|Authors: ||R.B. Cronje, I.M. Ratlapane|
|Keywords: ||flowering, leaf N, shoot growth, starch reserves, yield|
The post-harvest shoot growth cycle is a period to foster strong bearing shoots for the next season as high quality bearing shoots are the basis for a productive tree.
In South Africa soil application of fertilizers in litchi is generally done immediately after harvest irrespective of production area, number of post-harvest flushes and soil type.
In order to determine the effect of various application times, specifically of nitrogen (N), before and after harvest, a trial was conducted in the early production area of South Africa (near Malelane) on the cultivar 'Mauritius' ('Tai So') during 2014. Soil applications of nitrogen were done as follows: a) single application during last part of harvest, b) single application after harvest, c) split application during the last part of harvest and at hardening of the first post-harvest flush, d) no post-harvest application (application only before flowering) and e) current practice on trial farm (after harvest application). Soil and leaf nutrient analysis was done to determine the requirement of N for applications.
All other nutrients were applied in relation to the N amount.
Tree phenology was monitored on a regular basis.
Data for leaf N, tree starch content, shoot growth, flowering and yield were collected.
The results show that time of N application affects the time of flush emergence, hardening-off time and leaf N content.
Tree starch content and leaf N at specific times were positively correlated to shoot growth, flowering and yield.
However, further research is underway to confirm the above results.
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