Effect of Metrological Factors on Incidence of Aeromycoflora associated with foliar diseases of Potato

Aeromycoflora was collected from the atmosphere by using gravimetric Petri Plate Method containing 3 different medias(PDA, NA and WA). Among collected aeromycoflora, 14 fungi belonging to 9 genera were identified and purified. The most dominant types were Cladosporium sp. (10.67%), Alternaria alternata (10.30%) and Alternaria solani (7.80%) following the Aspergillus niger (7.27 %), Penicellium spp. (7.12%) and Fusarium oxysporum (7.02%) respectively. Alternaria solani was found to be pathogenic as the casual agent of early blight of potato and it was confirmed by performing pathogensity test on three available potato verities (Desiree, Cardinal, Faisalabad white).In correlation analysis with metrological factors, all of the collected fungi except Aspergillus niger, Aspergillus flavus and Drechslera sp. showed a negative correlation with relative humidity. Positive correlation was observed with temperature, rainfall and wind speed by all of the collected fungi except Aspergillus flavus, (negatively correlated with temperature and rainfall). The concentration of most of the collected aeromycoflora was found maximum in the months of March, April and May. Similarly the lower concentrations were observed in the months of December and January when average temperature was lowest with minimum to no rainfall. Gradual increase in disease incidence was observed with increase in concentration of Alternaria solani