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Use of airshear technology to reduce chemical spray rates for thinning apples


Oakford, MJ and Bound, SA and Jones, KM and O'Rielly, L, Use of airshear technology to reduce chemical spray rates for thinning apples, Australian Journal of Experimental Agriculture, 35 pp. 789-94. ISSN 0816-1089 (1995) [Refereed Article]

DOI: doi:10.1071/EA9950789


An experiment at the Grove Research Station in southern Tasmania compared the efficacy of low spray volume (LV) treatments of NAA applied by an airshear sprayer with that of the industry standard, airblast sprayer, high volume (HV) application of 4000 L/ha at 10 mg NAA/L to thin Red Delicious apple trees. By adjusting the concentration of NAA, the LV treatments of 100, 200, 400, and 800 L/ha were each applied at 4 rates of NAA representing 25, 50, 75, and 100% of the HV rate of 40000 mg/ha. All treatments were applied at full bloom and 9 days after full bloom. All chemical rates except 25% reduced crop load significantly compared with the control. Fruit weight and size improved in most cases at the 100, 75, and 50% chemical rates. Fruit numbers and mean fruit weight were fitted to polynomial models. This work shows that airshear technology is effective at volumes as low as 100 L/ha, which represents a major saving in spraying time. It also indicates that with effective spraying systems, chemical application rates can be reduced to 50-75% of label rates. This should give the apple industry the confidence to reduce rates and still produce crops of high quality fruit. © 1995 CSIRO.

Item Details

Item Type:Refereed Article
Research Division:Agricultural, Veterinary and Food Sciences
Research Group:Horticultural production
Research Field:Horticultural crop growth and development
Objective Division:Plant Production and Plant Primary Products
Objective Group:Horticultural crops
Objective Field:Pome fruit, pip fruit
UTAS Author:Bound, SA (Dr Sally Bound)
UTAS Author:Jones, KM (Mr Keith Jones)
ID Code:26551
Year Published:1995
Web of Science® Times Cited:6
Deposited By:Agricultural Science
Deposited On:2003-08-01
Last Modified:2007-06-26

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