الفهرس 
Effect of planting patternsOnly 14 pages are availabe for public view
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Abstract
three factorial experiments were conducted on a clay soil during 1992193 and 1993/94 seasons. ’l’he first experiment was conducted at the Experi~nental Station of the Faculty of Agriculture, Tanta University at Kafr El- Sheikh. ’I~E second and third experiments were conducted at Sakha Agricultural Itcscarch Station, Agricultural Research center. Exp. I : Response of sugar beet to ylarlting pattern and nitrogen rate : A split plot design with four replications was used. The main plots were assigned to planting patterns and the sub-plot to nitrogen rates as follows: A- I’la~iting patterns (main plots): The optimum plant population (46,666 plantslfed.) were used and distributed as follows : Platiting Ridge pattern width (c1n)90 cnl-2s 90 cnl-3s 75 cin-2s GO cm- 1 S 60 cnl-2s 50 cin-iS Hill spacing (cm)20 30 24 15 30 18
Plant distribution two sides two sides and middle two sides one side two sides one side 13- Nitrugeu mtcs (sub-plots): Four nitrogen rates, i.e. 60, 75, 90 and 105 kg N per feddan in the fonn of urea (46% N) were used samples of sugar beet plants were taken at 144, 161 and 176 days from sowing as well as at harvest for growth cliasacters determination. The results obtained can be summarized as follows: I- A. G t,o\vth : I- A. 1. Root Icllgtll : I3eet plants distributed on one side of 50cm ridges (50 cm-1 side) protiuced longer root than those distributed on two sides of 60 and 75 cm ridges (60 and 75 cin -2 sides) or on two sides and top of 90 crn ridges at all sampling clatcs except at 144 day Sroin sowing (DFS) in the first season. Increasing nitrogen rate from 60 to 105 kg/fed. substantially improved root length. No significat~t evidenced between the highest two nitrogen rates. The interactiot had a significant effect on root length at 161 and 176 DFS as well as at harvest in the first season, only. 1.A.2. Root dianleter : Beets of 50 cnl -1 side pattern produced the thickest root, whereas those of 90 ctn -3 sides produced the lowest ones. No significant difference in root diameter was evidenced among the 50 or 60 cin -1 side and 90 cm -2 sides at harvest in both seasons. The root diameter at 60 kg N/feddan was significantly lower than 90 and 105 kg Nlfeddan. No significant interaction was recognized. 13eets of 50 cm - 1 side pattern accumulated the greatest dry matter, while those of 90 c111 - 3 sides pattern accumulated the lowest one. Beets grown on one side of 50 or 60 cm ridges and on two sides of 90 cm ridges practically accutnulateci the same dry matter per plant at most sampling dates in both seasons. Increasing nitrogen sate from 60 up to 105 kg per feddan increased dry weight per plant. There was no significant difference between 90 and 105 kg Nlfedtlan it1 this respect. The interaction between planting patterns and nitrogel) rates had a significant eSfect on dry matter accumulation at all sampling dates ill tile first season, only (Table 7). I.A.4. Rootltop ra t’1 0 : I’he planting patterns revealed no significant differences in rootltop ratio except at 144 days from sowing in the first season. Rootltop ratio of sugar becl was significantly decreased by increasing nitrogen rate from 60 to 105 kg Nlfeddan at 144 days from sowing in 1992193 season. None of the interaction was significant. I.A.S. Leaf area index (LAI) : Planting pattern resulted significant differences in leaf area index at thc three sampling dates in both seasons in favour of beets grown on one side or 50 ant1 60 ctn ridges compared to those grown on two sides of 60 and 75 cm ridges 01. on three sides of 90 cm ridges. Leaf area index was gradually increased with increasing nitrogen rate from 60 up to 105 kg Nlfeddan. The rate of 90 1q: Nll’eddan did not sigtiificantly differ from 105 kg Nlfeddan in this respect ;it 144 anti 16 1 DFS in the second season. The interaction had a significant effcci on leaf asea index at 161 days from sowing in the first season, only. 1.A.6. Crop growth rate (CGH): I’lontinp patterns exerted significant effect on crop growth rate at all growth periods, except at the period (144-161 days) in the second season. Beets of 50 cm-1 side pattern significantly exceeded those of 90 cm-3 sides pattern in this respect. Crop growth rate was significantly affected by nitrogen rate, except at thc sccoi~d growth period at 1993194 scasoli. The crop growth rate at 105 kg Nlfedtlnli was significantly higher than at 60 and 75 kg Nlfeddan. None orthe intesnctio~ie xerted significant effect on crop growth rate in the two seasons. I.A.7. IWative growth rate (RGR) : Relative growth was significantly influenced by planting patterns in favour of beets for the 90 cm - 3 sides pattern compared with those for the 50 cxn - 1 side and 60 - 1 side patlesns at the first growth period in both season and the scconci growth period in 1992193 season. Relative growth rate was significantly dccreasccl by increasing nitrogen rate at the two growth periods in both seasons. None of the interaction was significant. I.A.8. Nct assi~~~ilartaitoe ~(N~A R): Net assilnilation rate was significantly influenced by plailting patterns, except at the growth period (1 61-176 days) in tlie second season. Beets grown on ow side of 50 or 60 cm ridges exhibited significantly tlie lowest net assimilatioii rate, while tliose grown on three sides of 90 cm ridges or on two sides of 60 cm ridges exhibited significantly the highest one. Nitrogen rates resulted significant differences in NAR at the two growth periods in the first season in favour of beets received 60 kg Nlfeddan compared to those received 75, 90 aid 105 kg Nlfeddan. The interaction planting patterns nitrogen rates for NAR was significant at the second period in the first season, only.