PRELIMINARY STUDIES ON THE GROWTH OF SHOOTS AND THEIR RELATION TO CROPPING IN THE ALPHONSO MANGO ONDER VENGURLA CONDITIONS

The Alphonso mango, the most important commercial variety of Western India shows irregular bearing habits. Various methods employed so far to secure regular crops have not given satisfactory results. As the production of flowers and fruits has a close relationship with the growth features of the preceding season and since the growth in turn is influenced by a variety of factors, it was decided to study the growth of shoots and their relation to cropping in the Alphonso mango under the conditions prevailing at Vengurla.

Preliminary studies were carried out during the 1967–69 period at the Regional Fruit Research Sub-Station (Mango), Vengurla, District Ratnagiri. Observations were commenced on trees which were seven year old. Uniform shoots of past season growth, numbering 50, were selected on each tree and the flushes emanating from each of the shoots periodically were studied for their extension, growth and flowering. Observations were also made in regard to the drying of the inflorescences, drop of fruits before attaining maturity and fruit developing up to full maturity, to study their Subsequent effects on growth of shoots.

The results point out that under Venguria conditions the production of new flushes of vegetative growth is restricted to the October-December period and that there is hardly any growth during the rest of the year. A substantial portion of these shoots produces flowers after a year. The extension growth made by the non-flowered shoots was much higher than that made by the flowered ones. Also the extension growth made by shoots which flowered, but did not set fruit, was higher than that made by shoots on which fruit developed up to various stages of maturity, thus showing an antagonism between productivity and growth.

Individual trees had varying amounts of vegetative growth and flowering the same season. Though, the tree producing larger number of vegetative flushes had comparatively less percentage of flowering (bases on the number of shoots produced) as compared to the tree with less number of vegetative flushes, there was hardly any difference in the overall flowering of the two trees.

The weather conditions alone at Vengurla do not seem to have encouraged the production of vegetative flushes during October-December period. It appears that the soil moisture condition and availability of nutrition during the period are mainly responsible for the occurrence of vegetative growth during the period. It seems possible to encourage vegetative growth every year not only in the October-December period, but also later up to February, by judicious irrigation and manuring so that increased production and regular bearing could be had. Comprehensive work on this aspect of mango culture is indicated.s