Abstract
This investigation was made to study the influence of cutting frequency on the relation between the exhaustion of root·stubble reserves and the regrowth of shoot in Italian ryegrass. The more frequent removal of leaves showed the less the total production of leaf and the root·stubble dry weight. Throughout all defoliation frequency, the 1st clipping led the most heavily declining both in the shoot yields, and in root·stubble dry weight. And with the progress of repeating of defoliation, the decrease of top yields and stubble·root dry weight following each defoliation were reduced. The concentration of available carbohydrate in root·stubble lowered parallel with clipping frequency. However, the concentration of nitrogen in root·stubble were higher in 50 days interval clipping than unclipping, and with increasing of the frequency the nitrogen concentration in root·stubble lowered. Increasing of clipping frequency appears to rise the ratio of cell wall substances and reserve substances in root·stubble.
