EFFECTS OF KNACK AND APPLAUD FIELD APPLICATIONS ON SWEETPOTATO WHITEFLY ADULT AND NYMPH HONEYDEW PRODUCTION

Authors: HENNEBERRY, THOMAS; JECH, LYNN; DE LA TORRE, THERESA; MAURER, JAMIE - WCRL TEMP EMPLOYEE

Submitted to: Arthropod Management Tests
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/1/2002
Publication Date: 12/31/2002
Citation: JECH, L.J., DE LA TORRE, T.M., MAURER, J. EFFECTS OF KNACK AND APPLAUD FIELD APPLICATIONS ON SWEETPOTATO WHITEFLY ADULT AND NYMPH HONEYDEW PRODUCTION. ARTHROPOD MANAGEMENT TESTS. 2002. FIELD AND CEREAL CROPS, F47.ASP.

Interpretive Summary: Cotton plots were located at the University of Arizona, Maricopa Agricultural Center, Maricopa, AZ. A 4-acre field was treated with Applaud (0.36 lb. (AI)/acre) on 13 Jul. On the same date, four 0.1-acre cotton plots were treated with Knack (0.05 lb (AI)/acre). The check was a 1-acre untreated cotton plot. Plots were subdivided to form a CRD with 10 observations/treatment. Treatments of 10 gpa at 300 psi were made with a spray boom mounted on a high-clearance tractor. On 19 Jul (6 DAT), 100-200 SPW adults were collected from the center of each plot with hand-held aspirators. SPW nymph-infested leaves were also collected from each plot. For adult honeydew collection, 2 leaf-clip cages with removable plastic bottoms were installed, one/leaf, on each of 5 laboratory-potted untreated cotton plants. Five SPW adults were confined in each cage for 48 h. Removable plastic cage bottoms with honeydew were held in a freezer until further processing. For nymph honeydew collections, 10 fifth-mainstem node leaves with petioles intact were harvested from each plot. Individual leaves were examined under a microscope to determine the numbers of living nymphs present. All adults were removed. Leaves with nymphs were placed in 10-cm diameter ventilated petri dishes. Leaf petiole ends were cut off at an angle and placed in cylindrical vials containing 50 ml of water. A vertical groove was cut into the side of each petri dish to accommodate the cotton-wrapped seedling stems. After 48 h, petri dish bottoms with honeydew were collected and held in a freezer. Adult honeydew in leaf-clip cage bottoms as described above and nymph honeydew in petri dish bottoms, in each case, were washed from the containers in deionized water and frozen. Frozen honeydew samples were lyophilized and reconstituted in 125 µl of deionized water. The identity and amounts of trehalulose, melezitose, glucose, fructose, and sucrose in the samples were determined using high-performance liquid chromatography and sampled sugars quantified by comparison with peak areas of known sugar standards. All data were analyzed using ANOVA and means separated after a significant F test using the method of LSD at P 0.05.

Technical Abstract: Cotton plots were located at the University of Arizona, Maricopa Agricultural Center, Maricopa, AZ. A 4-acre field was treated with Applaud (0.36 lb. (AI)/acre) on 13 Jul. On the same date, four 0.1-acre cotton plots were treated with Knack (0.05 lb (AI)/acre). The check was a 1-acre untreated cotton plot. Plots were subdivided to form a CRD with 10 observations/treatment. Treatments of 10 gpa at 300 psi were made with a spray boom mounted on a high-clearance tractor. On 19 Jul (6 DAT), 100-200 SPW adults were collected from the center of each plot with hand-held aspirators. SPW nymph-infested leaves were also collected from each plot. For adult honeydew collection, 2 leaf-clip cages with removable plastic bottoms were installed, one/leaf, on each of 5 laboratory-potted untreated cotton plants. Five SPW adults were confined in each cage for 48 h. Removable plastic cage bottoms with honeydew were held in a freezer until further processing. For nymph honeydew collections, 10 fifth-mainstem node leaves with petioles intact were harvested from each plot. Individual leaves were examined under a microscope to determine the numbers of living nymphs present. All adults were removed. Leaves with nymphs were placed in 10-cm diameter ventilated petri dishes. Leaf petiole ends were cut off at an angle and placed in cylindrical vials containing 50 ml of water. A vertical groove was cut into the side of each petri dish to accommodate the cotton-wrapped seedling stems. After 48 h, petri dish bottoms with honeydew were collected and held in a freezer. Adult honeydew in leaf-clip cage bottoms as described above and nymph honeydew in petri dish bottoms, in each case, were washed from the containers in deionized water and frozen. Frozen honeydew samples were lyophilized and reconstituted in 125 µl of deionized water. The identity and amounts of trehalulose, melezitose, glucose, fructose, and sucrose in the samples were determined using high-performance liquid chromatography and sampled sugars quantified by comparison with peak areas of known sugar standards. All data were analyzed using ANOVA and means separated after a significant F test using the method of LSD at P 0.05.