بر ميوه سيب رقم گلدن دليشز در شرايط آب و هوايي مشهد NAA بررسي اثر تنك كنندگي نفتالين استيك اسيد

Effect of naphtalenacetic acid (NAA) on thinning of apple(MAL US DOMESTICA, CV Golden Delicious) under Mashhad environmental conditions

In order to study the effect of different concentrations of NAA as chemical thinning on some characterizations of golden delicious apple and determination the optimum time of Hormones application, an experiment were performed in mashhad city in 1381. Several concentration of NAA in two dates include 10 and 23 days after full bloom sprayed. Final Fruitset Percentage of the year under treatment and the next year, fruit abscision, fruit density and other experiments about quility and quantity of fruits were examined. Remain fruits on trees Were counted each 25 days, 5 time after full bloom. Results show that: in the first stage of fruit accounting (35 days after full bloom) the highest percentage of the fruit dropping related to the application of 30 ppm and lowest fruit abscision related to the control. Therefore NAA had the best effect in the first stage of application. The spraying time had a significant effect on the fruit diameter and fruit volume. In the first stage of spraying produced fruits had more diameter and volume. Concentrations of NAA had significant effect on fruit abscision, fruit density, fruit set percentage and diameter. Interaction effect of time by concentration had significant effect on fruit length, firmness, volume, weight and total soluble solid. Highest length of fruits related to the first stage of spraying and concentration of 5ppm and lowest length related to the second stage of spraying and 30 ppm concentration. That it caused to produce pigmy fruits .The counting of formated fruits of under treatment trees in the year after spraying showed that there is not significant different statistical amoung them. By the way NAA didnot have effect on reduction of alternal bearing. According to the results of this study, for cultivar GOLDEN DELICIOUS in the environmental conditions of this investigation, application of 15 ppm Naphtalenacetic Acid 10 days after full bloom is recommended.