EFFECT OF LOCATION AND PLANTING DATE ON BOTTLE GOURD (LAGENARIA SICERARIA L.) PRODUCTIVITY AT DESERT SOILS

Two field experiments were carried out during the summer seasons of 2008 and 2009 to investigate the effect of two various agricultural sites (Ras Sudr region, South Sinai and Al-Maghara region, Middle Sinai) and four sowing dates (March 15^th, April 1^st, April 15^thand May 1^st) on growth, flowering, fresh fruits, seed yields, accumulated heat units and nutritional values of bottle gourd Egyptian variety. The results revealed that the emergence period (E_p), foliage fresh weight after 120 days from sowing, absolute growth rate (AGR), number of female flowers, average fresh fruit weight and carbohydrates content of fresh fruits were significantly influenced by agricultural sites. Delaying planting dates increased fresh and dry foliage weight of samples taken after 30 and 75 days from sowing date and decreased flowering period (F_p), while the earlier sowing dates increased fresh and dry foliage weight after 120 days from sowing, (AGR) and flowering characteristics enhanced in addition to increase seed and fresh yield and its contents of nitrogen, phosphorus and protein. As regard, the interaction among studied factors E_precorded the significant latest value in Al-Maghara on May 1^st, also, foliage fresh and dry weight significantly were affected with interaction and the highest value of (AGR) was recorded in Ras Sudr on March 15^th, while the earlier sowing dates whether in Ras Sudr or Al-Maghara significantly increased flowering characteristics, fruiting period, fresh fruits and seeds yield characteristics and the content of N, P and protein. Correlation and regression relationship revealed that high significant negative correlation between (F_p) and the accumulated dry mater after 30 days of sowing. The regression coefficient indicated that for each increase of one gram dry matter, (F_p) correspondingly decreased by 1.52 days, the same trend was observed between the average of weight and number of fresh fruits, where each decrease of 9.12 gram of each fruit/plant led to correspondingly increase one fruit. On the contrary, the correlation was significantly positive between number of female flowers and foliage dry weight after 120 days from sowing, number of fresh fruit and female flowers / plant besides fresh fruits yield ton/fed and number of fruits/plant. Base temperature of bottle gourd locale cultivar was 10.88˚C (51.58˚F) and the thermal times for 75% of plants emergence, the first flower, last fresh fruit and complete l±20 y mature phase are 57.6±6.6, 399.7±46.6, 1625±59.2 and 2476.0.8 heat units, respectively. So, it could produce the highest fresh fruits and seed yields when plants are sowing on March 15^th.