Assessment of Optimal Seeding Rate for Fine and Coarse Rice Varieties Using the Direct Seeded Rice (DSR) Method

Rice (Oryza sativa L.) is one of the most crucial cereal crops worldwide, serving as a staple food for a significant portion of the global population. Rice is the second most important staple food crop in Pakistan after wheat, and it is also a major export commodity. Concerning this, the current study aimed to evaluate the effects of different seed rates on the yield and yield-contributing parameters of rice varieties. The experiment was conducted over two consecutive kharif summer seasons, from 2020–21 and 2021–22, at the Pakistan Agricultural Research Council (PARC) Rice Program experimental area in Kala Shah Kaku, Lahore, Pakistan, by following a factorial randomized complete block design with three replications using coarse rice (KSK-133) and fine rice (Super Basmati) varieties. Different seed rates, including 27 kg/ha, 22 kg/ha, 17 kg/ha, and 12 kg/ha, were tested during the experiment. Different growth and yield-related attributes, such as plant height (cm), the number of productive tillers per plant, panicle length (cm), the number of grains per panicle, and grain yield (m−2), were recorded. The results showed that for KSK-133 and Super Basmati, the maximum grain yield was achieved at a sowing rate of 27 kg/ha in direct seed rice (DSR). The lowest yield was observed at a seeding rate of 12 kg/ha for KSK-133 and Super Basmati in DSR. Both basmati (Super Basmati) and coarse-grain (KSK-133) varieties exhibited similar responses to seed rate treatments, with the optimal performance observed at the highest seed rate of 27 kg/ha for both seasons. Grains per panicle and thousand grain weight emerged as critical determinants of yield, highlighting the need to balance vegetative growth with reproductive development. Breeding programs should focus on developing varieties that balance vegetative traits like tiller production and panicle length with reproductive traits to enhance overall yield. Based on these findings, it is concluded that using an optimal seeding rate of 27 kg/ha for direct-seeded fine and coarse rice varieties is beneficial in terms of tillers and higher yield.