FACTORS AFFECTING PANICLE PRODUCTION OF COCKSFOOT (DACTYLIS-GLOMERATA L) IN FINLAND .2. EFFECT OF JUVENILE PHASE, SOWING DATE, AND TILLERING

Cocksfoot cv. Haka was sown in a row stand at two-week intervals between 18.5.1988 and 10.8.1988 in Jokioinen. The panicle production of sample plants was studied before and after winter 1988/89 by growing the sample plants in a glasshouse in favourable conditions for panicle growth. The production of panicles per sample was significantly higher for the first two sowing dates (16.1-21.6) than at later sowing dates (0.1-8.1). In field grown stand the first two sowing dates produced significantly more panicles per meter of row than the later sowing times, too. An early sowing date was necessary for the abundant panicle production of cocksfoot in the first harvest year. In a separate pot trial a cocksfoot stand was established from one seed at two week-intervals between 6.6.1989 and 1.8.1989. Panicle production was measured in the fall 1989. All three first sowing dates produced a high number of panicles per pot (35.8-41.3) which indicates that the lateral tillers contribute greatly to the panicle production of cocksfoot. The stand of the last sowing date produced significantly less panicles per pot (11.8) than the earlier sowing dates. Floral initiation was observed to occur in the most advanced tillers already in the fall in the pot seeded trial.