Effects of plant density on sunflower premature ripening caused by Phoma macdonaldii

Celia Seassau (1, 2) , Emmanuelle Bret-Mestries (3) , Gregory Dechamp-Guillaume (1, 4) , Philippe Debaeke (1)

1 AGIR - AGroécologie, Innovations, teRritoires
2 INP - PURPAN - Ecole d'Ingénieurs de Purpan
3 Terres Inovia
4 ENSAT - École nationale supérieure agronomique de Toulouse

Premature ripening (PR) is one of the most important fungal diseases in France, responsible for high yield losses in sunflower crop in the main regions of production. Previous results indicated that girdling canker of the stem base, caused by Phoma macdonaldii, was its primary cause. Previous studies have reported the influence of nitrogen and water supply on the incidence and severity of PR but an additional study was required to analyse the effect of plant density on the level of attack for a more comprehensive cultural control of PR. This study supplements the known effects of crop management on sunflower PR and emphasizes the key role of crop canopy in understanding the processes involved in the development of the disease. This morphology could be manipulated through crop management (plant density, N fertilization) and probably breeding.

Mots clés: Crop management; Leptosphaeria lindquistii; Plant density; Plant morphology; Premature ripening

Domaines: Phytopathologie et phytopharmacie; Agronomie

Celia Seassau, Emmanuelle Bret-Mestries, Gregory Dechamp-Guillaume, Philippe Debaeke. Effects of plant density on sunflower premature ripening caused by Phoma macdonaldii. 18th International Sunflower Association Conference, International Sunflower Association, Feb 2012, Mar del Plata, Argentina. ⟨hal-03538175⟩