Fusarium Wilt Case Study

Fusarium wilt caused by Fusarium oxysporum f.sp. ciceris is a soil and seed borne disease affecting chickpea whichis widely distributed where chickpea is grown. It causes yield losses in the range of 12 to 100 % depending on the level of resistance of the genotype and suitability of environmental conditions for disease development. Management of soil borne diseases mainly involves use of preventive measures because it is harder to control the disease once established. Thiram and carbendazim are used in majority of the crops as seed dress fungicides against a wide variety of pathogens. The efficacy of the rates of these two fungicides against Fusarium wilt of chickpea was evaluated at four levels (0%, 50%, 100% and 150%) of the recommended rate
To ensure durability of resistance genes, host plant resistance (HPR) is used together with other methods of control in an integrated management. Fungicidal seed treatment is frequently used in conjunction with HPR and in this case carbendazim and thiram are chemical fungicides commonly used for control of soil borne pathogens. Fungicides can only be used in a limited scale, for example as seed dress in an integrated disease management approach (Wagara, 2005). In Kenya, these chemicals have not been exhaustively evaluated for efficacy against fusarium wilt pathogen of chickpea and also the optimal rates of these two chemicals had not been determined. Therefore, a study was conducted to determine the efficacy in application rates of carbendazim and thiram. The objectives of this study were, (i) To determine the efficacy of carbendazim and thiram rates in the control of Fusarium wilt and the impact on chickpea yield, and (ii) to determine the interaction effect of carbendazim and thiram rates with genotype on Fusarium wilt
Significant (P ≤ 0.05) differences were observed between carbendazim rates used. Treatment of chickpea with 150% carbendazim resulted in wilt incidence of 2.1% at 30 DAS, in both season I and II (Table 1). At 45 DAS, treatment of chickpea with 150% carbendazim resulted in 5.4% and 5.1% wilt incidence in season I and II, respectively (Table 1). At 60 DAS, treatment plots with 150% carbendazim had wilt incidence of 9.0% and 8.3% during season I and II, respectively. Treatment of chickpea with 100% carbendazim resulted in significant (P ≤ 0.05) difference in wilt incidence of chickpea. At 30 DAS, 3.3% and 3.4% wilt incidence was observed in season I and II at 100% rate of carbendazim. At 45 DAS, 9.4% and 8.9% wilt incidence was observed in 100% carbendazim treatment, for season I and II, respectively. At 60 DAS, treatment of chickpea with 100% carbendazim resulted in wilt incidence of 18.1% and 14.5% for season I and II, respectively (Table 1). Control treatment had wilt incidence of 5.6% and 5.9% in season I and II, respectively at 30 DAS. At 45 DAS, control treatment had wilt incidence of 19.9% and 19.6% in season I and II, respectively. At 60 DAS, control treatments (no fungicide) had 30.2% and 27.5% wilt incidence in seasons I and II, respectively. It was observed that significant (P ≤ 0.05) variations occurred between carbendazim rates