The practice of pressing down on young wheat plants by ground rolling or trampling has been used in Japan for a long time to increase yield. Among the reported effects of rolling are delays in spikelet formation, apical development, and internode elongation; however, the underlying mechanism is unknown. Wheat can be injured by frost if exposed to temperatures of −2 °C or lower after the jointing stage, and the risk is increased by a warm winter and early sowing. This review presents the results of research on the prevention of frost injury by rolling, the conditions for effective rolling, and how rolling delays spike development.
MIZUMOTO et al. (Thu,) studied this question.