An Improved Technique for Measuring Resistance to Root Pulling in Maize1

Root‐pulling resistance is one method for selecting maize (Zea mays L.) genotypes with superior resistance to root lodging. We compared a mechanical and a manual technique for speed, efficiency, and accuracy. The manual procedure for root pulling included a clamp and scale mounted onto a bipod and lever. The mechanical procedure consisted of a similar scale and clamp mounted to the boom of a small, maneuverable, skid‐steer loader. Three maize hybrids with a range of resistance to root pulling were used. Competitive plants were pulled at 20 days after flowering. The mechanical technique was considerably faster and required far less labor than the manual method. Mean root‐pulling values, measured as load‐kilograms per plant were significantly higher for the mechanical technique (182) than for the manual technique (154). The accuracy of the techniques was similar based on a homogeneity of variance test and comparisons of coefficients of variation from separate analyses of variance for each hybrid.