Effect of triterponic acid on morphological and physiological characteristics and yield of different potato cultivars

The effect of Triterponic growth regulator on yield and some morphological and physiological characteristics of three potato cultivars Agria, Marfona and Draga was studied in the Agricultural Experimental Station, Karaj in 2000. Triterponic acid was sprayed at four levels of 0, 150, 300 and 450 gha-1. Each concentration , was divided into three parts and sprayed on plants in three growth stages begriming of flowering, maximum flowering and one week after the second spray. This experiment as split-plot was carried out in four replications in a randomized complete block design. Potato cultivars were as main factor and levels of spraying as sub-factor. Fifteen days after spraying, sampling were done three time for determination of chlorophy1 a and b, together with assessment of some other morphological and physiological characteristics. The results indicated that application of Triterponic acid in the concentration of 300 gha-1 had significant effects on yield and other characteristics of different cultivars especially in Marfona.