The structure of the seed herbage of the pannonian clover (Trifolium pannonicum Jacq.) variety Snezhok in the conditions of the Kirov region

Abstract

The article presents the results of 2016-2020 study of the characteristics of growth and development of the pannonian clover variety Snezhok, bred at the Federal Agricultural Research Center of the North-East named N.V. Rudnitsky, while using the herbage for seeds. Uneven-aged herbage was assessed in the breeding nursery of 2016 sowing according to the characteristics of winter hardiness, the duration of individual interphase periods of development, plant height, structure of seed herbage, fruiting and seed yield. The overwintering of plants in all the years of research was high ‒ 100%. With an increase in the age of the stand, the prefloral (from growing to the beginning of flowering) and growing seasons from 47 to 72 and from 92 to 125-130 days (days) were lengthened. The height of plants in the phase of maturation of heads and seeds with the age of the stand also increased from 66.6 (1 year of use (y.u.)) to 97.1 cm (4 y.u.), the tendency of herbage to lodging increased from 0 (1 y.u.) to 30.9% (4 y.u.). In the first year of seed use (the 2 nd year of life (y.l.)), the minimum values of such structural indicators as the number of stems and heads per 1 m2 (245 and 151 pcs.), The content of generative stems in the total amount (42.8%), weight of seeds per 1 m2 (15.3 g). Starting from the 2 nd y.u. the listed structure indicators significantly increased and herbage stands were formed annually for three years, allowing them to be classified as highly productive: with the stem density of 366-405 pcs / m2 and a share of generative ones in them - 59.0-84.2 %, the number of heads - 350 -500 pcs / m2 , seed weight - 31.5-46.1 g / m2 . The level of seed productivity of pannonian clover depended to a greater extent on the age of the stand than on weather conditions during the period from regrowth to seed ripening. It was revealed that the biological (potential) seed yield in favorable years with sufficient technical support can reach 4.33 c/ha, while the actual (economic) average over the years of research was 0.54 c/ha, with changes from 0.20 (2017) up to 0.74 c/ha (2020).