Efficacy of various compounds as pruning wound protectants against mango die back disease.

M.A. Radwan

Abstract

Mango (Mangifera indica L.) is one of the most important fruits cultivated in Egypt. Dieback of mango is among several diseases responsible to low crop production. Dieback disease has become one of the most severe problems on all mango cultivars at El Qanater El Khairia Horticultural Research Station Farm, Agricultural Research Centre. Mango cultivars were differed in their reactions against the disease. Hindi Sennara, Alphonso, Ewais and Keitt were the highly susceptible while, Langra Benares, Fagr Kelan and Naomi were the most resistant ones. Isolation trails from die-backed mango twigs/branches confirmed that Lasiodiplodia theobromae (Syn: Botryodiplodia theobromae, Diplodia natalensis) was more frequently isolated fungus than others. Pathogenicity tests proved that L. theobromae is a causative fungus of this disease. Pruning does not always make a clean cut. Wounds caused by pruning may provide an excellent entry point for infection and often the branches are shattered. Lateral branches grow from below the pruning wound, but then often die, so wound protection is the recommended control strategy. Field trials were conducted in 2015 and 2016 by spraying ten treatments with various compounds as pruning wound protectants after pruning diseased Hindi Sennara cv. twigs/branches. All treatments decreased number of infected twigs/branches and increased number of fruits compared to control. The best treatments were T4 (pruning + Kema Zed), T3 (pruning +Topsin M 70) and T6 (pruning + Aliette) which recorded less number of infected twigs/branches and more number of fruits, compared to T1 (control).

Key words

mango, pruning, dieback, L. theobromae, treatments and fruit yields.