Strategies for rootstock and varietal improvement in apple: A review

Abstract

Low productivity in apple is mainly due to old senile orchards, low yielding varieties, poor orchard and canopy management as well as improper technical facilities. Rootstocks play an important role by influencing flowering, yield, nutrient uptake, canopy architecture and thereby fruit quality. Plant grown on seedling rootstock generally develop into large and vigorous canopy architecture and hence, is difficult to manage than the clonally propagated ones. For instance, the apple rootstock M 9, M 27, etc. induces larger fruit size and good quality fruits by better light interception and good aeration within the canopy than seedling rootstocks. Rootstocks provide a mean of controlling scion cultivar by modifying the size and shape of the trees through shorter intermodal length, altering the angle of the branches etc. and tend to make a cultivar adapted to wider climatic conditions, reduces the maturation time and also infers resistant to abiotic as wells as biotic stress and hence serve as an essential component in modern fruit production. Furthermore, it makes the orchards more uniform and productive and there is a need to complex underlying mechanisms which would ease future rootstock as well as cultivar breeding programme and therefore more concerted efforts are required to research of rootstocks and varieties of apple which will help to mitigate as well as exploit the beneficial effects and to overcome the problem facing by the fruit crop.