Fertilizers effect on yield and apples' fruits quality on leached chernozem

In the Central Ciscaucasia, including North Ossetia-Alania, in recent years, new fast-growing, immune, highly-productive varieties of apple trees of an intensive type have become widespread. The effectiveness of the use of fertilizers for growing new varieties of apple trees has not been studied. In this regard, a study was made of the responsiveness of three apple varieties to mineral and organic fertilizers (manure) and their combination. The apple orchard was studied on leached chernozem, covered by pebble from a depth of 50 cm and having a wash water regime. As a result of research, it was found that the use of mineral and organic fertilizers in this type of garden is an effective agrotechnological technique. The use of mineral and organic fertilizers increases the productivity of the fruits of the varieties Aidored, Florina and Stark-Nart by 20.0-130.4 % compared with non-fertilized control. The Florina variety was the most fruitful. Significantly less productive is the Aydored variety and especially Stark-Nart. In the control, respectively, Florin's variety - 22.0 t/ha, Aidored - 12.5 t/ha and Stark-Nart - 11.5 t/ha. Of the fertilized options, the best in all three varieties was N150P150K150: productivity was 40.5, 28.5, and 26.5 t/ha, respectively. The fertilizers under study affected the quality indicators of fruits in different ways. For Aidored variety, there is a tendency toward a decrease in the dry matter content and fruit acidity as the level of mineral nutrition increases, while the content of sugar, vitamin C, P-active substances, sugar-acid index and pectin substances increase. According to these indicators, N150P150K150 stands out as the best of the fertilized options. In relation to the Florin and Stark-Nart varieties, it should be pointed out that the patterns of action of fertilizers on the quality of fruits noted for the Aidored variety are identical, although the quantitative indicators are not the same. In particular, it can be noted that in terms of sugar content, Stark-Nart is inferior to two other varieties. And in terms of acidity, Florin is an advantage (the fruits are less acidic). Vitamin C is more in the fruits of the Aidored variety (9.3 mg / 100 g in the control), Florin is in second place, and Stark-Nart is in third (in the control of 8.0 and 7.1, respectively).