Effects of saline water and potassium fertilization on photosynthetic pigments, growth and production of West Indian Cherry

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ABSTRACT

Due to the scarcity of water in the semi-arid region of Northeast Brazil, in both quantitative and qualitative terms, the use of saline water in agriculture should be considered as one alternative for irrigated agriculture. This study therefore aimed to evaluate the photosynthetic pigments, growth and production of West Indian Cherry as a function of irrigation using waters with different salinity levels and potassium (K) fertilization, after grafting. The study was carried out in drainage lysimeters under greenhouse conditions, in a eutrophic Regolithic Neosol with sandy loam texture, in the municipality of Campina Grande, PB. The experiment was set in a randomized block design, to test two levels of irrigation water electrical conductivity - ECw (0.8 and 3.8 dS m^-1) and four K₂O doses - KD (50, 75, 100 and 125% of recommendation), with three replicates. The dose relative to 100% corresponded to 79.2 mg K₂O kg^-1 of soil. Irrigation with high salinity water stimulated the biosynthesis of chlorophyll b and carotenoids, while the chlorophyll a content and the growth of the cherry were reduced markedly in the post-grafting phase. The harmful effects of salinity on the total number of fruit and fresh mass of West Indian Cherry fruit were minimized with potassium fertilization.

Keywords: Malpighia emarginata, potassium, salt stress.

RESUMO

Diante da escassez hídrica, tanto em termos quantitativo como qualitativo, que ocorre no semiárido do Nordeste Brasileiro, o uso de água salina na agricultura deve ser considerado como uma alternativa para a agricultura irrigada. Neste contexto, desenvolveu este trabalho com o objetivo de avaliar os pigmentos fotossintéticos, o crescimento e a produçâo da aceroleira em funçâo da irrigaçâo com águas de diferentes salinidades e adubaçâo potássica, pós-enxertia. O estudo foi conduzido em lisímetros de drenagem em condiçöes de casa de vegetaçâo, no Neossolo Regolítico Eutrófico de textura franco-arenosa, no municipio de Campiña Grande, PB. Usou-se o delineamento de blocos ao acaso, testando-se dois niveis de condutividade elétrica da água de irrigaçao - CEa (0,8 e 3,8 dS m^-1) e quatro doses de potássio - DK (50, 75; 100 e 125% da recomendaçao), com tres repetiçöes. A dose referente a 100% correspondeu 79,2 mg K₂O kg^-1 de solo. A irrigaçao...