In-Vitro Evaluation of Fungicides, Biocontrol Agents and Plant Extracts Against Rice Sheath Blight Pathogen Rhizoctonia Solani.

Of the fourteen fungicides of different groups evaluated in-vitro against Rhizoctonia solani , Metalaxyl (0.1%), Mancozeb (0.1%), Tricyclazole (0.1%), Thiophenate methyl (0.1%), Carbendizm+ Mancozeb (0.1%) were proved to be most effective in inhibiting the growth of the fungus. Among the bio-agents screened, Trichoderma viride was most effective in restricting the growth of Rhizoctonia solani followed by Penicillium notatum where as Aspergillus niger was proved least effective. Among the thirteen plant extracts evaluated garlic extract (10%) was most effective in inhibiting the growth of fungus followed by calotropis (10%). Datura leaf extract (10%) was found to be least effective in inhibiting the growth of Rhizoctonia solani.

Survey of Turcicum Leaf Blight of Maize in Major Maize Growing Areas of Andhra Pradesh.

Northern corn leaf blight or turcicum leaf blight caused by Exserohilum turcicum (Pass.) Leonard and Suggs is one of the important diseases affecting photosynthesis with severe reduction in grain yield to an extent of 28 to 91%. Disease symptoms first appear on the leaves at any stage of plant growth, but usually at or after anthesis. The studies on survey reveals that high intensity of the disease was noted in the district where mean maximum temperature was below 320C and relative humidity was above 85 percent during the cropping season (June-October). The maximum PDI of 51 percent was recorded in Khammam district where the maximum temperature of 31.820C and the relative humidity of 87.5 percent was recorded whereas minimum (33 percent) PDI was recorded in Guntur district and it was due to high maximum temperature of 35.220C and low relative humidity of 76 percent.