Optimizing Sowing Date and Nitrogen Fertilizer Level for the New Rice Variety Sakha Super 300

Abstract

A field trial was performed in Randomized Complete Block Design (RCBD) with three replications at the Experimental Farm of Sakha Agricultural Research Station, Kafr ELSheikh, Egypt, during 2018 and 2019 rice growing seasons, to investigate the effect of three sowing dates (May 10th, June 1st and June 20th) and four levels of nitrogen fertilizer (0, 55, 110 and 165 kg N/ha) on the productivity of Sakha Super 300 variety. The results showed that the sowing date June 1st produced the highest grain yield 10.67 and 10.71 t ha-1 in both seasons. Nitrogen level of 165 kg N ha-1 produced the highest grain yield 10.50 and 10.45 t ha-1 without any significant difference with level of 110 kg N ha-1 in 2018 and 2019 seasons. The interaction between sowing dates and nitrogen levels was highly significant for number of panicles hill-1, panicle length, number of filled grains panicle-1, unfilled grains percentage and 1000-grain weight, as well as grain and straw yield and harvest index in both seasons. Interaction results showed that, the first sowing date (May 10th) with nitrogen level of 110 kg N ha-1 gave the highest grain yield 10.91 and 10.79 t ha-1. On the other hand the second sowing date (June 1st) with nitrogen level of 165 kg N ha-1 gave the highest grain yield 12.03 and 11.92 t ha-1 in 2018 and 2019 seasons. The highest values of accumulated growing degree days (GDD) and photo thermal units (PTU) were recorded when plants sown on May 10th. On the other hand the maximums heat use efficiency (HUE) was achieved when Sakha Super 300 sown on 1st June with application of 165 Kg N ha-1 in both seasons.