Stage of maturity often affects the yield, dry matter, specific gravity and color of potato tubers.

The condition of soil and microclimate are prerequisite for proper growth and development of a plant. The environment may be mediated by artificial filming with different colored polyethylene. The mechanism of lettuce growing under colored plastic film remains largely unknown. Thus, to investigate the impact of different plastic film on the growth environment, yield parameters and phytochemical properties of lettuce, the present study was performed. Five different colored polyethylene films viz. black, white, blue, olive and silver were used as a treatment factor, in filed condition. The results demonstrated that the soil pH, temperature and overall performance of lettuce, as well as the phytochemical composition, varied within the use of different films. The maximum soil pH and temperature were found under black filming plots. Additionally, the black colored plastic film exhibited the best values for most of the yield parameters studied over other plastic films, whereas the field with non-plastic film condition showed the worst data in the experiment. Phytochemical concentrations and nutritive value of lettuce were also significantly affected by the colored plastic treatments. Furthermore, the chlorophyll, anthocyanin, phenols and carotenoids contents were increased in plants grown in soil covered with black polyethylene. Vitamin C content was of 2.5 fold higher in the plants grown in the black film compared to control conditions. The application of plastic film led to elevated concentrations of macro and micronutrients in lettuce because of the direct effect of modified radiation under the plastic film. Taken together, it can be concluded that plastic filming could be used to enhance the yield and nutritional status of lettuce in natural plant production facilities.

An experiment was carried out to evaluate the effect of growth regulators viz., Gibberellin (GA 3), lemon juice and tamarind leaf extract on germination and vigor of lentil seeds. The experiment was conducted with BARI Masur-4 cultivar, and three growth regulators: gibberellin, lemon juice and tamarind leaf extract were used. Three concentrations of gibberellins (10, 20 and 30 ppm), three concentrations of lemon juice (2, 4 and 6 %) and three concentrations of tamarind leaf extract (0.05, 0.1 and 0.15%) with two soaking time duration: 6 and 12 hours and control were used. Gibberellin (GA 3) improved germination percentage, seedlings length, dry matter, germination index and vigor index of lentil. Lemon juice enhanced germination percentage, seedling length, vigor index and germination index in lentil. Tamarind leaf extract increased the germination percentage, vigor index and speed of germination in lentil. In comparison with plant growth regulators, length and weight was found to be positively correlated and in most cases relationships were significant.

The effect of vermicompost on dry matter and specific gravity of potato tubers under ambient storage condition was studied. Vermicompost was used at four rates viz. 0, 2, 4 and 6 t ha-1 over the four varieties of potato viz. BARI TPS-1, BARI Alu-28 (Lady Rosetta), BARI Alu-25 (Asterix) and BARI Alu-29 (Courage). Results demonstrated that processing parameters such as dry matter percentage (%) and specific gravity increased with increasing vermicompost levels while they decreased with the increasing storing period. Lady Rosetta and Asterix potato varieties can be safely stored at normal room temperature up to 60 days. There was no interaction between vermicompost rates and crop varieties. Hence, the potato growers of Bangladesh can use vermicompost at 6 t ha-1 for achieving better yield without affecting processing quality. SAARC J. Agri., 17(2): 173-184 (2019)

Purpose The research was performed to assess the effect of vermicompost and tuber size on the storage behavior of potato during the ambient condition.