Addition of nitrogen had no effect on yield and quality of apples in an high density orchard carrying a dwarf rootstock

Abstract

-The effect of N addition on apple yield and quality may vary according to the tree vigor. Apple trees developed over vigorous rootstocks had shown no response to N application in Brazil. In this study it was evaluated the effect of N addition to the soil on yield and quality of ´Royal Gala´ apples grafted on a dwarf rootstock (M.9). The orchard was planted in 1995 (2,857 trees ha -1 ) on an Oxisol containing 40 g kg -1 of organic matter and pH 6.0. The experiment was carried out from 1998 up to 2005. Treatments consisted of rates of N (0, 50, 100 and 150 kg ha -1 year -1 from 1998 to 2001, and respectively 0, 100, 200 and 300 kg ha -1 afterwards), all broadcasted within the tree row in two equal splits, at bud break and after harvest, as ammonium sulfate. Addition of N to the soil had no effect on fruit yield over the six years regardless of the applied rate. Averaged across treatments and years, fruit yield was 52.3 t ha -1 . Nitrogen in the leaves (average of 24 g kg -1 ) or in the fruits (average of 346 mg kg -1 ) as well as some attributes related to fruit quality (color, firmness, acidity, soluble solids, physiological disorders) were unaffected by N addition. Some plant parameters related to tree vigor, however, grew higher with the increase on N rate. Thus, it is not necessary to apply N to deep Brazilian soils containing high organic matter in order to assure good fruit quality and yield on high-density orchards carrying dwarf rootstocks probably because the N required for tree growth and fruit production is supplied from soil organic matter decay. Index terms: apple yield, M.9 rootstock, fruit quality, nitrogen. A ADIÇÃO DE NITROGÊNIO NÃO AFETOU O RENDIMENTO E A QUALIDADE DE MAÇÃS EM POMAR COM ALTA DENSIDADE E PORTA-ENXERTO ANÃORESUMO -O efeito da adição de N ao solo no rendimento e na qualidade de maçãs pode variar em função do vigor das plantas. Experimentos conduzidos no Brasil com macieiras cultivadas sobre porta-enxertos vigorosos não têm apresentado aumento no rendimento de frutos pela aplicação de N. Este trabalho objetivou avaliar o efeito da aplicação de N no rendimento e na qualidade de frutos de macieira cultivada em alta densidade sobre porta-enxerto anão (M.9). O pomar com a cultivar Royal Gala foi plantado em 1995, na densidade de 2.857 plantas ha -1 , em um Latossolo Bruno com 40 g kg -1 de matéria orgânica e pH 6,0. O experimento foi implantado em 1998 e foi encerrado em 2005. Os tratamentos consistiram da aplicação anual de 0; 50; 100 e 150 kg ha -1 de N de 1998 até 2001 e de, respectivamente, 0; 100; 200 e 300 kg ha -1 de N a partir da safra 2002-2003. Metade de cada dose foi aplicada no início da brotação, e o restante após a colheita, sempre na forma de sulfato de amônio. A aplicação de N ao solo não influenciou no rendimento de frutos em nenhuma das seis safras, independentemente da dose. Na média das doses e dos anos, o rendimento foi de 52,3 t ha -1 . A adição de N também não afetou a concentração de N nas folhas (média de 24 g kg -1 ) e nos frutos (media de 346 mg kg -1...

Fruit quality of ‘Eva’ e ‘Princesa’ apples grown under nitrogen fertigation in semiarid climate

“…This result was also identified in the scientific literature about different apple cultivars (Ernani et al, 2008;Roussos & Gasparatos, 2009;Han et al, 2011;Li-Zhi et al, 2012) and it could be explained by the low nitrogen demand of apple tree whether compared to other fruit species, as Ernani et al (2008) detach.…”

“…This result disagrees of those quoted by Nava et al (2007) who verified that apple size is more affected by the number of fruits per plant in relation to the nitrogen fertilizing provided. However, according to Ernani et al (2008), the nitrogen fertilizing in the first forty-five days after flowering, during cell division phase favors fruit growth and, consequently, fruit width, which probably occurred in this study, since at this time all plants had already received two nitrogen fertigations in their respective doses. A.…”

“…The excess of N, on the other side, also is harmful because it stimulates excessive plant development, with negative effects on bud and fruit quality, especially for color, conservation and incidence of physiological disorders (Ernani et al, 2008).…”

Quality peach produced in fertilizer doses of nitrogen and green pruning

“…It has direct effect on vegetative growth, yield and fruit quality, therefore the setting of the dose is necessary to ensure the best nutritional balance, replacing the exported quantity and maintaining the proportion between vegetative and reproductive growth. In addition to the dose, application times and the managements adopted in the culture can also affect the response of the applied nitrogen (Dolinski et al 2005;Jia et al 2006;Dolinski et al 2007;Brunetto et al 2007;Ernani et al 2008;Cuquel et al 2011;Falguera et al 2012;Olivos et al 2012;Pascual et al 2013;Souza et al 2013).…”

“…The response variations resulting from N increment can be evidenced in the quality of peaches by the change in skin color, with N resulting in an increase in the content of the skin pigments (Olienyk et al 1997), or in reduction (Daane et al 1995;Souza et al 2013), or even in keeping it unaltered (Ernani et al 2008;Falguera et al 2012).…”