A comparison of the performance and biological efficiency of new knapsack sprayers and a controlled droplet application (CDA) sprayer for the control of the diamondback moth, Plutella xylostella L. (Lepidoptera: Plutellidae)

• Published in: International journal of pest management Vol. 50; no. 2; pp. 121 - 127
• Main Authors: Shi-Jian, Guo, Geitz, Glenn, Franklin, Tom, Yin-Quan, Liu, Furlong, Michael J, Zalucki, Myron P, Cooper, Larry
• Format: Journal Article
• Language: English
• Published: London Taylor & Francis Ltd 01-04-2004; Washington, DC Taylor & Francis
• Subjects: Biological and medical sciences; cabbage; Control; Fundamental and applied biological sciences. Psychology; high volume; insecticide efficacy assessment; knapsack sprayer; Phytopathology. Animal pests. Plant and forest protection; Plutella xylostella; Plutellidae; Protozoa. Invertebrates; very low volume; Sprayer; Insecticide; high volume; insecticide efficacy assessment; Insecta; Pesticides; Pest and disease control; Droplet; Plutella xylostella; knapsack sprayer; Arthropoda; Lepidoptera; Cabbage; Hyponomeutidae; Invertebrata; very low volume
• ISSN: 0967-0874; 1366-5863
• DOI: 10.1080/09670870410001663714

Field trials and laboratory bioassays were undertaken to compare the performance and efficacy (mortality of diamondback moth larvae) of insecticides applied to cabbages with three high volume hydraulic knapsack sprayers (NS-16, PB-20 and Selecta 12V) and a controlled droplet application (CDA) sprayer. In field experiments, the high volume knapsack sprayers (application rate 500 - 600 L ha
 − 1
) provided better spray coverage on the upper and lower surfaces of inner leaves, the upper surfaces of middle and outer leaves, and greater biological efficacy than the CDA sprayer (application rate 20∼40 L ha
 − 1
). The PB-20 provided better spray coverage on the upper surface of middle leaves and both surfaces of outer leaves when compared with the Selecta 12V. However, its biological efficacy in the field was not significantly different from that of the other high volume sprayers. Increasing the application rate from 20 to 40 L ha
 − 1
for the CDA sprayer significantly increased droplet density but had no impact on test insect mortality. Laboratory evaluations of biological efficacy yielded higher estimates than field evaluations and there was no significant difference between the performance of the PB-20 and the CDA sprayer. Significant positive relationships were detected between insect mortality and droplet density deposited for both the PB-20 and the CDA sprayers.