EVALUATION OF THREE-WAY MAIZE (ZEA MAYS L) HYBRIDS FOR YIELD AND RESISTANCE TO MAIZE STREAK VIRUS AND TURCICUM LEAF BLIGHT DISEASES

Maize, a staple food crop in sub-Saharan Africa and many other parts of the world, is affected by many diseases that reduce yield. Disease management has mainly been reliant on chemical and cultural control options. However, such options are unsustainable to the smallh older resource poor farmers and environmentally unfriendly. A study carried out at the Harare Research Station evaluated eight three -way and four commercial maize hybrids for yield and resistance to Maize streak virus using controlled leaf hopper infestati on and Turcicum Leaf Blight under artificial inoculation. The objectives of the study were to identify hybrids that have multiple resistance to Maize streak virus and Turcicum Leaf Blight and to determine the relationship between disease severity and yield performance of the hybrids. The experiment was laid out in a split plot arrangement in a randomized complete block design with Disease type as the main plot factor while Maize hybrids were the subplot factor. Ratings of 1 (tolerant) to 5 (susceptible) based on streaked and blighted leaf surfaces were used. The hybrid 053WH54 had multiple resistance to Turcicum Leaf Blight and Maize streak virus. The hybrids 043WH61 and 043WH07 were high-yielding even at high disease pressure while 043WH41 and 013WH03 were relatively low yielding at low disease pressure. This showed the inherent genetic diversity of the hybrids. The hybrids ZS 225, 043WH61 and 043WH07 are recommended for production in areas with high prevalence of both diseases.