THE DEVELOPMENT OF A TWIG STRONGLY DEPEND S UPON BUD GROWTH-POTENTIALIN THE ROSE-SCENTED PELARGONIUM

Pruning, defoliation and transplanting experiments were carried out on a woody hybrid of Pelargonium in order to assess the importance of co rrelative inhibition. Compensatory growth following pruning appears to be an essentially global property of the plant : no direct correlatio n was found between neighbouring shoots. Nevertheless strong physiolog ical integration exists in the apical part of the shoot where reaction to pinching or defoliation will develop. Basal shoots of a plant, who se early development takes place in a stressed environment, show a sub stantial underdevelopment once replaced in favourable conditions. Sinc e competition or correlative inhibition can hardly be invoked here it is concluded that some memory of the suffered stress is kept at the le vel of the apex. A possible nature of this imprint is put forward.