Boron Nutrition in Coffee Improves Drought Stress Resistance and, Together with Calcium, Improves Long-Term Productivity and Seed Composition

Abstract

Coffee production around the world is under threat due to climate variability and change, and drought stress will increase in many coffee regions; nutrient management practices can enhance the adaptation capacity of coffee production. Considering that coffee is a crop sensitive to boron (B) deficiency, this research investigated how B nutrition improves resistance to drought stress in coffee under controlled conditions as well as how the interaction with calcium (Ca2+) influences productivity, seed composition, and soil fertility during a production cycle of 5 years. Under controlled conditions for seven months, coffee plants were submitted to water stress with and without B nutrition. In the field, the coffee plantation was exposed to two B rates (0.6 and 1.1 kg.ha−1-year−1) with a fixed calcium (Ca2+) rate and a control without Ca2+ and B. After 9 months of growth and seven months of water deficit, under controlled conditions, the application of B significantly (p −1.year−1 yielded 14% more than the control without B and Ca2+. An increase in the B rate to 1.1 kg.ha−1.year−1 with the same Ca2+ rate increased the productivity significantly (p p p < 0.05) inverse correlation between the B content of the green coffee beans and caffeine and unsaturated fatty acids (UFAs), mainly, oleic, linoleic, and linolenic acids, which are considered negative descriptors of the coffee quality.

Keywords

• coffee
• water stress
• caffeine
• fatty acids
• productivity