Peculiarities of a confectionery sunflower cultivation technology

Abstract

As of 2022, there are 22 names of confectionary sunflower in the State Register of Plant Varieties Suitable for Dissemination in Ukraine, accounting for almost 2% of the total number of cultivars and hybrids in the Register.

Valuable economic characteristics of confectionery sunflowers are significantly affected by weather. In particular, 39% of the seed yield variability is determined by weather conditions; the thousand seed weight variability - by 32%; the huskness variability- by 26%; the  the 3.8+ fraction proportion variability - by 41%; and the protein content variability - by 12%.

A review of literature on elements of the confectionary sunflower cultivation technology allowed us to identify major factors of the agricultural technology that affect such commercially important characteristics as yield and quality of seeds. These are basic tillage, optimal doses of mineral fertilizers, and plant density.

An increase in plant density augments the yields of confectionary genotypes. However, in thin sowing (up to 20,000 plants/ha), the yield of the commercially important large fraction of seeds is raised. Manufacturers prefer cultivars and hybrids with both large thousand seed weights and economically profitable yields. Most researchers agree that seed size decreases as plant density is increased, and therefore it is desirable to aim for a plant density in the field that can produce sufficiently large seeds without significant reduction in the total yield. The best genotypes combine both yield a lot and have large thousand seed weights.

Regarding the effects of basic tillage options on the confectionary sunflower yields, scientists' opinions are contradictory. In the southern steppe of Ukraine, the highest yield of confectionary sunflower seeds was harvested with moldboard plowing to a depth of 25-27 cm.

A positive effect of nitrogen fertilizers at doses of 120-160 kg/ha on thousand seed weight was proven by numerous studies. However, one should take into account that excessive nitrogen extends growing periods, reduces resistance to diseases, and contributes to stronger negative reactions to arid conditions.

Producers of confectionery seeds try to increase the yield of large seeds. Researchers report a high yield of large (4.5+) seed fraction, which in some cases can reach 83.6%. 3.8+ seed fraction is considered economically valuable. In the northern steppe, the yield of this fraction reached 81.4%, which was ensured by selection of genotypes, moldboard plowing, and thin sowing at a density of 20,400 plants/ha.

Seed specific weight is influenced by many factors, in particular, weather, varietal characteristics, and farming techniques. Specific weight increases when crops are thickened.

Therefore, the economic characteristics of confectionery sunflower genotypes vary widely due to varietal features and growing conditions (weather and climate, farming). Major elements of the confectionary sunflower cultivation technology are similar to those of the oil sunflower cultivation technology, but the former has certain peculiarities. High yields and desirable technological parameters of seeds are achieved via such farming factors as basic tillage, optimal doses of mineral fertilizers, plant density, and choice of a predecessor in crop rotation. The primary objective is to maintain economically profitable levels of seed yields in thin sowing, which is necessary to obtain large thousand seed weights. Particular attention is to be paid to studies of combined effects of farming techniques on the growth, development, and performance of confectionery sunflowers. Results of such comprehensive studies will allow for development of recommendations on the optimal application of farming techniques to reduce costs and raise the economic efficiency of confectionery sunflower cultivation.