Popis: |
First sunflower varieties sown in Argentina had been brought by immigrants from Russia. This germplasm was the base for both official and private nurseries to create new varieties adapted to the country by selection. In the 1960’s, many varieties were obtained from intercrosses with wild species in official nurseries. These new varieties had the characteristic of resistance to the diseases present in the crop at that time. In the 1970’s, in both official and private nurseries, re-selections on Russian varieties with black achenes were done and also, even if on a small scale, several varieties were registered. In the 1980’s the activity of official nurseries was predominant. Varieties were registered which originated from very extensive crosses, and they at are still used for the development of important lines due to their differential reaction to diseases. |