SPATIAL GROWTH OF CYNODON DACTYLON (L.) PERS.*

Summary. Small sprigs of Cynodon dactylon (L.) Pers., were planted and grown without competition from weeds and crops for 2 1/2 years. The plant spread by means of above‐ground creeping stolons and subterranean rhizomes which could also emerge as aerial shoots, producing in their turn new stolons and rhizomes. Initially there was linear extension of stolons and rhizomes, following which gaps in the sod were filled by stolon branching and new shoots. There was no preferential direction of stolon elongation and established sods developed an approximately circular shape and expanded concentrically. The rate of increase in sod area was similar in both years of observation but radial extension was smaller in the second year than in young plants. The mean sod area was 25 m2 after 2½ years of growth, and mean monthly area increment was 0·9 m2. Growth almost stopped in the cold season and exceeded 2 m2 per month in the summer. The plants had extended up to 3·9 m from the plant centre after 2 1/2 years. The number of flowering culms per sod, produced only in the warm season, was directly proportional to sod area; seeds were infertile in the Newe Ya'ar area. After 2½ years of growth about 70% of the rhizome dry weight was present in the upper 20 cm of soil. Few rhizomes penetrated deeper than 40 cm. More than 60% of the rhizomes were present within 1 m radius of the plant centre and 90% were present within 2 m radius. Croissance spatiale de Cynodon dactylon (L.) Pers.