Improved uniformity of spray deposition in a dense plant canopy: methods and equipment
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The global trend to shift from highly toxic pesticides to environmentally safe and less toxic chemicals requires, generally, very high spatial uniformity of the spray deposition. Effective penetration of the spray into a dense canopy can be achieved by utilizing fast air-streams. In contrast, slow and turbulent flow near the leaves and the stems is required for good deposition of the spray. A new sprayer was designed to achieve a sharp decline in air velocity to meet the two — seemingly contradictory — constraints, and thereby obtain effective penetration and coverage of dense canopy. In the present work, air ducts with several shapes of air outlets were developed and tested in an attmept to meet these requirements. Generally, a short and wide air slit created a moderate decline in air velocity; a longer and narrower air slit improved the uniformity of the air velocity along the slit outlet, and brought about a sharper decline in speed of the air-streams. Installing air deflectors at the air outlets added a slight upward motion to the air-streams and enhanced spray deposition on the underside of leaves. Preliminary field tests with the long and narrow air slit showed uniform spray deposition on all plant parts.
Key WordsDrop-tube sprayer dense canopy leaf-underside air characteristics spray deposi pesticide application
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- 3.Bache, D.H. (1985) Prediction and analysis of spray penetration into plant canopies.in: Application and Biology.Br. Crop Prot. Counc. Monogr. 28:183–190.Google Scholar
- 5.Frankel, H. (1986) Pesticide application, technique and efficiency.in: Palti, J. and Ausher, R. [Eds.] Advisory Work in Crop Pest and Disease Management. Springer Verlag, New York, NY. pp. 132–160.Google Scholar
- 6.Frankel, H., Steiner, B., Riven, Y. and Tzvieli, E. (1991) [Leaf coverage by a sprayer equipped with pulsating air-streams.]Mikun veHandasa beHaklaut 35(2):10–12 (in Hebrew).Google Scholar
- 7.Gan-Mor, S., Rylski, I., Nahir, D., Shpigelman, M. and Beres, H. (1983) [Improved yield of greenhouse tomatoes by pulsating air jets.]Hassadeh 64:50–55 (in Hebrew).Google Scholar
- 8.Matthews, G.A. (1992) Pesticide Application Methods. Longman, Singapore. 2nd ed.Google Scholar
- 9.Nahir, D., Gan-Mor, S., Rylski, I. and Frankel, H. (1984) Pollination of tomato flowers by a pulsating air jet.Trans. ASAE (Am. Soc. Agric. Eng.) 27:894–896.Google Scholar
- 10.Robinson, T.H. (1993) Large scale ground-based application techniques.in: Matthews, G.A. and Hislop, E.C. [Eds.] Application Technology for Crop Protection. CAB International Press, Wallingford, UK. pp. 163–186.Google Scholar
- 11.Rose, G. J. (1963) Crop Protection. Leonard Hill Ltd., London, UK. pp. 174–197.Google Scholar
- 13.Zur, I., Hedvati, R., Nevo, D., Kletter, E., Levi, R., Oren, H., Manor, G. and Geva, A. (1991) [A drop sprayer equipped with pulsating air-streams.]Mikun veHandasa beHaklaut 35(2):7–9 (in Hebrew).Google Scholar