Simulated Hail Damage on Spring Canola (Brassica napus L.): Non-Uniform Stand Reduction and Stem Cut-Off
Abstract
Hail damage in canola has been characterized with symptoms such as randomly broken stems and loss of plants. The effect on stand reduction and stem cut-off in canola has yet to be addressed. Two separate experiments, stand reduction and stem cut-off, were conducted at six environments using a factorial arrangement, with four growth stages and five levels of intensity as the two factors, and four replications for each treatment. Data on seed yield, seed oil, and seed protein from each plot of five environments, and yield contributing traits from twenty plants per treatment from four environments were taken. Seed yield losses increased as both growth stage and level of stem cut-off/stand reduction increased. A regression equation was developed to estimate the yield reduction resulting from different levels of stand reduction/stem cut-off at four growth stages. Highest seed yield reductions were 82% and 43% at 90% stand reduction/stem cut-off, respectively.