FLOODING AND SOIL TEMPERATURE AFFECT WATER RELATIONS AND PHOTOSYNTHESIS OF CITRUS ROOTSTOCK LEAVES
We evaluated the effects of the soil temperature (15, 25 and 35°C) and soil anoxia from flooding for 20 days on citrus rootstock seedlings of CT33 trifoliate, Carrizo citrange and Troyer citrange along with Tucuman, Pomeroy and Rubidoux trifoliates in a greenhouse. Flooding had no effect on shoot water potential (Ψs) at 25°C but at 15°C and 35°C, there were differences from non-flooded trees. Carrizo and Troyer had higher Ψs than CT33, and Tucuman had the highest Ψs among the trifoliates. Soil temperature was more important than flooding in determining plant water relations. At 35°C, ACO2 was reduced up to 14% of non-flooded plants in 4 days, particularly in CT33. In flooded seedlings, across the three genotypes, the decrease of Fv/Fm was highest at 35°C. Troyer rootstock maintained lower ACO2 at 35°C Based on leaf net gas exchange, chlorophyll fluorescence and water relations, above optimal soil temperature accelerates seedling deterioration. CT33 was less tolerant than Carrizo and Troyer at 35°C, whereas Tucuman, Pomeroy and Rubidoux had similar tolerance to anoxia regardless of soil temperature.
Alvaro Otero, , Carmen Goñi, and James P. Syvertsen, (2015). FLOODING AND SOIL TEMPERATURE AFFECT WATER RELATIONS AND PHOTOSYNTHESIS OF CITRUS ROOTSTOCK LEAVES. Acta Hortic. 1065, 1399-1406
citrus rootstock, anoxia, temperature, photosynthesis, abiotic stresses