Evaluation of Trichoderma bio-control agents and pre-cultivation seed treatments for the control of Cephalosporium maydis causing late wilt in maize (Zea mays L.).

BACKGROUND

Late wilt disease, caused by Cephalosporium maydis, is one of the most aggressive fungal diseases threatening maize production in Egypt and Mediterranean region. Biological control and pre-cultivation seed treatments are proposed among the best strategies to control C. maydis under greenhouse and field conditions. The objective of this study was to evaluate the effectiveness of Trichoderma bio-control agents as well as several pre-cultivation seed treatments (priming and coating) in controlling late wilt disease and improving maize production. Five isolates of C. maydis were isolated from infected maize plants collected from different Egyptian governorates. In vitro and in vivo experiments were performed to evaluate the efficacy of different treatments in the control of C. maydis.

RESULTS

Pathogenicity test revealed that isolate (5) of C. maydis, collected from Qalyubia governorate, was the most virulent against the Baladi maize variety. In vitro, five Trichoderma isolates (T1, T2, T4, T6, and T7) were the most antagonistic against C. maydis. Seed germination tests showed that "extra seed power"- a novel seed treatment- applied by either coating or priming, along with priming with either garlic or moringa extracts significantly outperformed other treatments in enhancing maize germination and seedling parameters. In greenhouse, the lowest significant disease incidence percentages for Giza 168 maize cultivar were achieved with T2, ESP coating, ESP priming, T4, moringa leaf extract priming at 1.0%, Premis Ultra 2.5% fungicide and garlic extract priming at 1.0%, respectively. The same treatments recorded the lowest significant disease incidence percentages for the same maize cultivar under field conditions. The previous results were supported by anatomical investigation of maize stem under different treatments. Moreover, significant improvements in plant height and yield parameters such as ear weight and length, and grain yield were achieved with the same treatments under infection conditions.

CONCLUSION

Bio-control treatments using T. asperellum (T2) and T. harzianum (T4) along with seed treatments using ESP by coating and priming were the most effective in reducing late wilt disease incidence and enhancing growth and yield parameters of maize under greenhouse and field conditions.