Plum is a seasonal fruit harvested around December to January and they flood in the local markets. The fruit is mainly cultivated in central highlands which offer best growing conditions for the fruits.
Altitude –1800m above sea level
Temperature – 150C to 240C is ideal for quality fruits
Rainfall- rainfall ranging from 1000mm is ideal
Soils – loamy, clay loam and sandy loam are ideal. The soil should be free draining with soil ph of 4.5-6.5
Sunlight –require full exposure, minimum of 6-8hrs exposure will be ideal for the crop to perform well.
Land should be ploughed well removing weeds and stumps from the field. Medium tilth is ideal for the crop hence no more secondary cultivations required. Wind breaks would be ideal for the crop to avoid damage to the trees and blossoms, agro- forestry trees can be planted on the field borders to act as wind breaks.
Done at the onset of rains, any other time can be good too especially for those farming using irrigation. Drip would be ideal to conserve water as moisture is made available around the root zone only. Dig holes one inch deep for transplanting; ensure the hole can accommodate manure. When transplanting grafted seedlings ensure that the graft union is about one inch from the ground. Ensure that the seedlings are set at the centre of the hole and the roots spread inside, care should be taken not to damage the roots as this may delay tree establishment.
Water young plants regularly for proper establishment, moisture during this stage is very critical. Mulching should be done to avoid moisture loss and to suppress weeds around the tree root zone. Maintain constant moisture during flowering and fruit formation, water stress around this stage will result to abortion leading to low returns.
Avoid fertilizing young plants until they start to blossom. As fruit set starts fertilize regularly using CAN with supplementary trace elements. Pruning is necessary to avoid excessive vegetative growth coupled with nitrogen application; this will help to remove unproductive branches, diseased and those attacked by pests. Also it’s good to regulate the amount of nitrogen applied, high application results to succulency which may attract pests
Keep the field weed free all through. Mechanical cultivation should be done before the trees start to blossom to avoid knocking down the flowers. Mulching will help in controlling weeds around the crop root zone.
Pest control and disease control
Pests include plum stem borer, mealy bugs, aphids, nematodes etc, appropriate insecticide can be used against the pests.
Diseases include root rot, powdery mildew, bacterial canker, fruit rot among others. Appropriate chemical may be used under the directives of crop scientist near you.
Field hygiene will help in disease management; use of clean planting materials will play part too. Always source grafted fruit trees from licensed tree nurseries to be sure of quality in terms of disease free material.
Maturity index, the fruit skin becomes very soft meaning its ready to be harvested. Apply pressure gently using the finger to determine mature fruits. Plum have the best flavor when left to ripen while on the trees.
Harvested fruits should be kept in shade or pre-cooled to remove field heat. The fruits should be packed well in fruit trays avoiding any form of injury to the fruit skin, bruised ones should be separated from the other fruits as the exposed ethylene may result in rapid deterioration of the fruits.