Науково-технічний бюлетень Інституту олійних культур НААН

Scientific and Technical Bulletin of the Institute of Oilseed Crops NAAS (ISSN: 2078-7316) / 2015 / 22 / P. 140-148
Influence of terms of sowing and plant care practices on weeds and yield in sunflower hybrid region
Poliakov A.I., Nikitenko O.V., Karaputa S.K.
A main direction for increasing production of sunflower seed is introduction of modern high-yield hybrids and new cultivation technologies. Weediness of crops is one of the most negative factors that reduce the effectiveness of measures to increase sunflower yield. To identify potential yield of new sunflower hybrids and their adaptability to adverse growing conditions it is necessary to know the optimal and allowable terms of sowing, chemical and mechanical methods of caring for plants, as weediness of crops is one of the most negative factors that reduce the effectiveness of measures to increase sunflower yield. To identify the optimal agromethods for growing sunflower hybrid Region in conditions of southern steppe of Ukraine we conducted this study in 2011-2013 on the fields of the Institute of Oilseed Crops of NAAS. Research object was sunflower hybrid Region. Sowing was carried out to a depth of seeding at 6-7 cm with 70 cm width between rows in three terms: the first (I) - at soil temperatures 6-8 ° C; the second (II) - at soil temperature 10-12 °C; the third (III) - at soil temperature 14-16 °C. Seeding rate - 50 thousand similar seeds per hectare. Care techniques for crops: 1 - pre and post-harrowing + 1 inter-row cultivation; 2 - pre-growth harrowing + 2 inter-row cultivations; 3 - 2 inter-row cultivations with and without herbicide use. Results of the research with weather conditions of 2011-2013 show that most number of the weeds at the end of sunflower growing season either when not using herbicides (20,3-24,0 plants per sq.m.), and when using herbicides (15,0-17,6 pcs./m2) was recorded during I sowing term (Table 2). When sowing in the II and III terms number of weeds decreased to 6,7-10,0 and 5,0-7,0 plants per sq.m. and up to 6,6-9,0 and 5,4-6,7 plants per sq.m. respectively. Same tendency was traced in other periods of weed counting. Depending on plant care number of weeds was different. Thus, the lowest number of weeds when using herbicide was noted when conducting pre-harrowing and two inter-row cultivations in first (15.0 plants per sq.m.) and third (5.4 plants per sq.m.) sowing terms. During the second sowing terms pre - and post-harrowing with one inter-row cultivation (5.0 plants per sq.m.) proved more effective. The most significant indicator of weed infestation is air-dry weight. Our research shows that this figure was lower with the second – 32,5 g per sq. m. and the third – 31,1 g per sq. m. sowing terms in addition to having pre-harrowing and two inter-row cultivations when using herbicide (Fig. 3). For other experiment options air-dry mass of weeds had grown to 34,6-294,3 g per sq.m. All of the above factors ultimately impacted sunflower yeild. Yield data analysis showed that the best sowing terms was the second one, when yield obtained was 2,38-2,49 t per ha (Table 3). Sowing in I and III terms led to a decrease in yield of 0,44-0,52 t per ha and 0,35-0,43 t per ha respectively. Yield of hybrid Region changed under the influence of agromethods of plant care. Thus, most of the yield was formed: with pre-harrowing + two inter-row cultivations (2,49 t per ha) or two inter-row cultivations only (2,48 t/ha). Increase in yield from using soil herbicide was received at the first (0,10-0,12 t per ha) and second (0,06-0,07 t per ha) sowing terms. In the absence of weeds in the third sowing term soil herbicide application was not effective. Highest sunflower yield of hybrid Region (2,49 t per ha) was obtained in the second term of sowing with herbicide application and having 2 inter-row cultivations. Thus, different sowing terms and plant care agromethods for sunflower crops have affected crop weediness, which further reflected on yield formation. On average in 2011-2013 the least crop weediness of sunflowers was established for the second and third sowing terms when having pre-harrowing and two inter-row cultivations. The highest yield of sunflower hybrid Region (2,49 t per ha) was obtained in the second sowing term with soil temperature at a depth of seeding at 10-12 °C and herbivide application when having pre-harrowing and two inter- row cultivations.
Citation: Poliakov, A., Nikitenko, O., & Karaputa, S. (2015). Influence of terms of sowing and plant care practices on weeds and yield in sunflower hybrid region. Scientific and Technical Bulletin of the Institute of Oilseed Crops NAAS, 22, 140-148.
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