Single-row Plots Research Articles

Joint contribution of individual plant attributes to seed yield of cowpea (Vigna unguiculata L.) in small plots

Twenty determinate cowpea accessions incorporating considerable phenotypic variability were grown in replicated single rows in a field experiment. Data for growth attributes was recorded at 27 days and around flowering at 49 days. Yield components and seed yield were measured at maturity. Exploratory regression analyses were used to relate seed yield to growth attributes and yiels components at a plot level to obtain information. which would suggest possible strategies in plant selection programs using single row plots. Within each line seed yield was related to total number of pods and to forage yield. Additional knowledge of other attributes did not provide further information about seed yield. In all but two lines yield per pod, harvest index and yield per geometric mean of total number of pods and forage yield, which we designate the geometric yield efficiency index, were independent of the size of plants in a plot and had low variability. Because of their low variability these quantities may be the useful indicators of seed yield of corpea when evaluated in small plots.

Colorado Potato Beetle Control on Tomatoes, 1982

Abstract ‘Campbell 28’ tomatoes were transplanted to a Sassafras sandy loam field on May 5. Single row plots were 25-ft long and 5-ft wide. A guard row buffered each treated row. Treatments were replicated 4 times in a randomized complete block design. Foliar sprays were applied with a self-propelled, high-clearance sprayer with a drop nozzle on each side of the row and one over the center calibrated to deliver 68 gal/acre at 200 psi. Plots were treated Jun 8, 18; Jul 5; Aug 2, 26 and Sep 9. Colorado potato beetles were counted on Jun 23 and 50 tomatoes from each plot were evaluated for beetle damage on Aug 20. Plots were irrigated when moisture was below normal.

Colorado Potato Beetle Control in Eggplant, 1982

Abstract ‘Florida Hibush’ eggplants were transplanted to a Sassafras sandy loam field on May 14. Single row plots were 12 ft long and 5 ft wide; a guard row buffered each treated row. Treatments were replicated 4 times in a randomized complete block design. Foliar sprays were applied with a self-propelled high-clearance sprayer with 1 drop nozzle on either side of the row and 1 nozzle over the center calibrated to deliver 68 gal/acre at 200 psi. Treatments were applied Jun 21 and 28; Jul 19; Aug 6 and 26; Sep 7. Plant defoliation ratings were recorded Jul 2 and Aug 25. Mature fruit were harvested on Jul 26; Aug 4 and 25; Sep 14; Oct 12. All fruit were examined for percent damage or scarred fruit caused by Colorado potato beetle feeding. Plots were irrigated when moisture was below normal.

Control of Sweetpotato Flea Beetle Larvae on Sweet Potatoes, 1982

Abstract Maryland white line sweet potato sprouts (Md-7257) were planted in single row plots (36-inch row spacing), 45-ft in length, on May 25. The spacing between plants within the row was 12 inches. The treatments were arranged in a randomized complete block design with 2 replications. Granular treatments were applied in a 6-8-inch band using a shaker can and then incorporated 2-4 inches into the soil on May 25. Mocap 6EC was applied broadcast at the rate of 6.0 lb ai/acre in 25 gal of water per acre. The spray was applied at 28 psi and the material was incorporated 4-6 inches on Apr 14. Soil temperature at the 4-inch depth at the time of preplant application was 28<C. Yield data were taken from the entire 45 ft of row. All roots were examined for flea beetle larvae injury (shallow writing on the roots).

Field Test of Piperonyl But0Xide as a Pyrethr0Id Synergist on Eggplant, 1982

Abstract ‘Harris 468’ eggplants were transplanted to a Sassafras sandy-loam field May 19. Single row plots were 8 ft long and 5 ft wide. A guard row buffered each treated row. Treatments were replicated 4 times in a randomized complete block design. Sprays were applied with a self-propelled, high-clearance sprayer, with 1 drop nozzle on each side of the row and 1 centered over the row, calibrated to deliver 68 gal/acre at 200 psi. Plots were treated Jun 3, 11, 18; Jul 2, 28; Aug 13. Parameters examined included percent defoliation (based on a rating scale of 0 to 10), CPB larval counts and total yield.

Field Evaluation of Foliar Insecticides in Kentucky, 1980

Abstract Burley tobacco was transplanted in silt loam soil on Jun 12 at Northfarm, Lexington. Spacing was 18 in between plants and 42 in between rows. Prior to the foliar application, 25-ft-long single-row plots with an untreated guard row on each side were established in randomized block design replicated 3 times. Twenty insecticides were applied Jul 30 with a CO2-powered backpack sprayer delivering 25 gal/acre at 40 psi, through 2 hollow-cone nozzles. Counts were taken on 5 plants in the center of each plot row for the tobacco flea beetle and the apterous green peach aphid 2 days after application.

Corn Earworm Control on Sweet Corn, 1981

Abstract ‘Silver Queen’ and ‘Apache’ were planted near Benson, NC on May 12 and May 21 respectively. Single-row plots were 10 ft long on 42-inch centers with 7-ft alleys between replications. Plots were arranged in a randomized complete block design replicated 4 times. Initial treatments were based on black light insect trap counts in excess of 5 moths per trap per night and direct field observation of eggs on silking corn. Initial treatment was Jul 14, with 6 subsequent treatments Jul 19, 21, 22, 25, 27, and 29. All applications were directed to the ear zone at the rate equivalent to 100 gal/acre using a 2.5 gal CO2pressurized hand sprayer equipped with a single hollow cone nozzle operated at 40 psi. All mature ears were harvested and divided into 3 damage classes. Corn earworm pressure was extremely light.

Corn Earworm and Fall Armyworm Control on Sweet Corn, 1981

Abstract ‘Silver Queen’ and ‘Apache’ were planted Jul 22 in single row plots 10 ft long on 42-inch centers with 7-ft alleys between replications near Benson NC. Plots were arranged in a randomized complete block design replicated 4 times. Initial treatments were directed to the whorl on Aug 7, with 4 subsequent treatments on Aug 12, 17, 23 and 28. Treatments were directed to the ear zone for 8 applications on Sep 1, 11, 15, 17, 21, 25, 27 and 29. All applications were applied at the rate equivalent to 100 gal/acre using a 2.5 gal CO2pressurized hand sprayer equipped with a single hollow cone nozzle operated at 40 psi. All mature ears were harvested and dii/ided into 3 damage classes. Corn earworm pressure was moderate while fall armyworm pressure was extremely heavy.

Insect Control on Eggplant, 1980

Abstract ‘Black Jet’ eggplant was transplanted in single row plots 15 ft long on May 22 near Benson, NC. Treatments were replicated 4 times in a randomized complete block design with 5 ft alleys between replications. Treflan (0.5 lb ai/acre) was incorporated preplant. Treatments were applied weekly from Jun 6 to Sep 5 for a total of 15 applications. Applications were made using a single hollow cone nozzle on a piston pump sprayer operated at 40 psi at a rate equivalent to 100 gal of water per acre. Colorado potato beetle and flea beetle counts were made on 3 plants per plot on Jun 27, Jul 17, 31, and Aug 14. Damage ratings for Colorado potato beetle and flea beetle were made on Aug 14. Fruit was harvested weekly from Jul 1 to Sep 1. Total fruit per plot were counted and graded for quality based on shape, color, and insect damage.

Tomato Fruitworm Control, 1982

Abstract Tomato seedlings were transplanted into 48-inch rows on Aug 2 at the Burden Research Center, Baton Rouge, LA. Single row plots 24 ft in length (12 plants/plot) were arranged in a randomized complete block design with 4 replications. Insecticides were applied with a hand-held CO2-pressurized sprayer delivering 100 gal/acre at 40 psi through a single spray nozzle containing a D-3 disc, No. 25 core, and 16 mesh strainer. Treatments were begun when ca 50% of the plants had set fruit. Applications were made on Sep 27, Oct 9, and 21. Ripening fruit were picked and examined for injury on Oct 14, 18, 27, and Nov 4.

Cowpea Curculio Control on Southern Peas, 1981

Abstract ‘Dixilee’ southern peas were direct seeded on May 26 near Benson, NC. Single row plots 10 ft long on 42 inch centers were arranged in a randomized complete block design replicated 4 times. Seven ft alleys separated blocks. Three applications were made, beginning at 75% bloom, on Aug 4, 8 and 13. Applications were made using a 2.5 gal CO2pressurized, backpack sprayer with a single hollow cone nozzle operated at 40 psi at a rate equivalent to 100 gal of water per acre. Ortho X-77 surfactant was added to all treatments. Cowpea curculio pressure was moderate. Damage was assessed Aug 15.

Foliar Sprays to Control the Tomato Fruitworm on No-Till Tomatoes, 1982

Abstract ‘UC-134-1-2’ tomatoes were direct seeded in single row plots 25 ft in length, on Jun 14. A John Deere Model 71 planter equipped with a vegetable hopper with a fluted no-till coulter was used for the planting. Seeding was made in overwintered rye which had been killed with Paraquat (1.0 pt) on Jun 5 and Devrinol (3.0 lb) on Jun 15. Round-Up (1.5 pt) was applied on Apr 15. Distance between rows was 6 ft. When plants were 2-3 inches tall they were thinned so as to provide clumps of 3 tomato plants spaced 12 inches apart. The plots were arranged in a randomized complete block design with 4 replications. The soil was a Norfolk ‘A’ loamy sand. All spray treatments were mixed in 10 gal of water and applied with a custom-built row crop sprayer. Each row was covered by 6 drop nozzles delivering 50 gal/acre at 90 psi. Treatments were applied Aug 15; Sep 2, 8, 15 and 30; and Oct 6. On Oct 18 the plots were harvested and 100 fruit/treatment/replication were examined for injury. Yields were taken on Oct 18.

Evaluation of Insecticides to Control Turnip Aphids and Cabbage Loopers on Cabbage, 1982:

Abstract 'Tropic Globe' cabbage was transplanted on Mar 1 into single row plots 30 ft in length. Distance between rows was 8 ft and space between plants was 2 ft. Treatment plots were replicated 3 times and arranged in a randomized complete block design. Pesticides were applied to the upper and lower sides of the foliage using a Solo 2.5 gal, knapsack, hand-operated, compressed-air sprayer at the rate of 70 gal/acre (20-25 psi) with a fan nozzle. Treatment for turnip aphids was made Apr 26 and a treatment for turnip aphids and cabbage loopers was made on May 12.

Cabbage Looper Control, 1982:

Abstract Seedling cabbage was transplanted into 48-inch rows on Feb 24 at the Hill Farm, Baton Rouge, LA. Single row plots 20-ft in length were arranged in a randomized complete block design with 4 replications. Insecticides were applied with a hand-held CO2 pressurized sprayer delivering 100 gal/acre at 40 psi through a single spray nozzle containing a D-3 disc, No. 25 core, and 16 mesh strainer. Spray treatments were applied on Apr 14 and Apr 26. A spreader sticker was added to all treatments. Evaluations were made on May 12 before heads fully developed by counting the number of leaves per plant with 1 or more holes ≥ 2 cm in area. The foliage injury rating was calculated as the mean number of leaves per plant with holes present

Control of Colorado Potato Beetles on Tomatoes with Combinations of Synthetic Pyrethroids and Piperonyl Butoxide, 1982

Abstract ‘UC-134-1-2’ tomatoes were direct seeded in single row plots 25 ft long on May 10. Distance between rows was 6 ft. When plants were 2-3 inches tall they were thinned so as to provide clumps of 3 tomato plants spaced 12 inches apart. The plots were arranged in a randomized complete block design with 4 replications. The soil was a Norfolk ‘A’ loamy sand. All spray treatments were mixed in 10 gal of water and applied with a custom-built row crop sprayer. Each row was covered by 6 drop nozzles delivering 50 gal/acre at 90 psi. Treatments were applied Jun 10, 25, 30, and Aug 5. In evaluating the teatments, direct counts of the number of Colorado potato beetle larvae/10 ft of row and the % defoliation were recorded. Yields were taken on Aug 25.

White Crub Control on Strawberries, 1981

Abstract A Four-year-old planting of 'Apollo' and 'Atlas' with a heavy infestation of Strigoderma arboricola (F.) was used for this evaluation. Single row plots 20 ft long were arranged in a randomized complete block design replicated three times. Rows were 40 inch apart. The soil was clay loam with a high percent of organic matter. A single application was made on Aug 27, 81. Soil moisture was adequate at this time. Liquid formulations were applied using a sprinkling can at a rate equivalent to 300 gal. water/acre. Granular formulations were applied over-the-row using mason jars as ' salt shakers'. Following treatment application, 1/4 inch of water was irrigated over the plots. Prior to this test, the entire plot was treated with Marlate 50W (4 lb/acre) on Aug 3 and Marlate 50W (4 lb/acre) plus Sevin 80W (2 lb/acre) on Aug 13. Treatments were evaluated by sifting 1 sq ft, 6 inch deep in 3 locations within the replication. Grubs were returned and the holes filled.

Foliar Sprays to Control the Colorado Potato Beetle on No-Till Tomatoes, 1982

Abstract ‘UC-134’ tomatoes were direct seeded in single row plots 25 ft long on May 10. A John Deere Model 71 planter equipped with a vegetable hopper with a fluted no-till coulter was used for the planting. Seeding was made in overwintered rye which had been killed with Paraquat (1.0 pt) on Apr 30 and Devrinol (3.0 lb) on Apr 10. Round-Up (1.5 pt) was applied on Apr 15. Each plot was buffered on either side by an untreated guard row. Distance between rows was 6 ft. When plants were 2-3 inches tall they were thinned so as to provide clumps of 3 tomato plants spaced 12 inches apart. The plots were arranged in a randomized complete block design with 4 replications. The soil was a Norfolk ‘A’ loamy sand. All spray treatments were mixed in 10 gal of water and applied with a custom built row crop sprayer. Each row was covered by 6 drop nozzles delivering 50 gal/acre at 90 psi. Treatments were applied Jun 10, 18, 30 and Aug 5. In evaluating the treatments, direct counts of the number of Colorado potato beetle larvae/10 ft of row and the % defoliation were recorded. Yields were taken on Aug 25.

Cabbage Insect Control 1981

Abstract 'Market Prize' cabbage was transplanted on Apr 16, near Benson, NC. Single row plots 10 ft long on 48-inch centers were arranged in a randomized complete block design replicated 4 times. Seven ft alleys separated blocks. Six applications were made on May 22, 29, Jun 5, 12, 19 and 26. Applications were made using a 2.5 gal, CO2 pressurized, backpack sprayer with a single hollow cone nozzle operated at 40 psi at a rate equivalent to 100 gal of water per acre. Ortho X-77 surfactant was added to all treatments. Imported cabbageworm pressure was moderate until Jun 8 when damage ratings were made. Cabbage looper pressure was moderate-heavy for the remainder of the test. Damage ratings for cabbage loopers were made on Jul 8.

Whorl Treatments for Control of European Corn Borer and Fall Armyworm in Sweet Corn, 1982

Abstract ‘NK 199’ was planted in single row plots 25 f t long on Jun 3. Treatments were replicated 4 times and arranged in a randomized complete block design. Foliar sprays were applied to the whorl using a propane compressed air backpack sprayer with 1 hollow cone nozzle/row delivering 25 gal water/acre at 40 psi. Granular insecticides were applied with hand-held shakers over the top of the plants. Applications were made on Jul 7 and 12. The corn was approximately 3 ft tall at the time of 1st application. Evaluations were made on Jul 23 by counting the number of damaged whorls per 10 plants in the middle of each plot. The larval population was approximately 60% European corn borer and 40% fall armyworm.

Corn Earworm Control on Sweet Corn, 1981

Abstract ‘silver Queen’ and ‘Apache’ were planted on Apr 16 and Apr 29, respectively, in single-row plots 10 ft long on 24-inch centers with 7-ft alleys between replications at Mcgee’s Crossroads, NC. Plots were arranged in a randomized complete block design replicated 4 times. Initial treatments were based on black light trap counts in excess of 5 moths per trap per night and direct field observations of eggs on silking corn. Initial treatment was Jul 1 with 3 subsequent treatments Jul 8 and 14. All applications were directed to the ear zone at the rate equivalent to 100 gal/acre using a 2.5 gal CO2pressurized hand sprayer equipped with a single hollow cone nozzle operated at 40 psi. All mature ears were harvested and divided into damage classes.