Deep Soil Cores Research Articles

Control of Rice Water Weevil with Fipronil in a Water-Seeded, Continuous Flood Culture, 1996

Abstract The experiment was conducted at the TAMU Agricultural Research and Extension Center at Beaumont and was designed as a RCB with 10 treatments and 4 replications. Each plot was 15 ft X 8 ft and surrounded by a metal barrier to prevent movement of insecticide. On 4 Apr, plots were fertilized with urea at 113 lb nitrogen/acre and treated with Odram 15G at 27 lb product/acre. Fertilizer and herbicide were incorporated into dry soil (League clay) with a rake. Pre-plant incorporated (ppi) treatments were applied to dry soil of designated plots with a 4 nozzle (tip size 800067, 50 mesh screens), hand-held, spray boom pressurized with CO2. Final spray volume was 29.7 gpa. These treatments were also incorporated into dry soil with a rake. Plots were permanently flooded (flood depth about 4 inches) on 5 Apr and hand-planted with sprouted seed at 130 lb dry seed/acre. To prepare sprouted seed, untreated seed (with no fungicides, insecticides, etc.) was soaked in water for 24 h, drained, and air-dried for another 24 h. Seed treatments were applied to sprouted seed according to the attached protocol provided by Rhone-Poulenc Ag Company. On 17 Apr, rice emerged through the water (12 d after planting). On 25 Apr (8 d after rice emergence through water), Furadan 3G was applied to designated plots with a hand-held shaker jar. On each of 16 May and 11 Jun (19 and 45 d after rice emergence through water), five 4 inch diam X 4 inch deep soil cores (each core containing at least 1 rice plant) were removed from each plot, washed, and inspected for immature RWW. On 6 Jun (at panicle differentiation), rice was fertilized with urea at 57 lb nitrogen/acre; thus, total nitrogen applied for the growing season was 170 lb/acre. At maturity (29 Jul), plots were harvested with a small plot combine and yields adjusted to 12% moisture. Insect counts were transformed using x + 0.5 and all data analyzed by 2-way ANOVA and DMRT.

Control of Rice Water Weevil with Karate in a Dry-Seeded, Delayed Flood Culture, 1996

Abstract The experiment was conducted at the TAMU Agricultural Research and Extension Center at Beaumont and was designed as a RCB with 10 treatments and 4 replications. Each plot was 15 ft X 8 ft and surrounded by a metal barrier to prevent movement of insecticides. On 17 Apr, plots were fertilized with urea at 68 lb nitrogen/acre and hand-planted with 90 lb seed/acre. Fipronil-treated seed was provided by Rhone-Poulenc Ag Company and was applied at the rate shown in the table. Fertilizer and seed were incorporated into dry soil (League clay) with a rake. On 18 Apr, plots were flush irrigated (temporary flood for 24 h, then drain). Rice emerged 24 Apr. From emergence of rice through the soil until application of the permanent flood on 16May(22d after rice emergence), rice was flush irrigated as needed. On 9 May, plots were sprayed with Facet 75DF, Bolero 8EC, and Basagran at 0.67 lb/acre, 3 pt/acre, and 1.5 pt/acre, respectively. Immediately prior to the permanent flood, designated plots were treated at the rates shown in the table with Karate 1EC or Fipronil 80WG using a 4 nozzle (tip size 800067, 50 mesh screens), hand-held, spray rig pressurized with CO2. Final spray volume was 29.7 gpa. Plots were fertilized -i with urea at 51 lb nitrogen/acre immediately before the permanent flood. Designated plots were treated post-flood at the rates and times shown in the table j with Karate 1EC and Dimilin 2L using the same methods and materials described for the pre-flood treatments. Furadan 3G was also applied post-flood at j the rate and time shown in the table to designated plots using a hand-held shaker jar. On each of 10 Jun and 8 Jul (25 and 53 d, respectively, after application of the permanent flood), five 4 inch diam X 4 inch deep soil cores (each core containing at least 1 rice plant) were removed from each plot. Rice j plants in cores were washed and immature RWW recovered from the roots. On 14 Jun, plots were fertilized with urea at 51 lb nitrogen/acre; thus, total nitrogen applied during the growing season was 170 lb/acre. At maturity, plots were harvested (26 Aug) with a small plot combine. Yields were adjusted to i 12% moisture. Insect counts were transformed using x + 0.5 and all data analyzed by 2-way ANOVA and DMRT.

Control of Rice Water Weevil with Diflubenzuron–Eup Experiment,1996

Abstract The experiment was conducted at the TAMU Agricultural Research and Extension Center at Beaumont and was a non-replicated experimental use permit (EUP) study with 4 treatments. Plot size was 4.77 acres. One d before planting, plots were fertilized by air with 55 lb nitrogen and 40 lb phosphorus/acre. Fertilizer was incorporated with a “do-all” On 23 Mar plots were drill planted (7.5 inches between rows) at 90 lb seed/acre. Soil type was Labelle. Seed was treated with Apron-FI, Vitavax 200 Flowable, Zinc Starter, and Release LC. After planting, plots were “rolled” to help cover seed and to create a firm seedbed. Plots were flush irrigated (temporary flood for 24h then drain) 2 Apr. Rice emerged 11 Apr. Rice was flush irrigated as needed until application of the permanent flood on 5 May (24 d after rice emergence). On 24 Apr, Facet 75DF and Stam 4E at 0.5 lb and 2 qt/acre, respectively, were applied by air. Urea at 60 lb nitrogen/acre was applied by air on 3 May. All diflubenzuron treatments and Furadan 3G were applied by air. Final spray volume for the diflubenzuron treatments was 10 gpa. On 30 May urea was applied by air at 55 lb nitrogen/acre; thus, total nitrogen for the season was 170 lb/acre. All aerial applications were made by M&M Air Service of Beaumont. On each of 26 May and 13 Jun (21 d and 39 d, respectively, after application of the permanent flood), twenty 4 inch diam X 4 inch deep soil cores (each core containing at least 1 rice plant) were removed from each plot. Rice plants in cores were washed and immature RWW recovered from the roots. On 7 Aug, plots were harvested with a John Deere 9400 combine. For yield data, 3 swaths (each swath 400 ft X 12 ft) in each plot were cut and total grain weight recorded. Yields were adjusted to 12% moisture. Insect counts were transformed usingx + 0.5 and analyzed by 1-way ANOVA and LSD.

Control of Rice Water Weevil with Fipronil in A Water-Seeded, Continuous Flood Culture–Eup Study, 1996

Abstract The experiment was conducted at the TAMU Agricultural Research and Extension Center at Beaumont and was a non-replicated experimental use permit (EUP) study with 4 treatments. Plot size was 3 acres. On 26 Mar, plots were fertilized by air with 110-40-0 at 113 lb nitrogen/acre. On the same day, plots were treated by air with Ordram 15G at 29.2 lb product/acre. Fertilizer and herbicide were incorporated into dry soil (League clay) with a “do-all”. On 27 Mar, a designated plot was treated with Fipronil 80 WG at 0.0325 lb (AI)/acre. The treatment was applied to dry soil using a large, 2-person spray boom equipped with 11 nozzles (tip size 80015, 50 mesh screens) and pressurized with CO2. Final spray volume was 10.6 gpa. Following application, the treatment was incorporated with a spike tooth harrow. Plots were permanently flooded then planted by air with sprouted seed on 30 Mar. Untreated and fipronil-treated seed were provided by Rhone-Poulenc Ag Company. Sprouted seed was treated with fipronil at the Beaumont Center by Rhone-Poulenc Ag Company officials. Seeding rate for all plots was 100 lb dry seed/acre. Due to levee breakage, plots were drained 6 Apr and reflooded by 8 Apr. Rice emerged through the water about 17 Apr (14 d after application of the permanent flood). On 30 Apr (13 d after rice emergence through the water) Furadan 3G was applied by air to a designated plot at 0.5 lb (AI)/acre. On 3 Jun, rice was fertilized with urea at 60 lb nitrogen/acre; thus, total nitrogen applied during the growing season was 173 lb/acre. All aerial applications were conducted by M&M Air Service of Beaumont. On each of 7, 15, 23 May; 6 Jun; and 4 Jul; twenty 4 inch diam X 4 inch deep soil cores (each core containing at least 1 rice plant) were removed from each plot. Cores were washed and inspected for immature RWW. Plots were not harvested due to mechanical and weather problems. Insect counts were transformed using x + 0.5 and data analyzed by 1-way ANOVA and LSD.

Control of Rice Water Weevil With Fipronil in A Dry-Seeded, Delayed Flood Culture, 1996

Abstract The experiment was conducted at the TAMU Agricultural Research and Extension Center at Beaumont. The experiment was designed as a RCB with 10 treatments and 4 replications. Each plot was 15 ft X 8 ft and surrounded by a metal barrier to prevent movement of insecticides. On 8 Apr, plots were fertilized by hand with urea at 68 lb nitrogen/acre. On the same day, plots were dry-seeded by hand with fipronil-treated or untreated seed at 90 lb/acre. Fipronil-treated seed was provided by Rhone-Poulenc Ag Company. Pre-plant incorporated treatments were applied on 8 Apr with a 4 nozzle (tip size 800067, 50 mesh screens), hand-held, spray rig pressurized with CO2. Final spray volume was 29.7 gpa. After spray applications, fertilizer, seed, and spray treatments were incorporated into dry soil (League) with a rake. Immediately after incorporating, plots were flush irrigated (temporarily flood for 24 h then drain). Rice emerged through the soil on 18 Apr. From emergence to application of the permanent flood on 10 May (22 d after rice emergence through soil), rice was flush irrigated as needed. On 30 Apr, plots were treated with Stam 4E and Basagran at 4.0 lb and 1.0 lb (AI)/acre, respectively. On 9 May, plots were treated again with Stam 4E and Basagran at 2.0 lb and 1.0 lb (AI)/acre, respectively. On 10 May (immediately before application of the permanent flood), plots were fertilized with urea at 51 lb nitrogen/acre. Furadan 3G was applied with a hand-held shaker jar 14 d after application of the permanent flood. On 4 Jun (approximately panicle differentiation), urea was applied by hand at 51 lb nitrogen/acre; thus, total nitrogen applied to rice was 170 lb/acre. On each of 6 and 25 Jun (27 and 46 d after application of the permanent flood) five 4 inch diameter by 4 inch deep soil cores (each core containing at least 1 rice plant) were removed from each plot, washed, and inspected for immature RWW. At maturity (5 Aug) plots were harvested with a small plot combine and yields adjusted to 12% moisture. Insect counts were transformed using (x + 0.05) and all data analyzed by 2-way ANOVA and DMRT.

Control of Rice Water Weevil With Fipronil in A Drill-Seeded, Delayed Flood Culture–Eup Study, 1996

Abstract The experiment was conducted at the TAMU Agricultural Research and Extension Center at Beaumont and was a non-replicated experimental use permit (EUP) study with 4 treatments. Plot size was 3 acres. On 26 Mar, plots were fertilized by air with 55-40-0 at 56 lb nitrogen/acre. Fertilizer was in-corporated with a “Do-all” on the same day. On 27 Mar, a designated plot was treated with Fipronil 80 WG at 0.0325 lb (AI)/acre using a large (11 nozzle, tip size80015, 50 mesh screens), 2 person, hand-held spray boom pressurized with CO2. Final spray volume was 10.6 gpa. Following application, the treatment was incorporated with a spike-tooth harrow. On 27 Mar, plots were drill-planted (7.5 inches between rows) with fipronil-treated or untreated seed at 90 lb/acre. Seed was treated with fipronil at 0.0325 lb (AI)/ cwt seed. All seed was provided by Rhone-Poulenc Ag Company which obtained untreated, registered seed from G&H Seed Co., Inc., Crowley, LA. Plots were “rolled” after planting to help cover seed and to create a firm seedbed. Plots were flush irrigated (temporary flood for 24th, then drain) on 5 Apr. Rice emerged 15 Apr. No differences in emergence were detected among the plots. From emergence to application of the permanent flood onl6May(31d after rice emergence), rice was flush irrigated as needed. On 24 Apr, plots were treated by air with Stam 4E and Basagran at 3 qt and 1 pt/acre, respectively. On 9 May, plots were fertilized by air with urea at 55 lb nitrogen/acre. Furdan 3G at 0.5 lb (AI)/acre was applied by air to the designated plot on 30 May (14 d after application of the permanent flood). On each of 5 Jun and 24 Jun (20 and 39 d after application of the permanent flood), twenty 4 inch diam X 4 inch deep soil cores were removed (each core containing at least 1 rice plant) from each plot. Rice plants in cores were washed and immature RWW recovered from the roots. On 3 Jun, plots were fertilized with urea at 60 lb nitrogen/acre; thus, total nitrogen applied to the plots for the growing season was 171 lb/acre. All aerial applications were made by M&M Air Service of Beaumont, TX. Plots were not harvested due to mechanical and weather problems. Insect counts were transformed using x + 0.5 and analyzed by 1 -way ANOVA and LSD.

Control of Rice Water Weevil with Karate in a Water-Seeded,Continuous Flood Culture,1996

Abstract The experiment was conducted at the TAMU Agricultural Research and Extension Center at Beaumont and was designed as a RCB with 8 treatments and 4 replications. Each plot was 15 ft X 8 ft and surrounded by a metal barrier to prevent movement of insecticide. On 12 Apr, plots were fertilized with urea at 113 lb nitrogen/acre and treated with Ordram 15G at 27 lb product/acre. Fertilizer and herbicide were incorporated into dry soil (League clay) with a rake. Plots were flooded to a depth of about 4 inches and hand-planted with sprouted seed at 130 lb dry seed/acre on 12 Apr. Rice emerged 23 Apr. At the times and rates shown in the table, designated plots were treated with Karate 1EC using a 4 nozzle (tip size 800067, 50 mesh screens), hand-held, spray rig pressurized with CO2. Final spray volume was 33.4 gpa. Furadan 3G was applied to designated plots at the rate and time shown in the table using a hand-held shaker jar. On each of 20 May and 17 Jun (27 and 55 d after rice emergence through the water), five 4 inch diam X 4 inch deep soil cores (each core containing at least 1 rice plant) were removed from each plot, washed, and inspected for immature RWW. On 6 Jun, plots were fertilized with urea at 57 lb nitrogen/acre; thus, total nitrogen applied during the growing season was 170 lb/acre. At maturity, plots were harvested (5 Aug) with a small plot combine. Yields were adjusted to 12% moisture. Insect counts were transformed using x + 0.5 and all data analyzed by 2-way ANOVA and DMRT.

A β-sitosterol assay for fine-root mass in soils

The structural complexity and spatial heterogeneity of soils make the direct measurement of biomass a tedious task. These difficulties have led to the development of indirect assays based on biochemical indicators. We have investigated the potential of β-sitosterol, a component of plant membranes, as an indicator of phytomass in soils. β-sitosterol was extracted from soil, root and litter samples with hot methanol, following the procedure used for fungal ergosterol, and quantified by HPLC. Concentrations in fine roots (<2 mm dia) of 16 herbaceous and woody plants ranged from 0.2 to 2.0 μg mg −1 organic mass (mean = 1.0, SD = 0.5). Concentrations in 2 cm dia × 15 cm deep soil cores collected under old field, deciduous hardwood and pine canopies ranged from 2.4 to 26.5 μg g −1 soil dry mass, equivalent to fine-root standing crops of 5–60 Mg ha −1. Microcosm studies indicated that in the early stages of decomposition β-sitosterol degrades at about the same rate as bulk litter. The β-sitosterol assay may facilitate the analysis of mycorrhizal associations and the quantification of total fine-root mass.

Control of Rice Water Weevil with Dimilin 25W, 1995

Abstract Experiments were conducted at the TAMU Agricultural Research and Extension Center Beaumont. Experiment I was designed as a RCB with 11 treatments and 4 replications. Each plot was 15 ft X 8 ft and was surrounded by a metal barrier to prevent movement of insecticides. Plots were drill planted (Midland silty clay loam soil) on 18 Apr at 75 lb Cypress seed/acre. Rice emerged 29 Apr (lid after planting). Rice was flush irrigated as needed until application of the permanent flood on 22 May (23 d after emergence). For weed control, Facet 50WP and Basagran were applied by aircraft on 11 May at 0.67 lb/acre and 1.5 pt/acre, respectively. Before application of the permanent flood, rice was fertilized on 22 May by aircraft with 110 1b N/acre and 40 lb P/acre. Urea was applied by aircraft at 60 lb N/acre at panicle differentiation (23 Jun). Therefore, a total of 170 lb N/acre was applied during the experiment. Dimilin 25W was applied with a 4 nozzle (tip size 800067, 50 mesh screen), hand held, CO2 pressurized spray rig. Final spray volume was 27.4 gpa. Furadan 3G was applied with a hand-held shaker. On 14 and 15 Jun (23 and 24 d after application of the permanent flood), 5, 4 inch diam X 4 inch deep soil cores (each core contained at least 1 rice plant) were removed from each plot. Rice plants in cores were washed and immature RWW recovered from the roots. Plots were sampled again as above on 3 Jul (42 d after application of the permanent flood). The middle 4 rows of each plot were harvested at maturity (28 Aug) with a small plot combine. Yields were adjusted to 12% moisture. Insect counts were transformed using x+0.5. All data were analyzed by 2 way ANOVA and DMRT.

Control of Rice Water Weevil with Karate 1Ec, 1995

Abstract The experiments were conducted at the TAMU Agricultural Research and Extension Center at Beaumont. Experiment I was water-seeded rice with continuous flood. The experiment was designed as a RCB with 6 treatments and 4 replications. Each plot was 15 ft X 8 ft and was surrounded by a metal barrier to prevent movement of insecticide. On 12 May plots were treated with Ordram 1 at 27 lb/acre and fertilized with urea at 110.5 lb N/acre followed by a light incorporation into dry, cloddy soil (League) with a rake. Plots were then flooded and sown (12 May) with presprouted Gulfmont seed at 130 lb dry seed/acre. To prepare presprouted seed, dry seed was soaked in water for 24 h then drained and allowed to air dry for 24 h before planting. Flood depth was about 4 inches and rice emerged through water 18 May–6 d after planting. Karate treatments were applied with a 4 nozzle (tip size 800067, 50 mesh screen), hand-held, CO2 pressurized spray rig. Final spray volume was 30 gpa. Furadan was applied with a hand-held shaker jar at the rate and time shown in Table 1. On 12 Jun (25 d after emergence of rice through water) 5, 4 inch diam X 4 inch deep soil cores (each core contained at least 1 rice plant) were removed from each plot, washed, and immature RWW recovered. At maturity (24 Aug) plots were harvested with a small combine and yields adjusted to 12% moisture. Insect counts were transformed using x+0.5 and all data analyzed by 2 way ANOVA and, where appropriate, DMRT.

Control of Rice Water Weevil with Fipronil, 1995

Abstract The experiments were conducted at the TAMU Agricultural Research and Extension Center at Beaumont. Experiment I was water-seeded rice with continuous flood. The experiment was designed as a RCB with 9 treatments and 4 replications. Each plot was 15 ft X 8 ft, surrounded by a metal barrier to prevent movement of insecticide. On 28 Apr, plots were treated with the herbicide Ordram 15G at 4 lb (AI)/acre and fertilized with 19-19-19 at 250 lb/acre (47.5 lb N/acre). Herbicide and fertilizer were applied by hand and lightly incorporated with a rake into League soil. Fipronil-impregnated fertilizer was provided by Rhone-Poulenc Ag Company. EXP60655A 1.65G was applied with a hand-held shaker jar. EXP60720A 80WG was applied with a 4 nozzle (tip size 800067, 50 mesh screen), hand-held, CO2 pressurized spray rig. Final spray volume was 32 gpa. EXP60655A 1.65G and EXP60720A 80WG were lightly incorporated with a rake into the dry soil. Following these operations, plots were flooded on 28 Apr and hand-planted (water-seeded) on the same day with appropriate presprouted treated or untreated seed at 130 lb dry seed/acre. To presprout seed, dry seed was soaked in water for 1 d then drained for 1 d. Seed treatments were applied to presprouted seed according to instructions provided by Rhone-Poulenc Ag Company. On 7 May (9 d after planting) rice emerged through the water (flood depth was about 4 inches). Furadan 3G was applied with a hand-held shaker jar. On 12 Jun, urea was applied to all plots at 50 lb N/acre (97.6 lb N/acre was applied for the entire experiment). From 24 May-1 Jun (17-25 d after rice emergence through the water), 5, 4 inch diam X 4 inch deep soil cores (each core contained at least 1 rice plant) were removed from each plot, washed, and immature RWW recovered. Sampling was repeated 22-26 Jun (46-50 d after emergence through the water). At maturity (16 Aug), plots were harvested with a small combine and yields adjusted to 12% moisture. Insect counts were transformed using x+0.5 and all data analyzed by 2 way ANOVA and, where appropriate, DMRT.

Control of Rice Water Weevil with Karate, 1994

Abstract The experiment was conducted at the TAMU Agricultural Research and Extension Center at Beaumont and was designed as a RCB with 7 treatments and 4 replications. Each plot was 15 ft × 12 rows (7 inches between rows) and was surrounded by a metal barrier to prevent movement of insecticide. Plots were drill planted 26 Mar at 100 lb seed/acre. Rice emerged 11 Apr. Rice was fertilized with urea near planting (29 Mar) at 122 lb/acre, 1 d before the application of the permanent flood (29 Apr) at 122 lb/acre, and at panicle differentiation (9 Jun) at 122 lb/acre for a total of 170 lb nitrogen/acre. The permanent flood was applied 30 Apr. From planting to the application of the permanent flood, rice was flush irrigated as needed. Facet and Basagran were mixed with crop oil and applied on 22 Apr at 0.75 lb (AI)/acre for each herbicide. Karate 1EC was applied at the rate and times shown in the table with a 4 nozzle (tip size 800067, 50 mesh screens), handheld, CO, pressurized spray rig. Final spray volume was 32 gal/acre. Furadan 3G was applied at the rate and time shown in the table with a hand-held shaker. From 25 to 26 May (25-26 d after application of the permanent flood), 5, 4 inch diam × 4 inch deep soil cores (each core contained at least 1 rice plant) were removed from each plot. Rice plants in cores were washed and immature RWW recovered from the roots. Plots were harvested at maturity (27 Jul) with a small combine. Yields were adjusted to 12% moisture. Insect counts were transformed using Vx + 0.5. All data were analyzed by ANOVA.

Control of Rice Water Weevil with Fipronil and Acephate, 1994

Abstract The experiment was conducted at the TAMU Agricultural Research and Extension Center at Beaumont and was designed as a RCB with 8 treatments and 4 replications. Each plot was 13 ft × 12 rows (7 inches between rows) and was sunounded by a metal barrier to prevent movement of insecticide. Plots were drill planted in League soil 19 Apr at 100 lb seed/acre. Rice emerged 29 Apr. Urea was applied 10 May at 148 lb/acre, 2 d before the permanent flood at 111 lb/acre, and at panicle differentiation (29 Jun) at 111 lb/acre for a total of 170 lb nitrogen/acre. The permanent flood was applied 23 May. Plots were flush irrigated as needed from planting to application of the permanent flood. Facet and Basagran were mixed and applied on 11 May at 0.5 lb (AI)/acre and 1.0 lb (AI)/acre, respectively. Insecticides were applied with a hand-held shaker at the times and rates shown in the table. From 15 to 17 Jun (23-24 d after application of the permanent flood), 5, 4-inch diam × 4 inch deep soil cores (each core contained at least 1 rice plant) were removed from each plot, washed and immature RWW recovered. Rice was harvested at maturity on 17 Aug and yields adjusted to 12% moisture. Insect count data were transformed using x + 0.5 and all data analyzed by ANOVA.

Control of Rice Water Weevil with Naturalis-L, 1994

Abstract The experiment was conducted at the TAMU Agricultural Research and Extension Center at Beaumont and was designed as a RCB with 7 treatments and 4 replications. Each plot was 15 ft × 12 rows (7 inches between rows) and was surrounded by a metal barrier to prevent movement of treatment insecticides. Soil type was League. Rice was drill planted on 26 Mar at 100 lb seed/acre. Rice emerged 11 Apr. From planting to application of the permanent flood, rice was flush irrigated as needed. Urea was applied near planting (29 Mar) at 122 lb/acre, 1 d before the permanent flood (6 May) at 122 lb/acre, and at panicle differentiation (9 Jun) at 122 lb/acre for a total of 170 lb nitrogen/acre. Facet and Basagran were mixed with crop oil and applied 22 Apr at 0.75 lb (AI)/acre for each herbicide. The permanent flood was applied 7 May (26 d after rice emergence). Naturalis-L treatments were applied at the rate and times shown in the table with a 4 nozzle (tip size 800067, 50 mesh screens), hand-held, CO2 pressurized spray rig. Final spray volume was 21.3 gal/acre. Furadan 3G was applied at the time and rate shown in the table with a hand-held shaker. From 31 May to 1 Jun (24-25 d after application of the permanent flood), 5, 4-inch diam × 4-inch deep soil cores (each core contained at least 1 rice plant) were removed from each plot. Rice roots were washed and immature RWW recovered. Plots were harvested at maturity (29 Jul) and yields adjusted to 12% moisture. Insect counts were transformed using vX + 0.5. All data were analyzed by ANOVA.

Control of Rice Water Weevil with Ntn 33893, 1991

Abstract The experiment was conducted at the TAMU Agricultural Research and Extension Center at Beaumont and was designed as a RCB with 4 treatments and 4 replications. Plots were 20 ft × 8 ft and broadcast planted at 70 lb seed/acre on 1 May. Seed was untreated (no fungicide) except that which was treated with 3 oz of NTN 33893/100 lb seed by Mobay employee Dr. Lyndon Almand. The seed-bed was cloddy and dry at planting after which plots were culti-packed to cover seed. Urea was applied at 63, 51, and 51 lb N/acre at planting, immediately before the permanent flood, and at panicle differentiation, respectively. Thiobencarb was applied pre-emergence at 4 lb (AI)/acre, and propanil and bentazon were applied at 4 and 0.75 lb (AI)/acre, respectively, 3 d before initiation of the permanent flood which was applied 24 d after rice emergence. From planting to permanent flood, plots were flush irrigated as needed. Bensulfuron methyl was applied at 1.0 oz (AI)/acre 6 d after initiation of the permanent flood. Furadan 3G was applied with a hand shaker at the times designated in the table. Five, 4 inch diam X 4 inch deep soil cores (each containing at least 1 plant) per plot were removed, washed and inspected for immature RWW 19 d after initiation of the permanent flood. At maturity, the middle 2.5 ft × 20 ft of each plot was harvested with a small combine. Yields were adjusted to 12% moisture. Where appropriate, data were transformed (Vx + 0.5) and analyzed by ANOVA.

Control of Rice Water Weevil with Furadan 4F, 1993

Abstract The experiment was conducted at the TAMU Agricultural Research and Extension Center at Beaumont and used a RCBD with 9 treatments and 4 replications. Plots were 10 ft × 12 rows (7 inches between rows) and drill planted at 100 lb seed/acre on 19 Apr. Rice emerged 2 May. Facet + Basagran were applied 21 May at 0.75 lb formulated material/acre and 0.75 qt/acre, respectively. The permanent flood was applied 7 Jun. Urea was applied at 68, 51, and 51 lb N/acre at the seedling stage, immediately before the permanent flood, and panicle differentiation, respectively. Granular carbofuran was applied with a hand shaker at the time designated in the table. Furadan 4F was applied with a 4-nozzle hand-held spray boom equipped with 800067 tips and 50 mesh screens. Final spray volume was 27.6 gal/acre and times of applications are recorded in the table. Five, 4 inch diam × 4 inch deep soil cores (each containing at least 1 plant) were removed, washed and inspected for immature RWW 22-23 d after initiation of the permanent flood. At maturity all the rice in each plot was harvested with a small combine. Yields were adjusted to 12% moisture. Data were analyzed using ANOVA and means were compared using DMRT where applicable.

Control of Rice Water Weevil with Carbofuran, 1992

Abstract The study was conducted in a commercial rice field farmed by Bill Dishman in Jefferson County, TX. The experiment consisted of 5 treatments with 4 replications arranged in a RCBD. Plot size was 16 ft × 8 ft. The field was broadcast planted at 110 lb seed/acre on 23 May and rice emerged 30 May. Nitrogen was applied at 50 lb and 100 lb/acre at planting and preflood, respectively. Phosphorus was applied at 40 lb/acre at planting. Propanil was applied preflood at about 3 to 4 lb (AI)/acre. The field was flush irrigated until 2 Jul when the permanent flood was initiated. Metal barriers were placed around all plots which were infested immediately before the permanent flood with 50 adult RWW per plot. RWW were collected from untreated, flooded rice. Granular carbofuran was applied with a hand shaker at the rates and times described in the table. Liquid treatments were applied with a 4 nozzle spray rig with 800067 tips and 50 mesh screens. Spray volume was 20 gal/acre. Rates and times are described in the table. Flowable Furadan was applied to urea by slowly pipetting the liquid onto the fertilizer in a glass jar which was continually agitated for 5 min. The carbofuran-coated urea was air dried and clumps were manually broken up and applied by hand. The carbofuran-coated urea was applied at 51 lb N/acre and 1.0 lb carbofuran/acre immediately before the permanent flood. On 27 Jul (25 d after initiation of the permanent flood) 10, 4 inch diam by 4 inch deep soil cores each containing about 1 plant were removed from each plot. Cores were washed and roots inspected for RWW larvae and pupae. Plots were not harvested because of poor and inconsistent weed control. Data were analyzed by ANOVA and where applicable means separated by DMRT.

A comparison of sampling methods for bibionid larvae (Diptera: Bibionidae) in grassland

SUMMARYThree extraction methods were compared for the recovery of bibionid larvae from grassland soil samples. Only wet‐sieving followed by flotation in a saturated salt solution yielded bibionids. No larvae were recovered either with modified Tullgren funnels or by slow immersion of soil cores into a saturated salt solution. The efficiency with which larval bibionid populations can be estimated is poor. Generally, smaller cores yielded more larvae per volume of soil. Most bibionids were found in the top 4 cm of soil. It is concluded that 10 cm diameter and 6–8 cm deep soil cores are an acceptable compromise between efficiency and sampling effort but sample size will largely be determined by the resources available for processing of samples.

Control of Rice Water Weevil with Nematodes, 1990

Abstract Experiments, designed as randomized complete blocks, were conducted at the Texas A&amp;M University Agricultural Research and Extension Center at Beaumont and its satellite station at Eagle Lake. Each of 2 experiments at Beaumont and a single experiment at Eagle Lake consisted of 5 and 8 treatments, respectively, all with 4 replications. Soil at Beaumont was Beaumont clay and that at Eagle Lake was Nada fine sandy loam. At the Beaumont location plots were 13 × 6 ft, broadcast sown to dry soil with 100 lbs seed/acre, and fertilized with urea at 110 lbs N/acre. Plots were flush irrigated (flooded for 24 to 48 h then drained) as needed until the permanent flood was applied on 4 Jun (22 d after seedling emergence through soil). On 30 May plots were treated with 3, 2, and 0.25 lbs (AI)/acre propanil, thiobencarb, and bentazon, respectively. Metal barriers were placed around plots to receive treatments applied to flood water. Treatments were applied as described in the tables. Nematode treatments were applied with a 4 nozzle hand-held boom sprayer using CO2, at 22 psi, as a propellant. Nozzles were LF 3, 80 degrees without screens. Final spray vol was 100 gal/acre. Nematode treatments were made at dusk with the spray boom positioned below the canopy to prevent drift. Furadan was applied with a hand-held shaker. At panicle differentiation (29 Jun) plots were fertilized with urea at 60 lbs N/acre. From 25 to 27 Jun, 5, 4-inch diameter × 4-inch deep soil cores were removed from each plot of Experiment 1. Each core contained a single plant with roots which were washed and inspected for immature RWW. Plots in Experiment 2 were sampled 9-10 Jul as in Experiment 1. At maturity plots in both experiments were harvested, yields adjusted to 12% moisture, and grain milled to determine quality. Plots at Eagle Lake were 13 × 6 ft, drill planted (6-inch row spacing) at 100 lbs seed/acre, and fertilized with urea and 16-20-0 at 45 lbs N/acre on 21 Mar. Seedlings emerged through soil between 5 and 7 Apr. Plots were flush irrigated as needed until the permanent flood was applied 11 May (34 to 36 d after seedling emergence). On 19 Apr molinate, propanil, and bentazon were applied at 3.0; 3.0; and 0.5 lb (AI)/acre, respectively, followed by an application of thiobencarb, molinate, and propanil at 2.0; 3.0, and 3.0 lbs (AI)/acre, respectively, on 3 May. Treatments as listed in the table were applied as described for the experiments at Beaumont. At panicle differentiation (1 Jun), plots were fertilized with urea at 45 lbs N/acre. On 7 Jun (13 d after application of treatments), plots were sampled, as in experiments at Beaumont, for RWW immatures. Plots were not harvested; thus, yield and milling quality are not available for the Eagle Lake experiment. Data for RWW densities were transformed using Vx + 0.5; yield and milling data were not transformed. Data were subjected to ANOVA and where appropriate DMRT.

Control of RWW with Carbofuran, 1991

Abstract The study consisted of 2 experiments conducted at the TAMU Agricultural Research and Extension Center at Beaumont. Experiment 1 was designed as a randomized complete block with 5 treatments and 4 replications. Plot size was 16 ft × 12 rows 7 inches apart. Rice was drill planted at 100 lbs seed/acre on 4 Apr and flushed with rain on the same date. Thiobencarb was applied preemergence on 9 Apr at 4.0 lbs (AI)/acre. Rice emerged 9 d after planting. Urea was applied at the seedling stage of growth on 26 Apr at 68 lbs N/acre. Propanil and bentazon were applied at 3 and 0.75 lbs (AI)/acre, respectively, on 6 May, 7 d before the permanent flood which was applied 30 d after rice emergence. Urea was applied a second time at 51 lbs N/acre immediately before the permanent flood. From rice emergence to the permanent flood, rice was flushed as needed. Flowable Furadan was applied to rice using a 4 nozzle spray rig with 800067 tips and 100 mesh screens. Spray vol was 20.5 gal/acre. Flowable Furadan was also applied to urea by slowly and gradually pipetting the liquid onto the fertilizer in a glass jar which was shaken continuously for 5 min. The carbofurancoated urea was air dried and clumps were.manually broken up and applied by hand. Granular carbofuran was applied with a hand-held shaker. Plots sprayed with flowable Furadan and treated with carbofuran-coated urea were surrounded by metal barriers to prevent movement of insecticide. Bensulfuron was applied at 1 oz (AI)/acre on 17 May, 4 d after the permanent flood. Urea was applied a third and fourth time at 51 lbs N/acre on 28 May and 12 Jun. Five, 4-inch diameter by 4-inch deep soil cores containing approximately 1 plant were removed from each plot on 4 Jun, 22 d after the permanent flood. Plants in cores were washed and roots inspected for RWW immatures. The middle 8 rows of each plot were harvested at maturity with a combine. Grain was cleaned, weighed, and yield adjusted to 12% moisture. Experiment 2 was designed the same as Experiment 1. Urea was applied preplant on 12 Jul at 68 lb N/acre followed by drill planting at 100 lb seed/acre on the same date. Plots were flushed 13 Jul and thiobencarb applied preemergence 18 Jul at 4 lbs AI/ acre. Rice emerged 8 d after planting. Propanil and bentazon were applied at 3 and 0.75 lbs Al/acre, respectively, on 31 Jul 7 d before the permanent flood which was applied 18 d after rice emergence. Urea was applied a second time at 51 lbs N/acre on 7 Aug immediately before the permanent flood. Flowable Furadan was applied to urea and granular carbofuran was applied to plots as described in Experiment 1. Evaluation of treatment efficacy and harvest methods were the same as in Experiment 1. Efficacy data from both experiments were transformed using Vx + 0.5. All data were analyzed by ANOVA and, where appropriate, means separated by DMRT.