A field experiments were conducted at Horticulture Research Station, El-Kanater El-Khiria, Horticulture Research Institute, Agriculture Research Centre, Egypt during 2016 and 2017 seasons to investigate the effect of different irrigation water levels i.e.,100, 75 and 50% of the crop evapotranspiration (ETc) and foliar application with some stimulant substances i.e., proline at 150 mgl -1 , potassium silicate at 2500 mgl -1 and putrescine at 10 mgl -1 as well as mulching treatments i.e., black polyethylene plastic, rice straw and sawdust mulches individually or in combination of treatments on vegetative growth characteristics, some bioconstituents, total yield and its components of taro plant under drip irrigation system and results interpreted. The results showed that that increasing water stress level from 75% to 50% of Etc decreased gradually all studied growth characteristics of taro plant (plant height, leaves number plant -1 , lamina dry weight plant -1 and leaf area (cm 2 ) plant -1 in the two seasons. In addition, increasing irrigation water stress resulted in decreasing of photosynthetic pigments (chlorophyll a, b and carotenoids) content in taro Original Research ArticleAbd El-Aal et al.; IJPSS, 29(4): 1-23, 2019; Article no.IJPSS.50956 2 leaves. Moreover, the increase in water shortage is regularly increased the proline content and antioxidant enzymes activity i.e., superoxide dismutase (SOD), peroxidase (POD) and catalase (CAT) in taro leaves compared to the full irrigation level (100% of ETc). Furthermore, different estimated yield characteristics of taro plant i.e., main corm length (cm), main corm diameter (cm), corms number plant -1 , corms fresh weight (kg) plant -1 , main corm fresh weight (g), corms fresh weight (kg) plot -1 , corms fresh yield (ton) fed. -1 and corm dry matter % as well as taro corm bioconstituents of N, P, K, crude protein and starch contents decreased by reducing irrigation water levels. In this respect, water stress level at 50% of ETc recorded the highest reductions in different estimated characteristics compared to 75% of ETc level and unstressed plant (100% of ETc). Regarding, the effect of foliar application with stimulant substances and mulching treatments, proline at 150 mgl -1 followed by potassium silicate at 2500 mgl -1 and putrescine at 10 mgl -1 as well as black polyethylene plastic mulch were the most effective treatments, respectively. As for the effect of interaction, the results showed that all the interactions between irrigation water levels and foliar spray with the stimulant materials as well as mulching treatments increased different estimated traits of taro plant i.e., vegetative growth characteristics, bioconstituents, yield and its components as well as water use efficiency compared to the control. In this respect, foliar spray with proline at 150 mgl -1 was the most superior treatment followed by putrescine at 10 mgl -1 and potassium silicate at 2500 mgl -1 under water stress levels i.e., 75 and 50% of ETc when compared with the untreated plants dur...

Two field experiments were carried out to study the effect of some stimulant substances, i.e., benzyladenine at 25, 50 ppm and blue green algae "Spirulina platensis" extract at 0.3, 0.6 % as well as yeast extract at 5, 10 % as individual treatments on growth and yield traits in addition to anatomical and chemical constituents of Solanum tuberosum L. The results showed a significant improving in the most of vegetative growth and yield characteristic with applied treatments compared with the control. Consequently, treating potato plants with spirulina algae extract at 0.6 or 0.3 % or yeast extract at 10 %, respectively three times lead to obtain vigorous vegetative growth of Solanum tuberosum L. plant with increasing in both of tuber yield and its quality characteristics.

Egypt to study the stimulation of the potato plant's cv. Picasso ability to tolerance low temperature and improving tubers yield and qualities through appropriate agricultural practices in parallel with the addition of adequate fertilizers of NPK plus micro-nutrients spraying and some anti-stress substances. The experiment included eight treatments consisting of two fertilization treatments in main plots and four antistress as sub plots. The results indicate that treating plants with a suggested nutrients program, along with foliar spraying with some minor elements and some anti-stress, such as selenium plus vitamin C or vitamin E in addition to a commercial anti-stress compound led to stimulating the plant's ability to tolerance low temperature and improved plant growth. Anti-stress commercial compound at 100 ppm concentration exhibited the significant superiority in most of vegetative growth traits (stem length-average number of both stems and leaves as well as fresh weight of stems and leaves and reflected so positively on the total yield of tubers, quality characteristics and the percentage of tubers starch. Also, results indicate that the remainder of the treatments recorded significant differences and gave values that reached the level of significance in most of the characteristics of vegetative growth and yield and its components, compared to the control treatment, which recorded the lowest values of all studied traits. Conclusively, the recommended program for planting in the offseason growing cycles will give the highest yield due to the balanced fertilization and anti-stress /anti-oxidants, as well as, in the same time will take care of the tubers quality. So that, the tubers yield will gain the 426 AHMED EL-ANANY highest values of economic competition in locally and international markets and to contribute as a good source of hard currency for Egypt.

The study assessed the effect of intercropping Patterns on the performance of potato plants, i.e., vegetative growth, tuber quality and yield as well as potato late blight,Phytophthorainfestansdisease epidemiology. Trials were carried out under a greenhouse and open field in