Field Studies of Bacillus SPP. for Biological Control of Meloidogyne Incognita in Cotton

Six Bacillus strains and two combinations were evaluated for biocontrol of root-knot nematode on cotton in the field at the Plant Breeding Unit of the E.V. Smith Research center and the Prattville research field of Auburn University. Bacillus strains were applied as an in-furrow spray on the seeds when planting with the rate of 1×10⁷ CFU/seed. Abamectin was applied to the seed as a seed treatment before planting and was included as a standard nematicide control. Plots were consisted of 2 rows, 25 foot long with 36 inch row spacing and were arranged in a RCBD with five replications. The Bacillus strains did not reduce plant stand which ranged from 85 to 92 plants per plot at 14 days after planting (DAP). Strain AP209 (B. mojavensis) significantly increased plant height and shoot/root fresh weights (SFW/RFW) at 37 DAP (P≤0.1). The numbers of root knot eggs per gram of root were significantly reduced by strain AP209 at 37 DAP (P≤0.1). B. mojavensis (AP209) also increased cotton yield by 23% following Abamectin and AP52 (B. subtilis subsp. subtilis) which increased cotton yield by 31% and 30% individually compared with untreated control plots. Strain AP209 (B. mojavensis) is a promising candidates for root knot nematode management in the field. Strain AP209 (B. mojavensis) and AP52 (B. subtilis subsp. subtilis) are promising biological candidates for yield enhancement in root-knot infested cotton fields.