Login | Create Account (DAF staff only)

Growth analysis and biomass partitioning of Cyperus iria in response to rice planting density and nitrogen rate

Awan, Tahir Hussain and Sta. Cruz, Pompe C. and Chauhan, Bhagirath Singh (2015) Growth analysis and biomass partitioning of Cyperus iria in response to rice planting density and nitrogen rate. Crop Protection, 74 . pp. 92-102. ISSN 0261-2194

Full text not currently attached. Access may be available via the Publisher's website or OpenAccess link.

Article Link(s): http://dx.doi.org/10.1016/j.cropro.2015.04.010

Publisher URL: http://www.sciencedirect.com/science/article/pii/S0261219415300120

Abstract

Cyperus iria is a weed of rice with widespread occurrence throughout the world. Because of concerns about excessive and injudicious use of herbicides, cultural weed management approaches that are safe and economical are needed. Developing such approaches will require a better understanding of weed biology and ecology, as well as of weed response to increases in crop density and nutrition. Knowledge of the effects of nitrogen (N) fertilizer on crop-weed competitive interactions could also help in the development of integrated weed management strategies. The present study was conducted in a screenhouse to determine the effects of rice planting density (0, 5, 10, and 20 plants pot−1) and N rate (0, 50, 100, and 150 kg ha−1) on the growth of C. iria. Tiller number per plant decreased by 73–88%, leaf number by 85–94%, leaf area by 85–98%, leaf biomass by 92–99%, and inflorescence biomass by 96–99% when weed plants were grown at 20 rice plants pot−1 (i.e., 400 plants m−2) compared with weed plants grown alone. All of these parameters increased when N rates were increased. On average, weed biomass increased by 118–389% and rice biomass by 121–275% with application of 50–150 kg N ha−1, compared to control. Addition of N favored weed biomass production relative to rice biomass. Increased N rates reduced the root-to-shoot weight ratio of C. iria. Rice interference reduced weed growth and biomass and completely suppressed C. iria when no N was applied at high planting densities (i.e., 20 plants pot−1). The weed showed phenotypic plasticity in response to N application, and the addition of N increased the competitive ability of the weed over rice at densities of 5 and 10 rice plants pot−1 compared with 20 plants pot−1. The results of the present study suggest that high rice density (i.e., 400 plants m−2) can help suppress C. iria growth even at high N rates (150 kg ha−1).

Item Type:Article
Business groups:Crop and Food Science
Keywords:Rice planting density Nitrogen rate Phenotypic plasticity Rice-weed competition Biomass partitioning
Subjects:Science > Invasive Species > Plants > Integrated weed control
Plant culture > Field crops > Rice
Plant pests and diseases > Pest control and treatment of diseases. Plant protection > Pesticides
Deposited On:06 Jul 2015 02:15
Last Modified:03 Aug 2015 03:14

Repository Staff Only: item control page