Stem rust race Ug99, also designated TTKSK （Puccinia graminis f. sp. tritici） cause stem or black rust, which is a serious disease of wheat worldwide. Field experiments were conducted at two sites during 2008 and 20...Stem rust race Ug99, also designated TTKSK （Puccinia graminis f. sp. tritici） cause stem or black rust, which is a serious disease of wheat worldwide. Field experiments were conducted at two sites during 2008 and 2009 growing seasons to evaluate the effectiveness of two new foliar fungicides： viz. Nativo 300 SC （trifloxystrobin 100 g L^-1 ＋ tebuconazole 200 g L^-1） and Prosaro 250 EC （prothioconazole 125 g L^-1 ＋ tebuconazole 125 g L^-1）, in controlling stem rust on susceptible wheat cultivar Duma. AmistarXtra 280 SC （azoxystrobin 200 g L^-1 ＋ cyproconazole 80 g L^-1） and Folicur 250 EC （tebuconazole） were used as checks. The treatment at each site and year included non-treated control and two spray applications of the fungicides at growth stages （GS） 55 （heading） and 65 （flowering）. Stem rust severities were scored using the modified Cobb scale at 14-day intervals after application. The data were used to calculate mean rust severity （MRS）. Stem rust epidemics were severe at KARI-Njoro in 2008 and the treatment effects on stem rust severities, grain yield and 1,000 kernel weights were significant at both KARI-Njoro and Mau-Narok sites. The fungicide treatments, significantly （P _〈 0.05） reduced stem rust severity, increased grain yield and 1,000 kernel weight of the susceptible wheat cultivar Duma compared to the non-treated control. Both fungicides： Nativo 300 SC and Prosaro 250 EC applied at the rate of 1.0 L hat were recommended for commercial use.展开更多
文摘Stem rust race Ug99, also designated TTKSK （Puccinia graminis f. sp. tritici） cause stem or black rust, which is a serious disease of wheat worldwide. Field experiments were conducted at two sites during 2008 and 2009 growing seasons to evaluate the effectiveness of two new foliar fungicides： viz. Nativo 300 SC （trifloxystrobin 100 g L^-1 ＋ tebuconazole 200 g L^-1） and Prosaro 250 EC （prothioconazole 125 g L^-1 ＋ tebuconazole 125 g L^-1）, in controlling stem rust on susceptible wheat cultivar Duma. AmistarXtra 280 SC （azoxystrobin 200 g L^-1 ＋ cyproconazole 80 g L^-1） and Folicur 250 EC （tebuconazole） were used as checks. The treatment at each site and year included non-treated control and two spray applications of the fungicides at growth stages （GS） 55 （heading） and 65 （flowering）. Stem rust severities were scored using the modified Cobb scale at 14-day intervals after application. The data were used to calculate mean rust severity （MRS）. Stem rust epidemics were severe at KARI-Njoro in 2008 and the treatment effects on stem rust severities, grain yield and 1,000 kernel weights were significant at both KARI-Njoro and Mau-Narok sites. The fungicide treatments, significantly （P _〈 0.05） reduced stem rust severity, increased grain yield and 1,000 kernel weight of the susceptible wheat cultivar Duma compared to the non-treated control. Both fungicides： Nativo 300 SC and Prosaro 250 EC applied at the rate of 1.0 L hat were recommended for commercial use.
