Samenvatting

Raspberries are high-valuable soft fruit for growers. But it is even more interesting for them to grow during wintertime when weather as in Portugal is still favorable, as the offer is low on the market and they can distinguish really easily and sell raspberries at high prices. ‘Sapphire’ is currently considered as the best variety on the market for raspberries, as its shows characteristics that attract the most customers: a really big size, firm, red, juicy and tasty fruit. Both the demand for this fruit and the margin for the grower are really high. However, as the propagation isn’t done into Portugal, growers face the problem of contaminated plants at arrival in Portugal with the oomycete Phytophthora rubi. As this is really hard to detect into the propagation field, as it can never express itself as expressing quickly, and symptoms can be confused with Pratylenchus penetrans, a nematode. So propagators cannot do anything currently. Phytophthora gender includes a large range of species well-known all around the world by growers for big damages that they occur to crops when they express. In that way, the current easiest and relevant solution for growers is to select at planting stage, the ones which show most chances to survive. In that way, a trial has been managed at The Summer Berry Company Portugal, in Herdade dos Almeidans 0, in Longueira-Almograve in the South-West coast of Portugal from November 2019 to December 2019 to determinate the amount of infected roots that a ‘Sapphire’ raspberry plant can properly live with. For that, received plants were selected by visual inspection and ranged according to their root infection into several classes: 0% of infection, 30% of infection, 50% of infection, 70% of infection and 100% of infection. Phytophthora rubi involvement has been checked by sending samples of the root system to a Spanish laboratory. Then, they have been transplanted and the crop has been managed as any ‘Sapphire’ crop at the company until the harvest. A follow-up has been done each week until flowering. Observed criteria were: vegetative and generative stages of development, number of dead plants, number of axillary buds, number of flower abortion and a fruit forecast. Data were analyzed according to the ANOVA One-way by Excel software. Statistically significant differences between infection modalities have been noticed for the number of dead canes and the number of laterals per cane. 0% infected canes got the best behavior with Phytophthora rubi with the lowest number of dead canes, one of the highest number of laterals during all the trial (around 13 laterals per cane) and one of the highest development stage (around 53). Levels of infection which have been considered acceptable in starting material are 0%, 30% and 50%. These results confirm that Phytophthora rubi can kill quickly highly infected canes. Phytophthora Pocket diagnostic® on-site testing kits cannot be considered as a relevant method to ensure ‘Sapphire’ raspberry plants are infected with Phytophthora rubi.