Comparative Efficacy of Different Approaches to Manage Meloidogyne Incognita onGreen Beans

Abstract

Comparative Efficacy of Different Approaches to Manage Meloidogyne Incognita on Green Beans A greenhouse study was conducted to compare the relative efficacy of different approaches to manageMeloidogyne incognita on green beans. These approaches included: chemical (fumigant, nonfumigant, seed dressing, and seed dip), biological (the egg-parasitic fungus, Paecilomyces lilacinus, and the mycorrhyzal fungus Glomus sp.), physical (soil solarization), and cultural practices (chicken litter, and urea). In total, nine different control materials and methods of applications were compared. Two important parameters were considered: plant response (plant growth and root galling), and nematode reproduction (production of eggs and the reproduction factor Rf). Results showed that the organic fertilizer, chicken litter, has severely affected the growth or survival of the seedlings. Therefore, this treatment was removed from the evaluation test. All other treatments were found to be effective against the nematode, but with different levels of efficacy. The eight treatments decreased (38.9-99.8%) root galling, increased plant growth and suppressed nematode reproduction. Based on three important criteria, namely: gall index (GI), egg mass index (EMI), and reproduction factor (RF), the tested materials and methods were categorized into three groups according to their relative control efficacy under our test conditions. These three groups were: 1) the relatively high effective group (GI=1.0-1.4, Rf=0.07-0.01) included: the fumigant dazomet, the non-fumigant fenamiphos, soil solarization, and seed-dip with fenamiphos; 2) the relatively moderate effective group (GI=3.4-4.0, Rf=0.24-0.60) included: seed dressing with fenamiphos, and urea; and 3) the relatively less effective group (GI=5.0, Rf=32.2-37.2) included: Paecilomyces lilacinus and Glomus sp....