Nitrate control and quality in hydroponic lettuce by using cow dung extract and nutrient solution

Hydroponically grown lettuce poses a high nitrate risk, raising concern about its quality. Therefore, this work was employedto determine the accumulation of nitrate in lettuce leaf and the phytochemical properties of hydroponic lettuce. Treatmentsconsidered as four different levels of aerated cow dung extracts (CD), viz., CD1 = 50 g.L-1, CD2 =100 g.L-1, CD3 =150 g.L-1 and CD4 =200 g.L-1 and four strengths of standard nutrient solution (S), viz, S1 = 30% of standard nutrient solution, S2 = 40% of standard nutrient solution, S3 = 50% of standard nutrient solution and S4 = 60% of standard nutrient solution. The experiment was carried out in a deep flow technique in semigreenhouse. In the case of cow dung extract, the highest total fresh weight (112.05 g/plant) was recorded from CD3 while the lowest in CD1 and for nutrient solution, the highest fresh weight (116.0 g/plant) was recorded from S4 while the lowest in S1. In the event of, nitrate and ascorbic acid content were statistically higher in CD4 followed by CD3 and the lowest in CD1. In case of nutrient solution, the nitrate content was highest in S4 and the lowest in S1. The highest fresh weight and almost all the parameters were found to be the best in CD3S4 and the lowest in CD1S1. Therefore, the analysis showed that CD3S4 would be the most preferable treatment combination for producing quality lettuce with the lower content of nitrate

Leaf gas exchange, physiological growth, yield and biochemical properties of groundnut as influenced by boron in soilless culture

Crops specific proper concentration of micronutrient application is necessary to improve the yield and quality of crops. Therefore, an experiment was conducted to identify the optimum dose of boron for groundnut plant. Six level of boron (B) application, B0 (0 ppm), B1 (0.5 ppm), B2 (1 ppm), B3 (2 ppm), B4 (4 ppm) and B5 (8 ppm) were evaluated. Photosynthetic rate, transpiration and stomatal conductance were increased for boron application but leaf vapor pressure deficit decreased. Physiological growth parameters, yield and yield contributing character, and shelling percentage was highest for B3. The values of biochemical traits including protein, oil and vitamin E content were higher for B4. Thus, leaf gas exchange showed that boron can be used to culture groundnut as it provides high yield and biochemical properties

Estimation of Yield, Photosynthetic Rate, Biochemical, and Nutritional Content of Red Leaf Lettuce (Lactuca sativa L.) Grown in Organic Substrates

This study aimed to evaluate the effect of organic substrates on the growth yield, photosynthetic response, and nutritional profile of red leaf lettuce grown in different compositions of cocopeat (CP), sawdust (SD), and rice husk (RH). The result showed that the properties of substrates were influenced variably by their mixing ratios. The highest water holding capacity and moisture content were found in CP, and it provided the preferable pH, electrical conductivity, bulk density, and air-filled porosity in association with other categories of the substrate. Cocopeat-based media provides ample microclimate conditions in the root region of plants and increased their height, number of leaves, and fresh biomass components. The utmost dry biomass of plant parts also remarkably increased in CP; L*, a*, and b* chromaticity of leaves remained unchanged. The maximum chlorophyll content was attained in CP substrate, except for chlorophyll a/b, which was higher in RH. The net photosynthetic rate (PN), transpiration rate (E), and nitrate in leaves were enhanced substantially in CP, while it was lower in SD. Biochemical compositions and nutrients in leaves were likewise stimulated under the culture of cocopeat-based media. Results indicate that cocopeat, sawdust, and rice husk are a possible substrates mixture in a volume ratio of 3:1:1, which would be a better choice in the cultivation of red leaf lettuce

Response of Boron and Light on Morph-Physiology and Pod Yield of Two Peanut Varieties

Boron is an important micronutrient that enhances vegetative growth and yield of crops, like peanut. Light also plays an important role in pegging of peanut. There has been little information regarding the application of boron and light in peanut in Bangladesh. Therefore, a field experiment was conducted to study the response of boron and light on morph-physiology and pod yield of two peanut varieties. Treatments considered two peanut varieties, namely, Dhaka-1 and BARI Chinabadam-8, three levels of boron (B), namely, 0-kg B ha−1 (B0), 1-kg B ha−1 (B1), and 2-kg B ha−1 (B2), and two levels of light, namely, normal day light (≈12 h light) and normal day light + 6 h extended red light at night (≈18 h light). Result revealed that days to first-last emergence and days to first-50% flowering took shorter times and vegetative growth, pods dry weight plant−1, pod yield, and germination were markedly increased with the application of boron. Vegetative growth and germinations were significantly increased in light, but the lowest leaf area, pods dry weight plant−1, and pod yield were found in light. Without germination, the highest vegetative growth, reproductive unit, and pod yield were observed from BARI Chinabadam-8. Days to first-last emergence, days to first-50% flowering, and number of branches plant−1 were found linearly related to pod yield

Reproductive development of two groundnut cultivars as influenced by boron and light

Boron is an important micronutrient that enhances reproductive growth of crops such as groundnut. Light also plays an important role for pegging of groundnut. There has been little information on the application of boron and light in groundnut in Bangladesh. A field experiment was conducted to study the effects of boron and light on the reproductive development of two groundnut cultivars. Treatments considered as two groundnut cultivars, viz., ‘Dhaka-1 (C1)’ and ‘BARI Chinabadam-8 (C2)’, three levels of boron (B), viz., 0-kg B ha−1 (B0), 1-kg B ha−1 (B1) and 2-kg B ha−1 (B2), and two levels of light, viz., normal day light (≈12-h light) and normal day light + 6-h extended red light at night (≈18-h light). Result revealed that the reproductive development, yield and shelling percentage of groundnut were markedly increased with the application of B. Due to imposition of light all of reproductive units increased but decrease number of pods and pod yield. The highest reproductive unit and yield were observed from ‘BARI Chinabadam-8’. Therefore, reproductive development could be improved by application of boron in improved cultivars (BARI Chinabadam-8) but not for under extended light. Keywords: Groundnut, Reproductive development, Light, Boron, Pegs, Pods, Shelling percentag

The effects of irrigation timing on growth, yield, and physiological traits of hydroponic lettuce

Crop-specific timing of irrigation is necessary to conserve irrigation water and improve yield of vegetables. Therefore, the experiment was conducted to identify the optimum irrigation timings for hydroponic lettuce plants. Three nutrient solution timings, T1(once a day at 0900 hours), T2(once on alternative days at 0900 hours), and T3(once at two-day intervals), and three varieties, ‘Legacy’ (V1), ‘Red fire’ (V2), and ‘Green wave’ (V3) were evaluated. Growth and yield parameters, including number of leaves, leaf length, leaf diameter, and fresh weight of leaves, and growth parameters, including leaf area (LA), leaf area ratio (LAR), leaf mass ratio (LMR), root weight ratio (RWR), relative growth rate (RGR), and net assimilation rate (NAR) were determined. The values of growth parameters were the highest for T1. The highest and lowest NAR and RGR values were obtained for T1 and T3, respectively. The values of most growth traits, including fresh weight, NAR, and RGR were higher for V1 than other varieties. T1 provides high yield with comparatively less irrigation water and nutrient solution so it can be used to culture lettuce using aggregate hydroponics as