Determination and analysis of soil receptivity to Fusarium solani f. sp. pisi causing dry root rot of peas

• Published in: Phytopathology 1994, Vol.84 (8), p.834-842
• Main Authors: OYARZUN, P. J, DIJST, G, MAAS, P. W. T
• Format: Article
• Language: English
• Subjects: agent pathogene; Agronomy. Soil science and plant productions; bioassays; biologia del suelo; Biological and medical sciences; biologie du sol; champignon; champignon du sol; dosage biologique; ensayo biologico; Fundamental and applied biological sciences. Psychology; Fungal plant pathogens; fungi; fusarium solani; Fusarium solani pisi; hongos; hongos del suelo; mathematical models; modele mathematique; modelos matematicos; netherlands; organismos patogenos; paises bajos; pathogenicity; pathogens; Pathology, epidemiology, host-fungus relationships. Damages, economic importance; pays bas; Phytopathology. Animal pests. Plant and forest protection; Pisum sativum; poder patogeno; pouvoir pathogene; soil biology; soil fungi
• ISSN: 0031-949X; 1943-7684
• DOI: 10.1094/Phyto-84-834

A procedure was developed to differentiate field soils according to their receptivity, ranging from suppressive to conducive, to fusarium solani f. sp. pisi, one of the most important soilborne fungi causing dry root rot of pea. Experiments were carried out with samples of natural soil collected from commercial fields that had had a low inoculum potential for root rot in peas in previous years. In bioassays with computer-controlled soil water potential, light intensity, air temperature, and relative humidity, dry root rot severity responses to a range of inoculum levels were determined. Disease severity in different soil samples at the same infestation level showed that soil as a substrate strongly affects the inoculum potential of F. s. pisi. In samples that were selected because they produced only dry root rot, the amount of native Fusarium in pea rhizosphere soil was uncorrelated with root rot severity. Univariate and multivariate models were examined for their adequacy to describe and compare disease response data. Principal component analysis carried out on a table of samples by Weibull fitted disease responses or on a table of samples by average disease responses produced a similar receptivity order (P less than or equal to 0.01) of the samples, but fitted values increased the quality of ordinations. Use of cluster analysis followed by a canonical variate analysis classified the tested soil into groups that differed significantly (P less than or equal to 0.05 on the basis of x2) in soil receptivity to F. s. pisi. The value of this technique for further ecological research is discussed.