Abstract:
Early blight is one of the most common and devastating disease of potato which is caused by the fungus, Alternaria solani. The antifungal activity of three plants extracts namely Azadirachta indica (Neem), Carica papaya (Papaya), Calendula officinalis (Marigold) and Four Chemical fungicides namely Topgan 50 WP(Copper oxychloride), Dithane M 45(Mancozeb), Bavistin 50 WP(Carbendazim) and Rovral 50 WP(Ipridione) as a treated check, was tested for the management of Alternaria solani in field condition. In the present investigation the maximum reduction of plant infection(45.74,43.37) and leaf infection (71.20, 73.57%) were observed from the Papaya and Marigold leaf extracts, respectively.The fungicides Bavistin and Topgan showed reduction of plant infection by 85.70% and 83.87%,respectively.Whereas leaf infection were reduced by 85.33% and 83.78% in case of Dithane M 45 and Topgan, respectively. In case of PDI, the Papaya leaf extracts (59.03%) and Rovral (85.70%) showed the maximum reduction of disease severity at 80 days after planting. The maximum yield increased was observed with Rovral (120.94%), Dithane M 45 (105.43%) and Papaya leaf extracts (80.92%) against the pathogen. All treatments significantly reduced the early blight disease incidence as well as increased the yield of potato compared to the infected control under field conditions.The present study revealed that Papaya leaf etracts and the chemical fungicides Rovral 50 WP and Dithane M 45 proved to be effective for the management of early blight of potato caused by Alternaria solani.
Description:
A Thesis
Submitted to the Faculty of Agriculture, Dept. of Plant pathology,
Sher-e-Bangla Agricultural University, Dhaka,
In partial fulfillment of the requirements
For the degree of
MASTER OF SCIENCE
IN
PLANT PATHOLOGY
SEMESTER: JANUARY - JUNE, 2016
