Location: Application Technology Research
Project Number: 5082-21620-001-017-S
Project Type: Non-Assistance Cooperative Agreement
Start Date: Sep 1, 2019
End Date: Aug 31, 2022
The objectives of this research are to use the ARS intelligent sprayer technology in Tennessee orchard and nursery environments to: 1) characterize target and non-target applications and the implications of reduced pesticide residue on non-target organisms, i.e., native pollinators and natural enemies, and 2) evaluate application rates to identify the most conservative spray rate that provides effective control and conserves pollinators and other beneficial insects.
Orchard Research: A sprayer retrofitted with intelligent spray control technology will be used to apply fungicides using either the manual mode or the intelligent mode. Applications will be made to uniform fields of seven-year old Golden Delicious trees, which are highly susceptible to bitter rot. Trees will be sprayed every two weeks and spray volume will be recorded. One week following each of four applications [spring (bloom), early-, mid-, and late summer] wild pollinators will be observed in four 1-square meter sections of the orchard floor in each treatment for 30 minutes for “snapshot” counts, and natural enemies will be observed on 3 branches on each of 10 trees per treatment. Arthropods will be collected, arthropod numbers recorded, and specimens will be identified to evaluate arthropod population diversity. When fruits begin to develop, three fruits per tree, 10 trees per treatment will be scouted for disease signs and symptoms in conjunction with beneficial arthropod “snapshot” counts. At plant development stage BBCH 78-79, approximately 120 days after bloom when fruits are 80 to 100% of harvest size, water sensitive cards will be placed in target trees, the nursery floor, and in nearby non-target vegetation just prior to the spray application to characterize intentional and non-target application (deposit density and coverage). Plant height and width in two directions will be measured and plant density will be estimated by placing a light meter on the orchard floor in the shadow of 10 trees per treatment on the same date that water sensitive cards are sprayed. Beginning and end of season tree growth data will be recorded (height, width in two directions). Nursery Research: A sprayer retrofitted with an ARS intelligent spray technology will be used to apply four different application rates to four sections of uniform #15 container size oak trees. Trees will be sprayed every three weeks and spray volume will be recorded. Trees will be scouted for a suite of arthropods and diseases. Pest presence, disease signs, symptoms, and damage, and natural enemies will be recorded 1 week after each application. In the spring, early summer, and late fall, periods representing a range of phenological stages and crop densities, water sensitive cards will be placed in target trees, the nursery floor, and in nearby non-target vegetation just prior to spraying to characterize the application (deposit density and coverage). The following day pollinators will be observed in three 1 m^2 sections of the nursery floor in each treatment for 30 minutes for “snapshot” counts, then collected and identified to evaluate pollinator number, and population diversity. Beginning and end of season tree growth data will be recorded (height, width in two directions, and trunk caliper). Plant density will be estimated by placing a light meter on the nursery floor in the shadow of 8 trees per treatment on the same dates that water sensitive cards are sprayed.