INTEGRATED MANAGEMENT OF GROUNDNUT ROSETTE DISEASE

An investigation was conducted to study the effects of cultural practices and host-plant resistance on rosette disease incidence and pod yields of elite groundnut genotypes during four growing seasons in Malawi. The effects of genotypes and cultural practices, and their interactions on rosette disease incidence were significant at pegging stage under high disease pressure in all seasons. The genotypic differences in disease incidence were spectacular under high disease infestation in all seasons. Resistant genotypes gave higher pod yields than susceptible genotypes under high disease incidence, irrespective of sowing time and plant population. However, pod yields were higher for early sown treatments at optimum plant population. There were no marked differences in pod yield between genotypes under low disease pressure. Overall, the combination of resistant genotypes with early sowing at optimum plant population exhibited the best performance under high disease infestation. Although the resistant genotypes gave the highest pod yields under high disease infestation, pod yields were consistently lower than the yields under low disease situation probably because of their susceptibility to groundnut rosette assistor virus (GRAV) component