Responses of warm-season turfgrasses and turf weeds to fertilization

Abstract

The responses of 6 warm-season turfgrasses and 12 turf weeds to fertilization were investigated in a pot experiment. The relationships between plant growth and fertilization were well represented using the inverse quadratic: y= (b₀+b₁x) / (1+b₂x+b₃x²) . From each regression curve, the“low fertilization response” (F₅₀ / Fmax) was calculated. It appeared that turfgrasses generally have a higher“low fertilization response”and lower maximum fertilization requirement. According to the“low fertilization response”and the maximum fertilization requirement, weeds were classified into three groups: Group I, Group II [Erigeron philadelphicus, Oxalis corniculata-type] and Group III [Digitaria sanguinalis, Poa annuatype] . From a comparison of the typical response curve of each group, it was indicated that lower fertilization might be of advantage to turfgrasses over weeds. Also, the T/R ratios of the turfgrasses were significantly larger than those of weeds under this condition. These indicate that a lower level of fertilization might be favorable for weed control management in warm-season turfgrasses.