USA trial shows that, if boron is deficient, the uptake of other nutrients, notably nitrogen, potassium and calcium, is reduced.
Boron also has an important role in pollen germination and fruit set, therefore boron nutrition affects yield, as shown in US studies.
Pre-flowering applications ensure good fruit set and full yield potentials are achieved. In addition, while boron is quickly taken up from the soil, it is relatively immobile in the plant, so foliar sprays are often more effective (trials in Vietnam).
Boron nutrition not only increases yield due to fruit number, but also due to fruit weight (trials in Vietnam).
Lack of boron (and calcium) increases the incidence of russeting, as shown in US trials.
Boron also has a positive influence on the level of cracking and shelf life of the fruit, as USA trial shows. Any cracks on the fruit shoulder increase water loss and susceptibility to pathogen attack.
Boron deficiency prevents root growth and disrupts cell membranes, which has a direct effect on plant’s uptake mechanism. On the other hand, excess boron can block the transportation of calcium, so it is important that accurate application rates are adhered to. Boron accumulates in the leaf margins, turning them black. Root death occurs where levels are particularly high. Soils with high levels of boron can be ameliorated by leaching.
|Boron at tomato growth stages|
|Establishment||Ensures good shoot growth|
|Vegetative growth||Ensures growth is not limiting|
|Flowering - fruit set||Maximizes flower set, development and fruiting|
|Fruit ripening - maturity||Ensures even ripening|