Browsing by Author "Khaitov, Botir"

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    Crop ecosystem responses and weed population under elevated temperature regimes
    (Bioscience Research, 2019) Bir, Md. Shahidul Haque; Aktar, Most Mohshina; Uddin, Md. Romij; Khaitov, Botir; Park, Kee Woong
    The negative effects of weed infestation in paddy fields and increasing temperature are considered as the main factors of reducing rice grain yield. This study conducted to reveal the competitive interaction between rice (upland rice Dongjin 1) and weeds with different densities at ambient and 0.8℃, 1.9℃, and 3.4℃ above ambient temperature in special phytotrons at Chungnam National University, Daejeon, Korea. The competition between rice and weeds was created in the following three treatments: 1. Natural occurrence of weeds is naturally grown from the soil seed bank, 2. Standard density, the following weeds were grown in the plots: EO (Echinochl oaoryzicola) 1g, Mv (Monochoria vaginalis) 1 g, Lp (Ludwigia prostrata) 1 g, Ek (Eleocharis kuroguwai) 15 tuber, Sp (Scirpus planiculmis) 15 tuber, SS (Sagittaria sagittifolia) 15 tuber, Lpr (Lindernia procumbens) naturally occurred, Rp (Rotala pusilla) naturally occurred. 3. High density, the following weeds were grown in the plots: EO=2 g, Mv=2 g, Lp=2 g, Ek=30, Sp=30, SS=30, Lpr naturally occurred, Rp naturally occurred. Results presented that rice growth parameters such as height, the number of tillers, and shoot dry weight were increased with the increase of ambient temperature. However, rice yield negatively correlated with the increase of temperature, especially, caused enhancing the panicle senescence at the pollination period and shortening the grain filling period. The lowest rice yield was observed in high weed density treatment followed by standard weed density of weed treatment compared to natural weed occurrence treatment. From the perspective of rice: weed competitions, generally weeds exhibited more competitive ability than rice in this interspecific competition.
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    Growth Response of Weed Species in a Paddy Field under Elevated Temperatures
    (Department of crop science, Chungnam National University, Daejeon 34134, Korea, 2018) Bir, Md. Shahidul Haque; Hien, Le Thi; Won, Ok Jae; Bo, Aung Bo; Ruziev, Farrukh; Umurzokov, Mirjalol; Jia, WeiQiang; Yun, Hye Jin; Khaitov, Botir; Park, Woong
    The present study aimed to investigate the growth response of rice and paddy weeds under varying temperatures created artificially in the phytotron under field condition. Rice (Oryza sativa L.), three annual (Ludwigia prostrata, Monochoria vaginalis, and Echinochloa oryzicola) and three perennial (Scirpus planiculmis, Eleocharis kuroguwai, and Sagittaria sagittifolia) paddy weeds were grown under different temperature regimes (ambient, ambient+0.8°C, ambient+1.9°C, and ambient+3.4°C). It was observed that the growth of both rice and paddy weed species increased with the elevation of temperature. However, the growth of weeds was much greater than that of rice under elevated temperature. The shoot dry weight of rice was 8.9%, 13.1%, and 30.4% greater at the ambient+0.8, +1.9 and +3.4℃, respectively compared to the ambient temperature. Among the paddy weed species, L. prostrate exhibited the most significant increased level of both dry weight and leaf area presenting 211.8% and 214.3% higher, respectively at the ambient+3.4℃ than that of the ambient temperature. Growth of E. oryzicola and M. vaginalis were slightly higher compared to the growth of rice under elevated temperature. The growth of perennial weed species of S. sagittifolia exhibited 124.8% higher dry weight at the ambient+3.4℃ than at the ambient. Our findings suggest that elevation temperatures might provide an even greater competitive advantage to weeds with concomitant negative effects on rice productio