Acta Univ. Agric. Silvic. Mendelianae Brun. 2019, 67(3), 787-795 | DOI: 10.11118/actaun201967030787

Vertical Distribution of Nutsedge (Cyperus spp. L.) and Bahiagrass (Paspalum notatum L.) Seed Bank in Rice Growth Cycle

Mohammad Yaghoubi Khanghahi¹, Hemmatollah Pirdashti¹, Mohsen Mohseni-Moghadam², Raheleh Roham³

¹ Agronomy Department, Genetics and Agricultural Biotechnology Institute of Tabarestan, Sari Agricultural Sciences and Natural Resources University, Sari, Iran

² Department of Horticulture and Crop Science, 1680 Madison Avenue, The Ohio State University, Ohio Agricultural Research and Development Center, Wooster, OH 44691, USA

³ Graduate Student, Agronomy and Plant Breeding Department, Lorestan University, Khorramabad, Iran

Weed management in rice continues to be a major challenge to the success of rice growers in northern Iran. Field experiments were conducted at Sari Agricultural Sciences and Natural Resources University to investigate the spatial distribution of weed seeds in the rice growth cycle in 2010 and 2011. Transplanting was done on June 6 in both years. Samples for seedbank analysis were collected 10 days before transplanting and emerged weed density was determined on three different dates during the growing season. Results indicated that nutsedge (Cyperus spp) and bahiagrass (Paspalum notatum) were the two most abundant weed species. The vertical distribution of weed seeds decreased by depth from 0.1 to 0.3 m, while weed pressure was the highest at the 0-0.1 m soil depth. There was no relationship between soil weed seedbanks (at different depths) and emerged weed populations, suggesting that weed seedbank data are not good predictors of weed seedling densities. Nevertheless, Kriging maps indicated that the spatial distribution of weed seeds was in accordance with seedling germination pattern. Also the regression coefficient for 0-0.1 m soil depth was R² = 0.17 and R² = 0.34 for relation between nutsedge and bahiagrass seedlings and their seedbank in 2010 and also, R² = 0.18 and R² = 0.05 in 2011, respectively. Therefore, results achieved from this depth can be used to predict the relationship between nutsedge and bahiagrass seedlings densities and weed seedbanks. The results of this study provide an option for the farmers growing rice to understand the dynamics of weed populations in a cost effective way.

Keywords: bahiagrass, kriging map, nutsedge, rice, spatial distribution, soil depth, weed

Grants and funding:

This research was supported by Genetics and Agricultural Biotechnology Institute of Tabarestan (GABIT), Sari Agricultural Sciences and Natural Resources University, Sari, Iran.

Received: December 13, 2018; Accepted: April 2, 2019; Published: June 27, 2019  Show citation