EVALUATION OF ADAPTIVE POTENTIAL OF APPLE ROOTSTOCKS UNDER ARID CONDITIONS OF ASTRAKHAN REGION
The results of the two stage study of apple-tree rootstocks on the irrigated plot of "Caspian scientific research institute of arid agriculture" are presented in the article. The purpose of the presented research consisted in the study and selection of apple-tree rootstocks with higher adaptative potential to arid conditions of the Astrakhan Region. As a result of study the high-adapted middle grown rootstocks 54-118 and 57-545 are selected and also semi-dwarfish rootstocks of 62-396, SK2, SK5 and dwarfish rootstocks of P60, CK3, CK4 characterized by high frost resistance of root system and drought resistance, good survival and compatibility with various apple-tree varieties. Over years of research the survival of rootstocks in the apple-tree collection nursery was good and averaged 87,8 %. Layers of an apple-tree of M9, M26, M4 and CK5 have had an absolute survival. The most powerful development and high number of standard rootstocks have P59 and P60 dwarf rootstocks, semi-dwarf rootstocks of 62-396 and SK2 and middle dwarf rootstocks of 54-118 and 57-545. Under the arid conditions of the Astrakhan Region the high survival of the leading zoned apple-tree varieties on the studied vegetative reproduced rootstocks (79-100 %) is established. The apple rootstocks of 62-396, SK3, R60, SK2, SK5, M9 had a rather good safety of survival buds (82-90%). Their safety was high at the middle grown rootstocks of 54-118, 57-545 (94,4-100%). The high quantity of saplings have had the combinations of apple varieties with rootstocks of P60, P59, 62-396, 54-118, CK2, CK3, CK7 (75-100%), low sapling quantity have had a superdwarf PB-4 rootstocks (59%), and also a dwarfish rootstock of P16 (60,5%).