The effect of a vegetation period on protein percentage in seed of the pea collection samples

The purpose of the study was to identify the effect of the length of a vegetation period of collection samples on protein percentage in pea seed. The study was carried out in the southern part of the Rostov region on the fields of the FSBSI «ARC «Donskoy» in 2017–2020. The objects of the study were 100 collection pea samples from the N. I. Vavilov ARIPGR (VIR), including 53 leafless samples and 47 leafy ones. The longest vegetation period on average for the collection (93.8 days) was identified in 2017. The intervarietal variability of this trait, expressed by a variation coefficient, this year was 5.5 % with a minimum value of 63 days and a maximum of 101 days. In the group of varieties of the leafless type, the intervarietal variability was 6.4 % (min. 63 days; max. 100 days), in the leafy group it was 4.2 % (min. 80 days; max. 101 days). In other years, there was a reduction of a vegetation period and a decrease in its intervarietal variability due to unfavorable weather conditions in the form of a lack and shortage of precipitation against the background of elevated and high air temperatures. But they also led to the maximum accumulation of protein in seeds of collection samples, thereby showing the greatest intervarietal variability of this indicator. The calculation of the correlation coefficient showed the absence of a correlation dependence of protein percentage on length of vegetation, both on average for the collection (r = 0.03+0.10) and for the groups of leafless (r = 0.08+0.14) and foliate (r = 0.05+0.15) leaf morphotypes. The construction of graphs with errors for groups of leafy morphotypes revealed samples with a protein percentage of more than 25.0 %. In the group of the leafless morphotype, they had a vegetation period of 78–80 and 83–85 days, and in the group of the leafy morphotype, it was 77–79 days on average over the years of study.