Prevalence and aetiology of Phytophthora fruit and stem rot of solanaceous and cucurbitaceous crops in the Pampas region of Argentina

Abstract

In Argentina, agriculture and horticulture industries account for 7% of the country’s employment. Moreover, this country is considered one of the major organic agriculture producers. Horticulture production is widespread all along the country, but the Pampas region is the most vital section because it provides the greatest economic wealth and houses 80% of the population of Argentina. The genus Phytophthora includes remarkably destructive pathogens to an extensive diversity of plant species, especially solanaceous and cucurbitaceous crops. Phytophthora diseases can affect roots, stems and fruits. Due to the increasing economic importance of this disease in Argentina, effective and feasible management strategies need to be established. The current study aims at describing Phytophthora species associated with rots in solanaceous and cucurbitaceous crops in the North-east of Buenos Aires. Field symptoms comprise the aerial parts of the plants in association with the humid conditions that prevail in that region. Phytophthora capsici was determined as the main pathogen causing stem and fruit rot of globe squash, eggplant, tomato and pepper. The prevalence was higher in globe squash, followed by eggplant, compared with the other hosts probably because of the structure of the crop and the susceptibility of the commercial cultivars used in the region. All P. capsici isolates obtained belonged to the A1 mating type and were sensitive to metalaxyl. The isolates of P. capsici tested were pathogenic to all the inoculated fruits, regardless of the host of origin.