Nitrogen nutrition and plant density influencing marketable head yield of broccoli in cold arid desert of Ladakh

Broccoli (Brassica oleracea L. var. italica) is emerging as a new cash crop in India where it is grown as an off-season vegetable in temperate hilly regions and fetches very high price in plains. Broccoli is high in antioxidant and anticancer compounds. The typical broccoli phytochemicals are sulphur containing compounds, including isothiocyanates, dithiolthiones and indoles. Several isothiocyanates have been shown to inhibit tumours, induced by chemical carcinogens. Indoles also play a role in cancer prevention. Ladakh, the high altitude coldest-desert of India, provides favorable climate during May-September for the cultivation of broccoli. Four nitrogen fertilization doses 50, 100, 150 and 200 kg.ha(-1) along with two plant densities 37037 plants/ha (S1) and 49383 plants/ha (S2) achieved by transplanting at a spacing of 60 x 45 cm and 45 x 45 cm, respectively, were used. Plant populations were the main plots and arranged in a complete randomized block design with three replications. Results revealed the significant effect of nitrogen fertilization on head yield and quality traits with the maximum at 200 kg ha(-1). Increment in head yield at higher nitrogen level was mainly due to increment in head weight. Plant densities could not exhibit significant effect on traits under study although head weight decreased slightly with the increase in plant density but the head yield increased which was due mainly to the result of higher number of plants per unit area.