الفهرس 
INTRODUCTIONOnly 14 pages are availabe for public view
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Abstract
In Egypt, potato production districts are focused at special Governorates such as El-Behyira, El-Garbia, El-Menofiya and El-Minia as well as newly reclaimed soils as Cairo – Alexandria desert road. Fayoum Governorate is not potato production district and rarely planted this crop. The scope of the current study was to investigate some cultural practices on growth, productivity and chemical composition under El-Fayoum conditions. Therefore, two field trials were imposed during the summer seasons of 2014 and 2015 at a private farm located at Tatoon, Etsa, El-Fayoum Governorate, Egypt, using potato cv. Spunta. Three cultural practices were examined, N rates (150, 200 and 250 kg fed-1), in-row spacing’s between plants (20 and 30 cm) and planting dates (Jan. 15, Jan. 30 and Feb. 14). The experimental layout was a split-split plot system based on a Randomized Complete Blocks Design with four replications where N rates, in-row spacing’s and planting dates were randomly distributed in the main, sub- and sub-sub plots, orderly.
The results exhibited that, N application at 150 kg fed-1 and in-row spacing of 20 cm were satisfactory on plant height, canopy dry weight and leaves area and their components whilst, significant and positive responses on the studied growth parameters were occurred when seed planting date was on Jan. 30 in comparison with Jan. 15 or Feb. 14. Seed planting date on Jan. 30 coupled with N application at 150 kg fed-1 recorded the highest magnitudes for canopy dry weight and leaves area plant-1.
Total tubers yield, number and weight of tubers plant-1 and average tuber weight were not, significantly, affected by N application over 150 kg fed-1. Number of tubers plant-1 and total tubers yield fed-1 were, significantly, surpassed at in-row spacing 20 than 30 cm while, vice versa for average tuber weight. Total tubers yield and its components were, significantly, enhanced with seed planting date on Jan. 30 compared with Jan. 15 or Feb. 14. Beneficial interaction effects between seed planting date on Jan. 30 by in-row spacing of 20 cm on total tubers yield and its components and between seed planting date on Jan. 30 by N rate at 200 kg fed-1 on tubers yield plant-1. Tubers yield plant-1 and fed-1 were, significantly, the maximum across seed planting date on Jan. 30 at in-row spacing’s of 20 and/or 30 cm with nitrogen application rate at 200 and /or 250 kg fed-1.
The effect of N rates and in-row spacing’s on different marketable and non-marketable tuber size grades were at par mean while, tuber size grades > 60 and 30 - 60 mm in diameter went forward and tuber size grades ˂ 30 mm in diameter and non-marketable went backward with seed planting date on Jan. 30than Jan. 15 and Feb. 14. The interaction between few levels of the studied factors showed promising effect on tuber size grades > 60 and ˂ 30 mm in diameter.
Various N application and spacing between plants did not reflect any appreciable influence on tuber dry matter, carbohydrates and leaf chlorophylls, N, P and K contents with the exception that, tuber carbohydrates content, truly, increased at 30 than 20 cm spacing between plants. Generally, seed planting date on Jan. 30 was positively remarkable on tuber dry matter, leaf chlorophylls and N contents whereas, the opposite was true on leaf P content.