Physiological indexes of custard apple as a function of nitrogen fertilization and humic substances

Abstract

Custard apple (Annona squamosa L.) is native to tropical America and it occurs spontaneously in the Brazilian northeast region, where it is exploited mainly at subsistence level owing to lack of adequate management and selected genetic material. In this study, we aimed to evaluate the physiological characteristics of custard apple as a function of nitrogen fertilization and application of humic substances in the municipality of Bom Jesus, Piaui state, Brazil. We adopted a randomized block experimental design with treatments arranged in a 4 × 2 factorial scheme, referring to four doses of nitrogen and the presence and absence of humic substances (Humitec ®). The following variables were evaluated: leaf area index (LAI), chlorophyll (A, B, and Total), and photosynthetic active radiation (PAR). The maximum agronomic efficiency for intercepted photosynthetically active radiation was registered under fertilization with 174.70 g/plant of N. RESUMO: A pinheira (Annona squamosa L.) é originária da América tropical, ocorrendo espontaneamente no Nordeste brasileiro, onde é explorada principalmente em nível de subsistência, pela falta de manejo adequado e material genético selecionado. O objetivo do presente trabalho foi avaliar características fisiológicas da pinheira em função de adubação nitrogenada e substâncias húmicas, em Bom Jesus-PI. Adotou-se o delineamento em blocos casualizados com tratamentos distribuídos em esquema fatorial 4 × 2, referentes às quatro doses de nitrogênio e a presença e ausência de substancias húmicas (Humitec ®). Foram avaliadas as seguintes variáveis: índice de área foliar (IAF), clorofila (A, B e Total) e radiação fotossinteticamente ativa (RFA). A máxima eficiência agronômica para radiação fotossinteticamente ativa interceptada é obtida com a dose de 174,70 g/planta de N. Physiological indexes of custard apple as a function of nitrogen fertilization and humic substances Índices fisiológicos da pinheira em função de adubação nitrogenada e substâncias húmicas

Effect of humic substances and nitrogen fertilization on yellow passion fruit cultivation in the Brazilian semiarid region

“…Due to the beneficial effects of HS to soils and plants, it is possible to find in the scientific literature, some studies aiming to increase the efficiency of nutrients absorption, particularly for N, through the association of N fertilizing with HS for important commercial fruit crops such as grape (Ferrara and Brunetti, 2008), pineapple (Baldotto et al, 2009), custard apple (Cavalcante et al, 2012(Cavalcante et al, , 2014 and guava (Nunes et al, 2014), although for yellow passion fruit information are still scarce. A study on the effect of HS on fruit quality of yellow passion fruit was made by Silva et al (2015).…”

Qualidade do maracujá amarelo fertirrigado com nitrogênio e substâncias húmicas

“…Os nutrientes devem ser aplicados em níveis compatíveis com as exigências da planta e com a forma de adubação utilizada, destacando-se que a aplicação via água de irrigação, fertirrigação, é atualmente de comprovada eficácia (Borges et al, 2006). (Loss et al, 2015) e, consequentemente, no crescimento radicular das plantas, aumento na absorção de nutrientes e a biossíntese de clorofilas (Ferrara & Brunetti, 2008;Baldotto et al, 2009;Cavalcante et al, 2012b;Cavalcante et al, 2014). 10,0 Silte( g kg -1 ) 277,30 (Gomes et al, 2006).…”

New Insights into MdSPS4-Mediated Sucrose Accumulation under Different Nitrogen Levels Revealed by Physiological and Transcriptomic Analysis

“…Previous studies have focused on the effects of nitrogen fertilization on apple physiology [27][28][29], whereas the reports on the molecular mechanisms of nitrogen regulating sugar metabolism in apple are not characterized. Here, RNA-Seq transcriptome analysis has been conducted to characterize the dynamic responses of different nitrogen levels toward apple fruit.…”