Influence of soil agro-techniques and rootstock on management of apple replant diseases

Abstract

The replant problem has shown symptoms of declining productivity and longevity of apple orchards in several apple-growing areas of Himachal Pradesh. Due to limited land and choice of crops for smaller microclimatic niches and incomparable economic equivalence of other fruits with apples, orchardists are compelled to replant old apple orchard sites with apples only. Therefore, standardization of suitable agrotechniques to combat the replant problem in apples for better field survival rate and productivity under replant conditions for the sustainability of the apple industry in the state and another part of the country is necessary. The present investigation was carried out using 20 soil agro-techniques combinations, comprising of four apple rootstocks viz., seedling, Merton 793, MM.111, and M.7, and five different soil agro-techniques namely soil fumigation, PGPR, biocontrol, combined (Soil fumigation + PGPR + Biocontrol) and control with three replications. The data revealed that Merton 793 rootstock improved the plant growth and vigour parameters, soil enzymatic activities, and microbial counts. Among the soil agro-techniques, similar results were recorded in the case of combined soil agro-technique. Furthermore, the interaction between rootstocks and soil agrotechniques revealed that combinations of Merton 793 × combined technique excelled with respect for growth and vigour traits, soil enzymatic activities, and bacterial, fungal, and actinomycetes counts over other combinations under replant situation.