CO2-ENHANCED FOLIAR DEFORMATION OF TOMATO - RELATIONSHIP TO FOLIAR STARCH CONCENTRATION

Two cultivars of greenhouse tomato (Lycopersicon esculentum Mill.) were grown with ambient or 1000-mu-l CO2/liter during Jan.-June 1987 and 1988. In both years, CO2-enrichment increased foliar deformation and foliar starch, but during the season, foliar starch levels decreased while deformation increased. 'Laura' had more deformation, while 'Michigan-Ohio' had higher foliar starch concentration. During an entire season, there was no significant relationship between foliar starch concentration and deformation severity. Foliar C exchange rates in the lower canopy were not affected by severity of deformation. Data from these experiments do not support the hypothesis that excess foliar starch is responsible for foliar deformation at elevated CO2.