Biological basis of sorghum cultivation in the North-West of the Non-Chernozem zone

Abstract

The need to restore the dairy cattle population and the feed base in the North-West region of the Russian Federation requires new sources of feed with high yield and nutritional values. The purpose of the research is to study the possibility of sugar sorghum introduction into the region for forage use. The research was conducted in 2017-2020 in the conditions of the Novgorod region. On plots with an area of 10 m2 in the third decade of May sugar sorghum was sown: a hybrid of the first generation Silosnoe 88, the Galia variety, the Laretz line. The predecessors were potato (2017, 2018, 2020) and vetch and oat mix (2019). The ability of sugar sorghum to stop developing and hibernate in unfavorable weather conditions, resuming vegetation when the weather improves, has been established. Intensive plant growth was observed at the end of July-August with the average daily growth of 1.9-5.0 cm. By the end of August, the plant height reached 245-280 cm, the yield of green mass was 110 t/ha (hybrid Silosnoe 88), 139.2 t/ha (variety Galia), 136 t/ha (Laretz line). In the extreme conditions of 2017, the yield of sorghum green mass was 21 t/ha. The yield of dry matter (DM) from 1 ha reached 6.8-13.4 t/ha. The protein content in the DM was 8.4-11.5 %, the yield of feed units was 0.76-0.82 kg/kg, the output of exchange energy was 9.7-10.1 MJ/kg. Sugar sorghum has an ability to grow back after mowing; in the conditions of the Novgorod region, the yield of green mass from two mowing (end of July, August-September) was lower (23.3-46.7 t/ha) than from the one at the end of August-September (44.3-139.2 t/ha). The Laretz line vegetation phases began 5-27 days later than those of the Silosnoe 88 hybrid and Galiya variety. The growing season of sugar sorghum ended in the phase of “heading of panicles - flowering”. Thus, a high plasticity and adaptability of sorghum varieties to unfavorable climatic conditions of the zone and their prospects for use in forage production have been established.