Influence of plant density and environment on productivity of tomato (Lycopersicon esculentum) in Siachen Sector

A field experiment was carried out to study the influence of plant density and environment on productivity of tomato at Field Research Laboratory (DRDO) Research Station Partapur, (Nubra Valley) in Siachen Sector (Jammu & Kashmir, India) at the altitude of 9500 ft MSL with an average annual temperature ranging from-25°C to 30°C where growing tomatoes in open field is risky due to fluctuating diurnal temperature and harvesting ripe tomatoes is difficult due to onset of winter at the time of maturity. The experiment consisted of four plant density (23000, 28000, 40000, and 62500 plants/ha) and two growing environments viz., Fibre Reinforced Polyethylene greenhouse and polycarbonate triple layer greenhouse. Planting of four week (old seedling of hybrid Tolstoi) was done during first week of May. The crop was trained as single stem system in both the greenhouses. The results revealed the significant effect of plant density on plant height, number of fruits per plant, days to first harvest, average fruit weight, fruit yield per plant, fruit length and marketable yield per hectare of tomato. Growing environments also exerted significant effect on various traits under study except fruit yield per plant and fruit diameter. Interaction effects were significant only for plant height, days to first harvest and average fruit weight. Fruit yield per plant was maximum in both the environments at lowest density i.e. 23000 plants/ha (2.64 and 2.42 kg/plant) but marketable fruit yield per hectare was maximum at the density of 40000 plants/ha (672.3 and 627.0 q/ha) whereas further increase in plant density up to 62500 plants/ha resulted in the decrease in yield. Plant density of 40000 plants/ha was found best under greenhouse condition considering the yield and quality of tomato.