Effect of Foliar Fungicide, Tillage and Variety on Maize Gray Leaf Spot (Cercospora zeae-maydis ) at Bako, Ethiopia

Abstract

Maize gray leaf spot (Cercospora zeae-maydis) is one of the major constraints of maize (Zea mays)production in Ethiopia, especially where warm humid environmental condition prevails. Thus,this study was conducted to determine effects of foliar fungicide, tillage and maize variety ongray leaf spot disease development at Bako, Ethiopia. The experiment was laid out in factorialexperiment in randomized complete block design in three replications. The treatments werethree maize varieties, four tillage practices and two levels of mancozeb 80% WP. Significantvariation was observed due to tillage x variety x fungicide interaction on severity, yield andyield components. BH-660 with conventional tillage and fungicide treatment gave the highestyield, while Phb-3255 with no-tillage and without application of fungicide gave the lowest yield.Similarly, lowest AUDPC and disease severity were recorded on BH-660 with conventionaltillage and one time tillage practices with application of fungicide. The disease resulted in grainyield loss of up to 4.7, 37.1 and 46.9% on BH-660, BH-540 and Phb-3255, respectively. Theaverage grain yield difference between sprayed and unsprayed plots of the same type of tillagepractice exceeded the break-even yield in all tillage practices. Minimum or no-tillage wasconfirmed to contribute to more disease and greater yield loss irrespective of the variety used.Thus, use of one time tillage x BH-660 without fungicide spray, 2 times tillage x BH-540 withfungicide spray and 2 times tillage x Phb-3255 with fungicide spray are recommended for themanagement of gray leaf.