**1. Introduction**

Global climate change along with abiotic stresses are one of the major constraints limiting factors to crop productivity that influences various agronomic characteristics, such as biomass and other growth traits, phenology, and yield-contributing traits, of various crops. Depletion of water resources, irregular rainfall pattern, impermanent periods of low water availability, moisture-holding capacity of the

soil, water losses through evapotranspiration and poor groundwater quality pushing agriculture closer to the water scarcity situations. Generally, the damage to crop plants due drought is unpredictable, but plants experience drought when either the water supply to the roots is limited or the loss of water through transpiration is very high. Severe droughts cause a substantial decline in crop yields through negative impacts on plant growth, physiology, and reproduction. The plant response to drought varies from species to species and cultivars, phenological stages of the plant, and the duration of plant exposure to the stress. Under drought, along with nutrient and water relations, vital physiological traits viz. chlorophyll content, photosynthesis, stomatal conductance, chlorophyll fluorescence, assimilate partitioning, canopy temperature depression, membrane stability, impaired radiation use efficiency and reduced absorption of photosynthetically active radiations were seriously disrupted. At the same time, several biochemical and metabolic processes contributing to general growth and development were constrained along with the production of reactive oxygen species (ROS) that negatively affect cellular homeostasis, expression of genes, synthesis of hormones. Sugarcane, a C4 plant, with a long life cycle is highly sensitive to water deficit and divided into four major phenophases, i.e., germination, formative/tillering, grand growth and maturity. Among these, the formative stage is considered as highly sensitive to drought stress [1, 2] as it required 550 mm of rainfall [3], causing a significant reduction in cane yield up to 50% [4]. Water is the major constituent of cane and approximately 2.97 lakh ha of cane area is prone to the drought that distributed cellular osmotic balance, decreased turgor, inhibited photosynthesis, inhibition of enzyme activities and cellular processes, root architecture and morphology and leading to a reduction in yield [5–7]. In point of these, this book chapter mainly focuses on the importance of physiological, biochemical, molecular traits along with root traits interventions related to drought for better management.
