Cultivar Differences in Milling Yields under Delayed Harvesting of Rice

Evaluation of milling performance of rice ( Oryza sativa L.) cultivars often has resulted in a wide range of values depending on the growing environment, and harvesting and drying methods. A common stress affecting milling yield evaluations is the delay in harvesting. This experiment was designed to evaluate the performance of 16 rice cultivars under 2 wk of harvest delay. Cultivar plantings were staggered to obtain simultaneous maturity during three consecutive seasons at Palmira, Colombia. A combination of harvesting and threshing‐time treatments was used. Harvesting was done at maturity, and 1 and 2 wk later. Threshing was done immediately after harvest and with a delay of 4 d. Total milled‐ and head‐rice yields were measured. Cultivar response to delayed harvesting followed four patterns ranging from constant head‐rice yields throughout the period to significant weekly reductions. Threshing delays reduced head‐rice yields by an average of 5.8% for all cultivars. Total milled‐rice yields was reduced 3% across cultivars by a 2‐week delay in harvest or by a 4‐day delay in threshing. Cultivar performance patterns detected could be used to check the reaction of other cultivars for harvest delay effects.