Biotic and abiotic factors affecting Cistus ladanifer production in cultivated plots from mainland Spain

The sustainable production of rockroses is being actively encouraged due to their contribution to rural development and circular economy. Particularly, rockrose (Cistus ladanifer L.) exploitation has great socioeconomic and environmental potential, since it is not only a source of essential oils and labdanum gum but also of residual products involved in biomass generation. Moreover, the management of rockroses has beneficial effects on the preservation of traditional landscapes and their biodiversity. It is considered that the cultivation of rockrose does not have high resource requirements, and very few pests and diseases are known to affect it, as plant extracts and essential oils of this crop have been described to have antifungal and antibacterial properties. However, in cultivated rockrose plots from Mainland Spain, a high number of plants were observed with symptoms of general yellowing and decline, eventually resulting in death. Samples were taken for pathogen diagnosis, and data were collected from environmental conditions in the area. Isolations were performed on culture media from crowns and stems, and fungal colonies were molecularly analysed by the amplification of their ITS (Internal Transcribed Spacer) DNA regions. Sequencing revealed the presence of the pathogenic species Macrophomina phaseolina, Fusarium acuminatum, F. equiseti, and F. tricinctum. Environmental data suggested the contribution of a prolonged period of rain in late spring, a crop field that was not subsolated, and plants from staking. This could indicate a combined effect of deleterious biotic and abiotic factors as the cause of the unexpected appearance of the symptoms and damage that occurred on the rockrose crop production, which suggests the need to develop an integrated management strategy in this kind of agroecosystem.