Impact of Stimulated Environmental Conditions on Downy Mildew Disease Dynamics in Ridge Gourd

Abstract

Significant effect ofelevated CO2 and temperature levels was observed on downy mildew severity in ridge gourd wherein, highest disease severity of 52.68 PDI was observed in open reference plot followed by ambient CO2 @410±25 ppm with normal temperature (46.80 PDI). Meanwhile, the lowest disease intensity of 13.49 PDI was recorded in chambers with ambient CO2 @410 ±25 ppm with 20C rise in temperature. Similarly, these weather variables significantly impacted the biochemical composition of ridge gourd leading to resistance/ susceptible reaction against the disease. In respect of total sugar content, the treatment with elevated CO2 @ 550 (±) 25 ppm with 2°C rise in temperature recorded highest total sugar content of 17.89 mg g-1 followed by the treatment with elevated CO2 @ 550 (±) 25 ppm with normal temperatures (14.28 mg g-1). In a similar fashion, substantial effect on phenolic content was recorded wherein, highest total phenoloic content of 129.25 mg/ 100g was recorded for the treatment with ambient CO2 @ 410(±)25 ppm with 2°C rise in temperature. Meanwhile, significant lowest total phenoloic content (109.65 mg/100g) was recorded in for ridge gourd grown in open/reference plot.