الفهرس 
Response of maize (Zea mays L.) to zinc application under different levels of nitrogen fertilizer
ABSTRACTOnly 14 pages are availabe for public view
 |  | from | 140 |  |  |
| | | from | 140 | | |
Abstract
Growth, ear characters and grain yield of maize (Zea mays L.) c.v. single cross 10 as affected by nitrogen and zinc fertilizer levels were studied during 2016 and 2017 seasons at the Agric. and Exp. Sta. at Giza, Fac. of Agric., Cairo University, Egypt. The soil type of the experiments was clay loam in texture where the soil fertility status cleared that soil was low in N and Zn. The experimental design was split plot in randomized complete block design in three replications. Nitrogen levels, i.e. 100, 120 and 140 kg N/fed. (one feddan = 4200 m2) occupied the main plots and zinc levels (0, 10 and 20 kg/fed.) were allocated in sub plots. The preceding crop was wheat in both seasons. Grains were sworn in hills 25 cm apart on the third week of May in both seasons. Thinning to one plant/hill was done before the first irrigation (18 days after sowing). Nitrogen (urea 46% N) and zinc (ZnSO₄) fertilizer were added in a split application, one half was applied before the first irrigation and the rest was added before the second irrigation. All other cultural practices were standard and kept uniform for all treatment in both seasons. N fertilizer had significant effect on number of days from planting to 50% silking and tasseling, number of green leaves/plant (in the first season), leaf area/plant (LA/Plant) and leaf area index (LAI) at 70 and 85 days, crop growth rate (CGR), relative growth rate (RGR), net assimilation rate (NAR), leaf area/topmost ear (LA/topmost ear), chlorophyll content in green leave and plant height (PH) in both seasons. All previous growth characters recorded the highest values at 120 kg N/fed. except number of days to 50% silking and tasseling which were at 100 kg N/fed