Reduced yields of ‘Earlicot’ apricot (Prunus armeniaca) grown in a relatively hot climate and methods to improve flowering intensity and yield

The European apricot (Prunus armeniaca) cultivar ‘Earlicot’ has high economic potential due to its high-quality fruit and early yields. ‘Earlicot’ has recently been introduced into Israeli orchards. The climate in Israel is relatively warm, although cold enough for cultivating high-quality stone fruit. However, the full potential of this new apricot cultivar was not being realised. The aim of this work was to understand the reasons for the low performance of ‘Earlicot’ and to identify methods to overcome them. In a 2-year study, we observed that ‘Earlicot’ flowered poorly. The problem of poor flowering and hence fruit-set was improved and yields tripled following application of the gibberellin inhibitor, uniconazole, at 500 mg l^–1 [1% (v/v) Magic™] during the period of floral differentiation (mid-May). In addition, we found significant positive relationships between the proximity of ‘Earlicot’ trees to the polleniser ‘Earlygold’ and the efficiency of fertilisation, as determined by the genetic marker S₈-RNase, the fruit-set percentage, and fruit yield. We also identified the early apricot flowering cultivar ‘311’ to be a fully-compatible polleniser for ‘Earlicot’. Fullcompatibility for cross-pollination will assure high fruit yields in ‘Earlicot’.