Relative consequences of interaction among Meloidogyne incognita, Fusarium oxysporum and tomato leaf curl Palampur virus on disease severity and growth of muskmelon

摘要

Abstract Muskmelon is an important cucurbitaceous crop grown during summers in Punjab. The crop suffers economic losses due to its vulnerability towards root knot nematodes (RKNs), Fusarium wilt and Tomato leaf curl palampur virus (ToLCPaV). Since in the field, muskmelon crop is exposed to all these three pathogens, the study was planned to investigate their effect on each other as well on muskmelon crop when inoculated individually and in different sequential combinations. Total thirteen treatments i.e. RKN alone, RKN + (ToLCPaV 10 days after, RKN + (Fusarium 10 days after), (RKN + Fusarium) + ToLCPaV 10 days after, RKN + Fusarium + ToLCPaV simultaneous inoculation, Fusarium alone, Fusarium + (RKN 10 days after), Fusarium + (ToLCPaV 10 days after), ToLCPaV alone, ToLCPaV + (Fusarium 10 days after), ToLCPaV + (RKN 10 days after), ToLCPaV + (RKN + Fusarium 10 days after) and Control were evaluated in a pot experiment for two consecutive seasons. The results revealed that, maximum reduction in growth parameters was recorded where all the three pathogens were inoculated simultaneously. Root galling index was more severe in treatments with prior inoculation of RKN (T2 4.5 and 4.28; T3 4.41 and 4.42) or with simultaneously inoculation of RKN with other pathogen (T5 4.56 and 4.50) in comparison to treatments where RKN was inoculated 10 days after other pathogen (T7 3.0 and 2.67; T11 3.11 and 2.06; T12 2.83 and 2.0) in both the years. Fusarium wilt was more severe, where F. oxysporum f. sp. melonis was inoculated along with M. incognita either simultaneously or in sequence (prior or latter) as compared to F. oxysporum alone. ToLCPaV severity was maximum (4.3 and 4.5) during simultaneous inoculation of all the three pathogens followed by virus alone (4.1 and 4.3) compared to virus inoculated 10 days after nematode (2.8 and 2.3) or virus inoculated 10 days after fusarium (2.3 and 3.0) during both the years, respectively.