Doses de potássio por gotejamento no estado nutricional do maracujazeiro

Abstract

RESUMOO objetivo deste trabalho foi avaliar o efeito de doses de potássio aplicadas via fertigação por gotejamento, sobre os teores de nutrientes, no solo e na solução do solo e nas folhas do maracujazeiro amarelo, na região semiárida do Piauí. O experimento foi realizado na área do Projeto Piloto de Fruticultura Irrigada da CODEVASF, no município de Santa Rosa do Piauí (06° 47´ 56´´S, 42° 17´17´´ W e altitude de 187 m). Utilizou-se o delineamento experimental de bloco ao acaso com cinco tratamentos e quatro repetições. ). The nutritional status of the plants was evaluated and the nutrient concentration in the soil profile and in the soil solution in the layers of 0.0-0.20 and 0.20-0.40 m were determined. The increase of potassium doses applied to the soil through irrigation water increased the potassium concentration and sodium in the soil. The potassium doses caused also significant increases of K in the leaves of yellow passion fruit and increased the plant nutritional state above the optimum level. The potassium concentration in the soil solution varied with plant growth until 132 days after transplant, and remained relatively stable thereafter.

Nutritional status of yellow passion fruit submitted to nitrogen sources by fertigation

“…Whether compared the magnesium contents found in the present study with those recorded by other authors, it is possible to identify that the range 1.3-1.45 g kg -1 is inferior to the interval 2.62-3.08 g kg -1 reported by Freire et al (2013) and to the average of 1.5 g kg -1 registered by Silva Júnior et al 2013. Moraes et al (2011) presented results that were also superior to the range of leaf Mg presented in this study, with an average range 2.55-3.55 g kg -1 . On the other hand, Malavolta et al (1997) consider the Mg range 3-4 g kg -1 as optimal for yellow passion fruit, therefore higher than the values found in this study.…”

Growth and Nutritional Status of Passiflora edulis f. Flavicarpa, With the Application of Organic Compound in Amazonian Soil

“…Freire et al (2013) observed potassium values varying from 17.5 g kg -1 among plants in the saline water treatment, without biofertilizer and without soil cover and 25.8 g kg -1 DM in plants treated with non-saline water, with biofertilizer and mulch. Moraes et al (2011) report that potassium is required in large quantities by passion fruit, a fact also observed in this work. According to Freitas et al (2011) the deficiency of this nutrient causes delay in flowering, reduction in fruit size and leaf area, consequently affecting photosynthesis and solids content in fruits, leaf fall and floral buds.…”

Macronutrient Concentration and Content in Passion Fruit Leaves Under Sampling Methods and N-K Fertilization Rates

“…These results were brought about by the high exchangeable K concentration in the soil of the experimental area (156 mg dm -3 in the 0-20 cm depth layer). Various studies have reported a positive effect on K uptake after K fertilization (SOUSA et al, 2008;MORAES et al, 2011;ALMEIDA, 2012). Nevertheless, an increase in K leaf concentrations after K fertilization does not necessarily imply an increase in yield.…”

“…Nevertheless, the mean P concentration obtained in the standard leaf of the cultivars was considered adequate, according to Moraes et al (2011) and Bataglia and Santos (2001). The latter authors state that the sufficiency range for P in the standard leaf is 0.15-0.25 dag kg -1 and in the adjacent leaf is 0.13-0.21 dag kg -1 .…”