Influence of sowing date on yield and yield attributes of rice genotypes and infestation by rice leafminer and rice stem borer

Abstract

2020 and 2021 seasons. The objective of study was to study the effect of three sowing dates (May1 st , May15 th and June1 st ) on yield, yield attributes of 21 rice genotypes, and infestation by rice leaf miner (Hydrellia prosternalis Deem.) and rice stem borer (Chilo agamemnon Bles.). Sowing date significantly affected all studied characters in both seasons. The highest values of flag leaf area, number of panicles per hill, panicle weight, total number of grains per panicle, percentage of filled grain, 1000-grain weight and grain yield were recorded in the earliest sowing date, while the lowest values were obtained with the latest one. Statistical analysis revealed that the rice genotypes were significantly different in all the studied traits. The highest values of grain yield and most of the studied characters were observed in Giza 179 and GZ10804-3-1-2-2-2, followed by Giza 178 and Sakha 108 rice cultivars. Rice leaf miner infestation significantly increased as the sowing was later. Giza 178 and Giza 179 rice cultivars suffered the highest infestation, followed by GZ 9399-4-1-1-2-1-2 and GZ 10778-17-1-6-1 promising lines. The rice stem borer infestation significantly decreased by delaying the sowing date. GRYT-26-17-178, GRYT-29-17-178 lines and Korea 27 rice genotypes recorded the highest infestation with both dead hearts and white heads.