R. Kumari - Department of Botany, Punjab Agricultural University, Ludhiana, Punjab, India.
S. Bedi - Department of Botany, Punjab Agricultural University, Ludhiana, Punjab, India.
A. S. Dhatt - Department of Vegetable Science, Punjab Agricultural University, Ludhiana, Punjab, India.
V. P. Sethi - Department of Mechanical Engineering, Punjab Agricultural University, Ludhiana, Punjab, India.

The effect of nutrient solutions with varying nitrogen forms was evaluated on yield and quality of coriander (cv. Punjab Sugandh) grown in soilless medium under polyhouse conditions. Crop was sown on three dates viz., October (main season), February, and July (off-season), respectively. In polyhouse, N (Nitrogen) was supplied in variable ratios of NO۳- to NH۴+ viz; ۱۰۰:۰ (T۱), ۷۵:۲۵ (T۲), ۵۰:۵۰ (T۳), ۲۵:۷۵ (T۴), ۰:۱۰۰ (T۵), respectively, keeping total N content constant. Fresh foliage was harvested ۳ times in each season at ۳۰ days interval starting from date of sowing. At each harvest, plant growth quality parameters including activity of antioxidants enzymes were determined. Irrespective of the seasons, the yield was significantly higher in polyhouse than soil-grown crop, and among the nutrient solutions, the solution of T۲ recorded significantly higher yield as well as growth and quality parameters during all the season. It could be concluded that NO۳- to NH۴+ ratio of ۷۵:۲۵ in the nutrient solution improved both yield and quality and is thus most suitable for coriander crop.

α-tocopherol, Ascorbic acid, Polyhouse conditions, Proline, Soilless medium.