Effect of Processed Calcite Particles on Apricot Cationic Nutrition and Fruit Quality.

We reported the preliminary results on the effects of processed calcite particles (PCP), applied at stage II and III of fruit development, on leaf cationic nutrition and some physical and chemical characteristics of apricot fruits (Prunus armeniaca L.). Approximately 30, 40, 50 days after bloom, 20 trees trained to vase were randomly chosen in a 10-year old orchard, located in the Middle Rhône Valley of France, sprayed with 1.5 kg/ha suspended in 100 L of water of PCP and compared with unsprayed trees. Fruit weight and diameter were measured from fruit set (April 18, 2007) to 3 days before harvest (May 16, 2007). Potassium, calcium and magnesium were determined by spectrochemical analysis by atomic absorption and emission in accordance with the IAOPN protocols on leaves and fruit sampled from 1 week before treatment, 1 and 3 weeks after application. Fruit harvested at the last picking were also analyzed for total soluble solids, titrable acidity, pH of the fruit juice. A sample of 20 fruits was stored in a cold room and daily observed for postharvest physiological disorders or pathogens cropped out. The application of PCP had no significant effect on apricot fruit growth, assessed as fruit diameter. However, the results obtained show that treated plants have nitrogen and cationic contents, in both leaves and fruits, closer to the standard reference levels of this region compared to untreated plants. Apricot fruits from PCP treatment showed higher total soluble solids and lower titratable acidity. Moreover, treated fruits showed a lower susceptibility to post-harvest physiological disorder or pathogen attacks.