Summary
Alachlor was more inhibitory toRhizoctonia solani growth than fluchloralin in potato dextrose broth (PDB). Infective capacity of the pathogen was not altered by growing it in a medium containing either of the herbicides. Cowpea seedlings grown in alachlor-treated soil were more susceptible toR. solani than those treated with fluchloralin and the untreated seedlings. Pre-sowing application of alachlor in soil (5 μl a.i./kg) aggravated damping-off whereas fluchloralin decreased the disease incidence to nearly half of that in untreated soil in greenhouse pot tests (av. temperature 31±5°C). Both herbicides reduced damping-off in pots kept at constant temperature of 30°C and increased the disease incidence at 20°C. Fungus growth in culture was stimulated at 20° but was strongly inhibited at 30°C by both herbicides. Growth inhibition by herbicides was maximum in PDB of pH 8 and decreased steadily up to pH 5.
Impact of fluchloralin and alachlor onR. solani damping-off of cowpea appears to be due to the predisposing effect by the herbicides on the susceptibility of the host and is influenced by atmospheric temperature.
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References
Altman J 1972 Increased glucose exudate and damping-off in sugarbeets in soils treated with herbicides. Phytopathology 62, 743.
Altman J and Campbell C L 1977 Effect of herbicides on plant diseases. Ann. Rev. Phytopathol. 15, 361–385.
Chandler J M and Santelmann P W 1968 Interactions of four herbicides withRhizoctonia solani on seedling cotton. Weed Sci. 16, 453–456.
Hill R L and Wright J L 1978 Pesticide Microbiology. Academic Press, London & New York.
Kataria H R and Dodan D S 1981 Pathogenesis ofPythium butleri on cowpea as influenced by two herbicides. Z. Pfl. krankh. Pfl. schutz. 88, 734–743.
Kataria H R and Dodan D S 1982 The influence of two herbicides on antifungal activity of some fungicides againstPythium butleri andRhizoctonia solani causing damping-off of cowpea. Pestic. Sci. 13, 583–588.
Neubauer R and Avizohar-Hershenson Z 1973 Effect of the herbicide, trifluralin, onRhizoctonia disease in cotton. Phytopathology 63, 651–652.
Romig W R and Sasser M 1972 Herbicide predisposition of snapbeans toRhizoctonia solani. Phytopathology 62, 785–786.
Wyse D L, Meggitt W F and Penner D 1976 Effect of herbicides on the development of root rot on navy bean. Weed Sci. 24, 11–15.
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Kataria, H.R., Dodan, D.S. Impact of two soil-applied herbicides on damping-off of cowpea caused byRhizoctonia solani . Plant Soil 73, 275–283 (1983). https://doi.org/10.1007/BF02197723
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DOI: https://doi.org/10.1007/BF02197723