More crops worldwide are lost to drought than any other stressor; drought is especially harmful to crops like coffee that require water for essential stages of their growth and development. Major droughts have risen in frequency in coffee heavyweight Brazil in recent years (2002, 2005, 2014, 2015), which not only impact indivdual farmer livelihoods, but can move the entire global coffee market.
Unfotunately, droughts are expected to increase in number and severity this century in many places, but especially in those that are already hot and dry. Most coffee farmers rely on rain to irrigate their fields and are in danger of losing their trees during extreme droughts. Numerous recent studies have shown that drought can lead to crop loss so severe that it causes the abandonment of farms and has contributed to the global spike in human migration.
By understanding how coffee plants respond to water shortage, it will be possible to develop or select new varieties that can better withstand the drought and extreme rainy conditions predicted to become normal over the next 50 years.
Because it is much more feasible for a farmer to adopt drought-tolerant plants than to install expensive irrigation systems, drought tolerance is one of the bedrock approaches of climate smart agriculture.
To this end, understanding the physiological and molecular impact of heat on the growth and development of coffee plants, and the identification and characterization of heat-tolerant genotypes is essential to coffee breeding programs. This project evaluates the physiological responses of 11 different C. arabica coffees to heat stress while they are seedlings in both field and growth chamber conditions, looking at parameters like carbon assimilation rate, stomatal conductance, and transpiration rate as well as growth aspects (plant height, total shoot length, plant weight) of heat sensitive and tolerant coffee cultivars. The project also characterizes the expression of heat-related genes in order to identify the key genes for heat tolerance. Information regarding disease resistance, yield, vigor and cup quality of the coffees is also being evaluated.
The project could lead to the identification of heat-tolerant coffees that could enter commercial production in coming years. But it will also provide essential information about the underlying mechanisms that allow a plant to tolerate drought, which breeders can use for the development of new climate-smart coffees.
The development of coffee cultivars tolerant to heat stress, as well as the development of technologies that help plants tolerate prolonged periods of high temperatures will be essential to maintaining global coffee production in the 21st century, and may avert disaster for individual farmers in drought-pr