Olive leaf spot, caused by the fungus Fusicladium oleagineum, is the most important leaf disease of olive trees in countries such as Italy, Spain, the United States, South America, Australia and New Zealand. Among its most serious symptoms is the defoliation of the tree, weakening it and causing crop losses between 10-20% depending on the year and location (Salman, 2017). The most characteristic symptoms are circular or annular spots appearing mainly on the upper side of the leaves, of variable size and dark colour due to the development of the spores. (López-doncel, 2000, Trapero, 2004). The pathogen survives during unfavourable periods (dry and hot weather) on infected leaves that remain on the tree. During rainy periods, new conidia are produced on foliar lesions, activating the disease (López-doncel, 2000, Trapero, 2004). Dispersal and infection takes place from mid-autumn to late spring, with maximum production during winter. Infection occurs between 8 and 24°C, with an optimum near 15°C and the presence of free water (López-doncel, 2000, Trapero, 2004). In areas with high disease rates at the end of winter, spring applications are essential, since the presence of new leaves favours the establishment of the fungus as they are highly susceptible and these same infected leaves will be the inoculum for the epidemics of the following cycle (autumn-winter). It is therefore advisable to carry out treatments at the beginning of autumn, at the end of winter and in spring (López-doncel, 2000, Trapero, 2004). Disease control is based on foliar application of fungicides, especially cupric compounds, which has caused significant environmental damage, especially in terms of the impact on soil microorganisms and human health. For this reason, the administrations are limiting the maximum number of applications and quantity of copper to be applied per season, reaching 4 kg/ha/year in organic farming (Regulation (EU) 2018/1981). In addition, the European Commission has included copper as one of the substances to be replaced, although there is currently no effective solution on the market. The application of products with formulations that optimise the action of this element, but at the same time reduce the copper content, is an imminent need. At TRICHODEX we have designed TRICOPPER. Formulated on the basis of microencapsulated copper heptagluconate, with only 5.5% of active material but with a higher efficacy than 50% copper oxychloride. With TRICOPPER we control leaf spot by 83.3% in preventive application and 49.6% in curative application, and we significantly reduce the amount of copper applied to the crop. TRICOPPER application times:
References
- Salman, M. (2017). Biological control of Spilocaea oleagina, the causal agent of olive leaf spot disease, using antagonistic bacteria. Journal of Plant Pathology, 99(3), 741-744.
- Regional Government of Andalusia
- López-doncel, l.m.; Viruega, j.r.; Trapero, A. 2000. Respuesta del olivo a la inoculación con Spilocaea oleagina, agente del Repilo. Bol. San. Vegetal-Plagas 26: 349-363
- TRAPERO, A.; BLANCO, M.A. 2004. Enfermedades. In: El cultivo del olivo. Barranco, D.; FernándezEscobar, R.; Rallo, L., eds. Regional Government of Andalusia and Mundi-Prensa, pp. 557-614.