Water deficit and retranslocation of K in coffee cultivars: a physiological and nutritional approach

• Grant number: 23/10336-8
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: September 01, 2023
• End date: August 31, 2024
• Field of knowledge: Biological Sciences - Botany - Pant Physiology
• Principal Investigator: José Lavres Junior
• Grantee: Guilherme Gramuglia Betta
• Host Institution: Centro de Energia Nuclear na Agricultura (CENA). Universidade de São Paulo (USP). Piracicaba , SP, Brazil

Abstract

The stress caused by the water deficit can compromise the coffee tree's development. A plant strategy to minimize the effects of water deficit is potassium (K) retranslocation via phloem, altering drought resistance mechanisms. The aim of this study is to evaluate the dynamics of K retranslocation in coffee varieties subjected to water deficit conditions, correlating with gas exchange parameters and chlorophyll a fluorescence, leaf water potential (¨w) and water use efficiency (WUE). The experiment will be installed in a greenhouse, using two varieties of coffee. The experiment will be installed in a randomized block design, in a 2 x 2 x 2 factorial scheme, with six replications, the first factor being related to the two coffee varieties, the second factor to the available K contents in the soil and the third factor to the availability of water in the soil. Throughout the experiment, evaluations of gas exchange and leaf water potential (¨w) will be carried out, and at the end of the experiment, the plants will be cut and separated into roots, orthotropic branches, plagiotropic branches and leaves to determine the potassium content in each organ; subsequently, the remobilization of K. Our general hypothesis is that the remobilization of K from reserve organs - such as the stem - to the leaves of the most nutritionally efficient genotype could be an important plant strategy to reduce the effects of water deficit.