Uticaj padavina i navodnjavanja na pomološko-tehnološke osobine plodova i prinose sorti šljive
Impact of rainfall and irrigation on pomological-technological characteristics of the fruit and on the yield of plum cultivars
Abstract:
The subject of the study, which included four cultivars and four variants, is an analysis of the climatic conditions in the South Serbia region; it also presents the first results that were achieved by irrigating plum cultivars. In the first variant, in mid-June, July and early August of 2003 and 2004, the selected cultivars were irrigated from a shallow surface canal, while the second variant was used as a control group. As for 2005, the work contains the results of the research performed on the studied cultivars in this year too, although this was a year with abundant rainfall, during which no irrigation was done. In comparison with the control group, the average size of the fruit in all the cultivars in the irrigated variant was larger by 4.0 x 5.2 x 5.4 mm; as for the stone, it was larger in this variant by 2.5 x 1.1 x 1.2 mm. The fruits from the third variant were smaller in size than the fruits of the irrigated variant - at the same time, they were larger than the fruits from the second nonirrigated variant. The fruit mass was larger with the irrigated variant by 7.7 g (19.3%) than the mass of the fruit in the control variant and it was also larger by 4.4 g (11.0%) than the fruit mass in the third variant. The stone mass was also bigger with the irrigated variant by 0.3 g (17.2%) than with the second one; in comparison with the third variant, it was bigger by 0.2% (11.4%). The flesh content did not show significant differences among the variants (it ranged between 95.6% and 95.5%). The average fruit yield in the irrigated variant was higher than that of the control variant by 11.19 kg per tree (5.595 t/ha or 34.9%) and/or the yield of the third variant, by 7.35 kg per tree (3.679 t/ha, or 23.9%). In the year that had significantly higher rainfall, the yield was higher by 3.6 kg per tree (1.8 t/ha, or 15.5%). A more significant increase in the fruit mass and the yield in comparison with the control group occurred in the early-ripening cultivars (Čačanska Lepotica and Čačanska Najbolja), than it was in the late-ripening cultivars (Čačanska Rodna and Stanley). On the average, the highest contents of the dry and soluble matter was recorded in the fruits of the control variant. When compared with the irrigated variant, this content was higher by 1.4% and 1.6%; in comparison with the third variant, this content was higher by 0.6% and 0.9%. The total sugar content was also higher, by 1.4% and 0.6% respectively. The control variant had a lower content of the total acids, by 0.37 and 16%, so that the ratio sugars - acids was the highest with the second control variant (12.5); it was slightly smaller in the third variant (10.1), and it was the lowest in the irrigated variant (8.1).