New Insights into Mango Malformation Disease Epidemiology Lead to a New Integrated Management Strategy for Subtropical Environments

Abstract

Mango (Mangifera indica) is regarded as the king of fruits in India, where it has been cultivated for at least 4,000 years and has great cultural and religious significance. Many Indian mango cultivars originated in the fifteenth century when the best selections of mango seedlings were propagated by grafting and planted in large orchards, in some cases numbering 100,000 trees. With the arrival of voyagers to India from Europe, mango was soon established throughout the tropics and subtropics. Mango malformation disease (MMD) is one of the most important and destructive diseases of this crop. It affects inflorescences and vegetative portions of the plant. Although trees are not killed, the vegetative phase of the disease impedes canopy development and the floral phase reduces fruit yield dramatically; substantial economic losses can occur since malformed inflorescences do not bear fruit. Significant advances have been made in understanding the etiology of MMD, which is caused by more than one agent. However, until recently little progress had been made on the epidemiology of this disease. The results that are discussed in this article are only for MMD caused by F. mangiferae.

Mango malformation: A fungal disease, physiological disorder or malady of stress

“…Fusarium mangiferae, another causative agent of mango malformation disease produces microconidia on live and dead malformed tissues. The distribution of F.mangiferae in the diseased tree suggests that apical buds are primary sites of infection (Gamliel-Atinskyet al, 2009 andFreeman et al, 2014). This was confirmed by another experiment in which mango was artificially inoculated with isolates of F.mangiferae (Freeman et al, 1999 andFreeman et al, 2014).…”

“…The distribution of F.mangiferae in the diseased tree suggests that apical buds are primary sites of infection (Gamliel-Atinskyet al, 2009 andFreeman et al, 2014). This was confirmed by another experiment in which mango was artificially inoculated with isolates of F.mangiferae (Freeman et al, 1999 andFreeman et al, 2014). Ploetz proposed a disease cycle that involves the fungus, F.mangiferaeand bud mite A.mangiferae in the development and spread of malformation disease (Ploetz, 2001 andFreeman et al, 2014).…”

“…Since its occurrence, mango malformation has been reported across many countries in the world including Australia, Brazil, Cuba, Egypt, South Africa, United States of America, United Arab Emirates, Bangladesh, etc. In India, northwest regions are more prone to the disease (Ploetz et al, 1999;Rymbai andRajesh, 2011 andFreeman et al, 2014). Gujarat, Maharashtra, Punjab, Himachal Pradesh, Madhya Pradesh, Uttar Pradesh, Jammu and Kashmir, Bihar and Haryana are also affected by this disease (Krishnan et al, 2009;Kumar et al, 2011 andFreeman et al, 2014).…”

“…In India, northwest regions are more prone to the disease (Ploetz et al, 1999;Rymbai andRajesh, 2011 andFreeman et al, 2014). Gujarat, Maharashtra, Punjab, Himachal Pradesh, Madhya Pradesh, Uttar Pradesh, Jammu and Kashmir, Bihar and Haryana are also affected by this disease (Krishnan et al, 2009;Kumar et al, 2011 andFreeman et al, 2014). The maximum economic loss reported in India is 86% (Kumar et al, 1993 andRymbai andRajesh, 2011).As per studies, mango malformation can be defined as fungal disease of mango caused by Fusarium species leading to abnormal growth of vegetative shoots and inflorescence (Kvas et al, 2008).…”

“…The disease produces hypertrophied tissue in both the vegetative shoot and inflorescence. Vegetative malformation retards the canopy development whereas the floral malformation leads to economic loss as malformed inflorescence do not bear the fruits (Freeman et al, 2014).It can be classified into two distinct classes: Vegetative malformation: Vegetative malformation mainly affects young seedlings in nurseries. Malformation involves appearance of small shoot lets possessing small scaly leaves, forming a bunch like appearance on shoot apices.…”