Application of Burkholderia cepacia and Trichoderma virens, alone and in combinations, against Meloidogyne incognita on bell pepper

Bell pepper (Capsicum annuum L.) seeds and seedlings were treated with thre e potentially beneficial microbes, applied alone and in combinations, to co mpare effects of these formulations on root-knot nematode (,Meloidogyne inc ognita) populations and on plant growth in the greenhouse. Individual treat ments (applied as seed coatings and seedling drenches) were formulations of Burkholderia cepacia strains Bc-2 and Bc-F, and of Trichoderma virens stra in Gl-3. Combination treatments were BcF+Gl-3. Bc-2+Gl-3, Bc-F+Be-2, and Bc -F+Bc-2+Gl-3. At transplanting, pepper seedlings were each inoculated with 10 000;M. incognita eggs or left uninoculated, and harvested 10 weeks later . Nonviable microbe formulations of each individual strain were also applie d; these were tested only on nematode-inoculated plants. No treatment consi stently affected plant growth. Numbers of eggs + second-stage juveniles (J2 ) per g root were significantly lower with the Bc-2, Bc-F, and Gl-3 treatme nts than in the untreated controls, and highest with the nonviable Gl-3 tre atment. This indicates that the viable preparations suppressed M. incognita numbers on pepper under the greenhouse test conditions. Importantly, the e gg +J2 numbers recorded from combination treatments were not significantly different from untreated controls, suggesting that strain combinations decr eased biocontrol effectiveness relative to applications of individual micro bes.