Features of accumulation and consumption of soluble carbohydrates by plants of soft winter wheat varieties

The results of three-year research (2016–2019) conducted in the fields of the State Enterprise Experimental Farm "Dnipro" of the SЕ Institute of Grain Crops of NAAS of Ukraine with soft winter wheat was presented. The soft winter wheat was placed on black fallow (on background of N30P60K30) and after sunflower (on background of N60P60K60). It was found that winter wheat plants had a not the same ability to accumulate soluble carbohydrates in years with different weather conditions. The analysis of plant samples showed that the largest number of these substances had synthesized in the autumn 2017. It was found that in the plots with black fallow during the period from November 20, 2017 to January 10, 2018, the amount of soluble carbohydrates (total amount of mono- and disaccharides) in the tillering nodes of winter wheat plants of Uzhynok variety decreased from 41.2 % to 34.7 % (by 6.5 %), Nyva Odeska variety – from 43.9 % to 32.7 % (by 11.2 %), Kokhanka variety – from 45.0 % to 42.6 % (only by 2.4 %). From January 10 until the resumption of spring vegetation, the carbohydrates were consumed most intensively by plants of the Uzhynok and Kokhanka varieties. It was found that despite the lower doses of mineral fertilizers applied to presowing cultivation, winter wheat plants accumulated more soluble carbohydrates in all years after black fallow than after sunflower. On average for three years of research, the highest consumption of sugars during the winter both in leaves and in tillering nodes, regardless of the forecrop, was observed in plants of the Uzhynok variety. It was found that the winter wheat plants of Kokhanka variety consumed soluble carbohydrates more economically than the Uzhynok and Nyva Odeska varieties, and grew more intensively in early spring. The content of sugars in the tillering nodes of Kokhanka variety during resumption of spring vegetation was 28.4 % for black fallow and 25.9 % after non-fallow forecrop. Key words: winter wheat, variety, soluble carbohydrates, forecrop, background of nutrition.