Keeping in view the yield losses instigated by heat stress in several crops, we carried out an experiment to explore the curative effect of exogenous applications of proline on the morpho-physiological, biochemical, and water-related attributes of okra genotypes under high-temperature stress (controlled conditions). Four contrasting genotypes C1, C2, C3, and C4 heat tolerant and heat sensitive genotypes were selected from a diverse panel of okra genotypes (n = 100) to examine plant responses to high-temperature stress and exogenous application of proline. Four-week-old seedlings were subjected to heat stress by gradually increasing the temperature of a growth chamber from 28/22 °C to 45/35 °C (day/night) and sprayed with an optimized proline concentration 2.5 mM. The experiment consisted of a factorial arrangement of treatments in a completely randomized design. The results showed that there were maximum increases in shoot length (32.7%), root length (58.9%), and shoot fresh (85.7%). The quantities of leaves per plant were increased by 52.9%, 123.6%, 82.5%, and 62.2% in C1, C2, C3, and C4 after proline application. On the other hand, only root fresh weight decreased in all genotypes after proline application by 23.1%, 20%, 266.7%, and 280.8% (C1, C2, C3, C4). A lower leaf temperature of 27.72 °C, minimum transpiration of 3.29 mmol m⁻² s⁻¹, maximum photosynthesis of 3.91 μmol m⁻² s⁻¹, and a maximum water use efficiency of 1.20 μmol CO₂ mmol H₂O were recorded in the genotypes C2, C1, C3, and C4, respectively. The highest enzymatic activity of superoxide dismutase, peroxidase and catalase were 14.88, 0.31, and 0.15 U mg-protein in C2, C1, and C3, respectively. Maximum leaf proline, glycinebetaine, total free amino acids, and chlorophyll content 3.46 mg g⁻¹, 4.02 mg g⁻¹, 3.46 mg g⁻¹, and 46.89 (in C2), respectively, due to foliar applications of proline. Another important finding was that heat tolerance in okra was highly linked highly linked to genotypes’ genetic potential, having more water use efficiency, enzymatic activities, and physio-biochemical attributes under the foliar applications of proline.

Effect of various combinations of potting substrates was assessed to enhance vegetative growth, plant productivity and mineral composition of Caladium bicolor. Different substrates like leaf compost, farmyard manure, coconut compost, compost and perlite were used in different combinations with silt. Bulbs were sown in pots filled with different combinations of potting substrates, which were arranged under completely randomized design (CRD), with three replications, and totally there were ten treatment combinations. Application of different treatments of growing media either alone or in combinations led to considerable improvement in plant growth characteristics as compared to respective control. However, response differed according to the type of media manipulation. The highest stimulatory effect with maximum plant growth in terms of early sprouting, plant height, leaf area, chlorophyll contents, fresh and dry weights of tubers was observed in plants treated with silt+leaf compost+perlite combination; this combination significantly enhanced plant growth (30−150%) as compared to control. In case of NPK and protein contents, treatment combination of silt+leaf compost+coconut compost was greatly affected which lowered the pH, increased available organic matter and consequently maximized nutrient uptake by the plants. The best selection of conventional organic and inorganic potting media is the key to successful mass propagation of containerized plants. Generally, it could be concluded that application of potting mixes with silt, perlite, leaf composts and coco-based residues is a good cultural practice to improve the crop productivity and provide a better growing environment for plants.