Phytophthora capsici: the diseases it causes and management strategies to produce healthier vegetable crops

Abstract

Vegetable crops are exposed to constant infection by numerous diseases, including those caused by the oomycete Phytophthora capsici. This microorganism is a polyphagous plant pathogen, capable of infecting dozens of plant species, including cultivated plants and weeds. The aim of this review is to address topics related to etiology and symptoms of the diseases caused by this oomycete (leaf blight, root rot, crown rot and fruit rot), as well as the integration and application of different control alternatives, such as genetics, cultural, physical, biological, and chemical. Crops such as sweet pepper (Capsicum annuum), chili pepper (Capsicum spp.), tomato (Solanum lycopersicum), eggplant (S. melongena), cucurbits (Cucumis sativus, Cucurbita spp.), among others, are subject to considerable economic losses induced by this pathogen. High soil humidity, high temperatures, resistance structures of the pathogen (oospores), scarce availability of resistant cultivars and a reduced range of effective fungicides are conditions that difficult the management of diseases caused by P. capsici in the field. Despite the irrefutable importance of this pathogen, the existing information regarding its integrated management is limited. Therefore, a successful management will depend to a great extent on its knowledge and its control. Thus, the joint application of different control strategies seeks to maintain the pathogen at low population levels and also keeping the epidemics under the threshold of economic loss. At the end, an integrated pest management approach for P. capsici could result in higher economic returns, long-term sustainable harvests, reduction of the environment impact and better quality products for consumers.

Espécies fitopatogênicas de Phytophthora

“…As espécies de Phytophthora são encontradas atacando suas hospedeiras desde a fase de mudas até a fase de colheita. Podem infectar todos os órgãos da planta, causando tombamentos de mudas, podridões de raízes e colo, podridões de flores e frutos, além de "queimas" e manchas nos órgãos aéreos (ERWIN & RIBEIRO 1996;RISTAINO & JOHNS-TON 1999;RIZZO et al 2002;AGRIOS 2005;DUNS-TAN et al 2010;SALTOS et al 2022). Entretanto, por serem patógenos predominantemente habitantes do solo, espécies de Phytophthora são fortemente associadas ao tombamento de mudas e a podridões de raízes e de colo (ERWIN & RIBEIRO 1996;AGRIOS 2005).…”

“…Um exemplo de espécie de Phytophthora que ataca suas hospedeiras principalmente a partir do solo, com pouca dispersão aérea, é P. capsici, que causa grandes perdas em hortaliças (RISTAINO & JOHNSTON 1999;GRANKE et al 2012, SALTOS et al 2022. Phytophthora capsici possui uma ampla gama de hospedeiras, pertencentes, principalmente, às famílias Solanaceae, Cucurbitaceae e Fabaceae (Tabela 1).…”

“…Phytophthora capsici possui uma ampla gama de hospedeiras, pertencentes, principalmente, às famílias Solanaceae, Cucurbitaceae e Fabaceae (Tabela 1). O patógeno causa tombamento de mudas, podridões de raízes e colo (Figura 1A), queimas foliares e podridões de frutos próximos ou em contato com o solo (LAMOUR et al 2012;REIS et al 2018;SALTOS et al 2022). O ataque de P. capsici pode ser devastador em alguns plantios de abóboras (Cucurbita spp.…”

Phytophthora capsici on Capsicum Plants: A Destructive Pathogen in Chili and Pepper Crops

“…A solution to reduce these effects on the oomycete is the use of active ingredients such as mandipropamide and dimethomorph, considered molecules with low to medium risk of resistance [79,80]. In order to reduce the selection pressure by the phytopathogen, the farmer must have a wide range of molecules applied in periodic and scheduled rotation during each crop cycle [81], and even use mixtures that have systemic and protective modes of action.…”

“…Integrated disease management (IDM) aims to minimize the biological activity of the pathogen and increase crop productivity, involving the use of various techniques in favor of the environment by avoiding the excessive use of chemical molecules and reducing control costs of P. capsici [80]. To effectively manage diseases caused by P. capsici in Capsicum, different management strategies should be integrated in either agroecological, conventional or other production systems [81]. Usually a single strategy is ineffective for the management of P. capsici [80]; for this, IDM is based on…”