ABSTRACT
Apple trees grown on seedling rootstock often develop into large and vigorous trees making its management difficult. By using vigorous rootstocks only few trees can be accommodated per hectare making the productivity less profitable. Several dwarfing rootstocks of apple are available which need support system and incur heavy investment during orchard establishment. It would be ideal to obtain a tree with very good root system, to avoid the need for supporting systems and also with a low height, which can be achieved using the interstem. Therefore, in the present investigation M9 clonal interstem comprised of 2,4,6 and 8inches length were grafted between seedling rootstock and scion of two cultivars i.e., Red Delicious and American Apirouge which are most common and predominant cultivars in orchards of Kashmir. The average sapling height was to the tune of 38.85cm and 41.01 cm in Red Delicious and American Apirouge during first year of study. There was a progressive increase in the height of plant with decreasing interstem length. In both the apple cultivars stem diameter increased with decrease in interstem length but was lower than control during both the years of study, The rootstock influences the biometric parameters of the grafted trees. The results showed that increased interstem length significantly decreased sapling height and growth whereas, days taken to sprouting and survival per cent were non significant. Thus, it appeared as if the dwarfing rootstock genotype used as an inter-stem functioned as a kind of physical restriction to water movement and probably reduced the hydraulic conductance of the whole tree.
ABSTRACT
Allelopathy is a natural and eco-friendly process causes agricultural plants to generate phytotoxins called "allelochemicals" that hinder or promote growth. The chemical substances generated through allelopathy can be potential tool to control agricultural important pests. Allelopathy can replace agrochemicals for crop disease and pest management. Agrochemical used in agriculture pollute the environment, lowers food quality, and increases disease-resistant biotypes. An agronomist can collaborate with a molecular scientist or plant breeder to selectively boost disease suppression by understanding allelopathy's physiological foundation. Allelochemicals are natural pesticides that fight disease, weeds, and insects, according to experts. Disease management strategies have been redesigned recently. Frequently, structural modifications or the synthesis of chemical analogs increase their bioactivity. Even though the progress in this regard is sluggish, some encouraging results are emerging, and many more are anticipated in the near future. This review attempts to discuss these characteristics of allelopathy for the rational management of diseases.