Search

The recent surge in interest in fruit growing without the use of agrochemicals in order to safeguard environmental and human health has led to increased awareness of organic fruit production (OFP). Despite the widespread use of the method, there is little information on its nutritional aspects, especially in Hungary. Therefore, the aim of this three-year study was to investigate the nutrient status in an organic apple management system and the impact of nutrient applications on nutrient uptake and on the environment. The research was undertaken at the orchard Fruit Research Station of the University of Debrecen in Debrecen-Pallag, Hungary, during 2009-2011. Three cultivars (’Reanda’, ’Rewena’, and ’Retina’) were selected for the study. In the plantation, only organic manure was applied (stable manure, 30 t ha-1 in 2007). The effect of organic methods was monitored by soil and leaf analyses, as well as field observations. Leaf analysis results indicated significantly lower N, K, Mn, Cu and Zn content in cultivar ‘Retina’ than in ‘Reanda’ and ‘Rewena’. Results suggested that mobility and availability were unbalanced and obstructed, especially in the case of Ca. The study also demonstrated that the lower nutrient content of soil and also the generally poorer uptake of Ca and Zn in organic apple orchards resulted in higher production risks as compared with conventional or integrated ones. We conclude that a more balanced and more efficient nutrient supply system is needed for organic farms in order to achieve good quality and profitable yield.

A field experiment was conducted in an integrated apple orchard (Malus domestica Borkh.) established on a lowland chernozem soil in East-Hungary, to investigate if flower analysis could be used to diagnose the nutritional status of the trees. In April 2008, during full bloom, flowers and leaves were collected. Leaves were collected again in August, at the standard sampling time from the same trees. The content of nitrogen, phosphorous, potassium, calcium magnesium and boron were measured in flowers and in leaves. Correlation analyses were carried out to establish the relation s between nutrient contents in same and different plant part s. In flowers the following ratio was found between nutrients: N:P: K:Ca:Mg:B -10: l.35:7: 1.7: I :0,02. From result s it was evident that flower as organ contain significant and comparable amount of nutrients like as leaf. The N, K and Ca content were higher in leaves than in flowers at full bloom. The opposite was true for B. The P and Mg content of flower were quite equal with leaf P and Mg at full bloom . All examined nutrients were significantly affected by cultivars both in flowers and leaves. Significant correlation, was found between flower P and leaf P, flower B and leaf B (P=O.O 1) and flower K and leaf K at blooming time (P=0.05). Significant, but weaker correlation was also found between flower K and leaf K and between flower Mg and leaf Mg al JOO days after full bloom (P=0.05). Moreover, strong, but negative correlation was observed between flower B and leaf B at 100 clays after full bloom (P=O.O 1). Within flowers, the strongest positive correlation was found between Mg and B content (P=O.O 1). Strong positive correlations were also recognised between flower K and flower N, Ca and Mg and between N and Ca in the flowers (P=0.01). The strongest correlation was found between K and P in leaves at full bloom (P=O.O 1 ). Strong significant correlation was observed between N and B in the leaves collected at standard sampling time (100 DAFB) (P=0.01). Strong, but negative correlations were found bet ween leaf Mg and leaf P, K and between leaf N and leaf P at 100 days after full bloom (P=O.O 1).

The year of 2007 was critical for fruit growers in the region of Easter-Hungary. Several orchards were suffered frost damages. Significant frost damage was also happened in the orchard of Tedej Rt., which caused total fruit failure in the orchard. Our study was conducted in the integrated apple orchard (Malus domestics Borkh.) established on a lowland chemozem soil in East-Hungary, to investigate how frost changes the mineral content of different apple species. Leaf samples were collected 100 days after full bloom both in 2006 and 2007. The concentrations of nitrogen, phosphorous, potassium, calcium and magnesium were measured in leaves. The absence of fruits caused a smaller accumulation of nitrogen and magnesium in leaves. Falling down of flowers and fruit sets hindered the translocation of the uptaken phosphorous, potassium and calcium towards fruit sets. Due to fruit failure the vegetative processes became dominant. Leaves larger amount of phosphorous, potassium and calcium stored. Besides the absolute element content, the ratio of the different elements was also determined. Majority of calculated ratios were removed from optimal values due to frost. Both absolute content of nutrients and their ratios pointed out that the frost damage significantly affected the uptake of nutrients and their storing processes.