The Effects of Planting Date on Growth Traits and Yield of Different Rice Cultivars Grown in Dry Conditions

Abstract

【Objective】 Planting date is an important factor impacting plant growth and ultimate yield. The purpose of this paper is to investigate how sowing date affects growth traits and ultimate yield of different rice varieties cultivated in dryland, aimed to provide guidance for farmers to select optimal agronomic management practices. 【Method】 The experiment was conducted in a field and examined three rice varieties: early-mature japonica, middle-mature japonica and late-mature japonica. For each variety, we compared the impact of five planting dates - 25 and 30 April, 5, 10 and 15 May - on its growth and yield traits. 【Result】 In terms of average yield, the three varieties were ranked in the order of early-mature japonica > late-mature japonica > medium-mature japonica. Delaying the planting date of the early-mature variety to 15 May significantly increased its SPAD at filling stage, while planting the late-mature variety on 30 April increased its SPAD at elongation stage compared to other sowing date. In general, delaying the planting date of the early-mature variety or early planting the late-mature variety can increase the areas of their top three leaves. As the sowing date delayed, dry matter accumulation in all three varieties first decreased followed by an increase. Similar trend was also found for the change of plant height of the early-mature japonica. A right sowing date can benefit the grain filling. The sowing date did not have a noticeable effect on seed-setting rate and 1 000-grain weight but could significantly impact both spike numbers and grain number, with the coefficient of variation of the former reaching 20.9% and that of the latter being as high as 23.7%. 【Conclusion】 Our experimental results showed that under dry cultivation, planting the early-mature japonica between May 10 and May 15, and the late- and the medium-mature japonicas between April 30 and May 5 in central region of Jilin province could increase rice yield when other agronomic managements were the same.

Keywords

• rice cultivation
• sowing date
• rice variety
• agronomic management practice