Evaluation of Curvularia lunata as an Biological Control Agent in Major Weeds of Rice Paddies

Common water-plantain (Alisma plantago-aquatica L.), arrowhead (Sagitaria trifolia L.) and Echinochloa spp. (L.) are among the most important damaging weeds of rice paddies. In this research, Curvularia lunata (Waker) Boedijn was isolated from the said weeds. Then, its effect in different growth stages, i.e. seed, 2-3 leaf stage (seedling) and also in greenhouse conditions was examined in Alisma plantago-aquatica, Sagitaria trifolia, Echinochloa spp., and five rice cultivars including 2 bred (Sepidroud and Khazar) and 3 indigenous (Ali Kazemi, Hashemi and Binam) ones in a totally random design with three replications. To do so, pure fungal colonies and a spore suspension containing 10 6 conidia/ml distilled water were used. The disease rating caused by this fungus in the 2-3 leaf stage (seedlings) of the said weeds was more than that in the rice cultivars. Also, the fungus decreased the germination of the weeds seeds. Results showed that in the evaluation of the disease rating, the studied rice cultivars showed no significant reaction to greenhouse conditions while weeds’ reactions were significant. The greatest effect of C. lunata was on Alisma plantago-aquatica. The evaluation of fresh weight, dry weight and height of the said weeds and rice cultivars indicated that the above-mentioned fungus could affect these traits in weeds and rice cultivars and would reduce them. Hence, Curvularia lunata can be considered as a probable agent for the biological control of Alisma plantago-aquatica, Echinochloa spp., and Sagitaria trifolia provided that modification of rice cultivars is done with useful traits. [Mohammad Reza Safari Motlagh. Evaluation of Curvularia lunata as an Biological Control Agent in Major Weeds of Rice Paddies. Life Science Journal. 2011;8(2):81-91] (ISSN:1097-8135). http://www.lifesciencesite.com.