الفهرس 
Growth analysisOnly 14 pages are availabe for public view
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Abstract
7%- f i e l d experiments were-conducted a t the experimental farm of the Faculty of Ag~iculture, Tanta University at Kafr El-Sheikh dwing 1974 and 1975 secsens, to study the effect of plant population and nitrogen fertilizer levels on growth, yield and yield components of toll and dwapf corn cultivars . Each experiment included one sf the t&ee corn cultivars , ttAme~icnne arlyn, ”Hybrid lgl*a nd *IPue.br,2 ” . The plant populations of 15,000 ; 20,000 and 309000 plants per feddan were used in combination with the nitrogen fertilizer levels of 80, 100 and 120 Kilograms per feddon for every cultivar. A split plot design with four eplicates was used in each expe~iment, The combined analysis conduoted between the three cultiv6r;s every year. The planting dates were July 5-th, 1974 end May 8-th, 1975. The measurements on growth characteristics were taken at 42, 76 and 97 days from sowing . The results obtained can be summarized as follows : A, Growth analysis : 1- Plant and ear heights (em.): Increasing the plant populations decreased plant height, but increased ear height. Plant and ear heights increased by increasing nitrogen levels. The cultivars differed in their plant and ear heiets. Plant and eor heights in t2American earlyzt was the t a l l e s t while IvPue.br .21f wzs the shortest. 2- DPy matter and distribution 2 a. Dry matter per plant: The increase in dry matter per plant obtained with decreasing plant populations and increasing nitrogen levels. ”Arnericnn early” had heavier dry matter per plant than the other two cultivars of the three growth stages in both seasons. The short corn tfPue.br.21t was the lowest in t h i s respect. b. Dry mntter distribution: The percentage d i s t r i - bution of dry matter of leoves, stems (except a t the first sample) and tnssels increased, but of ems decreased by increasing plant populations and decreasing nitrogen levels. The cultivars differed in percentages of oll organs at the three growth stages in both seasons. The - 102 - highest one in pxoportion of leaves and tassels was the short corn aP~e,br,2~T~h.e highe~p ropor t ion of stet& was obtained from 13Americm emlyfl. ”Hubrid 19” was the highest in proportion of ems.