title: Effects of pre-harvest chemical application on rice desiccation and seed quality.
abstract: Pre-harvest desiccation may increase the efficiency of seed production. Field studies were conducted to determine the effects of diquat, paraquat, and ethephon applications on grain moisture, grain weight, and seed germination of hybrid rice Yanliangyou 88 (Oryza sativa ssp. indica) and conventional rice Wuyunjing 7 (Oryza sativa ssp. japonica). In 2013, we tested 12 treatments applied at four weeks (Yanliangyou 88) and six weeks (Wuyunjing 7) after heading. Results showed that reductions in moisture content were significant two and four days after chemical application. Chemical applications had no adverse effects on 1000-grain weight, germination percentage, or germination index, but there were negative effects on the percentage of normal seedlings. Desiccation effects increased with increase in the period after application, while the effect of ethephon combined with diquat or paraquat on desiccation was limited compared with that of diquat or paraquat alone in a short period after application. In 2013, chemical applications reduced the moisture content by from 0.5% to 6.4%, the germination percentage by from 0% to 3.3%, and the percentage of normal seedlings by from 13.3% to 100.0%. Among the treatments, diquat applied at 120 g/ha resulted in effective desiccation with fewer negative effects on grain weight and seed germination in 2013 and 2014. Therefore, diquat may have potential as a pre-harvest chemical desiccation treatment for rice. These results may provide a basis for developing and implementing protocols for large scale field trials.
authors.affiliation: Laboratory of Seed Science and Technology, State Key Laboratory of Crop Genetics and Germplasm Enhancement / Jiangsu Collaborative Innovation Center for Modern Crop Production, Nanjing Agricultural University, Nanjing 210095, China.
authors.forename: Yong-qi
authors.initials: YQ
authors.lastname: He
authors.affiliation: Laboratory of Seed Science and Technology, State Key Laboratory of Crop Genetics and Germplasm Enhancement / Jiangsu Collaborative Innovation Center for Modern Crop Production, Nanjing Agricultural University, Nanjing 210095, China.
authors.forename: Jin-ping
authors.initials: JP
authors.lastname: Cheng
authors.affiliation: Laboratory of Seed Science and Technology, State Key Laboratory of Crop Genetics and Germplasm Enhancement / Jiangsu Collaborative Innovation Center for Modern Crop Production, Nanjing Agricultural University, Nanjing 210095, China.
authors.forename: Liang-feng
authors.initials: LF
authors.lastname: Liu
authors.affiliation: Laboratory of Seed Science and Technology, State Key Laboratory of Crop Genetics and Germplasm Enhancement / Jiangsu Collaborative Innovation Center for Modern Crop Production, Nanjing Agricultural University, Nanjing 210095, China.
authors.forename: Xiao-dan
authors.initials: XD
authors.lastname: Li
authors.affiliation: Laboratory of Seed Science and Technology, State Key Laboratory of Crop Genetics and Germplasm Enhancement / Jiangsu Collaborative Innovation Center for Modern Crop Production, Nanjing Agricultural University, Nanjing 210095, China.
authors.forename: Bin
authors.initials: B
authors.lastname: Yang
authors.affiliation: Laboratory of Seed Science and Technology, State Key Laboratory of Crop Genetics and Germplasm Enhancement / Jiangsu Collaborative Innovation Center for Modern Crop Production, Nanjing Agricultural University, Nanjing 210095, China.
authors.forename: Hong-sheng
authors.initials: HS
authors.lastname: Zhang
authors.affiliation: Laboratory of Seed Science and Technology, State Key Laboratory of Crop Genetics and Germplasm Enhancement / Jiangsu Collaborative Innovation Center for Modern Crop Production, Nanjing Agricultural University, Nanjing 210095, China.
authors.forename: Zhou-fei
authors.initials: ZF
authors.lastname: Wang
mesh_terms: D003890:Desiccation / Q000379:methods*; D005504:Food Analysis; D018525:Germination / Q000187:drug effects / Q000502:physiology*; D006540:Herbicides / Q000008:administration & dosage*; D012275:Oryza / Q000187:drug effects* / Q000254:growth & development*; D012639:Seeds / Q000187:drug effects / Q000254:growth & development*
chemical_list: D006540:Herbicides
keywords: Chemical desiccant; Rice; Seed desiccation; Seed germination