Global competition is increasing the pressure on agriculture to produce higher quality, affordable produce.
The grower who prospers in the future must use their resources productively, manage risk wisely, and maximize their returns on the investments to their crop. Fertilisers are an important investment each grower makes. In order to maximize the returns on this investment, growers must balance the needs for Nitrogen, Potassium, and Phosphorous with the crops’ requirements for secondary and micro nutrients.
Without adequate amounts of each element available at each growth stage, the maximum potential of the crop can not be achieved. The importance of micro nutrients has been thus far underestimated. Mobilisation of minerals from the soil and corresponding uptake by the root are also related to the quantity of root surface that comes in contact with the mineral1 .
Because plants sometimes grow at rates that are faster than the ability of the roots to absorb and translocate minerals to the critical leaf and or berry tissues, foliar sprays can often help overcome a deficiency or maintain optimum nutritional levels of those critical tissues. Therefore foliar application can be used as an adjunctive method of plant nutrition. Zinc and Boron – how important are they? Zinc is taken up by plant roots as Zn2+.
A major factor which affects Zinc uptake is restricted root growth. Any factor which affects root development or the rates of diffusion of zinc in the soil may cause zinc deficiency, e.g. soil compaction, high water tables, container grown plants.
Cold weather may also restrict root development and reduce microbiological release of zinc from soil organic matter2 . Zinc has a low mobility within plants. The ease with which zinc is transferred to younger tissue is depressed further in zinc deficient plants. Zinc deficiency symptoms include decreased stem length, reduced number of buds, resetting of terminal leaves, small misshapen leaves and often, chlorosis.
Zinc applications are best made two weeks before flowering as Zinc influences flowering and fruit set. A common disorder in grapes linked to Zinc deficiency is “Hen and Chicken” .