Effects of fertilizer amendments and rootstock type on apple rhizosphere

The aim of the project is to understand how different types of fertilizer amendments affect the microbial communities in apple rhizosphere and whether the choice of rootstock has an effect. Two rootstocks were used, the first being the widely used commercial dwarf rootstock, Malling 9, and the second was the more recent disease-resistant dwarf rootstock Geneva 41. Four fertilizer treatments were applied, chicken litter, yardwaste compost, calcium nitrate using fertigation, and a no-treatment control. The 16S rRNA marker gene was amplified using the 515F-806R primer-pair. Sequencing was performed by Genome Sequencing Center of Virginia Tech (Blacksburg, VA) on Illumina MiSeq instrument using the 500-cycle v2 kit.