THE EFFECT OF THE AMINO ACID TRYPTOPHAN ON GROWTH AND YIELD OF THREE POTATO CULTIVARS (Solanum tuberosum L.) GROWN IN DESERT AREA

Abstract

An experiment was conducted during the growing season of 2013-2014 in Tomato Development Project belong to Basrah Agricultural Director, Khor Al-Zubair. The aim of the experiment was focused on the effect of three potato cultivars (Draga, Arnova and Provento) and spraying with three concentrations of Tryptophan ( 0, 100 and 200 ml.l-1 ) on growth and yield of potato (Solanum tuberosum L.) grown in desert area. Split Plot Design was used according Randomized Complete Block Design (R.C.B.D) with three replication. Least Significant Differences (L.S.D) Multiple Range Test was used at probability of 0.05. Results showed that Draga cultivar gave significant increases in plant height, main stem diameter, dry weigh of vegetative growth, tuber number .plant-1 6.10 tuber and total plant yield 387.0 g as well as the marketable and total yield 3.43, 3.78 ton.donum-1, respectively. While Brovento cultivar gave asignificant increases in total leaf number and leaf area.plant-1. Sprying with 200ml.l-1 tryptophan gave significant increases in plant height, main stem diameter, stem number, total leaf number, leaf area, dry weigh of vegetative growth, tuber weigh 73.33 g, total plant yield 414.2 g, marketable and total yield 3.78, 4.05 ton.donum-1, respectirely. While the 100 ml.l-1 tryptophan gave significant increases in tuber number.plant-1 5.76 tuber. The interaction between both factors gave significant effect in all Vegetative traits and yield. Key words: Potato, cultivars, amino acid, tryptophan, yield,