Effects of Meloidogyne incognita, Alternaria dauci and Fusarium solani on carrot in different types of soil

Abstract

Effects of Meloidogyne incognita, Alternaria dauci and Fusarium solani were studied on carrot (Daucus carota L.) growth, chlorophyll, carotenoid and proline contents in different types of soil. Plants grown in 20:80 and 40:60% sand:clay soil mixtures showed a significant increase in root dry weight, chlorophyll and carotenoid contents compared to plants grown in 100% clay soil. However, use of 60:40 sand:clay resulted in a similar root dry weight, chlorophyll and carotenoid contents as was found in carrots grown in 100% clay soil. Inoculation of plants with M. incognita, A. dauci or F. solani caused a significant reduction in root dry weight, chlorophyll and carotenoid contents in all soil types as compared to their respective control. Inoculation of plants by A. dauci caused the greatest reduction in root dry weight followed by F. solani and M. incognita in different sand and clay mixtures. Use of 20:80, 40:60 or 60:40 sand:clay mixtures caused a significant increase in proline content of plants over those grown in 100% clay soil. Similarly, inoculation of M. incognita, A. dauci and F. solani caused a significant increase in proline content in all soil types compared to their respective control.