二種酢漿草屬(Oxalis)雜草的發芽特性及化學防治

Abstract

Creeping woodsorrel (Oxalis corniculata L.) and pink woodsorrel (Oxalis corymbosa DC.) are common perennial broadleaf weed. There were widely distributed in lawns, potted plant nurseries, flower beds, gardens, and greenhouses. In this study, the effects of temperature, pH, osmotic potential and planting depth were determined for creeping woodsorrel under controlled environments. The optimum temperatures for seed germination ranged from 12 to 24℃ of creeping woodsorrel. Maximum germination 90.8% was obtained in 16 days under 16℃ Under the water potential -0.1~-0.8 MPa, seed germination decreased significantly. Around 45% seeds germinated under imbibition condition of pH 4.5-5, and 5.3% of germination occurred in the condition of pH7. Seedling emergence was maximum from soil surface on creeping woodsorrel, no emerged seedling was observed buried depth 4-5 cm. We tested normal field used rate (x) and reduced rate (0.75x) of 13 herbicides on creeping woodsorrel and pink woodsorrel. Pre-emergence test showed that metazachlor, metribuzin, oxadiazon, and pendimethalin provided 100% control on creeping woodsorrel and good for control by oxadiazon on pink woodsorrel. On 15-20 leaves creeping woodsorrel, post-emergence application of flazasulfuron, metribuzin, resulted in 96.9-100% reduction of fresh weight at 35 days after foliar application, on 30-40 leaves pink woodsorrel, provided more then 80% control. Fluroxypyr and triclopyr also provided 80.1-90.3% control at two Oxalis weeds.