A field experiment was conducted for two seasons to study the effect of maleic hydrazide (mh) on a mixed stand of perennial grasses and to investigate the interrelationships of nitrogen fertilizer treatments, mowing schedules, and application rates of growth retardant. Mh limited the height and dry weight of clippings of all species including kentucky bluegrass, orchard grass, and quack grass at both 4 and 8 lb/acre. The higher rate gave best results. Mh reduced the number and height of orchard grass and quack grass seed heads and reduced the heights of bluegrass seed heads so that their presence was not objectionable. It reduced growth of grasses throughout the period of normally heavy growth. A slight increase in growth of treated grass followed during the summer which was attributed to utilisation of carbohydrates accumulated during growth suppression. Mh caused thinning of the sod during the spring, which favoured encroachment of weeds. Normal stand density returned during the summer, but weed problems remained. Low cutting increased the clipping weights but not the number of mowings necessary. Plots cut high had greater density of grass and better colour. (Author/publisher)
Abstract