Drought can be referred to as a meteorological period without significant rainfall and it is one of such major abiotic stresses that contributes to a huge reduction in crop yield throughout the world. Plant shows a broad range of physiological, morphological, and biochemical changes such as reduced photosynthetic accumulation, altered gene expression, etc. Under the drought stress which ultimately causes reduced growth as well as poor grain yield. Drought stressconditions trigger production of ROS, which disrupts the dynamic balance between ROS production and ROS scavenging systems and its accumulation depends on the intensity as well as duration of water stress, and it varies among species. A plant species that has a better inherited genetic response allowing it to rapidly deploy its antioxidant enzymatic and non-enzymatic defense system, can tolerate drought better than a plant species with a poor antioxidant defense system. Furthermore, enzyme and protein encoding drought specific genes have the ability to enhance drought tolerance. These two enzymatic and genetic engineering strategies are unique and vital tools, which can be used to help alleviate the world’s future problems related to energy, food, and environmental stresses, particularly drought. This chapter attempts to discuss developments in understanding effects of drought stress and underlying mechanisms in plants for its alleviation.
Part of the book: Drought
The application of remote sensing in quantifying the crop health status is trending. Sensors can serve as early warning systems for countering climatic or biological aberrations before having negative impacts on crop yield. Remote sensing applications have been playing a significant role in agriculture sector for evaluating plant health, yield and crop loss (%) estimation, irrigation management, identification of crop stress, weed and pest detection, weather forecasting, gathering crop phenological informations etc. Forecast of crop yields by using remote sensing inputs in conjunction with crop simulation models is getting popular day by day for its potential benefits. Remote sensing reduces the amount of field data collection and improves the precision of the estimates. Crop stress caused by biotic and abiotic factors can be monitored and quantified with remote sensing. Monitoring of vegetation cover for acreage estimation, mapping and monitoring drought condition and maintenance of vegetation health, assessment of crop condition under stress prone environment, checking of nutrient and moisture status of field, measurement of crop evapotranspiration, weed management through precision agriculture, gathering and transferring predictions of atmospheric dynamics through different observational satellites are the major agricultural applications of remote sensing technologies. Normalized difference vegetation index (NDVI), vegetation condition index (VCI), leaf area index (LAI), and General Yield Unified Reference Index (GYURI) are some of the indices which have been used for mapping and monitoring drought and assessing vegetation health and productivity. Remote sensing with other advanced technologies like geographical information systems (GIS) are playing a massive role in assessment and management of several agricultural activities. State or district level information systems based on available remote sensing information are required to be utilized efficiently for improving the economy coming from agriculture.
Part of the book: Arid Environment