NO 3 – , K + , and chlorophyll index in fertigated grapevines in the semi-arid region of Brazil

Abstract

Evaluating the effects of N and K supply on grapevines (Vitis vinifera L.) and the techniques for nutritional diagnosis is of great importance for fertigation management of this crop. This study evaluated the effects of N and K fertigation on the soluble concentrations of NO 3and K + in the petiole sap and on the leaf chlorophyll index in drip irrigated 'Syrah' grapevine (from 17 June 2013 to 25 Nov 2014). The treatments consisted of five levels of N (0, 15, 30, 60 and 120 kg ha -1 ) and K 2 O (0, 15, 30, 60 and 120 kg ha -1 ), combined in an incomplete 5 2 factorial scheme in 13 combinations and arranged in randomized blocks with four replications. We determined NO 3 and K + concentrations in petiole sap, leaf chlorophyll index, grapevine cluster mass and number per plant, mean grapevine cluster mass, and phenolic composition. High NO 3 concentrations contributed positively to grapevine yield; however, increased K+ concentrations caused a negative response of sap. For 120 kg N ha -1 rate, NO 3 in the sap and chlorophyll index showed higher values at the flowering stage, while high values for K + were observed during the grape-ripening stage.

Intelligent System for Monitoring Water Content and Solute Concentrations in Soil Cultivated with Fertigated Lisianthus

“…Consequently, there is increasing pressure to optimize the management of the water used in irrigation and ensure optimal production and economic returns to avoid salinity and other environmental damages [9,10].…”

Polinômios fracionários e planejamento de Littell e Mott em ensaios de nutrição mineral de plantas

“…Quanto ao número de pontos, o planejamento é composto por t = 1 + 2 k+1 + 2k pontos distintos, ou tratamentos, isto é, t = 13 para k = 2 fatores e t = 23 para k = 3 fatores. Na área de nutrição mineral de plantas, este planejamento vem sendo muito utilizado nas duas últimas décadas por diversos autores como Lavres Junior e Monteiro (2003), Bonfim-Silva, Monteiro e Silva (2007), Silveira e Monteiro (2010), Silveira e Monteiro (2011), Megda e Monteiro (2015), Silva et al (2018), Silva et al (2022), que realizaram diferentes ensaios para estudar a influência de diversos nutrientes, tais como o nitrogênio, potássio, cálcio e enxofre na fixação dos macronutrientes, nas características morfológicas e produtivas, como também, na qualidade da produção.…”