CHARACTERISTICS OF IMMATURE ASPARAGUS PLANTS AS POSSIBLE INDICATORS OF THEIR FUTURE YIELD

Asparagus yield potential depends on the size of plants and photosynthesis rate as well as on carbohydrates distribution in the previous year. The question occurs if some characteristics of young plants of different cultivars are correlated with their yield potential. Seven asparagus cultivars originating from countries under different climatic conditions have been included in the experiment established in 2008. The size of summer stalks, their number and diameter as well as the height of plants were measured. At the end of vegetation period crowns were dug out and their fresh and dry weight as well as storage root number, their diameter and number of buds were determined. Total soluble sugar content in roots was also analysed.
There were found to be present big differences in all plant parameters among cultivars. The differences in the size of the underground part were bigger than those in the over-ground part of plants. For example the differences in the weight of summer stalks between the weakest and the strongest cultivars amounted to 76% while in the weight of a crown to 132%. On the contrary, the differences among cultivars in number of summer stalks were bigger than those in storage roots. Cultivars differed in photosynthetic production, which can be expressed among others by the amount of total sugar in crowns. This value ranged from 180 g to 506 g per plant. On the basis of preliminary results it can be concluded that differences among cultivars seem to be bigger in the size of underground part than in over-ground part of plants and there are great differences in total sugar amount in the storage roots in immature asparagus plants. These differences might be correlated with the yield potential of mature plants.