Wheat is a globally important crop used as a main staple food in various countries of the world. The current study was conducted with the objective to evaluate the effect of a high temperature (HT) on osmolytes (starch, sucrose, total soluble sugars, total soluble proteins and proline), physiological parameters (Chl-a, Chl-b, photosynthesis rate, transpiration rate and stomatal conductance), antioxidant enzymes (superoxide dismutase, catalase and peroxidase) and agronomic traits (flag leaf area, spike length, and thousand grain weight) during the grain filling and anthesis stages of wheat cultivars (Fakhr-e-Bhakar, Raj-3765, Jimai-22 and Bayraktar-2000) collected from different regions of the world. Separate experiments for both stages were conducted in a glasshouse and treated with two different temperature regimes, i.e., optimum (OT) (24 °C day; 14 °C night) and high temperature (HT) (32 °C day; 22 °C night) in RCBD for two weeks. The data for osmolytes, antioxidant enzymes and physiological contents were collected at days 3, 5, 7, 9 and 13 after the start of plant stress, while the agronomic traits were collected at maturity. The data obtained were subjected to a statistical analysis using the statistix8.1 and R-program. HT stress significantly reduced all the traits except for the membrane damage, transpiration rate, proline and total soluble sugars, whose values increased considerably in the genotype Bayraktar-2000. However, under both regimes of temperature Fakhr-e-Bhakkar showed a high tolerance against HT stress, as revealed by physiological, biochemical and agronomic evaluations. Moreover, correlation, PCA and heat map analyses indicated that all types of traits are significantly interconnected in determining the crop potential to sustain its growth under HT stress.

Background: There is an increased need for intercropping practice in drylands to increase land-use efficiency. Canopy cover is a great tool to assess agricultural yield, as it is an indicator of plant health and productivity. Methods: The smartphone-based application Canopeo was used to measure the canopy cover (CC) of Clitoria under mixed intercropping with Leucaena and with four (4) fertilization levels (Control, 200 kg, 300 kg and 400 kg of NPK). Forage yield and (CC) were measured during six (6) consecutive harvests. Moreover, forage quality (NPK and protein) was analyzed. Result: The results revealed a high positive correlation between (CC) with crop yield and quality. Also, the application of fertilizers produced higher (CC) associated with higher yield and forage quality. The relatively low correlation of (CC) with yield in intercropping may be due to the high competition of the Leucaena tree. However, the whole intercropping system was positive (with an LER of 2.4), indicating better land-use efficiency. The results concluded that intercropping in drylands would result in better land use. While the application of NPK fertilizers will increase crop (CC), which in turn will reflect in higher forage yield and quality.

Successful afforestation in arid lands requires rapid, uniform seed germination and good quality seedlings. Seed priming is a pre-treatment of seeds to improve germination and produce seedlings that withstand changing environmental conditions. Therefore, the present study aimed to test the effects of seed priming on Vachellia tortilis seed germination, nursery seedlings quality and the response of produced seedlings to imposed drought stress. Seed samples of V. tortilis were primed in three concentrations of osmo-priming solutions (polyethylene glycol (PEG-6000)) and three concentrations of hormonal priming solutions (Gibberellic acid (GA3)). Then, the effects were monitored during seed germination, nursery seedling development, and in the greenhouse under three successive cycles of drying and rewatering treatments. During germination, seed priming resulted in a higher total germination percentage (TGP), accelerated uniform germination (higher germination index (GI) and lower mean germination time (MGT)), and increased seedling vigour index (SVI). The recorded improvement in germination was associated with stimulation of antioxidant enzymes (peroxidase (POD) and polyphenol oxidase (PPO)) and hydrolytic enzymes (Polygalacturonase (PG) and α-amylase) activities in primed germinated seeds. While in the nursery, priming significantly improved the quality traits of seedlings, including root collar diameter, shoot-to-root ratio, sturdiness quotient, and Dickson’s quality index. GA3-300ppm, GA3-200ppm, and PEG-10% treatments resulted in increases in total dry weight of 160%, 121%, and 64%, respectively. The high-quality seedlings produced resulted in better growth and survival under imposed drought stress in the greenhouse. The findings concluded that seed priming is crucial for enhancing the germination and quality of V. tortilis seedlings.