Kasvua hillitsevien aineiden käytöstä krysanteemin ja joulutähden viljelyssä

Authors

• Erkki Kaukovirta Helsingin yliopiston puutarhatieteen laitos

DOI: https://doi.org/10.23986/afsci.71602

Abstract

The article gives preliminary information on the studies started in 1961 and dealing with the effect of the growth inhibiting substances Amo 1618, CCC-preparation Cycocel and Phosfon D on chrysanthemum (Bonaffon de Luxe) and poinsettia (Gloria). Treatment was effected by mixing the used quantity of the preparation into the soil before planting. In the second year the poinsettia treatment consisted of watering the pots with a solution containing 3 g CCC and 1.5 g Amo 1618 per one litre of solution directly after planting, five days after planting or 14 days after planting. 50 ml per pot of the solution was administered. In the chrysanthemum experiment in 1962 attention was also paid to how the different soil mixtures, sand, clay and peat influence the effectivity of Phosfon D and Amo 1618. From results achieved up to now it appears that Amo 1618 is not suitable for the treatment of chrysanthemums since it retards the flowering too much, in these experiments as much as up to two months (Table 3). Likewise the treatment of the variety Bonaffon de Luxe with CCC or Phosfon D, docs not seem profitable since 1) a sufficient retardation in the growth of the stems is achieved by short day treatment (–47 %) and pinching (—11 %), and 2) the treatment decreased the number of flowers in the pinhed plants. In the treatment of poinsettia CCC gave the best results. The height of the treated plants was 37 % smaller. Treatment with Amo 1618 as well as with CCC increased the number of injured bracts, the former by 35—65 %, the latter by 15—35 % depending on the time of the treatment. CCC treatment administered two weeks after planting proved in this respect to have the smallest effect. It is also apparent that the quality of the soil type affects the effectivity of Phosfon D and Amo 1618. In the experiment the retarding effect of Phosfon D on the growth of stem was only one fifth and that of Amo 1618 20 % smaller in clay soil than in sand and peat.