オドントグロッサム類における葉枯れ症状の発生と制御

抄録

Three cultivars of Odontoglossum Intergeneric hybrid orchid, Velano (Odontioda Marie Noel‘Velano’), Polka (Odontonia Moliere‘Polka’) and Rubis (Odontioda Picasso‘Rubis’) were studied to ameliorate the development of leaf burn occurred after transplanting. The symptom, started at the tip of a leaf and spread to the petiole, began to appear 4-6 weeks after they were potted from the flasks in which they had been cultured. The leaf eventually abscised. The leaf burn did not occur in new leaves in Velano and Polka, but it did occur in Rubis. The severity of symptom differed among cultivars and it reduced significantly in the case where the plants were kept in high humidity for 80 d after they were potted from the flasks, but the high humidity did not retard the growth of plants. The leaves with leaf burn tended to contain higher Ca than those without leaf burn. There was, however, no significant difference in the concentrations of N, P, K and Mg between normal leaves and those with the leaf burn. The tip-burn in a high humidity environment can be avoided by using suitable cultivars.