EFFECT OF ADDITION POTASSIUM AND SPRAY (HUMIC AND FULVIC) ACIDS APPLICATION ON SOME GROWTH AND YIELD CHARACTERISTICS OF SQUASH, CUCURBITA PEPO L.

Abstract

A field experiment was conducted during the autumn season 2017 at one of the fields in Al-Hamdaniya area of the Abu-Ghraib district 15 km west of Baghdad, in a salty clay loam texture soil. To study the effect interaction of three levels of additionpotassium0, 75 and 150 kg.h-1 (K1 , K2 and K3) respectively and mixture of ( humic and fulvic) acids, 0, 250 and 500 mg l -1 (H0 , H1 and H2) respectively, on some growth and yield characteristics of squash zucchini Cucurbita pepo L. A randomized complete block design (RCBD) with Split Plot distribution with three replications was used. The levels of addition potassium occupied the main plots. The mixture of acids levels were occupied sub plots, the most important results that have been obtained, Increasing of additionpotassium as K2, K3 resulted in a significant increasing in some traits under study (dry weight of shoot, total soluble sugars concentration, proline concentration, fertilizer use efficiency, Concentration N, P, K comparison with K1. Also the high addition potassium (K1, K2) caused a significant increasing in fertilizer use efficiency (43.00, 52.07%) respectively comparison with K0 (3.94%), increasing of addition potassium as K2 resulted in a significant increasing in some traits under study (Plant length, leaf area, number of fruits comparison with K0, K1. Also the high addition potassium (K2) caused a significant increasing in total yield 22.83 ton.ha-1 comparison with K0, K1 (15.70, 20.43ton.ha-1). Also the high addition potassium (K2) caused a significant increasing in respectively N, P, K. Increasing of humic and fulvic acids as levels H2, H3 resulted in a significant increasing in some traits under study (Plant length, leaf area, number of fruits, comparison with H0. Also the high level (H2) caused a significant increasing in total yield 20.02 ton.ha-1 respectively comparison with H0 (19.26 ton.ha-1). Also, the high (H2) caused a significant increasing in respectively N, P, K. The interaction between of the study factors were significant at most of measurement characteristics. The treatment K2XH2 gave the highest value in total yield (23.50 ton.ha-1) comparison with K0XH0 (14.84 ton.ha-1).