Physiological response of tomato to trifloxystrobin and tebuconazole: Implications for photosynthetic efficiency

A field experiment was conducted to study the impact of Nativo (trifloxystrobin combined with tebuconazole) on photosynthetic efficiency involved in improving the productivity of tomato. The different concentrations of fungicide, Nativo, were applied at 35-40 days after treatment (DAT) and 55-60 DAT in tomato. Leaf area was significantly reduced by the application of Nativo 75WG (tebuconazole 50 % + trifloxystrobin 25 % WG) at 400 g ha-1 in tomato, irrespective of the seasons, thereby reducing the growth analytical parameters such as leaf area index and leaf area duration. Among the treatments, Nativo 75WG at 400 g ha-1 in tomato recorded a higher photosynthetic rate, decreased stomatal conductance and transpiration rate. The rate of photosynthesis, chlorophyll index, soluble protein and sugar accumulation were augmented by the treatment Nativo 75WG at 400 g ha-1 in tomato, thereby producing maximum dry matter and ultimately, higher yield. All the yield contributing parameters were effectively increased by the foliar spray of trifloxystrobin coupled with tebuconazole in tomato and maximum yield was noticed in Nativo 75WG at 400 g ha-1 in tomato. It was concluded that foliar spray of Nativo 75WG at 400 g ha-1 during 35-40 DAT and 55-60 DAT in tomato was found to be optimum in increasing the yield to 18 % over control with increased photosynthetic efficiency, nutrient uptake and dry matter accumulation.