The effect of different irrigation and fertilizer applications on Kabaaşi apricot cultivar's vegetative development and yield

This study was carried out in order to determine the effects of different irrigation intervals and fertilizer (N, P, K) dose on the plant growth, fruit quality and yield parameters of Kabaaşı apricot cultivar in 2016 and 2017 conducted at Apricot Research Institute Directorate, Battalgazi Campus. Plant material used in this study were 27 Kabaaşı apricot trees planted in 2011 with 10x10 m arrangement and were tested with 10, 20, 30 days irrigation interval with N, P, K fertilizer doses applied in autumn and spring. Physiologically, flowers, leaves and harvest dates of the trees and total yield were recorded and the pomological characteristics of fruits were examined. Vegetative characteristics of the trees included; trunk, main and shoot diameters and shoot length measured twice a year, starting the beginning of plant development and ending period of development of trees. Fruit characteristics were determined for two years and harvest dates were recorded. The leaf water content and nutrient element contents were also measured in two years of the study. In March of 2016, the temperature is the spring was lower than 0 °C and the fruits were affected by frost and no significant yields were obtained therefore some of the measurements were could not be done. In following year the average yield was about 64.8 kg per tree. Statisticly higest yield were obtained obtained from 10 day (85.7 kg) and 20 days (74.4 kg) with higest fertilizer application. On the other hand the lowest yied was from 30 day irrigation interval treatment with the lowest fertilizer applied treatment. Plant growth parameters in the first year of the current study such as percent change in trunk and main branch diameters (17.7 - %25.8; 16.1 - %39.8) and diameter and length of shoots (8.2 - 11.6 mm; 72.2 - 127.6 cm) were higher than second year of the study for the respective parameters (8.2 - %16.20; 8.6 - %22.2; 3.7 - 4.5 mm; 17.4 - 25.0 cm). This difference was attributed the late spring frost occurred in the first year of the study that resulted in no or low fruit yield. Results of the study indicated that there was no significant effect of fertilizer doses on fruit sizes in the first year of the study and similar statistical results were also observed among irrigation treatments. In the second year, it was observed that fruit sizes in 30 day irrigation interval trials were larger than other treatments probably due to the low yield from that irrigation treatment.