Evaluation of the incidence of powdery mildew (Sphaerotheca fuliginea) on bottle gourd

Powdery mildew caused by Sphaerotheca fuliginea on local cultivars of bottle gourd was found greatly in fluenced by the natural epiphytotic condition both from the farmers’ fields and experimental plot at Research and Demonstration Farm Ruzaphema, Nagaland (India). The maximum intensity ranges from 51.45 ? 86.90 per cent in local cultivar at 95DAP during the peak month of June 2005 with average temperature (29.25 ºC), dew point (27.4 ºC),relative humidity (84.7 %) and rain fall (3.78 mm), respectively. Disease intensity and per cent plant infection were non significantly correlated with the relative humidity, rainfall, temperature and humidity at (P =0.05).However, per cent of infection and disease intensity was found significant and positively correlated with dew point in both the fields. Due to genetically adopted factors with the host cultivars significant difference on the yield records from both the fields ranged between 20.18 - 24.55 t/ha under Nagaland condition and can be used for future breeding programme for developing resistant variety.