Psa, Pseudomonas syringae pv.actinidiae, is the causal agent of actinidia bacterial canker, considered the most serious disease of this crop. It can, in more virulent cases, cause the death of plants, calling into question the sustainability of the sector and causing significant economic losses in the main kiwifruit producing countries, including Portugal (EPPO, 2011/054). This disease, detected in Portugal in 2010, shows high aggressiveness and a very fast dispersion, having, nowadays, a generalized distribution in the producing regions. Worldwide, the industry linked to the kiwi sector is engaged in developing disease control strategies to contain the pandemic and minimize the economic losses of producers, but without positive results.
The kiwifruit crop is completely dependent on an effective pollination process and there is a direct relationship between fruit size and pollination efficiency. The kiwifruit is a dioecious plant pollinated by wind and bees, however, the pollination process depends on several components, including synchronization of flowering between male and female varieties and the viability and germination capacity of pollen grains. Often the varieties grown in Portugal respond less well to the abiotic conditions of our region because they were developed elsewhere in the world. The difficulty in the pollination process has led to the development of assisted pollination techniques to bridge pollination deficits and achieve optimum calibres in kiwi orchards. However, the efficiency of pollination practices in our region has not been quantified and is important for optimising the productivity of nationals.
In what concerns the propagation materials for the kiwifruit crop, these originate from other countries as happens with other fruit species. This situation is disadvantageous, both from an economic and agronomic point of view, since the existing varieties were developed for soil and climate conditions different from those in our country. It is therefore imperative to identify quality plants, well adapted to our environmental and soil variables, less susceptible to disease and producers of quality pollen that could constitute a set of progenitors for future generations, with the aim of increasing productivity, as is done in other producing countries.
