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The progressive increase in the earth’s temperature due to anthropogenic activities is a major concern for humanity. The ensuing heat stress (HS) severely impacts plant growth, endangering ecosystem quality and world food security. Plant growth, physiological processes and final amount of edible products are affected by HS to an extent that reflects the physical damages, physiological commotions and biochemical alterations incurred at various growth stages. Therefore, a better understanding of plant behaviour in response to HS has pragmatic implications for devising counter-measures, alleviation strategies, and for acknowledging the differences between HS and the companion drought stress. Conventional breeding, biotechnological and molecular approaches are used to develop HS tolerant genotypes in plant species bred for food/feed uses. Recent achievements in the omics techniques result in a better knowledge of the molecular mechanisms involved in HS. However, shrewd management of crop practices is still helpful to improve plant resilience to HS. Suitable sowing time, seed priming, bacterial seed treatment, nutrient and water management, exogenous application of osmo-protectants, and conservation of soil moisture are important tools to improve plant behaviour under the critical HS scenarios determined by climate change and global warming.

Drought stress affects plant growth and development by altering physiological and biochemical processes resulting in reduced crop productivity. Zinc (Zn) is an essential micronutrient that plays fundamental roles in crop resistance against the drought stress by regulating various physiological and molecular mechanisms. Under drought stress, Zn application improves seed germination, plant water relations, cell membrane stability, osmolyte accumulation, stomatal regulation, water use efficiency and photosynthesis, thus resulting in significantly better plant performance. Moreover, Zn interacts with plant hormones, increases the expression of stress proteins and stimulates the antioxidant enzymes for counteracting drought effects. To better appraise the potential benefits arising from optimum Zn nutrition, in the present review we discuss the role of Zn in plants under drought stress. Our aim is to provide a complete, updated picture in order to orientate future research directions on this topic.

Biomass sorghum increasingly constitutes the feedstock for methane production. Optimization of crop management for this use is far from being achieved under warm dry climate. To fill the gap of knowledge, five cultivars of Sorghum bicolor were cross combined with three seeding times (ST) at 20-day intervals from 1st May 2016 and 2017, in a field experiment conducted in Pakistan. Late vs. early seeding determined a 23% loss in dry biomass yield (DBY), but no variation in specific methane yield (SMY). Therefore, methane yield per hectare (MY), their product, staged a 22% loss with late vs. early seeding, reflecting DBY loss. Biometric and compositional changes were shown in late vs. early seeding: smaller plants with lower protein, sugar and fibre content, associated with a hastening in crop development despite non-limiting ambient conditions until maturity. This comprehensive effect explains the yield reductions incurred by late seeding in this and other studies where irrigation could fully compensate lack of precipitation during crop growth. The five cultivars, three of which being dual-purpose genotypes (grain and biomass), and the other two fibre genotypes, staged significant DBY, SMY and MY differences (-28%, -14% and -16%, respectively) between worst and best performing cultivar. Significant seeding time × cultivar interactions indicate a slight advantage across seeding times for dual-purpose vs. fibre genotypes in DBY, whereas in MY none of the two groups clearly prevailed. Results obtained in this experiment complement previous outcomes with cultivars and harvest times, supporting bio-energy growth under warm dry climatic conditions.