Biological approaches for the management of replant disease: a mini review

Replant disease in many temperate fruits is a serious and challenging issue that has been reported
across almost all apple growing regions of the world including India where Himachal Pradesh is
traced as a highly affected state. The symptoms includes abnormal growth and development,
yield and quality decline of plants caused by continuous cultivation of same crops on same piece
of land. The variations in growing habitat of exported and imported planting material, mono-
cropping results in a decline in the ability to absorb water and nutrients, pH change coupled
with persistence of soil borne pathogens, deviation in climatic conditions of fields and types of
soil are ascribed as some of the amenable factors. Despite the heavy losses incurred on
purchasing of new seedlings owing to continuous death in already established orchards, farming
community of the state is desperately looking for a viable scientific solution. Furthermore, it
leaves the youth no choice but to either replace apple by an alternative crop or to seek a job that
provides them better income. Crop rotation or changing sites has been practiced since ancient
times by some apple orchardists and could be a preferred strategy for mitigation of replant
problem. Application of soil amendments for instance oilcakes, compost, mustard was reported
to be effective in managing soil-borne fungi and plant parasitic nematodes along with the use of
plant growth-promoting rhizobacteria which aggressively colonize the rhizosphere/plant roots,
thereby enhancing the growth, and yield of plants when applied to seed or crops. Integrated
management is helpful in combating this serious problem. Therefore, this review aims to
describe different practices that pertains to reducing the replant problem in the old orchard sites.