No abstract

The aim of our two-year study was to evaluate fruit decay and Monilinia fruit rot in three controlled atmospheres (CA), ultra-low oxygen (ULO) and traditional storage methods on apples for a duration of several months storage period. Four phytopathological treatments were studied under each storage condition: 1) 48 healthy fruit per unit, 2) 48 injured fruit per unit, 3) 47 healthy fruit and 1 brown rotted fruit per unit, and 4) 47 injured fruit and 1 brown rotted fruit per unit. Our results clearly demonstrated that fruit loss during storage is highly influenced by storage conditions and health status of the stored fruits. In the 2005 experiment, the lowest and largest fruit decay occurred under the ULO and traditional storage conditions, respectively (Table 1). The fruit decay was significantly different for the different storage methods. Fruit decay was fully suppressed in ULO storage except in the treatments of injured and injured + 1 brown rotted apple. Under CA and traditional storage conditions, when healthy fruit was stored, fruit decay was significantly lower compared with injured fruit including 1 brown rotted fruits. However, half of the fruit decay was caused by M. fructigena in CA store irrespective to phytopathogenic treatments. In 2006, results were not so consistent on cv. Idared but were not essentially different from the 2005 experiments.

Temporal development of brown rot (Monilinia fructigena) on fruits was analysed in two organic apple orchards on three apple cultivars in Eastern Hungary from 2002 to 2006. The threeparameter logistic function gave the best fit to brown rot over four non-linear growth functions in all cultivars, years and orchards. Depending on location, year and cultivar, disease increased continuously from 6 to 8 weeks before harvest up to harvest, reaching 19-37% of disease incidence. Disease variables of Y f , the final disease incidence; β, relative rate of disease progress; AUDPC S , standardized area under disease progress curve; T 1.5 , the time when disease incidence reaches 1.5% (day), and M, the inflection point were derived from the three-parameter logistic function. The disease variables of Y f , β, and AUDPC S were used in a computer simulation for predicting temporal brown rot development, and the disease variables of T 1.5 , M, and Y f were used to determine threshold values for epidemic intensity. Afterwards these were used to construct a fundamental model for developing a brown rot forecasting and management strategy (BRFMS). The fundamental model contained four parts: i) data insertion and analyses by computer simulation of pathogen submodels, ii) calculation of yield loss threshold levels based on disease incidence, iii) determination of epidemic intensity levels and iv) a decision module with suggestions for disease management practices for each epidemic intensity level. The fundamental model was supplemented with the prediction of occurrence of the first fruit rot symptoms and with the insect injury prediction related to brown rot development in order to complete a BRFMS for organic apple orchards. In a 3-year field evaluation from 2006 to 2008, season-long application of BRFMS treatments reduced the number of sprays against brown rot by 22-33% compared with the treatments of general spray schedules against brown rot.

In a 2‐year study, elder aphid (Aphis sambuci) dynamics over time and berry yield were evaluated in two production systems (integrated and organic) and in two winter pruning treatments (trees pruned to four and eight scaffolds) in two black elderberry orchards in Hungary. In the organic production system, the first aphid colony was observed 1–2 weeks earlier (late‐March) in both years and locations compared to the integrated programme. The number of aphid colonies then increased until mid‐May in both years, reaching a maximum number of aphid colonies of 11.2 on 100 scaffolds in the integrated production system and of 38.9 in the organic programme. Then, the number of colonies decreased and reached a zero value at mid‐June in the integrated production system and 2 weeks later (early July) in the organic one in both years and locations. First autumn aphid colonies were observed in early September in the integrated production system but 2 weeks earlier (late August) in the organic one in both years and locations. The number of aphid colonies between mid‐April and mid‐June indicated a larger increase on trees pruned to eight scaffolds compared to trees pruned to four scaffolds. Both the total number of aphid colonies and the area under the aphid colony curves (AUACC) were significantly lower (P < 0.001) in the integrated treatments compared with organic ones. Across all treatments, both measures were significantly lower (P < 0.05) on trees pruned to four scaffolds compared with trees pruned to eight scaffolds. However, when the effect of pruning on the number of aphid colonies was analysed separately for integrated and organic plots, pruning caused significant differences in aphid colony numbers and AUACC in the organic plots. Berry yield was significantly higher (P < 0.05) in the integrated treatments compared with the organic ones, but pruning showed no significant effect on yield. Overall, pruning to four scaffolds resulted in a lower aphid colony number in the organic production system compared to the integrated one. Thus, winter pruning may be useful as an aphid control strategy in organic elderberry orchards.

In this study, possibilities of environmentally-benign plant protection against blossom and twig blight were summarized for organic stone fruit orchards. Symtomps of Monilinia laxa (Aderh. & Ruhl.) Honey) were described and then cultivar susceptibility to blossom and twig blight was discussed. Several sustainable plant protection methods were selected and discussed in details such as mechanical, agrotechnical, biological, and other non-chemical control possibilities (stone powders, plant extracts and restricted chemical materials).