Growth and production components of West Indian cherry cultivated with saline waters and potassium fertilization/ Crescimento e componentes de producao da aceroleira cultivada com aguas salinas e adubacao potassica

Due to water limitations in terms of both quantity and quality in the semi-arid region of northeastern Brazil, the use of waters with high concentrations of salts become necessary in irrigated agriculture. Thus, this study aimed to evaluate the growth and production of grafted West Indian cherry under saline water irrigation and potassium fertilization. The experiment was carried out in drainage lysimeters under protected environment conditions, using a Regolithic Neosol with sandy loam texture. Treatments resulted from the combination of two levels of electrical conductivity--ECw (0.8 and 3.8 dS [m.sup.-1]) of irrigation water and four doses of potassium (50, 75, 100 and 125% of the recommendation of Musser), arranged in a randomized block design, with three replicates. Irrigation water salinity of 3.8 dS [m.sup.-1] markedly inhibited the growth in stem diameter and mean fruit weight of West Indian cherry. Potassium fertilization mitigated the deleterious effects of salt stress on the relative growth in stem diameter of the rootstock, total number of fruits and total fresh mass of fruits of West Indian cherry, with highest values in plants irrigated with water of lowest level of salinity associated with the highest dose of [K.sub.2]O. Key words: Malpighia emarginata, salt stress, osmoregulation Devido as limitacoes hidricas tanto em termos quantitativos como qualitativos na regiao semiarida do Nordeste brasileiro, o uso de aguas com elevadas concentracoes de sais torna-se necessario para agricultura irrigada. Deste modo, objetivou-se com este trabalho, avaliar o crescimento e a producao da aceroleira enxertada sob irrigacao com agua salina e adubacao potassica. O experimento foi conduzido em lisimetros de drenagem sob condicoes de ambiente protegido, utilizando-se um Neossolo Regolitico de textura franco-arenosa. Os tratamentos resultaram da combinacao entre dois niveis de condutividade eletrica da agua de irrigacao--CEa (0,8 e 3,8 dS [m.sup.-1]) e quatro doses de potassio (50, 75, 100 e 125% da recomendacao de Musser), dispostos no delineamento de blocos casualizados, com tres repeticoes. A salinidade da agua de irrigacao de 3,8 dS [m.sup.-1] inibiu acentuadamente o crescimento em diametro caulinar e o peso medio de frutos da aceroleira. A adubacao potassica mitigou os efeitos deleterios do estresse salino sobre o crescimento relativo do diametro caulinar do porta-enxerto, numero total de frutos e a massa fresca total de frutos de aceroleira, com os maio