The effects of Arthrobotrys oligospora and Arthrobotrys conoides culture filtrates on second stage juvenile mortality and egg hatching of Meloidogyne incognita and Meloidogyne javanica

Culture filtrates (CF) of two species of the nematophagous fungi, Arthrobotrys oligospora and Arthrobotrys conoidesat three concentrations (۲۵%, ۵۰% and ۱۰۰%) of stock, were tested on the mortality of second stage juveniles (J۲) and egg hatching rate of Meloidogyne incognita and Meloidogyne javanica. Results showed that the percent juvenile mortality was directly proportional to concentration of the filtrates. Egg hatching rate of these nematodes was inversely affected by increasing concentrations. Also CFs had various impacts on the mortality of J۲ and egg hatching rate. In case of M. incognita maximum J۲ mortality (۲۸.۹۸%) occurred after ۲۴ hours of exposure to A. conoides filtrate at concentration of ۱۰۰%. The minimum toxicity (۱۲.۵% J۲ mortality) was recorded for A. oligospora at ۲۵% filtrate concentration. At the same time, the highest rate of J۲ mortality of M. javanica (۱۹.۱۸%) belonged to the ۱۰۰% concentration of A. conoides, while minimum toxicity belonged to ۲۵% concentration of A. oligospora causing ۹.۰۹% mortality. Maximum egg hatching rate for M. incognita (۳۰.۷۵%) belonged to control and minimum hatching rate (۱.۲۵%) belonged to ۱۰۰% concentration of A. conoides. The highest hatching rate of M. javanica (۳۶.۲۵%)belonged to control and minimum hatching rate (۱.۲۵%) occurred at ۱۰۰% concentration of A. conoides.

Keywords:

Arthrobotrys oligospora , A. conoides , culture filtrate , mortality , egg hatching rate , Meloidogyne incognita , M. javanica