(FFECT OF SOME PLANT GROWTH REGULATORS AND POTASSIUM SOURCES ON GROWTH, DEVELOPMENT AND NUTRIENT UPTAKE IN POTATO (Solanum tuberosum L

Abstract

The objective of this work was to evaluate the response of potato plants to some growth regulators (paclobutrazol and mepiquat chloride) and potassium sources (potassium sulphate, commercial potassium and rock potassium) on growth, development, nutrients uptake, tubers quality and yield productivity. For this goal two field experiments were conducted at the experimental farm of Ahmed Ourabi Agricultural cooperative Association, Cairo, Ismaellia desert road at Kalubia Governorate. The first experiment was carried out during the two seasons of 2013/2014 and 2015/2016, while the second experiment was laid out during season 2017/2018 (winter season). Three different potassium fertilizer sources were applied as follow: Potassium sulphate was added at the rate 200 kg/fed. (recommended dose) control. Commercial potassium was sprayed at the rate 1 g/l. Rock potassium was added at the rate 300 kg/fed (during soil preparation) accompanied either with spraying paclobutrazol (PBZ) 50 ppm or mepiquat chloride (MC) 150 ppm in the 1st experiment, in addition to, PBZ 25 ppm and MC 300 ppm in the 2nd experiment. Spraying was carried out twice for each at four and six weeks after sowing, while the control plants were sprayed with distilled water. All agriculture management and fertilization with NPK were carried out as usually recommended for open field potato crops production, according to Ministry of Agriculture.