Articles
INFLUENCE OF SOME NUTRITIONAL AND MICROCLIMATIC FACTORS ON GREENHOUSE TOMATO YIELD AND ON OCCURENCE OF SOME PHYSIOLOGICAL DESEASES
Experiments were carried out in two locations of the same 1 ha greenhouse, temperature and light intensity differences between two locations being of 2—4°C and 300—2000 lux respectively.
Largest number of flowers was observed at the lower temperatures, while fruit setting was by 8—12% higher at the warmer location where the P, K and Mg contents of soil as well as early yields were also higher particularly for the first vegetation period.
It appeared that infavourable nutritional conditions i.e. excess, deficiencies or lack of balance of the nutrient supply affected yields to a higher degree than adverse microclimatic conditions.
Physiological defects of fruit seem to depend mainly on climate conditions.
Vitreousness deformations and hollows occurs mostly at lower temperatures while blotchy ripening is more frequent in varmer conditions.
Acidity of fruits is also higher at lower temperatures on the other hand, in warmer conditions and when yields are higher, dry matter, sugar and asorbic acid contents of fruit tend to decrease.
It thus appears that occurence of physiological diseases and fruit quality are strengly dependent on a complex of factors, among which climatic and nutritional conditions are the important.