Apple cultivation in India is restricted to Northwestern Himalayan region comprising the states of Jammu and Kashmir, Himachal Pradesh, Uttarakhand and to a small extent in north-eastern states. The area and production of apple in India has increased signiſcantly but low productivity is still a matter of concern to the farmers as well as the scientists. The low productivity has been attributed to various reason such as sloppy lands, shallow, unirrigated and less fertile land beside inadequate nutrition and improper plant protection measures. It has necessitated the apple growers to change over to more efficient orcharding system by the use of critical inputs like water and fertilizers. The reports on fertigation under high density plantation in developed countries are encouraging but such information under Indian conditions is limited. Therefore, it was proposed to study the effect of different levels of fertigation and three different rootstocks on apple under high density plantation.

An experiment was carried out at Fruit Research Station, Seobagh, Kullu and Department of Pomology of Dr YS Parmar, UHF Nauni, Solan to ascertain the effect of different fertigation treatments on fruit yield and quality parameters of apple under high density plantation. The experimental site represented submontane zone of Himachal Pradesh, situated at an elevation of 1,350 m above mean sea level and with latitude 32 1’N and longitude 77 2’E. The planting material consisted of six-year-old apple plants of cvs. Red Fuji and Scarlet Gala grafted on three clonal rootstocks, viz., EMLA-106, EMLA-7 and EMLA-111. The plants were spaced at 3 mx 3 m. Each treatment was applied to both the cultivars on every rootstock. The results are presented as mean performance of both the cultivars on individual rootstocks. There were four fertigation treatments, viz., full dose of N, P and K through drip, 2/3 dose of N, P and K, ½ dose of N, P and K and 1/3 dose of N, P and K, whereas, full dose of N, P and K in soil as a single application consisted the control treatment. The basic dose for one-year-old plant under high density (3 m ª 3 m) was ſxed to half