EFFECT OF NITROGEN FERTILIZER RATES AND WEED CONTROL TREATMENTS ON WEEDS GROWTH AND PRODUCTIVITY, QUALITY AND ECONOMIC FEASIBILITY OF TARO CROP

Abstract

Two field experiments for taro vegetable crop were carried out in ElKanater El-Khiria, Horticulture Research Station, Kalubia Governorate, Egypt, in a split plot design during the two successive 2015 and 2016 seasons. This study aimed to investigate the effects of two nitrogen fertilizer rates at 90 or 120 kg/ fed. in main plots and nine weed control treatments in sub plots i.e. Harness at one liter/ fed., Sencor at 300 g/ fed. and Stomp extra at 1.7 liter/ fed. each individual and/ or plus Roundup at one liter/ fed., Roundup individual, hand hoeing twice after 25 and 40 days from sowing and untreated check (control) on weeds growth and vegetative growth, yield, quality and economic feasibility of taro. The main findings of this research revealed that nitrogen fertilizer rate at 90 kg/ fed. gave the highest decrease in dry weight of weed categories i.e. , broadleaf weeds, grassy weeds and total weeds in both seasons and increased diameter and weight of taro corm in the second season. Whereas, taro plant height, taro number of leaves/ plant and uptake of nitrogen by weeds were increased by application of nitrogen rate at 120 than 90 kg/ fed. during the two seasons without any significant differences in the yield of taro, its components, chlorophyll content and chemical analysis characterized. The use of Stomp extra at 1.7 liter/ fed. applied as post-sowing plus Roundup at one liter/ fed. after 25 days from sowing applied as taro pre-emergence above soil surface exhibited significantly decreased in dry weight of total weeds by 96.9 and 95.1 % in first and second seasons, respectively. Application of Seconr at 300g /fed. plus Roundup at rate of one liter/ fed. reduced the previous total weeds by 93.3 and 94.5% and increased taro yield (43.6 and 43.5%) in the first and second seasons, respectively. Thus, these herbicides can broaden weed control weed spectrum with long weed control season, which minimize taro yield by weed competition, consequently eliminated N uptake from soil and improved protein and starch accumulation in favor taro crop yield. Also, it can be advised as alternative hand hoeing to weed control in this crop with economic feasibility and delectable herbicides residues and under permissible levels which accompanied with high quality for taro growth characteristics i.e. plant height, number of leaves/ plant and chlorophyll reading in leaves, corm length, corm diameter, corm weight, corm fresh yield, dry matter % and chemical of taro corms (protein percentage, starch percentage and total nitrogen of corm yield).