Integrated control of mango blossom malformation in South Africa

Abstract

Mango malformation disease (MMD) is a serious disease worldwide, causing severe economic losses annually. In South Africa, recommendations for managing MMD are to break out malformed inflorescences when clearly visible. Despite these recommendations, high incidences of MMD were reported during the 2010 to 2012 seasons. The aim of this study was to develop an integrated strategy for optimum control of MMD and to determine the effect of prochloraz on malformation. Treatments included removal of malformed inflorescences alone and/or in combination with one or several prochloraz sprays applied at various times. Percentage infection was calculated and yield data were recorded at harvest. Removal of malformed inflorescences in year one resulted in a decrease in malformation from 19.9% to 3.55% over the four-year period (Trial A), but no significant differences were observed between the treatments. Yield data did not differ significantly between treatments but there was a significant increase in yield from the first to the second year, which then remained constant. Spraying of prochloraz-Zn at three-week intervals combined with removal of malformed inflorescences at regular intervals (Trial B) resulted in a significant decrease in disease incidence. The combined prochloraz and sanitation treatments significantly increased yield over three seasons by 26.9 t ha⁻¹.

Keywords:

• flower
• fungicide
• inflorescences
• integrated strategy
• Mangifera indica
• panicles
• ‘Sensation’