Soaking seeds with paclobutrazol enhances winter survival and yield of rapeseed in a rice-rapeseed relay cropping system

Document Type: Research Paper

Authors

1 College of Plant Science and Technology, Huazhong Agricultural University, Wuhan 430070, Hubei Province, P. R. China.

2 Department of Botany, GC Women University, Faisalabad, 38000, Pakistan

3 College of Plant Science and Technology, Huazhong Agricultural University, Wuhan 430070, Hubei Province, P. R. China

4 Huazhong Agricultural University

Abstract

Rice-rapeseed relay cropping is an effective way to use winter fallow fields and increase
land use efficiency. However, the overlapping period of 10–15 days for rice-rapeseed
cultivation results in reduced winter survival and less yields. Therefore, in this study, we
investigated if the treatment of oil rape seeds with paclobutrazol (PAC) improves its winter
hardiness and yields by altering its crop morphology. First, a pot experiment was conducted to
determine the appropriate PAC concentration to soak seeds upon seedling growth and the
germination rate. Another pot trial was performed to check the responses of different rapeseed
cultivars to the proposed treatment. Rapeseed was cultivated in no-tillage rice fields at an
experimental site in Wuhan from 2009 to 2011. In the absence of PAC treatment, rapeseed sown
in pots and rice fields showed excessive elongation of the crown, which resulted in low yields
and yield-related traits at maturity. Soaking seeds in PAC improved seedling growth, seedling
survival and crown diameter, but decreased the crown length during winter. The most effective
concentration of PAC was 4 mg/L and higher concentrations significantly reduced seed
germination rates. Our results demonstrated that rapeseed sown in rice fields after the seeds had
been soaked with PAC improved seedling quality at the wintering stage and yield at maturity.

Keywords