OPTIMIZATION OF PLANT DENSITY OF <i>CYAMOPSIS TETRAGONOLOBA</i> L. ON THE LEACHED CHERNOSEMS OF WESTERN CISCAUCASIA
Guar (Cyamopsis tetragonoloba (L.) is new for Russia agricultural crop that is used in industrial applications, such as the gas and oil producing, and food industry. Guar gum is a valuable component of the technological processes of many sectors of the national economy, but now it is fully imported. To reduce dependence on foreign guar gum, we started Cyamopsis tetragonoloba breeding. Two best lines have become the “fathers” of two guar varieties ‘Vektor' and ‘Sinus' that were recorded in the State Register of Breeding Achievements Permitted for Use. The aim of the work was to find the best seeding method for different in morphological type guar varieties. The experiments were carried out on the trial fields (grain row-crop rotation) of Agricultural Holding “Kuban” (located in the central zone of Krasnodar Krai) from 2017 to 2018 according to the methodology of field research. Soil - chernozems leached. The humus content - 3.5 % (for humus determination I. V. Tyurin methodology was used). The content of mobile compounds of phosphorus was 50.8 mg/1kg of soil (for phosphorus mobile compounds determination Machigin method was used), the content of potassium - 307 mg/1kg of soil, the content of nitrogen - 14.7 mg/ 1kg of soil. Variety ‘Vektor' (single-stem morphological type) is better adapted to a dense plant stand. Its yield under conditions of row seeding was 21.7 centners per hectare, which is 2.8 centners per hectare higher than the yield of the ramous variety ‘Sinus'. Under conditions of wide-space sowing (row spacing 45 cm), the yield of both varieties was equal - 21.7-22.4 centners per hectare. The yield of variety ‘Sinus' was 22.2 centners per hectare when the row spacing was 70 cm that is 3.7 centners per hectare higher than that of the variety ‘Vektor'. The lowest guar pod was formed at a height of 8-9 cm under conditions of row seeding, and at a height of 5-7 cm under conditions of wide-space sowing. This will undoubtedly lead to an increase in losses during harvesting. Bottom pods of the ‘Sinus' variety were formed not only on the main stem but also on numerous lateral branches. This also increases the losses compared to the single stem morphological type.