Influence of structural indices on seed yield of white melilot of pivdenny variety depending on application of herbicides Treflan 480 and Pulsar 40 in conditions of the South Steppe of Ukraine

Abstract

With an optimal ratio of structural indicators, the maximum yield of seeds is formed, but if one or several structural elements are insufficiently developed, the crop can be compensated by other structural indicators. Separate structural elements are formed at different stages of ontogenesis, therefore, for their successful development, various agrotechnical conditions are needed.

The seed production of a culture depends on many factors. To a large extent, the structural indicators of the white clover plant suffer from unwanted weeds. It should be noted that in recent years, the “List of Pesticides and Agrochemicals Permitted for Use in Ukraine” has no herbicides designed to protect the seed crops of the white one-year clover from unwanted weeds. Therefore, there was a need for certain efficacy in the use of Treflan 480 and Pulsar 40 preparations with different rates of their introduction, establishing their effect on plant stand density and structural structural indicators.

The purpose of the research was to study the effect of structural indicators on the yield of white clover seeds of Pivdenny variety depending on the use of Treflan 480 herbicides and Pulsar 40 at different rates of their application.

Studies were conducted on the experimental field of the Institute of Irrigated Agriculture NAAS in 2015-2017. In accordance with the requirements of generally accepted methods of conducting research on the IPA 22 "Scientific basis for the production, procurement and use of feed to obtain competitive animal products (" Feed and feed protein ")".

The soil of the experimental plot is dark chestnut, medium loamy, typical of the irrigated lands of the Southern Steppe of Ukraine.

A single-factor experiment, fourfold repetition, placement of options randomized, was laid by the method of randomized blocks. The total experience area is 900 m², the accounting area of one plot is 24 m².

In the experiment we used white clover seeds of the annual variety Pivdenny (originator - Institute of Irrigated Farming, NAAS, Ukraine). According to the experimental design, the pre-emergence herbicide Treflan 480 was used with application rates of 1,5-2,5-3,0-4,0 l/ha and the post-emergence herbicide Pulsar 40 application rates of 0,5-0,75-1,0-1,5 l/ha.

On average for the years 2015-2017 gg. a significant effect of the Pulsar 40 herbicide on the white clover plant density was found in comparison with the control variant as well as to the variants with the introduction of Treflan 480. It was found that the maximum value of the standing density of the white clover plants before cleaning was 127 pcs/m²  Pulsar 40 herbicide with an application rate of 1,0   l/ha.

On average, according to the factor, the highest indicator of the standing of crop plants – 117,9 pcs/m² was achieved using the herbicide Pulsar 40, which later had a significant impact on seed yield.

According to the research results, it was established that in the process of plant growth and development during the growing season when using the soil herbicide Treflan 480, the indicators of the structural elements of the white sweet clover plants were large compared to the control. The mass of 1000 seeds on the variants when using the soil herbicide Treflan 480 did not have significant changes at various rates of application, and was 1,93-1,95 g.

The most productive for the growth and development of plants of white clover Pivdenny was the treatment of crops with the Pulsar 40 herbicide at different application rates in comparison with control and the Treflan 480 herbicide.

The simulated correlation schemes between the indicators of structure and seed yield made it possible to establish a significant difference between the studied herbicides Treflan 480 and Pulsar 40.

On average, over three years of studies of the use of herbicides in the spring, contributed to a significant increase in structural indicators compared with the control options.

Analysis of the interrelation of the structure elements with the yield of white clover Pivdenny showed that all the studied variants treated with Treflan 480 and Pulsar 40 herbicides with different application rates had a high correlation.

In the conducted studies, the most important indicator characterizing the effectiveness of the studied variant is seed yield, which directly depends on many factors. It was noted that the highest yield of crop seeds was obtained in the variants with the maximum percentage of weed death.

Conducted researches determined the influence of structural indices on the seed yield of white melilot of Pivdenny variety depending on the studied herbicides Treflan 480 and Pulsar 40 at different application rates. The highest yield of seeds (840,0 kg / ha), as well as the best structural indices of  white melilot, were obtained by using the herbicide Pulsar 40 at the rate of 1,0 l/ha where the optimal plant standing density of white melilot provided the appropriate development of the crop plants. Under the conditions of Southern Steppe of Ukraine, the seed yield of white melilot of Pivdenny variety directly depended on the crop’s plant standing density, the number of bunches per plant, the number of seeds per bunch, 1000 seeds weight. The application of herbicides contributed to the better formation of a large number of generative organs of the studied crop, which subsequently influenced the seed productivity of white melilot of Pivdenny variety that is proved by the simulated indices of structural elements.