MANGO MALFORMATION - A REVIEW OF WORK DONE AT THE HORTICULTURAL RESEARCH INSTITUTE, SAHARANPUR, INDIA

Mango malformation is a serious malady which has so far eluded a proper diagnosis of this causative agent. The malformation on mango inflorescence has been known since 1891 (4), but the disease on young seedlings in the nursery was first reported from Saharanpur (1). On young seedlingS the disease appears at quite an early stage. Even three to four month old plants have been found affected. The malformed bunch may be formed at apex or lower down at leaf axil. The characteristic symptom is the formation of tiny leaf rudiments crowded on small thickened shoot and its secondary branchlets. The damage caused at this stage is serious, as up to 18 per cent of the month old seedlings are affected and this goes on increasing. In an experimentalplot 76 seedlings left over for a period of 2 years, shewed hunderd per cent infection at the end (3).

However, the greatest damage is caused to panicles on which the main symptom is the total or partial suppression of flowers by formation of small leaf rudiments. If flowers are present there may be little or no fruit set. There are many variations in the symptoms produced on the inflorescence. Various grades from a totally malformed and compact type to a loose form are found. It is quite common to find a few malformed spikes in an otherwise healthy inflorescence or vice-versa. The percentage of bisexual flowers was found to be much less in affected panicles than in the normal ones.