Gas exchange, growth, yield and beverage quality of Coffea arabica cultivars grafted on to C. canephora and C. congensis
Gas exchange, leaf carbon isotope discrimination, growth, yield and beverage quality were evaluated for two Coffea arabica cultivars, Catuai and Mundo Novo, grafted on C. canephora and C. congensis progenies growing in open fields in Sao Paulo, Brazil. During the years 1994-97, grafting resulted in an average increase in bean yield of 151 and 89 percent for Catuai and Mundo Novo, respectively. Sensory analysis and ratio between the monomers and dimers of caffeoylquinic acid (chlorogenic acid] revealed thatthe beverage quality of the C. arabica was not altered by grafting. Shoot growth was significantly greater in grafted plants, showing an increase of 52 percent in total leaf area compared with the non-grafted plants. Under conditions of water excess in the soilthere was little difference in the transpiration and stomatal conductance rates between the grafted and non-grafted plants, but the net photosynthesis was higher in grafted plants. With an accentuated water deficit in the soil in the dry period, the grafted plants showed significantly higher transpiration and stomatal conductance rates than the non-grafted plants, and similar values to those of C. canephora. Carbon isotope discrimination was greater in the grafted plants, suggesting greater root hydraulic conductance. The results suggest that the better performance of the grafted plants during the dry period was due to the greater capacity of the root system of C. canephora to provide water to the shoots thereby maintaining greater gas exchange in the leaves and consequently a greater carbon gain.
| Main Authors: | , , , , |
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| Format: | biblioteca |
| Published: |
2001
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| Subjects: | COFFEA ARABICA, COFFEA CANEPHORA, COFFEA CONGENSIS, CARBON, ACIDO CLOROGENICO, RENDIMIENTO DE CULTIVOS, VARIEDADES, CLIMA ARIDO, INTERCAMBIO DE GASES, INJERTO, CRECIMIENTO, ISOTOPOS, CONDUCTANCIA FOLIAR, HOJAS, FOTOSINTESIS, CONDUCTANCIA HIDRAULICA DE RAICES, BROTES, ESTOMA, TRANSPIRACION, |
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