Recently was "Tu Bishvat", the New Year for trees in the Jewish calendar that one of the signs of this day is the almond blossom. The almond is the first deciduous tree to bloom after the winter rains in Israel and is the precursor of spring. For growers this is a sign that the deciduous fruit tree season is approaching, and some decisions are needed to consider before the season starts.
First, the grower must decide about dormancy-breaking treatment. In areas where the amount of chilling hours may be marginal, spraying dormancy breaking agents (oils) is a common practice for improving yields. It has been found that the foliar application of Haifa Bonus before the oil spray reduces the oil application rates as explained in a previous post .
Secondly, the grower must decide when to start the fertilization program. After bud breaking, nitrogen and potassium are used from stored reserves in the tree from the previous year application. If the post-harvest fertilization was good. If the last season post-harvest fertilization was good, the tree reserve is expected to sustain the tree for about 45 days (see here explanation), but soon the tree must absorb nitrogen and potassium from the soil in large quantities.
Therefore, it is good practice to give the first application of fertilizer shortly before or at the beginning of the bud break. This application will fill the soil reserves so it will be available soon as the tree's roots will start to be active and absorb nutrients. The best way to deliver the nutrients to the root zone is by fertigation through technical irrigation application even if the irrigation season did not start. A common recommendation for fertilizer application at the pre bud breaking stage is 150 Kg per hectare of Poly-Feed 20-20-20.
After the application of the fertilizer at the pre-bud break stage the grower can start to apply the fertilizer according to a fertilization program, based on the tree phenological stages. This is an example of fertilization program for an apple orchard in Israel, which was done using Haifa's Nutrinet fertilization software.
NutriNet fertilization program for 1 hectare in Israel:
