Studies on growth and yield indicators for kohlrabi (Brassica oleracea) plant treated with mineral fertilizers and root enhancers

Abstract

An experiment was conducted at the Department of Horticulture and Landscape Gardening, College of Agricultural Engineering Sciences, University of Baghdad, Iraq during the autumn season of 2017. The objectives of this research were to study the effects of different mineral fertilizers and root enhancers on the growth and yield of kohlrabi plants. The effects of five fertilizer treatments viz., Control - 25% of recommended dose of fertilizer (RDF); RDF (100 kg N/ha, 120 kg P2O5/ha and 120 kg K2O/ha; 25% RDF with adding of high nitrogen (FAN) NPK fertilizer (30:10:10); 25% RDF with adding of high phosphorus (FAP) NPK fertilizer (13:40:13) and 25% RDF with adding of high potassium (FAK) NPK fertilizer (15:5:30) and three root enhancer treatments viz., Control (No root enhancer); Inicium @ 1 ml/L and Disper @ 1 ml/L. The experiment was laid out in factorial experiment with randomized complete blocks design (RCBD), with three replications. The results showed that 25% RDF with FAN treatment of fertilizers excelled significantly better compared to other treatments for the vegetative growth traits represented by plant height (68.57 cm), number of leaves/plant (19.53), leaf area/plant (906.50 cm2) and dry weight/plant (236.60 g). The root enhancer inicium @ 1 ml/L produced significantly higher plant height, number of leaves/plant, leaf area/plant and dry weight/plant amounting to 67.18 cm, 18.60, 854.90 cm2 and 226.14 g, respectively compared to control where no root enhancer was applied. The interaction of 25% RDF with FAK x Inicium @ 1ml/L gave significantly higher stem diameter (10.21 cm), stem weight (465.70 g) and stem yield (27.32 t/ha) of the kohlrabi plant compared to other treatments.