Forestry Advance Access originally published online on January 10, 2007
Forestry 2007 80(2):201-209; doi:10.1093/forestry/cpl050
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Variography and kriging allow screening Pinus pinaster resistant to Armillaria ostoyae in field conditions
1 Centro de Investigacións Ambientais de Lourizán, Apdo. 127, Pontevedra, 36080 Spain
2 Departamento de Biología y Producción de los Vegetales, Ingeniería Técnica Forestal, Universidad de Extremadura, Avenida Virgen del Puerto 2, Plasencia, 10600 Spain
* Corresponding author. E-mail: rzas.cifal{at}siam-cma.org
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Abstract |
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Armillaria ostoyae is an important disease of Pinus pinaster in north-west Spain, which kills trees following a heterogeneous spatial structure. In a progeny trial of P. pinaster seedlings, spatial heterogeneity and autocorrelation of neighbour mortality caused by A. ostoyae impeded proper analysis of the disease incidence. We used variography and kriging methods to describe the spatial distribution of the infection probability and the genetic variation of the resistance to A. ostoyae among families. The spatial structure of disease incidence was modelled, and the probability of survival was corrected by kriging at each tree location. Cumulative mortality 3 years after planting was 65.1 per cent. Significant differences among P. pinaster families in terms of mortality to A. ostoyae were found, with low individual (h
= 0.08) and moderate family (h
= 0.35) heritability estimates. According to a theoretical semivariogram, the patch size of the disease incidence was 
63 m wide. This is the first time variography and kriging are used to select P. pinaster resistant to Armillaria root rot. It is concluded that geostatistics provides forest pathologists with a powerful tool for screening resistant trees in field conditions.