Abstract
The characteristics of growth and green mass formation of the first-generation sweet sorghum hybrid ‘Silosnoe 88’ for fodder production purposes were studied in 2017–2024 in the Novgorod region on sod-podzolic medium-cultivated soil. The sowing was carried out in the third ten-day period of May with a seeding rate of 20 kg/ha and a row spacing of 15 cm, observations and records were conducted according to generally accepted methods, the yield of green mass was determined during the shooting phase (up to the «heading of panicles» phase). The data obtained during the research period on agrome
teorological indicators, timing of phenophases and yield of green mass of ‘Silosnoe 88’ sweet sorghum served as the basis for conducting correlation and regression analyses. A dependence of the duration of interphase periods of vegetation on the sum of active (above 10 °С) temperatures at all stages of plant development was established, but a closer relationship (r = 0.95–0.99) was observed in the interphase periods: "sowing – young growth", "young growth – tillering", "tillering – shooting". An increase in the amount of precipitation affected the duration of the interphase periods “young growth – tillering”, “shooting – heading of panicles”, “heading of panicles – flowering” (r = 0.80–0.90). During the “young growth – tillering” period, a correlation was established between the yield of green mass of ‘Silosnoe 88’ sweet sorghum hybrid and the amount of precipitation (r = -0.59), the amount of active temperatures (r = -0.61), and the duration of the period (r = -0.75). The regression equation (R
2
= 0.56) showed that a reduction in the duration of the “young growth – tillering” period by 10 days was accompanied by an increase in green mass yield by 21 t/ha. The obtained dependencies indicate that for the successful cultivation of ‘Silosnoye 88’ sweet sorghum, the presence of favorable agrometeorological factors is necessary at the initial stages of its development, especially during the "young growth – tillering" period. It is during this period that its productive potential is laid.