| Popis: |
Alternating light and dark periods applied during the moist terminal phase of sporogenesis reduced conidial yield of Peronospora tabacina on tobacco, Pseudoperonospora cubensis on cucumbers, and Helminthosporium turcicum on maize but did not affect the yields of Erysiphe cichoracearum on tobacco. This photoinhibition of conidiation increased with increasing light intensity and duration and frequency of the interrupting light periods. It was also increased with increasing leaf temperature. Lengthening the dark intervals between lightening periods to 2, 3, and 4 h removed the photoinhibition in P. cubensis, P. tabacina, and H. turcicum, respectively. A suggestion is made to use illumination as a controlling device of fungal plant diseases in greenhouses. |
