Spreading of diseases in strawberry - legume intercropping

Not only yield and quality parameters, but also phytosanitary state of crops is an important parameter in developing and evaluating of new growing techniques. Intercropping becomes more popular in recent years in integrated growing and sustainable farming systems. A strawberry-legume intercrop trial was established at the Pūre Horticultural Research Centre (Pūre HRC) in 2014. It combined strawberry (Fragaria × ananassa Duch.) growing in rows with legumes grown between rows under open field conditions. Three legumes species were used as intercrop in the trial: two local genotype of broad bean (Vicia faba var. major), peas (Pisum sativum spp. 'Ambrozija' and 'Capella') and alsike clover (Trifolyum hybridum 'Namejs'). No nitrogen fertilizers were applied in treatments with legume intercropping. As a control, two treatments were used. First - traditional growing with nitrogen fertilizer application, second NDASH traditional growing without nitrogen fertilizer application. Spreading and severity of strawberry leaf diseases and grey mould (caused by Botrytis cinerea) on berries were evaluated on strawberries. Leaf spots were evaluated for two growing seasons in 2014 from 8 August until September 29 and in 2015 from May 28 until September 10; grey mould was evaluated on berries for one season in 2015 from June 26 until July 22. It was observed that the dominant strawberry leaf disease was common leaf spots (caused by Mycosphaerella fragariae). Its severity was significantly higher in intercrop with alsike clover and peas, but no significant differences were observed between both controls and treatments with bean intercropping. No differences were observed in damages caused by Botrytis between the treatments. Obtained results show that intercropping with broad beans has no negative influence on phytosanitary state of strawberries in Latvian climatic conditions. Taking in to account agro-ecological services of broad beans, this intercropping system may be perspective in future.