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To overcome difficulty in phytopathogenic fungi control during storage of apple fruits, the effect of different storage conditions on the occurrence and development of Fusarium avenaceum and Alternaria alternata infections on apple cultivar “Cripps Pink” was investigated during and after storage. Inhibitory effects of wild oregano essential oil on apple fruit rots caused by F. avenaceum and A. alternata were also tested as possible rot control measure. Artificially inoculated apple fruits were kept in cold storage with normal (NA) and controlled (CA) atmosphere for 95 days and at room temperature only. The obtained results indicated that different storage conditions significantly affect necrosis development on apple fruits caused by F. avenaceum and A. alternata after storage, as well as during shelf life.

The objective of this research was to determine the effects of chemical thinning with α-naphthaleneacetic acid (NAA) and nitrogen (N) fertilization, as well as their interaction in relation to fruit set and physical properties of apple cv. Golden Delicious Reinders®. Nitrogen rates used were 30 and 60 kg•ha −1 N applied at the pink bud stage. NAA for fruit thinning was applied at the rates of 10, 12 and 14 µl•l −1. Fruit set was increased by increasing the amount of N applied while the efficacy of NAA for fruit thinning was not linearly correlated to the concentration of the chemical. The total number of fruits per tree was inconsistently reduced in NAA treatments at 30 and 60 kg•ha −1 N, while total yield was reduced by thinning at 60 kg•ha −1 N, meaning that apple trees are more responsive to NAA application at higher N supply. At sufficient N supply, fruits responded more intensively to thinning with NAA by increasing their growth. Thinning with NAA caused a significant decrease in flesh firmness only in fruits from unfertilized plot.

Fusarium species are increasingly detected as the causal agents of decay of stored apple fruits. Fusarium avenaceum is particularly significant due to its predominant occurrence among Fusarium species in stored apple fruits and its ability to produce mycotoxins. Treatments with 1-methylcyclopropene (1-MCP) and different storage conditions affect the aggressiveness of F. avenaceum and development of fungal-caused decay in stored apple fruits. In this study, apple fruits (cv. 'Granny Smith') were treated with 1-MCP, and artificially inoculated with F. avenaceum. The isolate used for inoculation, originating from apple fruit, was identified based on morphological characteristics and by polymerase chain reaction (PCR) using a species-specific primer pair (FA-ITSF and FA-ITSR) for F. avenaceum. After inoculation, treated and untreated fruits were stored at room temperature and cold-stored under dynamic controlled atmosphere (DCA). Diameters of necrotic lesions were measured after 7, 14 and 21 days of incubation on fruits stored at room temperature, while necrosis diameters on DCA-stored fruits were measured immediately at the end of storage period (143 days), and after 7, 14 and 21 days of additional incubation at room temperature. The results show that treatment with 1-MCP inhibits the development of F. avenaceum on apple fruits during storage under DCA. However, after storage, i.e. during incubation at room temperature, no significant difference between 1-MCP-treated and untreated fruits was observed. On fruits stored at room temperature only, no difference between 1-MCP-treated and untreated fruits was observed. However, 1-MCP-treated fruits stored at room temperature only developed significantly smaller necrosis lesions compared to 1-MCP-treated and DCA stored fruits. It infers that both 1-MCP treatment and DCA storage inhibit fungal decay caused by F. avenaceum on apple fruits. However, the effects do not persist after storage.