NUTRIENT STATUS OF CHESTNUT ORCHARDS. II. SEASONAL NUTRIENT VARIATION IN THE INNER BARK IN TWO ORCHARDS WITH DIFFERENT INCIDENCE OF BLIGHT

This study aimed to investigate the seasonal nutrient variation in the phloem of chestnut trees in two orchards with different degrees of blight incidence (caused by Cryphonectria parasitica). Bark samples were collected (April 1999-March 2000) from ten trees in two orchards, one healthy (H-orchard) and one affected (D-orchard) by blight.
In the H-orchard, healthy trees were sampled, while in the D-orchard, both diseased and healthy trees were sampled.
The phloem was analysed for macro and micronutrients.
Soil nutrient content was also determined.
There was a clear seasonal trend in the nutrient concentration in the phloem.
Significant differences in nutrient concentration in the phloem were observed: Ca and Ca/N ratio were higher in the H-orchard and N, K and Fe concentrations were lower.
The higher Ca/N ratio in the H-orchard was the most marked distinction between the two orchards; this difference was greater in June.
In the D-orchard, significantly higher Ca concentrations were detected in the healthy trees, but no differences in Ca/N ratio were observed between healthy and blight affected trees.
Significantly higher N levels in the phloem of the south-west facing samples, when compared with the north side, were detected from November to March.
Soil fertility parameters were found to be better balanced in the H-orchard, while inorganic N and soil acidity were very high in the D-orchard.

III International Chestnut Congress

E. Portela, J. Louzada

Castanea sativa, Cryphonectria parasitica, soil analysis, foliar analysis, phloem analysis, Ca/N ratio, copper

https://doi.org/10.17660/ActaHortic.2005.693.74