This study was carried out at Sids Horticulture Research Station, Bani Sueif Governorate, Agriculture Research Center, Egypt during the two late fall seasons of 2016/2017 and 2017/2018 seasons, respectively. The objectives of this study were to investigate the proper planting date from two dates i.e. at the middle of September and at the middle of October, foliar spraying with six treatments stimulative i.e. amino acids (as amino zeid 85 %) at 0.5 g/ L, proline at 0.5 g/ L, pho-k 2.5 g/ L, green top star at 2.5 cm3/ L, adenosine triphosphate (ATP) at 0.2 g/ L, mixture consists of potassiumoxide (50 % W/V) at 2.5 cm3 plus phosphoric acid (85 %) at 1.5 % and micronized sulpher (85 %) at 2.5 g/ L as well as the control treatment (spraying with tap water) in addition to their interactions under the condition of low temperature, on the vegetative growth parameters, number of days to 50 % of flowering plants, number of flowers/ plant, fruit set %, yield and its components (ton/ fed.), fruit quality, some chemical contents in the fruits and cold injury index (%)as well as cold tolerance index (%)of eggplant plants (Solanum melongena L.) Black berry F1. The experimental design was split–plot, where the two planting dates were assigned in the main plots and the previous foliar spray treatments were randomly distributed in the sub plots with three replications per treatment. The results of the experiment demonstrated that:
The surpass planting date under this investigation was at the middle of September which was occurred the highest significantly increases in the vegetative growth characters, the earlier of flowering, the marketable and total yield, fruit quality, concentrate each of the total chlorophyll contents in the fresh leaves, the total sugars contents in dry fruit, the cold tolerance index (%)and decreasing the cold injury index (%)as well as the un-marketable fruits yield as compared with the later planting date i.e. at the 15th of October which gave the lowest values of the all previous traits beside of delaying the flowering, increasing the un-marketable yield, the cold injury index (%)of the plants and decreasing the tolerance index (%)under this conditions of low temperature. No significant values were detectedin fruit set %, ascorbic acid contents in the fresh fruits and the total phenol contents in the dry fruit, between the 1st and the 2nd planting dates in the two late fall seasons, respectively.
Regarding to the marked stimulatory effect of spraying with some stimulative treatments, it was concluded that, foliar spraying with green top star at 2.5 cm3/ L followed by amino zied at 0.5 g/ L thenthe mixture consists of potassiumoxide at 2.5 cm3 plus phosphoric acid at 1.5 % and micronized sulpher at 2.5 g/ L significantly increased the vegetative growth characters, the earlier of flowering, number of flowers/ plant, fruit set %, the marketable and total yield (ton/ fed.), the total chlorophyll, fruit quality, ascorbic acid, the total sugars, the total phenol, the cold tolerance index (%)and decreasing the cold injury index (%) as well as the un-marketable fruits yield.
On the contrary, the lowest results of all the previous characters were obtained when the plants foliared with proline at 0.5 g/ L followed by adenosine triphosphate at 0.2 g/ L as compared with the control (untreated plants) which sprayed with tap water.
Concerning to, the results of the interactions between the two studied factors i.e.planting dates and spraying with some treatments were used in this investigation elucidated that, the surpassing interactions treatment which was occurred with the highest means values over all the other interactions were obtained by the interaction between the 1st planting date at the middle of September and foliar spraying eggplant plants with green top star at 2.5 cm3/ L followed by amino zied at 0.5 g/ L then the treatment of potassiumoxide at 2.5 cm3 plus phosphoric acid at 1.5 % and micronized sulpher at 2.5 g/ L, which produced significant increases of the marketable and total yield, fruit quality, the cold tolerance index (%)as well as decreasing the un- marketable yield and the cold injury index (%) as compared with the rest of the interactions, these findings were true in the both late fall seasons, and this superior results continued until the beginning of summer season.