Effects of Different Planting Densities and Planting Spaces on the Growth and Yield Attributes of Rice under Irrigated Condition

Abstract

Background: Rice is a staple food for majority of the world’s population. Biotic and abiotic factors can affect its growth, yield and quality attributes. An open field experiment was conducted during the rice-growing period from March to October 2015 to identify the effects of different planting densities and planting spacing on the growth attributes and yield performances of a high tillering capacity Indica rice variety (IR-28).
Materials and Methods: The experiment was conducted under lowland condition in the research farm of Tsukuba International Center, Japan with four different planting densities and three replications in a randomized complete block design. Four different planting densities were selected as high density (15x20cm), standard density (15x30cm), medium density (25x25cm) and low density (30x30cm). Rice growth traits including plant length, tiller number, SPAD value and leaf color; yield and yield components consisting of panicle number per unit land area, spikelet number per panicle, ripening ratio, and 1000 grain weight were compared.
Findings: The greatest grain yield was obtained from high planting density which was 6.5 ton per ha and the lowest (5.8 ton/ha) was from medium planting density. Low planting density increased plant length, tiller number per hill, SPAD value (chlorophyll content), leaf color beside panicle number per hill, spikelet number per panicle and percentage of ripened grain.
Conclusion: This study clearly elucidated the effects of planting density on rice crop and helps farmers in the achievement of optimum yield. Thus, to obtain a satisfactory yield, planting density must be considered based on soil type and production requirement.