The group of pome fruit mainly concerns apples and pears. Lack of nutrients and nutrient disorders have a high impact on yield and quality and thus affect the outcome extraordinarily. Low nutrient contents identified by foliar analysis can be cured with a minimum of nutrients applied via the leaves. Nutrients that are applied via the soil to correct deficiencies during the vegetation period take too long to reach the fruits and leaves or are taken up by weeds growing beside the trees. There are many important nutrients for pome fruit while these three should be explained detailed.
The central and economically most important nutrient which leads to disorders is Calcium. Bitter pit spots and cork spot make apples nonmarketable while foliar calcium sprays eliminate these nutrient disorders easily. Senescent breakdown during storage can be another major problem. As there is a great competition between vegetation and fruit development it is important to spray Calcium directly on the fruit as Calcium is very immobile and its translocation is slow, especially under stress conditions such as drought.
Nitrogen is most importantly responsible for boosting growth, maximizing flowering, fruit set and growth resulting in higher yields. While low Nitrogen can be a problem for most species of fruit trees, excessive Nitrogen can equally have negative effects. Pome fruit Nitrogen programs vary according to many factors. The grower must monitor tree growth, leaf nutrient levels, yield and fruit quality in order to make annual adjustments to the Nitrogen program. Deviations of the optimum can be fixed with Nitrogen containing foliar sprays.
Boron plays a significant role in pollination success, contributing to pollen tube germination and fruit development. It can be relevant for the tree´s ability to translocate Calcium from the roots to other parts of the tree. Deficiencies can contribute to poor fruit set. But growers should be aware that excessive Boron applications have the potential for direct toxicity to the crop leading to premature fruit maturity and early fruit drop. Foliar applications of Boron are effective to prevent drought spot, checking and cracking of the fruit surface, internal corking of the fruit as well as shoot dieback.
Pome Fruit The group of pome fruit mainly concerns apples and pears. Lack of nutrients and nutrient disorders have a high impact on yield and quality and thus affect the outcome extraordinarily.