Amali Al-Ahmad(1)* and Bayan Muzhar(2)
(1). Administration of Horticulture Research, General Commission for Scientific Agricultural Research, Syria.
(2). Horticulture Research, General Commission for Scientific Agricultural Research, Syria.
(*Corresponding author: Amali Al-Ahmad. E-Mail: Amale-alahmad@hotmail.com(
Received: 27/10/2024 Accepted:26/02/2025
Abstract
The research was conducted in the Tartous governorate (Beit Yusef-Draikish) on apple trees (cv. Golden Delicious) grafted onto the rootstock “Malus domestica Borkh” during the two seasons of 2019-2020. The objective was to investigate the effects of manual and chemical thinning, with and without calcium nitrate spray, on the nutrient content of leaves (Ca, Mg, Zn, B) and the productivity of the apple trees. The study included six treatments at two levels: the first level “no spray”, while the second involved spraying with calcium nitrate. Results indicated a significant difference in production during the 2019 season between the two levels (114.58 and 130.88 kg/ tree, respectively). In the season (2020), the production was significantly lower than the first season in both levels, the first (63.27 kg/ tree) and the second (72.33 kg/ tree) levels. In the first season, both thinning treatments led to a noticeable decrease in production compared to the control; however, the calcium nitrate spray treatment resulted in significantly higher production at 137.5 kg per tree. In the second season, each treatment showed a significant increase in production compared to the control (49 kg per tree, a light fruit load). Applying thinning techniques during the heavy load season resulted in a better balance in annual load as the productivity in the first and second seasons was 87.76 and 85.00 kg/ tree in manual thinning, 88.57 and 85.79 kg/ tree in chemical thinning, 97.40 and 100.56 kg/ tree in the calcium nitrate foliar spray treatment with manual thinning, and 101.49 and 98.30 kg/ tree in the calcium foliar spray treatment with chemical thinning. Thus, foliar spraying with calcium nitrate combined with chemical thinning proved to be the most effective treatment for enhancing apple productivity, followed by foliar spray treatment with calcium nitrate combined with manual thinning.
Keywords: Apple, Golden Delicious, Calcium nitrate, Zinc, Boron, Nutrients, Productivity.
Full paper in Arabic: PDF