Bacterial Strains Effect on the Nursery Plants Growth of 'Granny Smith' Apple Grafted on M-9, MM-106, and MM-111 Rootstocks

Abstract

Sapling treatment with plant growth promoting bacterial strains (PGPBs), is not spread on a wide scale for horticultural crops; basically, their application in fruit crops has not received much attention. For this reason, 'Granny Smith' apple was grafted on three clonal rootstocks using the chip budding method on 15 May 2013; at the end of the vegetative season, saplings with shoot lengths of 40 or less than 40 cm were selected as plant materials for the second year of research (2014) at the Abant Izzet Baysal University, Bolu, Turkiye to consider bacterial strains including Burkholderia gladia BA7, Bacillus subtilus OSU142 and Bacillus megatorium M3 in combination with different apple clonal rootstocks effectivity on the growth of saplings. Considering the results, the sapling weight at initially recorded between 8.6 and 36.0 g, the sapling weight at the end of the growing season 66.6-110.7 g, and the sapling weight increase rate between 181.7 and 789.1%. Root fresh and dry weight and root dry mater ratio obtained respectively 34.9-61.6 g, 15.3-34.1 g, and 44.8-57.8%. Sapling shoot length at the beginning was recorded between 15.1 and 35.6 cm, sapling shoot length at the end of the growing season ranged from 77.7 to 103.7 cm, sapling shoot length increase rate between 150.4 and 549.3%, and the number of lateral branches varied between 1.0 and 7.5 pcs. Briefly, bacterial strains application combined with the different apple rootstocks significantly affected all the evaluated characteristics of apple saplings. In light of the result findings, bacterial application in the nursery of apples as well as other fruit crops would be advised for better development and organically production of nursery plants.