POTASSIUM NUTRITION IN PHYSIOLOGICAL ASPECTS AND IN THE CONTROL OF DOWDYY IN DIFFERENT LETTUCE CULTIVARS

• Grant number: 22/13079-3
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: January 01, 2023
• End date: December 31, 2023
• Field of knowledge: Agronomical Sciences - Agronomy - Crop Science
• Principal Investigator: Renato de Mello Prado
• Grantee: Liniker Pedro Saldanha
• Host Institution: Faculdade de Ciências Agrárias e Veterinárias (FCAV). Universidade Estadual Paulista (UNESP). Campus de Jaboticabal. Jaboticabal , SP, Brazil

Abstract

Lettuce (Lactuca sativa) although being the most consumed vegetable in the world, the incidence of Bremia lactucae (lettuce mildew) greatly reduces the productivity of this vegetable. A sustainable alternative to control this disease would be the combination of the use of more resistant cultivars associated with the optimization of potassium nutrition. However, it is not yet known whether the improvement of potassium nutrition is more effective in susceptible cultivars or with complete or incomplete resistance to downy mildew of lettuce. For this, this research will be carried out to verify the effect of potassium nutrition on the development of Bremia lactucae and its interference in the photosynthetic aspects in lettuce cultivars with susceptibility and with complete and incomplete resistance to the pathogen. Experiments will be carried out at UNESP Campus de Jaboticabal under controlled conditions, with cultivars that present different levels of resistance to the pathogen, Solaris (susceptible), Jade (complete resistance) and Laís (incomplete resistance). The experiments will be arranged in a 2x2 factorial scheme, with absence and presence of the pathogen and absence and presence of K in the nutrient solution (6mmol L-1), arranged in completely randomized blocks with 6 replications. The pathogen will be inoculated into plants using sporangia washed from infested tissues of the host and shaken in deionized water. The analyzes to be carried out in each experiment will be: potassium content, production of dry and wet mass of the plants, quantum efficiency of photosystem II, green color index, chlorophyll and carotenoids content, number of leaves, leaf area and severity of illness.