Somen Acharya

A study was conducted on Ladakhi local radish to determine the effects of Aloe vera gel and Chlorpropham [isopropyl N-(3-chlorophenyl) carbamate] (CIPC) treatments on postharvest quality under cold desert conditions of Leh-Ladakh in the year 2019−20. Radish roots were treated with 100 % Aloe vera gel and 10 % CIPC before being stored in a zero-energy semi-underground structure for 90 days. Physiological [weight loss, moisture content] and biochemical parameters [total soluble solids (TSS), anthocyanin content, titratable acidity, total antioxidant activity, sugars, minerals and inorganic anions] were measured after 30 days. At the end of the experiment, the maximum weight loss 19.79 % was recorded in the control, while 15.20 % and 13.33 % weight loss were recorded with the application of CIPC and Aloe vera, respectively. Total soluble solids , sugars and anions increased initially but declined after 60 days. No significant changes were observed in mineral content across treatments, although sodium levels were slightly lower in treated samples. Aloe vera gel showed potential as a natural, biodegradable coating to enhance shelf life & quality of radish under high-altitude cold desert storage, offering a sustainable alternative to synthetic chemicals like CIPC.

Food waste disposal is regarded as a source of contamination in the environment. There is little information on whether food waste compost can be used in agriculture, especially in the subtropics. The study examined the effect of food waste compost on onion (Allium cepa L) cultivation under an open experimental field condition in a subtropical climate. Standard methods were used to analyze the soil physicochemical parameters (pH, electrical conductivity, total dissolved solids, soil moisture, water holding capacity, total organic matter, phosphorus, potassium, manganese, iron, copper, and zinc) of control and treatment plots. Standard methods were used to measure all other morpho-physiological parameters. The plant height, the number of leaves per plant, the length and width of the leaves, the neck diameter, the relative water content of the leaves, the ash content of the leaves, and the root length were all measured. The treatment group had higher soil fertility than the control group. During the experiment, plant height, leaf number, leaf length, and leaf width all increased. Most morphophysio-chemical parameters in the treatment group onion plants were higher than in the control group after harvest. The yield of control plots was 13.64 t ha⁻¹ and the yield of treatment plots was 32.04 t ha⁻¹. Therefore, from this study it might be concluded that the compost from food waste has the potency to increase the soil fertility followed by the higher onion production. Hence, food waste can be used to prepare compost for higher onion production under sub-tropical conditions. Graphical Abstract

Aims: The trans-Himalayan high-altitude cold desert regions of India is characterized by a rugged topography at an altitude ranging from 2550 to 7742 meters above sea level. It has a vast geographical area of 72976 km² with very little cultivated area of about 13726 hectare. Hydroponic is a soilless cultivation technique which may produce fresh vegetable in areas where environmental stress (cold, heat, dessert etc.) and limited space or on non-arable land is a major constrains for agriculture production. Methodology: The experiment was conducted under open natural ventilated double layer polycarbonate green house in cold desert high altitude conditions of Leh, India. The hydroponic structures were designed for crop production (viz. leafy greens, vegetables, fruits etc) in deep water culture (DWC) and nutrient film technique (NFT) hydroponic techniques and compared them with conventional soil grown system. Nutrient solution for growing vegetables was prepared and standardized. Results: The result obtained has shown that crop yield was significantly higher in hydroponic system as compared to traditional system for all crops. The recorded increase in yield for various crops in hydroponic system compared to soil grown system were: arugula 221%, atriplex 248%, coriander 288%, fenugreek 208%, lettuce 293%, mint 237%, mustard 227%, spinach 294%, cucumber 533%, strawberry 280%, summer squash 229% and tomato 345% which were significantly higher. Hydroponics can be explored to grow vegetables round the year especially for leafy greens. The hydroponic systems may come out as a valuable asset to forward and remote area of trans-Himalayan region for growing fresh vegetables where cultivated land and availability of the water are the limiting factors for crop production.

Soil and water from the trans-Himalayan high-altitude region contain high concentrations of various heavy metals. Vegetables and cereals such as cabbage, spinach, and wheat are most prone to heavy metal accumulation from soil and water which can be toxic for human consumption. It has yet to be studied how consumption of vegetables and cereal with excess heavy metal content can affect human health in high altitude areas. To this end, the objectives of this study are (a) quantify the concentrations of Aluminum (Al), Iron (Fe), Cobalt (Co), Boron (B), Lead (Pb), Arsenic (As), Cadmium (Cd), Selenium (Se), Copper (Cu), and Zinc (Zn) in three crops (wheat, cabbage, and spinach), and (b) evaluate the health risk of excess dietary heavy metal consumption in the local adult population using non-carcinogenic and carcinogenic parameters. A total of 60 samples were analyzed for minerals and potentially toxic elements using Inductively Coupled Plasma-Optical Emission Spectrometry (ICP-OES). Results found that spinach has a high mineral content than wheat and cabbage. The estimated daily intake (EDI) of each metal in each crop was less than the limit of permissible value. The hazard index (HI) of three plant species, and target hazard quotient (THQ) were less than the threshold level (< 1). The carcinogenic risk (CR) value in all the crops was less than the unacceptable risk level (1 × 10⁻⁴). These findings suggest that consumption of wheat, spinach, and cabbage does not have any significant effect on human health due to presence of elevated heavy metals at this high altitude region. Graphical abstract .

The present study evaluated the growth response, yield and nutritional quality of lettuce and spinach grown in different hydroponic systems viz. circulated nutrient film technique (NFT) system and noncirculated system and compares them with conventional open field condition. Lettuce and spinach both exhibited significant improvement in leaf area, fresh weight and yield in NFT system of hydroponics compared to open field condition. However, plant height, root length and number of leaves per plant did not differ significantly among the treatments. There was 169 and 107% higher lettuce yield in NFT and non-circulating system, respectively, whereas the corresponding increase in spinach was 190 and 124%. Significantly higher content of nitrate, phosphorus and sulphur was observed in hydroponically grown lettuce and spinach, especially in NFT system. Higher soluble sugar content in hydroponic spinach as well as in lettuce indicated better quality produce in hydroponic system which affects the sweetness and crispness of leafy vegetables. Overall, from the study it can be said that NFT system of hydroponics is performing better than other growing systems for rapid harvesting, higher productivity and quality produce of leafy vegetables. Since NFT system requires small space, this system may be promoted in urban areas of India as an alternative to conventional farming.

Currently hydroponic cultivation is gaining popularity all over the world because of efficient resources management and quality food production. Soil based agriculture is now facing various challenges such as urbanization, natural disaster, climate change, indiscriminate use of chemicals and pesticides which is depleting the land fertility. In this article various hydroponic structures viz. wick, ebb and flow, drip, deep water culture and Nutrient Film Technique (NFT) system; their operations; benefits and limitations; performance of different crops like tomato, cucumber, pepper and leafy greens and water conservation by this technique have been discussed. Several benefits of this technique are less growing time of crops than conventional growing; round the year production; minimal disease and pest incidence and weeding, spraying, watering etc can be eliminated. Commercially NFT technique has been used throughout the world for successful production of leafy as well as other vegetables with 70 to 90% savings of water. Leading countries in hydroponic technology are Netherland, Australia, France, England, Israel, Canada and USA. For successful implementation of commercial hydroponic technology, it is important to develop low cost techniques which are easy to operate and maintain; requires less labour and lower overall setup and operational cost.

Most of the potential bioprospecting is currently related to the study of the extremophiles and their potential use in industrial processes. Recently microbial cellulases find applications in various industries and constitute a major group of industrial enzymes. Considerable amount of work has been done on microbial cellulases, especially with resurgence of interest in biomass ethanol production employing cellulases and use of cellulases in textile and paper industry. Most efficient method of lignocellulosic biomass hydrolysis is through enzymatic saccharification using cellulases. Significant information has also been gained about the physiology of thermophilic cellulases producers and process development for enzyme production and biomass saccharification. The review discusses the current knowledge on cellulase producing thermophilic microorganisms, their physiological adaptations and control of cellulase gene expression. It discusses the industrial applications of thermophilic cellulases, their cost of production and challenges in cellulase research especially in the area of improving process economics of enzyme production.