Effect of mineral, organic and bio-fertilizers on growth, yield, quality and sensory evaluation of Kohlrabi

摘要

Field experiments were carried out on Kohlrabi (Brassica oleracea var. gongylodes) ‘Purple Vienna cv.’ atthe Experimental Farm of the Faculty of Agriculture, Moshtohor, Benha University, Egypt, during the winterseasons of 2009 and 2010 under drip irrigation system. This study aimed to investigate the effect of organicmanure and/or mineral N-fertilizer with or without biofertilizer inoculation on growth, yield and quality ofkohlrabi knobs. Results show that using 50% mineral-N + 50% organic-N combined with biofertilizer, improvedplant growth, yield and knob quality compared to other N-fertilizer systems. Inoculation of kohlrabi transplantswith biofertilizer gave good results in this respect. Therefore, this treatment gave the best growth and increasedtotal yield with the best knob quality as compared with uninoculated one. The highest content of nitrate in knobs(803.84 mg kg-1 DW) was recorded by using 100% mineral-N treatment (average in both seasons). Whereas,adding 100% organic-N recorded the lowest content of nitrate in knobs (387.75 mg kg-1 DW) average of bothseasons. It is worthy to mention that nitrate concentration in tested kohlrabi knobs is still in the safe border forhuman consumption. Finally, kohlrabi plant contains good amounts of antioxidants substances positioned to beat the forefront of salad plants.