Wpływ regulatorów wzrostu na zdrowotność, wzrost i wybijanie sałaty w pędy kwiatostanowe [The effect of growth regulators on the healthiness, growth and sprouting of inflorescence shoot of lettuce]

Abstract

Investigations were carried out under greenhouse conditions on lettuce cv. Ilanka. Seeds were sown in January 1982 and 1984. Lettuce was cultivated to middle of June up to full flowering time. It was found that the preparation fenoprop (2,4,5-trichlorofenoxypropionic acid as a dimethylamine salt) in concentrations of 10, 20 and 50 mg·dm^-3 significantly decreased latex tipburn symptoms. Fenoprop increased the healthiness of the plants because treated plants were also less attacked by grey mould Botritis sp. Fenoprop also inhibited head formation in lettuce, but the weight of these plants was never smaller than control ones. Sometimes the weight of plants treated with fenoprop was significantly higher than of the control plants. Lettuce plants without heads had bolted earlier. Only the concentration of 100 mg·dm^-3 of fenoprop retarded plant growth. The effect of K-NAA (potassium salt of α-naphthaleneacetic acid) on lettuce was weaker than the effect of fenoprop. After K-NAA treatment at a concentration of 25 mg·dm^-3, lettuce plants formed normal heads but latex tipburn symptoms were retarded.