Submitted to: Fungicide and Nematocide Tests
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/1/2003
Publication Date: 5/1/2003
Citation: CHEN,W. ., SHORT,R.W., MCPHEE,K.E., MUEHLBAUER,F.J. FIELD EVALUATION OF CHEMICALS IN CONTROLLING CHICKPEA ASCOCHYTA BLIGHT, 2002. FUNGICIDE AND NEMATOCIDE TESTS. Vol 58. FC033. DOI:10.1094/FN58. 2003.
Interpretive Summary: The efficacy of five chemicals (four fungicides and one laboratory chemical) in controlling Ascochyta blight was evaluated in Pullman, WA and Genesee, ID. Results showed that the most effective fungicides are Headline, Bravo and Quadris. Two application rates (either full rate or half rate) did not significant effect in reducing disease severity. The effective fungicides did significantly reduce disease severity and increase yield on susceptible cultivar Spanish White. However, the effect of these fungicides on resistant cultivar Dwelley is marginal.
Technical Abstract: The effectiveness of five chemicals (four fungicides and one laboratory chemical) in controlling Ascochyta blight of chickpea was evaluated at two locations. The five chemicals and their applied full rates were Headline (10.4 fl oz/A), Bravo Weather Stik (1.4 pt/A), Quadris SC (9.2 fl oz/A), Tilt (4 fl oz/A), and salicylic acid (4.2 oz/A, 10 mM in 0.01% Silwet L-77 from Lehle Seeds, Round Rock, TX). These chemicals were applied either at the full rate or at a half rate, and each of the rates was applied either once or twice on two chickpea cultivars Dwelley (resistant) and Spanish White (susceptible) with four replications. Water was sprayed as a control. Disease severity was recorded based on a 1-to-9 scale. Yield data were taken as ounces per harvested area (20 sq ft). Disease ratings and yield data showed differences between cultivars and among chemicals at both locations. No differences between number of applications (once versus twice) were observed except for the third disease rating and yields on the Genesee location only. Application rates (full rate versus half rate) did not show any significant difference except for the third disease rating on the Genesee location only. Chemical sprays on the resistant cultivar Dwelley did not improve disease control or yield except for the third disease rating on Genesee location only. On the susceptible cultivar Spanish White, significant differences were observed among the chemicals in disease ratings and yield. The fungicides Headline, Quadris and Bravo were effective in controlling Ascochyta blight on chickpea.