Abstract
Collection of crop loss assessment values adjacent to halipads has allowed a comparative investigation to determine which hailfall characteristics were related to the degree of loss to wheat, corn and soybean crops in Illinois. Establishment of such relationships is important information because it indicates which characteristics must be measured, either with hailpads or other hail-sensing devices, to provide meaningful evaluations of hail suppression project results and useful data for crop-hail studies. Because of factors related to the thickness of wheat stands, wheat losses were found to be closely related to the frequency of hailstones with diameters >0.25 inch. Corn and soybean losses exhibited varying seasonal relationships with either hailstone frequency and/or hailfall energy values. Corn losses in May related only to stone frequency, whereas corn losses in later growth stages (July-August) related well to both stone frequency and energy. A given number of hailstones falling in May produced considerably less corn damage than the same number in the June-August period. Soybean losses also related to both energy and stone frequency, although marked seasonal variations existed with each characteristic. An energy value of 1.0 ft-lb ft−2 produced, on the average, soybean loss of 12% in May, 15% in July-August, and 61% in June. Derived relationships indicated that 100 hailstones ft−2 (each >0.25 inch diameter) produced a 42% soybean loss in June, but only a 13% loss in July-August. The high correlations between crop losses and hailstone frequency and/or energy values indicate that potential crop losses in uncropped areas can be estimated from hail-sensing devices that measure both hail characteristics.
