CHEMICAL CONTROL OF BACTERIAL BLIGHT OF WALNUT

Bordeaux mixture (alone and supplemented with iron sulphate or Kasumin), Kocide and Kasumin were tested for the control of walnut blight in Alcobaça (Portugal). Cultivar Rego was used, and seven sprays were applied at weekly intervals after 31 March 1994.

The disease intensity was measured by counting spots on leaf samples collected in July, by recording external damage to fruits on July and September, and damage to seeds after the fruits were harvested and dried.
Dimensions of dried fruits were also taken.
Treatments were compared using the pathometric variables incidence and severity.

On all treatments, no correlation was found between levels of external damage to fruits and of damaged seed tissues.
Significant differences in dried fruit volume were observed among treatments.
Copper compounds, especially Kocide, were the most effective, although none of the treatments could provide an adequate control of the disease.

Differences among treatments apparently result from their action on the process of infection, the development of the disease after penetration of the pathogen being unchecked in all instances.

A simple key for recording disease intensity on fruits is proposed and discussed.

III International Walnut Congress

J.M.S. Martins, C. Pinto de Abreu, J.A. Gomes Pereira

Walnut blight, control, disease measurements

https://doi.org/10.17660/ActaHortic.1997.442.58