Atmospheric precipitation is the major input to the soil water balance. Its amount, intensity, and temporal distribution have an indubitable influence on soil moisture. The aim of the study (conducted in the years 2010–2013) was to evaluate soil water balance in an apple orchard as determined by daily rainfall. The amount and intensity of rainfall and daily evapotranspiration were measured using an automatic weather station. Changes in soil water content was carried out using capacitance probes placed at a depth of 20, 40 and 60 cm. The most common were single events of rainfall of up to 0.2 mm, while 1.3–3.6 mm rains delivered the greatest amount of water. A significant correlation was found between the amount of daily rainfall and changes in water content of individual soil layers. The 15–45 cm and 15–65 cm layers accumulated the greatest amount of high rainfall. The study showed a significant influence of the initial soil moisture on changes in the water content of the analysed layers of the soil profile. The lower its initial moisture content was, the more rainwater it was able to accumulate.

The aim of the research was to evaluate effects of different rootstocks and management practices to counteracting replant disease in an apple orchard. The experiment was conducted in the Experimental Orchard of the National Institute of Horticultural Research in Dąbrowice, Poland, in 2014–2020. Apple trees of the cultivar ‘Ligolina’ were planted in autumn of 2013 at spacing of 3.8 × 1.4 m in the rows of an apple orchard that had been grubbed up in spring. The following experimental setups were used: (i) two types of rootstocks of different growth vigour (M.9, P14); (ii) replacement of soil in rows of trees with virgin soil; (iii) fertigation with ammonium phosphate; (iv) control (cultivation in the exhausted soil). Replantation significantly limited the growth of apple trees by reducing the cross- sectional area of the tree trunk, and the number and length of annual shoots. Fruit yields of apple trees grown on the replantation site were significantly lower than those of the trees grown in virgin soil. The use of ammonium phosphate fertigation had a positive effect on the growth and yield on the replantation site, especially when it was combined with the use of a stronger-growing rootstock (P14). The most effective environmentally friendly method of eliminating the apple replant disease is the replacement of the exhausted soil with virgin soil, i.e. soil that has not been used for growing fruit trees before.

The aim of this research was to prepare the basis for the certification of the apple orchard protection program by determining disappearance models for active ingredients (AIs) of plant protection products (PPPs) in fruits. Field trials were carried out in a conventional apple orchard protected with PPPs in accordance with the currently adopted program. Residues of their AIs were determined using Agilent GC-MS/MS 7000D and LC-MS/MS 6470 QQQ, and their decreases were expressed by the exponential formula: R _t = R ₀ × ^{e–k × t}. Of all the AIs found in mature fruits, captan disappeared at the fastest rate [t _(1/2) in the range of 9 to 13 days], followed by fluopyram [t _(1/2) = 13 days], tebuconazole [t _(1/2) = 14 days] and carbendazim [t _(1/2) in the range of 24 to 32 days]. With the exception of dithiocarbamates and some fungicides (e.g., Captan 80 WDG) based on captan and methyl thiophanate, other insecticides and fungicides currently recommended can be used up to 3 months before harvest practically with virtually no restrictions. From July 15 to August 15, the chemicals effective at application rates not exceeding 0.3 kg of AI per ha should be used. To protect apples against storage diseases, PPPs that are effective at a dose ≤ 0.1 kg AI per ha (e.g., certain triazoles or strobilurins) and applied not later than 1 month before harvest, should be used.