized with urea at 68 lb N/acre (170 lb N/acre applied during entire growing season). On 19 May and 2 Jun (21 and 35 d, respectively, after application of the permanent flood), five, 4 inch diam. by 4 inch deep mud cores (each core contained at least one rice plant) were removed from each plot. Cores were washed into a 40 mesh screen bucket and RWW larvae and pupae recovered and counted. On 22 Jul (106 d after rice emergence), plots were harvested with a small plot combine. Yields were adjusted to 12% moisture. RWW data were traformed using x and all data analyzed by ANOVA and mea separated by LSD. Results On the first sample date, RWW populatio were very high in the untreated; thus, RWW infestatio were more than adequate to achieve the experimental objective (Table 1). Greater than 90% control of RWW occurred when Mustang Max was applied from immediately before to 7 d after the permanent flood. Best control (98%) was achieved when Mustang Max was applied 3 d after the permanent flood. Data from previous years confirm this result. Mustang Max applied 10 d after the permanent flood gave the poorest control (34%). On the second sample date, RWW populatio in the untreated were relatively low, so results are not as meaningful as those from the first sample date (Table 1). 9

13 Mustang Max Timing for Rice Water Weevil Control Highest yields were associated with those treatments providing the best control of RWW (applicatio of Mustang Max from immediately before to 7 d after the permanent flood). The average yield increase of these treatments over the untreated was 128l lb/acre. Given a price of rice of $6.50 cwt and the cost of a Mustang Max application [ lb (AI)/acre] of $12.42/acre, the average net return on an effective treatment is over $70/acre (estimate does not include increased hauling and drying costs associated with higher yields). These data show that the best timing of application of Mustang Max was immediately before to 7 d after the permanent flood. Application 10 d after permanent flood was not effective, because RWW probably laid most of their eggs before this treatment. Early applicatio (pre-emergence to 14 d after emergence) provided some control of RWW. This suggests that early applicatio of Mustang Max for fall armyworm, chinch bug and other early season pests, also may provide some control of RWW. Table 1. Rice water weevil (RWW) and yield data from timing of Mustang Max experiment. Beaumont, TX No. RWW/5 cores Yield Treatment timing a May 19 Jun 2 (lb/a) Untreated 75.0 a 24.0 ab 5775 f PRE 21.8 c 6.0 c 6360 de E 19.5 c 14.8 abc 6385 de 7 DAE 24.3 c 22.8 ab 6490 cde 14 DAE 19.5 c 27.3 ab 6643 bcd BF 5.5 d 17.0 abc 7098 ab 1 DAF 6.3 d 13.0 bc 6998 ab 3 DAF 1.3 d 12.8 abc 6942 abc 7 DAF 2.3 d 9.0 c 7187 a 10 DAF 49.5 b 30.3 a 6074 ef a All treatments (other than the untreated) were Mustang Max applied at lb (AI)/acre; PRE = preemergence; E = at emergence; DAE = days after emergence; BF = immediately before flood; DAF = days after flood. Mea in these colum followed by the same letter are not significantly different at the 5% level (ANOVA and LSD). 10

14 Rice Water Weevil Control with Mustang MAX Tank-Mixed with Selected Preflood Herbicides Beaumont, TX 2003 Introduction Many Texas rice farmers control rice water weevil (RWW), Lissorhoptrus oryzophilus, by a preflood application of Karate Z tank-mixed with herbicides. This method of RWW control requires no application cost. Previous research by the Entomology Project showed that tank-mixing Karate Z with selected preflood herbicides did not affect efficacy of Karate Z. Control of RWW was similar when Karate Z was applied alone or in combination with selected herbicides. The objective of this experiment was to compare RWW control using Mustang MAX alone and in tank-mix combinatio with selected preflood herbicides. Materials and Methods The experiment was conducted in 2003 at the TAMU Agricultural Research and Exteion Center at Beaumont. The experiment was designed as a randomized complete block with 16 treatments and four replicatio (see Table 1 for treatment descriptio). Plot size was 18 ft x 4 ft (seven rows, 7 inches between rows) with each plot surrounded by a metal barrier to prevent interplot movement of fertilizer and pesticides. On 5 Apr, plots were drill-planted with Cocodrie rice seed at 90 lb/acre and hand-fertilized with urea at 56.7 lb N/acre. On 7 Apr, a rainfall served as a flush (temporary flood for hours followed by drain). Rice emerged 19 Apr through League soil. On 7 May (18 days after emergence), all plots were sprayed with Stam M-4 at 4 qt/acre. The herbicide was applied using a two-person spray rig equipped with 13 nozzles (tip size 80015, 50 mesh scree) and pressurized with CO 2 (20-30 psi). Spray width was 21.7 ft and final spray volume was 12.3 gpa. One week later on 14 May, plots were sprayed with the treatments shown in Table 1 using a handheld, three nozzle (tip size , 50 mesh scree) spray rig pressurized (20-30 psi) with CO 2. Spray width was 4 ft and final spray volume was 28.8 gpa. On 15 May (26 days after rice emergence), all plots were hand-fertilized with urea at 56.7 lb N/acre followed by the permanent flood. On 20 May (5 days after treatment applicatio), plots were visually rated for phytotoxicity. Within each replication, general phytotoxicity compariso were made between two plots sprayed with a specific herbicide without or tank-mixed with Mustang MAX. If there was no visual difference between the two plots, the comparison was assigned the value 0; if more phytotoxicity was observed in the plot sprayed with the tank-mix containing Mustang MAX, the comparison was assigned +1; if the converse was observed, the comparison was assigned -1. On 28 May, plots were hand-fertilized with the final application of urea at 56.7 lb N/acre. Thus, total N applied to the plots during the experiment was lb/acre. On 7 and 21 Jul (23 and 37 days, respectively, after application of the permanent flood), five, 4 inch diameter by 4 inch deep mud cores (each core contained at least one rice plant) were removed from each plot. Cores, including the roots of rice plants, were washed into a 40 mesh screen bucket. The screen bucket was placed in a pan of fresh water. Immature RWW were recovered from the water and mud in the screen bucket and pan. On 16 Aug (119 days after rice emergence), plots were harvested with a small plot combine. Yields were adjusted to 12% moisture. RWW count data were traformed using x and RWW count and 11

15 Muatang Max and Herbicide Interaction yield data analyzed by ANOVA and LSD. Phytotoxicity data were analyzed using the nonparametric statistics sign test. Results and Discussion In this experiment, Mustang MAX and treatment herbicides were applied at the highest labeled rates, primarily to detect any possible negative effects of the test herbicides on Mustang MAX RWW control efficacy. The assumption was that negative effects most likely would be observed at high rather than low rates of both Mustang MAX and the test herbicides. Also, all plots were sprayed with Stam M-4 (a broad spectrum herbicide) prior to treatment applicatio which were performed 1 day before the permanent flood. Ideally, all weeds should have been hand-pulled before treatment applicatio, but due to labor and time cotraints, we opted to control early emerged weeds in all plots with Stam M-4. Thus, all plots were relatively weed-free prior to treatment applicatio. Thus, the experiment was not designed to detect weed control differences among treatments, rather, the experiment was designed to detect differences in phytotoxicity and RWW control among treatments. Of all the tank-mix treatments, only the Stam M-4 with Mustang MAX produced significantly more phytotoxicity than without Mustang MAX (Table 1). Plot compariso in all replicatio showed more phytotoxicity in the tank-mix than Stam M-4 alone. However, yield of the tank-mix treatment was not significantly different from the yield of Mustang MAX alone. Thus, the increased phytotoxicity did not result in a significant yield loss. This interaction needs to be investigated further in In general, populatio of RWW were relatively high in all treatments without Mustang MAX which helped make experimental results meaningful. For all tank-mix treatments, populatio of RWW were significantly lower than in the corresponding herbicide only treatments (Table 1). Populatio of RWW in all herbicide only treatments, except Ricestar, were not significantly different from the untreated (Table 1). The Ricestar only treatment had 45% fewer RWW than the untreated. Perhaps Ricestar has some iecticidal properties? This will be investigated further in Populatio of RWW in all tank-mix treatments were not significantly higher than in the Mustang MAX only treatment; thus, none of the test herbicides in combination with Mustang MAX adversely affected control of RWW. However, Stam M-4 and Arrosolo 3-3E tank-mix treatments had significantly fewer RWW than the Mustang MAX only treatment (Table 1). Perhaps these herbicides increase the activity of Mustang MAX? This possibility will be investigated in All tank-mix treatments outyielded their corresponding herbicide only treatments. However, the Basagran and Regiment tank-mix treatments did not significantly outyield their corresponding herbicide only treatments. This will be investigated further in The average yield increase over the untreated of all tank-mixes containing Mustang MAX was 770 lb/acre. 12

16 Muatang Max and Herbicide Interaction Table 1. Mustang MAX/herbicides tank-mix study. Beaumont, TX Trt No. Description Rate (lb ai/a) Phytotoxicity rating a No. RWW/5 cores Yield (lb/a) 1 Untreated ab 6784 efg 0 2 Mustang MAX ef 8080 a 3 Stam 80 EDF a 7152 def fgh 8139 a 5 Stam M b 6996 defg +1 b gh 7669 abc 7 Arrosolo 3-3E 4 qt/acre 61.8 ab 6691 fgh h 7766 ab 9 Basagran 1 qt/acre 62.8 ab 7288 bcd efg 7684 abc 11 Grandstand R bc 6662 fgh ef 7235 cde 13 Regiment bc 6208 h de 6535 gh 15 Ricestar cd 6899 defg efg 7851 a a 0 = no difference in phytotoxicity in tank-mix and herbicide only treatments; + 1 = more phytotoxicity in tank-mix than herbicide only treatment; -1 = less phytotoxicity in tank-mix than herbicide only treatment. b +1 = in all replicatio, the tank-mix produced more phytotoxicity than the herbicide only treatment; according to the nonparametric statistics sign test, the probability of this occurring is only which is highly significant. Mea in a column followed by the same letter are not significantly different (P = 0.05, ANOVA and LSD). 13

17 Rice Water Weevil Populatio and Damage Relative to Planting Date Beaumont, TX 2003 Introduction The objectives of this experiment were to determine planting date influence on rice water weevil (RWW), Lissorhoptrus oryzophilus, populatio and damage, and to evaluate control of RWW with labeled iecticides. Materials and Methods The study was conducted at the Texas A&M University Agricultural Research and Exteion Center at Beaumont in 2003 and coisted of five experiments (five planting dates). Each experiment coisted of six treatments replicated four times in a RCB design. The six treatments are described in the tables. Plots size was 18 ft x 4 ft (seven rows, 7 inches between rows of drill-planted Cocodrie at 90 lb/acre). Each plot was surrounded by a metal barrier to prevent interplot movement of iecticides and fertilizer. Planting dates were 13 Mar, 1 Apr, 15 Apr, 30 Apr, and 16 May. All rice received the same total amount of urea fertilizer (170 lb N/acre) applied by hand as a three-way split (at planting, preflood and panicle differentiation for Mar and Apr planting dates) or two-way split (preflood and panicle differentiation for the May planting date). All experiments were flushed (48 h temporary flood then drain) after planting to encourage early emergence. From emergence of rice through League soil to application of the permanent flood (about 3 wks after emergence of rice), rice was flushed as needed. All rice was hand-sprayed after rice emerged with a tank mix of Arrosolo 3-3E at 2 qt/acre, Facet 75DF at 0.5 lb/acre, Basagran at 1.5 pt/acre and crop oil concentrate. Icon 6.2FS was applied to seed using the ALe Sak@ method and all other iecticides were applied at the rates and times in the tables with a hand-held, three nozzle ( tip size, 50 mesh scree) spray boom pressurized with CO 2 (20-30 psi). Spray width was 4 ft and final spray volume was 28.8 gpa. About 2 wks after emergence, rice plant stands were estimated for each plot by recording the number of plants in three, 3 ft sectio of rows. About 3 and 5 wks after application of the permanent flood, each plot was sampled for RWW by removing five, 4 inch diam. x 4 inch deep mud cores (each core contained at least one rice plant). Plants including roots were washed into a 40 mesh screen bucket and immature RWW were recovered and counted. At maturity, plots were harvested with a small plot combine. For the three earliest planting date experiments, straw from main crop harvest was removed, plots were hand-fertilized with urea at 100 lb N/acre, and flooded. At maturity, these plots were harvested to obtain ratoon crop data. All yield data were adjusted to 12% moisture. RWW count data were traformed using x and all data analyzed by ANOVA and LSD. Results Experiment 1: Mar 13 planting date All iecticide treatments effectively controlled RWW and produced main and ratoon crop yields higher than the untreated (Table 1). Mustang MAX gave equivalent control applied before or after the permanent flood. 14

18 Rice Water Weevil Populatio and Damage Relative to Planting Date Experiment 2: Apr 1 planting date All iecticide treatments effectively controlled RWW and produced main and ratoon crop yields higher than the untreated (Table 2). Mustang MAX gave equivalent control applied before or after the permanent flood. Experiment 3: Apr 15 planting date All iecticide treatments effectively controlled RWW and produced main and ratoon crop yields higher than the untreated (Table 3). Mustang MAX gave equivalent control applied before or after the permanent flood. Experiment 4: Apr 30 planting date All iecticide treatments effectively controlled RWW and produced main crop yields higher than the untreated (Table 4). Mustang MAX applied after the permanent flood gave better control than before the permanent flood. Experiment 5: May 16 planting date Mustang MAX did not provide control comparable to the other iecticide treatments (Table 5). However, all iecticide treatments outyielded the untreated. 15

19 Rice Water Weevil Populatio and Damage Relative to Planting Date Table 1. Planting date (Mar 13) and rice water weevil (RWW). Beaumont, TX Treatment No. RWW/5 cores Yield (lb/a) Rate Plants/ft of (lb ai/a) Timing a row 3 wkaf b 5 wkaf Main Ratoon Total Untreated a 19.5 a 6071 d 1846 b 7917 d Icon 6.2FS ST c 2.5 c 7068 ab 2301 a 9369 ab Karate Z 0.03 BF c 7.8 b 6320 cd 2245 a 8565 cd Mustang MAX BF b 9.3 b 6576 bcd 2158 a 8734 bc Mustang MAX DAF c 12.0 ab 6773 abc 2159 a 8932 abc Dimilin 2L DAF ab 7.0 b 7180 a 2329 a 9508 a a ST = seed treatment; BF = immediately before flood; DAF = days after flood. b wkaf = weeks after flood. Mea in a column followed by the same or no letter are not significantly different (P = 0.05, ANOVA and LSD) Table 2. Planting date (Apr 1) and rice water weevil (RWW). Beaumont, TX Plants/ft of Rate No. RWW/5 cores Yield (lb/a) Treatment (lb ai/a) Timing a row 3 wkaf e 5 wkaf Main Ratoon Total Untreated a 18.5 a 6179 b 2713 b 8891 b Icon 6.2FS ST b 7.8 ab 7027 a 2842 ab 9869 a Karate Z 0.03 BF c 2.0 b 7234 a 2868 a a Mustang MAX BF c 6.5 b 6949 a 2980 a 9929 a Mustang MAX DAF c 4.8 b 7197 a 2962 a a Dimilin 2L DAF c 6.5 b 7130 a 2907 a a a ST = seed treatment; BF = immediately before flood; DAF = days after flood. b wkaf = weeks after flood. Mea in a column followed by the same or no letter are not significantly different (P = 0.05, ANOVA and LSD) 16

20 Rice Water Weevil Populatio and Damage Relative to Planting Date Table 3. Planting date (Apr 15) and rice water weevil (RWW). Beaumont, TX Treatment Rate (lb ai/a) Timing No. RWW/5 cores Yield (lb/a) Plants/ft of row 3 wkaf b 5 wkaf Main Ratoon Total Untreated a Icon 6.2FS ST b Karate Z 0.03 BF c Mustang MAX BF bc Mustang MAX DAF bc Dimilin 2L DAF c a ST = seed treatment; BF = immediately before flood; DAF = days after flood. b wkaf = weeks after flood. Mea in a column followed by the same or no letter are not significantly different (P = 0.05, ANOVA and LSD) 17

21 Rice Water Weevil Populatio and Damage Relative to Planting Date Table 4. Planting date (Apr 30) and rice water weevil (RWW). Beaumont, TX Plants/ft Rate No. RWW/5 cores Yield Treatment (lb ai/a) Timing a of row 3 wkaf b 5 wkaf (lb/a) Untreated ab 22.0 a b Icon 6.2FS ST 9.5 bc 8.3 b a Karate Z 0.03 BF 9.4 c 2.8 cd a Mustang MAX BF 10.8 a 6.3 bc a Mustang MAX DAF 11.4 a 1.8 d a Dimilin 2L DAF 11.1 a 5.5 bc a a ST = seed treatment; BF = immediately before flood; DAF = days after flood. wkaf = weeks after flood. Mea in a column followed by the same or no letter are not significantly different (P = 0.05, ANOVA and LSD) Plants/ft Table 5. Planting date (May 16) and rice water weevil (RWW). Beaumont, TX Rate No. RWW/5 cores Yield Treatment (lb ai/a) Timing a of row 3 wkaf b 5 wkaf (lb/a) Untreated a 11.5 c 7124 b Icon 6.2FS ST c 2.3 d 7589 a Karate Z 0.03 BF c 15.5 bc 7610 a Mustang MAX BF b 22.0 ab 7570 a Mustang MAX DAF bc 26.5 a 7384 ab Dimilin 2L DAF c 10.3 c 7597 a a ST = seed treatment; BF = immediately before flood; DAF = days after flood. wkaf = weeks after flood. Mea in a column followed by the same or no letter are not significantly different (P = 0.05, ANOVA and LSD) Summary of all planting date experiments Statistically, compariso among experiments are not legitimate, so the following discussion is preliminary (the study needs to be repeated at least one more year for legitimate compariso to be made). First, overall RWW populatio were highest in the earliest planting dates (13 Mar, 1 Apr and 15 Apr) and lowest in the latest planting dates (30 Apr and 16 May). This information is contrary to planting date studies conducted in southwest Louisiana. Second, all iecticide treatments effectively controlled RWW. Third, highest overall yields were produced in the 1 Apr planting date experiment, but high yields also were produced in the 13 Mar, 15 Apr and 30 Apr planting date experiments. Lowest yields were produced in the last planting date experiment. The following table (Table 6) summarizes planting date yield data from the study: 18

22 Rice Water Weevil Populatio and Damage Relative to Planting Date Table 6. Mean data for Planting date study. Beaumont, TX Planting date Treated yield a (lb/a) Untreated yield (lb/a) Difference (lb/a) Mar Apr Apr Apr May a Average yields of all iecticide treatments. Based on these data, yield benefits of the iecticide treatments generally decreased as planting date increased. This suggests that rice fields with high yield potential benefit the most from these iecticide treatments. Fourth, the average yield benefit of the iecticide treatments over all planting dates was 814 lb/acre (Table 7). Every iecticide treatment produced an average yield advantage of at least 700 lb/acre. Table 7. Yield differences for Platnting date study. Beaumont, TX, Yield (lb/a) difference (treated-untreated) Treatment Mar 13 Apr 1 Apr 15 Apr 30 May 16 Mean Icon 6.2FS Karate Mustang MAX (bf) Mustang MAX (af) Dimilin 2L Mean = 814 Fifth, across all planting dates, iecticide treatments gave an average net return of $40.66/acre (Table 8). 19

23 Rice Water Weevil Populatio and Damage Relative to Planting Date Table 8. Net return of treatment for Planting date study. Beaumont, TX Cost of control Net return a ($/A) Treatment ($/acre) Mar 13 Apr 1 Apr 15 Apr 30 May 16 Mean Icon 6.2FS b Karate c 5.55 d Mustang MAX c 5.77 e Mustang MAX f g Dimilin 2L h Mean a based on $6.50/cwt price of rice; does not include added hauling and drying costs. b 90 lb/acre seeding rate. c applied immediately before permanent flood. d $385/gal with no aerial charge (tank-mix with preflood herbicides). e $205/gal with no aerial charge (tank-mix with preflood herbicides). f applied after permanent flood. g includes aerial charge of $7.15/acre. h includes product ($155/gal)and aerial charge of $7.15/acre. 20

24 Does Rice Water Weevil Damage Predispose Rice to Increased Sheath Blight Severity? Beaumont, TX 2003 Introduction Rice water weevil (RWW), Lissorhoptrus oryzophilus, damage generally appears before the sheath blight (SB) organism, Rhizoctonia oryzae, causes injury to rice. Perhaps RWW damage predisposes rice to SB. The objective of this experiment was to investigate the interaction between RWW and SB damage. Materials and Methods The experiment was conducted at the TAMU Agricultural Research and Exteion Center at Beaumont in The experiment was designed as a split split plot with main plots being the rice varieties Jefferson or Cypress, sub plots being untreated or Icon 6.2FS-treated seed for RWW control, and sub sub plots being uninoculated or inoculated with the SB organism. The experiment coisted of six replicatio and plot size was 18 ft x 4 ft (seven rows, 7 inches between rows). Jefferson and Cypress were selected because the former is resistant to SB and RWW and the latter is susceptible to SB and RWW. Designated seed was treated with Icon 6.2FS at 0.05 lb (AI)/acre given a seeding rate of 90 lb/acre. Designated plots were inoculated with the SB organism on 3 Jun which coincided with rice canopy closure. The inoculum was prepared by Don Groth, and applied by hand by Groth and Mo Way. Each inoculated plot received approximately 100 ml of inoculum which was spread over the middle five rows. On 1 Apr, plots were drill-planted. On the same date, all plots were handfertilized with urea at 42.5 lb N/acre. Plots were flushed (temporary flood for 48 hours followed by drain) immediately after planting and fertilizing. Rice emerged through League soil on 18 Apr. From rice emergence to application of the permanent flood, rice was flushed as needed. On 28 Apr, plots were sprayed with Arrosolo 3-3E at 2 qt/acre, Basagran at 1.5 pt/acre, Facet 75DF at 0.5 lb/acre and CS-7 at 1 pt/acre. This tank-mix was applied with a two-person spray rig (13 nozzles, tip size 80015, 50 mesh scree, 21.7 ft spray width and 12.8 gpa final spray volume) pressurized with CO 2 (20-30 psi). On 12 and 28 May, plots were hand-fertilized with urea at 59.5 and 68.0 lb N/acre, respectively. Thus, total N applied to the plots during the growing season was 170 lb/acre. Immediately after application of urea on 12 May, plots were permanently flooded (24 days after rice emergence). On 4 and 18 Jun (23 and 37 days, respectively, after application of the permanent flood), five, 4 inch diameter by 4 inch deep mud cores (each core contained at least one rice plant) were removed from each plot. Cores (including rice roots) were washed into a 40 mesh screen bucket which was placed in a pan of clean water. The bucket was agitated in the water which forced immature RWW (larvae and pupae) to rise to the surface of the water where they were counted. Mud remaining in the bucket also was ipected for immature RWW. On 29 Jul, Groth visually rated plots for SB severity using a 0-9 scale (0 = no SB; 9 = all rice infested with SB). On 3 Aug (107 days after rice emergence), plots were harvested with a small plot combine. Yields were adjusted to 12% moisture. RWW counts were traformed using x and all data analyzed by ANOVA and LSD. 21

25 Rice Water Weevil and Sheath Blight Interaction Results and Discussion Main plot effects: SB severity was similar in Jefferson and Cypress (Tables 1 and 2). This was unexpected, since Cypress generally is more susceptible to SB than Jefferson. The experiment will be modified in 2004 by replacing Jefferson with a more SB-resistant variety and replacing Cypress with Cocodrie. Significantly more RWW were recovered in Cypress than Jefferson on both sample dates. This confirms previous research which shows Jefferson to be more resistant to RWW than Cypress. Cypress outyielded Jefferson by almost 1000 lb/acre. Sub plot effects: SB ratings were not significantly different between RWW-protected and - unprotected plots (Tables 1 and 2). This implies that RWW damage did not predispose rice to SB injury. Populatio of RWW were significantly greater in RWW-unprotected plots which yielded significantly less than RWW-protected plots. Thus, the Icon 6.2FS seed treatment performed well. Yields of RWW-protected plots were about 400 lb/acre more than RWW-unprotected plots. Sub sub plot effects: SB severity was higher in inoculated than uninoculated plots, but the difference (although significant) was not dramatic (Tables 1 and 2). Next year, uninoculated plots will be sprayed with Quadris to reduce the amount of Abackground@ SB. RWW populatio and yields were not significantly different between uninoculated and SB-inoculated plots. Interaction effects: For SB ratings, a main plot x sub sub plot significant effect indicated that Cypress and Jefferson did not respond similarly to SB inoculation (Tables 1 and 2). In fact, Cypress inoculated plots had more severe SB than Jefferson inoculated plots. However, Jefferson uninoculated plots had less severe SB than Cypress uninoculated plots. For RWW populatio, a main plot x subplot significant effect on the first sample date indicated that Cypress harbored more RWW in untreated plots than Jefferson. Overall, data suggest that RWW damage did not predispose rice to increased SB severity. Table 1. Rice water weevil (RWW) sheath blight (SB) interaction study. Beaumont, TX RWW Sheath No. RWW/5 cores Yield Variety Treatment a blight b SB rating c 4 Jun 18 Jun (lb/a) Jefferson T SB T NI U SB U NI Cypress T SB T NI U SB U NI a T = treated with Icon 6.2FS at 0.05 lb ai/a; U = untreated b SB = inoculated with SB inoculum; NI = not inoculated c Sheath blight rating 0 (no disease) to 9 (plant collapsed) 22