Floral biology of 'Bulida' apricot trees subjected to postharvest drought stress

Drip irrigated 'Bulida' apricot trees (Prunus armeniaca L., on Real Fine ap ricot rootstock) were submitted to drought stress by withholding irrigation for two different postharvest periods for two consecutive years. The first treatment (T-1) started immediately after harvest, and lasted 1 1/2 months , while the second treatment (T-2) started when the first treatment finishe d and lasted 2 months. These stress treatments were compared with a control treatment (T-0), which was irrigated throughout the year so that it receiv ed an amount of water equivalent to 100% of the crop evapotranspiration (ET c) demand. Flowers from the three treatments showed similar quality (fresh weight, petal surface area and pistil length) and frequent macrostyle (stig ma located above the anthers). A lower percentage of pollen germination was observed in grains from the following year's bloom in plants from the T-1 treatment. The T-1 drought stress also induced a significant decrease in fr uit yield, due to an increase in fruitlet drop, which led to significantly lower fruit set. The T-2 treatment did not affect these processes and was n ot critical as regards apricot yield. The fruits harvested met the required standards of quality in all treatments.