Hail has damaged soybeans in Iowa rather frequently in recent years. Although no figures are available on the extent of these losses to soybeans alone, the annual estimated losses from hail damage to all crops in Iowa from 1936 to 1946 may show their probable significance. These losses, shown in table 1, were compiled from township assessors' reports. Crop losses due to hail damage apparently were considerably above average from 1942 to 1946. During this same period soybean acreage and 'production reached an all-time peak in Iowa (table 2).

The expanded acreage and production of. soybeans together with the increased incidence of hail has resulted in a large increase in the hail insurance written on this crop. Little was known regarding the evaluation of hail losses to soybeans when these experiments were initiated. Neither farmers nor hail adjustors knew the recovery to expect after soybean crops were damaged by hail at different stages of plant development. To provide this information was the principal objective of the investigations reported in this bulletin.