This study evaluated effects of crosswind on the variable rate sprayer application treatments spray coverage and\ndeposition on different citrus canopy sizes. The axial-fan airblast sprayer retrofitted with variable liquid- and air-assist rates\nwas field-tested with different crosswind conditions on small (about 2 m tall and < 1.5 m wide) and medium-sized (about 3 m\ntall and < 2.5 m wide) canopies. Crosswinds of 1.3, 2.7, and 4.0 ms-1 on the canopies being sprayed were generated using the\nstationary conical air shaker as the air blower unit. Water sensitive papers (WSPs) were used to collect droplet deposits and\nimage processing software was used to analyze the WSPs scanned at 600 dpi. Percent spray coverage on the WSPs was found\nto be one of the most suited parameters to evaluate the effectiveness of spray application treatments. Overall, the variable rate\nspray application treatments had comparable spray coverage on respective canopies (front, middle, and across WSP locations in\nthe canopy) during all crosswind conditions. For both types of canopies, spray coverage was higher on the canopy front and\ndecreased as the spray penetrated inside (i.e. canopy middle) and across. Due to coalescing, larger droplets (Dv,0.5 [volume\nmedian diameter] = 838 to 2,624 �µm) were formed on the WSPs located on canopy front, whereas coalescing reduced as the\nspray penetrated inside (Dv,0.5 = 391 to 1,625 �µm on canopy middle) and across the canopy (Dv,0.5 = 307 to 508 �µm).
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