The application of Light Emitting Diodes (LEDs) in agricultural sector has become popular in recent years. LEDs can even be used in total absence of natural sunlight in raising indoor vegetables and ornamental plants. Appropriate light spectral regions must be studied according to crop species or varieties, especially for plants with high commercial values. The present experiment was conducted to determine the effects of monochromic LED of Red (R) and Blue (B), and their combinations at 1:1, 1:2 and 2:1,at 18 W and 240 V, on production of Lactuca sativa cv. Fire Red in controlled laboratory environment in total absence of natural light. Each LED irradiation treatment was assigned as sub plot with photoperiods (PPs) ranging from 12 h to 18 has main plots in a split plot design to study their combined effects on growth, pigment and ascorbic acid (AA) contents of this attractive red colour vegetable. Seedlings in moist jiffy blocks at one week after sowing were transferred to polyvinyl chloride (PVC) troughs of 5 cm diameter containing quarter strength Hoagland solution at electrical conductivity ranging from 1,100 to 1,300 μS/cm and pH 6-7. Plants were grown with nutrient film technique at a distance of approximately 8 cm below LED. Results obtained showed that R was not appropriate for growing this vegetable while analysis of variance indicated that plants irradiated with B gained the greatest plant height at five weeks at harvest, but these plants had the lowest number of leaves. Highest fresh weight (FW) as marketing attribute of this vegetable was obtained with 18 h PP. When combined 18 h PP with BR or 2BR, it was the best for production of L. sativa cv. Fire Red with the highest anthocyanin content.
Functional property changes in Phaleria macrocarpa fruit during ripening on tree were studied. Results showed that juice extracted from fruit flesh had low acidity and soluble solid content. Fruit acidity decreased but soluble solids increased as the fruit ripened. In terms of antioxidant content, ascorbic acid, DPPH free radical scavenging activities and total phenolic content were, however, the lowest in fully ripe fruit flesh while the unripe fruit flesh had the highest. High percentage of these antioxidants was water soluble. This study suggests that the unripe fruits should be harvested for valuable medicinal product development instead of the fully ripe fruits.
Mango as a climacteric fruit is known to have increased auxins with concomitant increased ethylene and carbon dioxide production during ripening. Such hormonal properties alongside many other nutritional benefits prepared in the form of compost extract were tested for enhancing production of medicinal bitter gourd of Momordica charantia. This cucurbit was planted on field beds at 0.8 x 0.5 m followed by application of compost extract prepared with anaerobic decomposition of rotting mango fruits, fish wastes of gills and internal organs and brown sugar at different ratios in plastic containers. The results obtained showed that mango:fish wastes:sugar compost extract of 2:1:1 applied to soil around the root collar at 10 ml at fortnight intervals allowed the plants to gain the highest mean number of fruits per plant of 18.3, mean individual fruit weight of 25.95 g or mean yield of 11.80 tonnes per hectare. Mango compost extract is, hence, beneficial in organic production of this medicinal bitter gourd.