الفهرس 
Introduction
Effect of cultivarsOnly 14 pages are availabe for public view
 |  | from | 87 |  |  |
| | | from | 87 | | |
Abstract
Two field experiments were carried out at privet farm at Gerga Sohag Governorate, Egypt during the growing summer 2007 and 2008 seasons. The purpose of this to study was to evaluate the response of two cultivars of cucumber to various plant densities and nitrogen fertilization rate on productivity under Sohag conditions.
Each field trail included thirty-six treatments represented the combination between two cucumber cultivars (Medina and Prince), six plant densities (120000, 60000, 40000, 30000, 24000 and 20000 plants/fed) and three nitrogen fertilizer (50, 100 and 150 kg N/fed) rates.
Split-split plot design with four replicates was used in this experiment. Two cucumber cultivars were allocated in the whole plots; six plant densities were distributed in sub plots. While three nitrogen fertilizer rats were randomly distributed in the sub-sub plots.
Each plot size was 12.6 m2. It contained three ridges each of them was 3 m long and 140 cm in wide. The experimental site was prepared and sowing was done in both sides of each ridge 13th and 14th of March in the first and second seasons, respectively by sowing two seeds per hill. Growing plants were thinned to one plant just before first irrigation.
The obtained results could be summarized as follows:-
1. Main stem length (cm.):
The two studied cucumber cultivars i.e., (Madena and Prince) significantly affected main stem length (cm), Prince cultivar gave higher of length main stem than Madena cultivar, in both seasons.
Main stem length gradually increased with increasing plant density from 20000 up to 120000 plants/fed. Also, increasing N rates, significantly increased this parameter in both seasons.
All possible interactions significantly affect cucumber plant length in both seasons. However, the triple interactions of Prince cultivar, plant density at 120000 plant/fed. and application of 150 kg N/fed. resulted in the highest main stem length.
2. Number of branches/plant:
Cultivar type significantly affect this trait in the first season. Moreover, Prince cultivar surpassed Medina cultivar by (19.40 and 6.47%) in the first and second season, respectively.
Plant densities significantly affect number of branches/plant. The highest values i.e., (3.83 and 3.94) were resulted from (30000 plant/fed.) in the first and second season, respectively. Increasing nitrogen fertilizer levels significantly increased number of branches/plant.
All possible interactions affected significantly this character in the first season, except the triple interactions, which had significant effect in the second season only.
3. Number of leaves/plant:
Number of leaves/plant significantly influenced by cucumber cultivars type in both seasons, where the Prince cv. was superior than Medina cv.
Plant densities significantly affect on this trait in both seasons. The values significantly increased as the plant density decreased in the in the first and second seasons, respectively.
Application nitrogen fertilizer levels significantly increased number of leaves/plant with increasing the nitrogen rate up to 150 kg N/fed. these results hold good in the two experimental seasons.
Results reveal that all possible interactions significantly affect on this trait in both seasons. Furthermore, the highest number of leaves i.e. (165.3 and 171.0) were produced by the interaction among prince cultivar, 20000 plant/fed and 150 kg N/fed. in the first and second season, respectively.
4. Plant dry weight:-
Data obviously show that plant dry weight significantly affected by cultivars type in both seasons.
Data that the various plant densities effect on this trait, the differences were announced and statistically approved in the both seasons the highest values were obtained from the lowest plant density.
Application of different nitrogen rates significantly affect on this character in both seasons.
All possible interactions significantly effect on this trait in both seasons. Furthermore, the highest values were produced by the interaction among Prince cultivar, 20000 plants/fed and 150 kg N/fed. in both seasons.
It could be concluded that planting of Medina Cv. at plant density of 120000 plants/fed. and fertilized with 150 kg N/fed. may be recommended for highest total yield with acceptable fruit quality reducing N fertilizer rate to 100 kg N/fed. may achieve the highest early yield. These recommendations could be applied under Sohag Governorate Conditions, Egypt.