Management of Volunteer Corn Seedlings in Dry-Seeded Rice

The demand for corn is increasing in Asia for feed and biofuel. It is grown in the rice-corn cropping system. During harvest of corn, however, seeds drop on the soil surface and become problems as volunteer corn seedlings in the subsequent dry-seeded rice crop, in which the suppressive effect of standing water is absent. A study was conducted in screenhouse and field conditions to evaluate the effect of rice herbicides on the management of volunteer corn seedlings. In the screenhouse experiment, bispyribac-sodium at 0.030 and 0.045 kg ai/ha provided complete control of corn seedlings. Fenoxaprop + ethoxysulfuron and penoxsulam + cyhalofop did not provide effective control of corn seedlings. In the field, the sole application of bispyribac and sequential application of oxadiazon and bispyribac suppressed corn biomass by 60% - 82% and 89% - 91%, respectively, as compared with the nontreated control. The results of this study demonstrate that, in the absence of other management strategies, volunteer corn seedlings in dry-seeded rice systems can be managed by using bispyribac-sodium.