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Demonstration of Spray Nozzles and Adjuvants to Optimize Pesticide Application in Variable Wind Conditions

Grant Recipient:

Hawaii Agriculture Research Center
99-193 Aiea Heights Drive, Suuite 300
Aiea, Hawaii 96701-3911

Project Period:

August 1998 - July 1999

Principal Investigator:

Lance T. Santo

Description
The project cooperators constructed a portable spray boom which they used for demonstrations on in Kula, Maui and Waimea, Hawaii. The boom height and spacing was adjustable. After reviewing the literature and evaluating nozzles for adaptation by a small farmer with minimal cost and technical knowledge, they chose the TurboDrop nozzle by Greenleaf Technologies. The nozzle consists of a removable venturi to draw air into the nozzle and a spray tip. They tested different sizes of TurboDrop venturi and flatfan nozzle tips (TwinJet and XR). They were able to demonstrate that the TurboDrop Venturi and nozzle reduced pesticide drift and runoff, improved penetration of the pesticide into the leaf canopy, improved leaf coverage and reduced nozzle clogging.

Project goals and objectives
1) improve pesticide application to maximize the effectiveness of crop protection chemicals and to minimize use and drift;
2) demonstrate the effectiveness of various designs of flood, cone and flatfan nozzles on spray pattern and coverage;
3) determine the effectiveness of the venturi nozzle on spray patterns in variable wind conditions and at different operating pressures; and
4) show the effect of spray adjuvants on the spray patterns of different nozzles.

Outcomes
The project cooperators constructed a portable spray boom which they used for demonstrations on in Kula, Maui and Waimea, Hawaii. The boom height and spacing was adjustable. After reviewing the literature and evaluating nozzles for adaptation by a small farmer with minimal cost and technical knowledge, they chose the TurboDrop nozzle by Greenleaf Technologies. The nozzle consists of a removable venturi to draw air into the nozzle and a spray tip. They tested different sizes of TurboDrop venturi and flatfan nozzle tips (TwinJet and XR). They were able to demonstrate that the TurboDrop Venturi and nozzle reduced pesticide drift and runoff, improved penetration of the pesticide into the leaf canopy, improved leaf coverage and reduced nozzle clogging. The reduced drift was so obvious that visual observation was sufficient. The two demonstrations, attended by over 50 farmers, stimulated the interest of farmers on both Maui and Hawaii and additional nozzles were purchased to loan to farmers. The venturi nozzles have now been adopted by most of the major farmers on all of the islands, especially areas with strong normal tradewinds. Most of the farmers in the major vegetable growing areas on Oahu, Maui and Hawaii now use these nozzles on a regular basis.

Project Links
not applicable

American Farmland Trust