الفهرس | Only 14 pages are availabe for public view |
Abstract The present study was carried out as an attempt to investigate the effects of topdressing times of different levels of nitrogen fertilizer and fulvic acid as well as their various interactions on growth, yield and its components, chemical constituents and nitrogen use efficiency of cabbage plants. Two field experiments were carried out during the winter seasons of 2017/2018 and 2018/2019 at the Experimental Station Farm of the Faculty of Agriculture, Alexandria University, Abies, Alexandria, Egypt. Thirty six treatment combinations, representing all possible combinations among four levels of N fertilization (0,40,60 and 80 kg N/fed, N0, N1, N2 and N3, respectively), three times of topdressing (three, four and five times of equal application ; T3, T4 and T5, respectively) and three concentrations of fulvic acid ( 0, 100 and 200 ppm as soil drenching ;F0,F1 and F2 respectively), were studied in a split-split plots layout in randomized complete blocks design, with three replications in both seasons. The levels of N fertilizer occupied the main plots and the topdressing times (frequency of in –season N application) were considered as sub-plots, while the levels of fulvic acid were arranged in the sub - sub plots. Cabbage seedlings (C.v. Balady) were transplanted on October 10, 2017, and October 22, 2018. The obtained results could be summarized as follows. 6.1-Unfolded (inedible) leaves characters 1. Raising the level of applied N fertilizer from 0 up to 80 kg /fed was associated with progressive and constant increases in the number and fresh weight of unfolded leaves but decreased their percentages either to plant or head weight and dry matter content 121 2. The studied three treatments of the frequency of in -season N applications were not significantly differed in their effects on the tested characters of inedible leaves. 3. Soil applications of fulvic acid did not reflect significantly differ in their effects on the tested , parameters of unfolded leaves ,meanwhile the percentage of outer leaves either to plant or head weight significantly increased with FA at 200 ppm, in the second season. |