Changes in solar energy efficiency of purple-flowered pea cultivars during the breeding period from the 1920s to the 2000s

In modern studies of photosynthetic activity of agricultural plants, much attention is paid to the issues of increasing the efficiency of light use by the plant cover and the efficiency of converting solar energy into dry matter. It is noted that this is the main option for increasing the potential yield of promising varieties. Taking it into the account, we conducted a retrospective study of the efficiency of photosynthetically active radiation (PAR efficiency) in varieties and genotypes of field peas. On average, the PAR efficiency in field and sowing peas was 1.38% and 1.39%, respectively. Depending on the vegetation conditions, it varied from 0.94% to 1.60% in field peas and from 0.88% to 1.64% in white-flowered sowing peas. In dry conditions with a strong lack of water, a decrease in the PAR efficiency is noted in the studied field pea genotypes (on average, by 1.75 times), and in modern varieties and genotypes of the crop - by 2.43 times compared to more favorable vegetation conditions. As a result of crop selection, an increase in the PAR efficiency is noted from 1.26% in peas bred in the 1920-1950s to 1.56% in peas bred in the 1990-2000s. Under optimal conditions, the Zaryanka variety was characterized by high PAR efficiency values - 2.20%. And the Natasha variety was characterized by the highest PAR efficiency (0.98%) - in dry conditions. The Natasha pea variety can be recommended as a source of high PAR efficiency for creating pea varieties for arid regions of the country. And the Zaryanka variety is for varieties grown in the conditions of optimal moisture for the crop.