Simulating Hail Damage On Cotton Fruiting Branches in Arizona

Hail damage occurs each year in many areas where cotton is grown, and accurate estimations of crop yield loss are important for taking management actions and adjusting hail insurance claims.  Insurance adjusters use a step-by-step procedure from National Crop Insurance Services to assess the effects of hail damage on cotton.  The assessment includes estimations of cotton yield reductions by stand loss (plant totally or partially destroyed and main stem growth point lost), by fruiting branch removal, and by boll loss at different growth stages.  Current data on the yield loss estimation was developed from field experiments in southern states.  The information is not applicable to southwestern states such as Arizona and California, in which cotton is grown in a much longer growing season.  In this study, we estimated cotton yield loss by different levels of fruiting branch removal at different growth stages in Arizona. If the main growth point is undamaged during hail storm during the eight fruiting branches to sixteen fruiting branches stage, growers could recover 80% to 100% of their cotton yield under growing conditions in Arizona.  However, management practices might need to be adjusted after hail damage to increase cotton boll setting on top branches.