Increasing fruit set and fruit size in problem cultivars

This project is currently continuing as project KIT1A, Evaluation of alternative chemical thinning programs for apples.  The reason for not requesting a continuation of project KIT3A was due to the fact that the title was misleading and the project needed to be better defined.  The results from the chemical thinning work done in project KIT3A is currently being published in South African Journal of Plant and Soil, Response of ‘Cripps’ Red’ and ‘Cripps’ Pink’ to different chemical thinning programmes.  Some work was already done on alternative chemical thinning agents like ammonium thiosulphate, but this work needs to run for another few seasons before the data will be published.  The second aspect that was investigated in this project is the efficacy of the growth regulator prohexadione-Ca to indirectly increase fruit size by reducing shoot growth competition.  This work is summarised in the M.Sc.Agric.-thesis by Mariska Smit, Shoot growth control of apple, pear and plum trees with prohexadione-calcium.  This work is also currently being prepared for three refereed publications.  Further work on this growth regulator is being funded by the relevant chemical company.