ABSTRACT
Planting bioenergy crops on land previously used for citrus production may offer an alternative source of revenue for growers looking for alternative-to-citrus crops. However, residual herbicides used in citrus production may adversely affect alternative crops. This study evaluated effects of three herbicides (bromacil, norflurazon, and simazine) commonly used in citrus production on the bioenergy crop Sorghum bicolor 'Topper 76-6'. Plants were exposed to herbicides in soil for 1-5 weeks and observations of effects on photosynthetic quantum yield, leaf greenness, height, and biomass were made. Results indicate that concentrations of bromacil and norflurazon greater than 0.09 and 0.07 mg/kg and simazine >0.46 mg/kg will impair growth and development in similar soils. Concentrations below these may also be toxic.
