Optimizing hill seeding density for high-yielding hybrid rice in a single rice cropping system in South China

Danying Wang; Song Chen; Zaiman Wang; Chenglin Ji; Chunmei Xu; Xiufu Zhang; Bhagirath Singh Chauhan

doi:10.1371/journal.pone.0109417

Optimizing hill seeding density for high-yielding hybrid rice in a single rice cropping system in South China

PLoS One. 2014 Oct 7;9(10):e109417. doi: 10.1371/journal.pone.0109417. eCollection 2014.

Authors

Danying Wang¹, Song Chen¹, Zaiman Wang², Chenglin Ji¹, Chunmei Xu¹, Xiufu Zhang¹, Bhagirath Singh Chauhan³

Affiliations

¹ State Key Laboratory of Rice Biology, China National Rice Research Institute, Hangzhou, Zhejiang, China.
² Key Laboratory of Key Technology on Agricultural Machine and Equipment, South China Agricultural University, Guangzhou, Guangdong, China.
³ Queensland Alliance for Agriculture and Food Innovation, University of Queensland, Queensland, Australia.

Abstract

Mechanical hill direct seeding of hybrid rice could be the way to solve the problems of high seeding rates and uneven plant establishment now faced in direct seeded rice; however, it is not clear what the optimum hill seeding density should be for high-yielding hybrid rice in the single-season rice production system. Experiments were conducted in 2010 and 2011 to determine the effects of hill seeding density (25 cm×15 cm, 25 cm×17 cm, 25 cm×19 cm, 25 cm×21 cm, and 25 cm×23 cm; three to five seeds per hill) on plant growth and grain yield of a hybrid variety, Nei2you6, in two fields with different fertility (soil fertility 1 and 2). In addition, in 2012 and 2013, comparisons among mechanical hill seeding, broadcasting, and transplanting were conducted with three hybrid varieties to evaluate the optimum seeding density. With increases in seeding spacing from 25 cm×15 cm to 25 cm×23 cm, productive tillers per hill increased by 34.2% and 50.0% in soil fertility 1 and 2. Panicles per m2 declined with increases in seeding spacing in soil fertility 1. In soil fertility 2, no difference in panicles per m2 was found at spacing ranging from 25 cm×17 cm to 25 cm×23 cm, while decreases in the area of the top three leaves and aboveground dry weight per shoot at flowering were observed. Grain yield was the maximum at 25 cm×17 cm spacing in both soil fertility fields. Our results suggest that a seeding density of 25 cm×17 cm was suitable for high-yielding hybrid rice. These results were verified through on-farm demonstration experiments, in which mechanical hill-seeded rice at this density had equal or higher grain yield than transplanted rice.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Agriculture / instrumentation
Agriculture / methods*
Chimera / growth & development*
China
Humans
Oryza / growth & development*
Seasons
Seeds / growth & development*
Soil / chemistry*

Substances

Soil

Grants and funding

The authors are grateful for grants from the National Rice Industry Technology System (CARS-01-04A), the 3 Nong 6 Fang Program, and the Five-twelfth National Science and Technology Support Program (2011BAD16B14). The authors state that the funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.