The Time For Nitrogen Is Now
By Kenny Beeton
Nitrogen fulfils various important roles in fruit production, from as early as Flowering and cell division phases. Nitrogen also plays a critical role in protein synthesis and is a constituent of amongst others, amino acids, having a direct effect on fruit production and fruit quality. Nitrogen requirements for the next crop should have been determined by now, based on the previous season’s production which has led to depletion in Nitrogen reserves.
Nutrient extraction per ton of fruit and optimum leaf content are important figures to bear in mind when planning your Nitrogen strategy for the coming season per cultivar group, as they do vary and should be applied accordingly.
Nitrogen fertilisation should be within the first window of your fertilization program stretching from August to October, where 40% to 50% of the required Nitrogen should be applied.
Low soil temperatures during the winter months (Particularly In the colder production areas) negatively impact the uptake of nutrients as trees and roots are still in a dormant phase. Foliar application of LB Urea is of critical importance directly after harvest to initiate flower induction and will have a direct impact on a green blossom, required to set a good quality crop for the following season. LB Urea sprays will generally be applied from June to the end of July. Soil applications should ideally start with the onset of spring when root activity is noted with the first signs of a root flush.
It is important to take a few factors into consideration when commencing with Nitrogen applications in your citrus orchards. Sandy soils for instance will be more prone to the loss of nutrients through leaching vs soils rich in organic matter. For this reason, application dosages should be maintained at a level where leaching can be kept to a minimum, while over application rates in “richer” soils should also be avoided.
Boost N is a water-soluble macro element blend with chelated micronutrients for foliar feeding and fertigation.
Boost N: 5kg – 12.5kg per ha, on bearing trees
Boost N: 5kg per ha, on non-bearing trees
Juvigor is a young tree supplement formulated specifically to promote growth and vigour in young non-bearing trees.
Juvigor: 1kg per ha, applied monthly from the onset of spring throughout summer