Efficacy Evaluation of Fungus Syncephalastrum racemosum and Nematicide Avermectin against the Root-Knot Nematode Meloidogyne incognita on Cucumber

Abstract

The root-knot nematode (RKN) is one of the most damaging agricultural pests.Effective biological control is need for controlling this destructive pathogen in organic farming system. During October 2010 to 2011, the nematicidal effects of the Syncephalastrum racemosum fungus and the nematicide, avermectin, alone or combined were tested against the RKN (Meloidogyne incognita) on cucumber under pot and field condition in China. Under pot conditions, the application of S. racemosum alone or combined with avermectin significantly increased the plant vigor index by 31.4% and 10.9%, respectively compared to the M. incognita-inoculated control. However, treatment with avermectin alone did not significantly affect the plant vigor index. All treatments reduced the number of root galls and juvenile nematodes compared to the untreated control. Under greenhouse conditions, all treatments reduced the disease severity and enhanced fruit yield compared to the untreated control. Fewer nematodes infecting plant roots were observed after treatment with avermectin alone, S. racemosum alone or their combination compared to the M. incognita-inoculated control. Among all the treatments, application of avermectin or S. racemosum combined with avermectin was more effective than the S. racemosum treatment. Our results showed that application of S. racemosum combined with avermectin not only reduced the nematode number and plant disease severity but also enhanced plant vigor and yield. The results indicated that the combination of S. racemosum with avermectin could be an effective biological component in integrated management of RKN on cucumber.

Testing various biocontrol agents against the root-knot nematode (Meloidogyne incognita) in cucumber plants identifies a combination of Syncephalastrum racemosum and Paecilomyces lilacinus as being most effective

“…The fungus S. racemosum was isolated from soil samples infected by RKN and maintained on a potato-sucrose maltextract agar (PSMA) medium, which was the same strain Sr18 used in the previously published paper by Huang et al (2014). Spore suspension of S. racemosum was inoculated on potato sucrose (PS) liquid medium to a final concentration of 10 7 spores ml À1 (Sun et al, 2008).…”

“…up to $400 million annually (Huang et al, 2014). M. incognita infection can alter the levels of amino acids and organic acids and reduce chlorophyll contents (Saikia et al, 2013).…”

“…In China, the filamentous fungus Syncephalastrum racemosum has been used as a biological control agent against several nematodes (Sun et al, 1999(Sun et al, , 2008. S. racemosum has been reported to reduce the RKN populations in soils and roots, and this reduction was reflected in the increased cucumber yield (Huang et al, 2014;Sun et al, 2008). As previously described in detail, the reduction of disease severity caused by S. racemosum may be attributed to the direct parasitism on nematode and the secondary metabolites produced by this strain in the soil (Hashem and Abo-Elyousr, 2011;Sahebani and Hadavi, 2008).…”

Novel point mutations in β-tubulin gene for carbendazim resistance maintaining nematode pathogenicity of Paecilomyces lilacinus

“…are obligatory and substantial parasites of many economic crops (Javed et al 2006). Controlling root-knot nematodes is of major economic importance to the agricultural industry of China (Huang et al 2014). Meloidogyne arenaria, M. incognita and M. javanica are the main species responsible for yield losses in vegetable cropping areas (Sikora andgenus play a crucial role for their important phytosanitary implications often pave the way to emergent, opportunistic or well-known pathogenic fungi on cultivated crops (Bertrand et al 2000;Dimartino et al 2011;Gallo et al 2011;Starr et al 1989;Vitale et al 2011Vitale et al , 2014.…”

Root colonization and effect of biocontrol fungus Paecilomyces lilacinus on composition of ammonia-oxidizing bacteria, ammonia-oxidizing archaea and fungal populations of tomato rhizosphere

“…can cause dramatic yield losses by attacking a wide range of crops, including such economically important plants as tomato and cucumber (Huang et al 2014a). To control these destructive plant parasitic worms, chemical nematicides, such as organophosphate and carbamate, are used for their immediate action and effectiveness (Oka et al 2009).…”