Weed species diversity in three rice-based cropping patterns under upland environment
2017
Mercado, M.J.T. | Zablan, L.J. | Lapitan, V.C.
Weeds are major constraints that limit plant growth and yield in upland crop production. However, as one of the primary producers within the farming systems, weeds are important components in the upland agroecosystem. Weeds play significant roles in maintaining the biological diversity of the system as well as in nutrient cycling and soil preservation. However, weed species diversity is affected by different agricultural practices employed in particular farming system. This study aimed to examine the diversity of weed species in three rice-based cropping patterns such as Rice-Rice, Rice-Corn, and Rice-Mungbean under upland environment. Rice was planted as first crop in 2015 wet season and then rotated either with rice, corn, and mungbean as second crops in 2016 dry season. Weed diversity assessment and identification were performed during the early vegetative (EV), early reproductive (ER) and late reproductive (LR) stages of the crops. At first cropping, the highest Shanon's diversity (H') value was detected during ER stage with H' of 2.26 while the lowest average H' value (1.68) was at EV stage. During the second cropping, the highest (H'=2.28) and the lowest (H'=1.01) diversity values were at ER and LR stages of rice on Rice-Rice system, respectively. Total number of weeds consisted of broadleaves, sedges, and grasses were highest at ER on both croppings while it was lowest at EV and LR on the first and second cropping, respectively. In three cropping patterns, broadleaves were the most dominant followed by grasses and then sedges in two croppings. Results indicated that crop growth had major effect on the diversity of weeds in three cropping patterns. As crops continued to grow, shading was enhanced which suppressed the growth of the different weed species underneath the crops and therefore affected the weed diversity.
显示更多 [+] 显示较少 [-]