“…plant breeding to obtain drought-tolerant cultivars is a strategic alternative, as it increases the resilience of crops…”
Edgard Henrique Costa Silva is an undergraduate and postgraduate professor of agronomy at the Universidade do Oeste Paulista – Unoeste.
Silva is an agronomist from the Federal University of Tocantins and has an M.Sc. and a Ph.D. in agronomy from the State University of São Paulo.
The scenario is unsettling. On the one hand, there is an increase in demand for food; on the other hand, there is a growing need to farm and harvest food with less socio-environmental impact, in increasingly unstable climatic conditions.
Life depends on water, which is involved in the most varied physiological processes of plants and, when it is at levels below ideal, triggers adaptation reactions: plants go from a growing situation to a survival situation, which is problematic. Lack of water is also commonly associated with high temperatures, which characterizes another important stress for plants. The “new agriculture” needs to keep this in mind, as the stresses caused by lack of water and high temperatures have reduced agricultural yields.
Strategies against water deficit
Several strategies can be adopted to mitigate the effects of water deficit. One of them is irrigation, although this is a technology accessible only to a limited number of farmers and regions. Artificial water supply can significantly contribute to maintaining yields when facing unstable climatic situations. Focusing on the growing of the plant root system, with the objective of exploring deeper layers of the soil profile, can also be interesting to mitigate water stress. Other strategies are: using quality seeds, adopting sustainable soil management, using bioinputs that promote drought tolerance, etc.
“Producing more with less water is a skill that agriculture will have to develop or improve”
Furthermore, plant breeding to obtain drought-tolerant cultivars is a strategic alternative, as it increases the resilience of crops without involving significant additional costs, as the technology would be “built-in” in the propagation material. It is known that some genotypes develop morphological and/or physiological mechanisms that allow them to tolerate, up to certain levels, the lack of water. There are also varieties that require less water to cultivate or that are capable of recovering after a period of drought. For genetic improvement, it is essential to identify these genotypes that are drought tolerant or more efficient in water usage so that they can be incorporated into a program with well-defined objectives.
Even so, although drought tolerance is an important attribute in modern cultivars, the varieties developed must also present a competitive agronomic performance. It is expected that the new cultivars will reach the same yields or more (and with the same quality) as those that already have adequate water conditions in the soil.
Harvesting more food with less water is a skill that agriculture will have to develop or improve. Obtaining drought-tolerant cultivars has a strong impact on food security, in addition to being directly related to the United Nations Sustainable Development Goals (SDGs) number 2 (zero hunger and sustainable agriculture), 6 (drinking water and sanitation), and 12 (responsible consumption and production).