High versus low volume spraying of potatoes

Abstract

The data show that, under the severe disease conditions that prevailed in Prince Edward Island in 1962 and 1963, the fungicide applied in 120 gallons of water per acre gave better control of late blight on the foliage, higher yields of tubers, and better control of tuber rot than the same fungicide, applied at the same dosage, but carried in 40 gallons of water per acre. It was also evident, in both types of equipment used, that better disease control may be gained when the boom carries drop nozzles. The data recorded on insect control indicate that there was very little difference between high and low volume spraying, or between the two patterns of nozzle placement, on the control of flea beetles. With these insects, the close similarity among the control results was probably caused by their propensity to move frequently from one plant to another. In the case of the aphids, which are relatively inactive, the high volume spray gave much superior control to the low volume one. The nozzle arrangements on the high volume machine did not cause much difference in the control of aphids, the arrangement having drop nozzles being but slightly superior. With the low volume equipment, the use of drop nozzles resulted in superior control of this pest. It is concluded, therefore, that high volume sprayers are, in general, more efficient than low volume sprayers under the conditions that prevail on Prince Edward Island and that growers who use the latter type could improve the control of disease and insects by fitting the boom with both top and drop nozzles.