カトレアの生長と化学組成に及ぼす培養液濃度と培養土の影響

Abstract

Effects of 4 levels of nutrient solution and 5 potting media on growth and chemical composition of plant parts of a Cattleya hybrid, C. Ray Park×Lc. Oakland ‘MARIA’, AM/AOS, were examined.1. Cattleya plants, av. 27.8g fresh wt, were potted in Bora (pumice) on Mar. 22, 1979, in 12cm diameter polyethylene pots. Twenty ml of nutrient solution was given weekly, 28 times from April 21 to Oct. 26. Nitrogen, phosphorus, potassium, calcium and magnesium were included in a standard nutrient solution (St solution) at concentrations of 231, 46.5, 117.3, 80.1 and 12.2ppm, respectively. Four treatments were as follows: 1/3St, 2/3St, St and 4/3St. Calcium, magnesium and microelements were included at the same concentration in all treatments. Rate of fresh weight increase was best in plants receiving St solution. Root growth of plants receiving 4/3St was slightly inferior to that of plants receiving St solution. Nitrogen, phosphorus and potassium in the leaves increased with increasing concentrations of nutrient solution.2. Cattleya plants, av. 27.7g fresh wt, were potted on Mar. 22. 1979, in 12cm diameter polyethylene pots. Five potting media were as follows: Bora+peat moss (3:1)mix, Bora+peat moss (2:1)mix, Bora+peat moss (1:1)mix, hemlock bark (well-decomposed) and sphagnum moss. Twenty ml of 1/3St solution per pot was given weekly, 28 times from April 21 to Oct. 26. Plants grown in Bora+peat moss (1:1) mix grew best. Nitrogen phosphorus, potassium, calcium and magnesium contents (% dry weight) of leaves were 1.20, 0.17, 1.86, 1.14, and 0.92, respectively. Rate of fresh weight increase and root growth of plants grown in sphagnum moss and hemlock bark were inferior to those of plants grown in Bora+peat moss(1:1) mix. Magnesium content of leaves of plants grown in sphagnum moss and hemlock bark was 0.57 and 0.50%, respectively. These magnesium values seemed to be low as compared to those of leaves of plants grown in Bora+peat moss (1:1) mix.