OFF-SEASON FLOWERING RESPONSE OF MANGO CULTIVARS TO POTASSIUM NITRATE

A first trial was then carried out over a two year period onto four year old grafted trees using a 4% solution of potassium nitrate. Sixty varieties from a 250 variety collection, which showed same growth stage at the end of March by which time the new leaves develop their full green colour and buds are at an active developing stage, were selected for the experiment.

The cultivars originated from a wide spectrum of mango growing countries. Spraying was carried out 3 times at 14 day intervals.

The mean % of canopy flowering response over the 2 year period showed that after the second spraying 7 introduced and 3 local varieties flowered over 50%. Other varieties showed a marked response to flowering only after the third spraying. Nine varieties showed 70% flowering and over. Yields are also recorded.

During flowering and thereafter the inflorescence and developing fruits were protected with pesticides.

By utilizing potassium nitrate on selected cultivars during the off-season and also during the in-season thus ensuring increased and regular production, we can guarantee two mango bearing periods.

Statistical data from this trial will prove more conclusive as the trees get older and additional information obtained from potassium nitrate treatment to the remaining trees in the collection. The use of this flowering inducer during the off-season alone on early medium and late varieties coupled with the in-season crop does imply an extended mango harvesting period stretching at least over a five month's period.

Resulting from this valuable information this experiment has led the way to further investigations of the response to potassium nitrate in combination with pruning.

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