Effect of ascorbic acid, proline and jasmonic acid foliar spraying on fruit set and yield of Manzanillo olive trees under salt stress

• Manzanillo olive yield was improved by spraying ascorbic acid.
• Ascorbic acid at 3000 ppm enhanced fruit quality traits.
• Proline, jasmonic acid spraying gave a slight enhancing effect in this respect.

A field experiment study was carried out during two successive seasons during 2011 and 2012 in Manzanillo olive orchard about 14 years old grown in sandy soil under drip irrigation system from well at El Maghara Station (Desert Research Center), North Sinai Governorate, Egypt. Treatments of ascorbic acid (2000 and 3000 ppm), proline (75 and 150 ppm) and jasmonic acid (15 and 30 ppm) and tap water control foliar sprayed were carried out at three times a year started at full bloom with 4 weeks intervals.Briefly, ascorbic acid, proline and jasmonic acid enhanced all studied leaf characters, fruit set, yield and fruit quality traits. Ascorbic acid at 3000 ppm proved to be most efficient treatment in this respect.