The article considers the research results on the influence of the seeding rate on formation of anatomical features of the monoecious helm stems of the Diana breed. According to the experiment scheme, the seeding rate is from 0.1 to 2.7 million pieces of germinating seeds per hectare. The size of each plot is 10 × 10 m (100 m2). The tier is 3-fold. Nature of the change in the thickness of the bast-fibered layer depending on the seeding rates was studied. The results of the research showed that the thickest bast-fibered layer (530.5-636.4 μm) is formed due to the seeding rates of 1.8–2.7 million pieces / ha. Thus, there is a reason to assume that the increased seed rates allow achieving the best yields indicators of the bast-fibered substances. It is noteworthy that each seeding rate is characterized by a certain amount of elementary fibers in the stems: stems from crops with the seeding rate of 0.1–0.6 million pieces / ha have the smallest number of primary and secondary fibers. The largest cells of primary and secondary fibers are found in the stems from crops with the seeding rate of 0.1–0.6 million pieces / ha, the smallest - due to the seeding rate of 1.8–2.7 million pieces / ha. Consequently, the size of both primary and secondary fibers decreases when the seeding rate is increased. The data of the research conclusively prove that the size of the inner lumen of the elementary fibers decreases both lengthwise and edgewise when the seeding rate is increased. Stems that are grown on the plots with the seeding rate of 1.8 -2.7 million pieces / ha have a thick bast-fibered layer (530.5–636.4 μm) with the largest amount of primary and secondary fibers (6918, 4-8302.6 cm) of a regular multi-faceted shape with a small internal lumen lengthwise and edgewise (2.9–4.2 μm and 2.2–2.7 μm).

When solving problems aimed at increasing the yield of cannabis and the marketability of the industry, improving the quality of products and reducing its cost, and ultimately restoring the previous size of the sown area, seed seeding rates are of great importance. Research in our experiments was carried out with a hashish-free variety of monoecious cannabis of the Central Russian type Diana. Studies have shown that in thickened crops by the time of harvesting, the number of fallen plants reaches 5-19 pieces per 1 m2 or 3.79-10.67%. The dependence of plant height on the area of nutrition is most clearly shown in the flowering phase: with a decrease in seed seeding rates, the height of plants increases. In this phase, the greatest growth of plants occurs, which reaches 87.7-119.1 cm. With the expansion of the area of supply is greatly enhanced by the formation of items such as plant height, stem thickness at the root collar and the base of the inflorescence, the mass of the stem, which together determine the length of the inflorescence of the plant. With the thickening of crops, the yield of stems and fibers tends to increase. The highest yield of stems and fiber was obtained at a seeding rate of 3.2 million units per 1 ha. With an increase in the seeding rate, the yield of total and long fiber increases. The yield of short fiber decreases noticeably with an increase in the seeding rate. The highest yield of long fiber 26% was provided by thickened sowing with a seeding rate of 3.2 million units per 1 ha.

The purpose of the study is to study the possibility of using leguminous crops for grain as potato precursors. Field experiments were carried out in 2017–2019 in Krasnoarmeyskiy district of the Chuvash Republic. The soil of the experimental plot is gray forest, heavy loam granulometric composition with a humus content in the arable layer of 3.9%, mobile phosphorus - 140 and exchange potassium - 160 mg/kg of soil, pH - 5.1 units. Narrow leaf lupine, soybeans and fodder beans for grain were used as potato precursors; control was employed steam (vetch barley mixture for green fodder). Potato planting was carried out on May 10. The repetition of the experiment is 3 times, the size of the plots is 1.5 per 10 m, an area of 15 m2. The planting scheme of potatoes is 70 by 30 cm with embedment of tubers to a depth of 6 ... 8 cm. In the experiment, an early ripe variety Udacha was grown. Before planting, the tubers were treated with the insecto-fungicide Emesto Quantum (0.32 l/t). Plant care included pre-emergence and two post-emergence row-spacings cultivation, hilling, and weeding. The best precursors for potatoes are narrow-leaved lupins and soybeans. In these cases, there is a significant increase in tuber yield by 31.2 and 30.8%, dry matter - by 6.7 and 9.2%, and starch - by 4.3 and 5.5%, respectively.

The article considers the prospects of introduction of new elements of hemp cultivation technology in order to accelerate the production of seeds and increase the yield of stems, seeds and fiber. It is revealed that the forced reproduction of seeds of hemp varieties should be organized at the following optimal parameters of the basic elements of agricultural cultivation and seed production: in the nursery of primordial seeds with a wide-row sowing of 70 cm with a seeding rate of 0,3 million/ha and decapitation of plants in the phase of 3 pairs of leaves; on the site of original seeds with a wide-row sowing of 70 cm with a seeding rate of 0,6 million/ha and decapitation of plants in the phase 3 pairs of leaves; on elite crops with a wide-row sowing seeding rate of 0,9 million/ha and decapitation of plants in the phase of 3 pairs of leaves; on reproductive crops with wide-row sowing 45 cm with a seeding rate of 1,2 million/ha and decapitation of plants in the phase of 3 pairs of leaves.

The article considers and presents the main economic and biological parametres of new hashish-free varieties of androgenous hemp of the Central Russian type. The authors studied four zoned and recommended the following varieties of androgenous hemp into production: Diana, Ingreda, Antonio and Juliana. The research was carried out in 2013-2015 on the experimental base of Chuvash Research Institute of Agriculture. The objects of the research were androgenous hemp varieties: Diana, Ingreda, Antonio and Juliana. A comparative study of the varieties by a complex of economically valuable traits was carried out on a control seed plot. Experimental plots were 2-row, row width - 0.45 m, row length - 5.0 m, plot area - 4.5 m2. Repetition was sixfold. Sowing was carried out with a hand marker, the seeding scheme was 5x45 cm. According to the analysis, it was revealed that androgenous hemp has a high population uniformity by gender. It was established that early maturity of androgenous hemp varieties allows them to be cultivated both for seeds and fiber, which significantly increases the economic production efficiency. Androgenous hemp plants ensure simultaneous maturation of plants, which, in turn, allows mechanized harvesting to be carried out. A promising and noteworthy direction of hemp selection work is development of the so-called unisexual hybrids. It was revealed that the basis for creation of unisexual hemp is hybridization: dioecious varieties are taken for the maternal form, and monoecious varieties - for the fatherly one. In this regard, the question of creating the so-called unisexual hemp hybrids has been and remains an eternal topic of scientific research