EVALUATION OF THE BIOLOGICAL AND ECONOMIC EFFICIENCY OF THE HERBICIDE TIVITUS IN TANK MIXTURE WITH SURFACTANTS IN CORN CROPS
OBJECT OF STUDY
Formation process of species and numerical composition of weeds in corn crops at application of herbicide Tivitus and the adjuvant.
SUBJECT OF STUDY
Weed species composition, herbicide efficacy, corn productivity.
During the work general scientific research methods were used, the main of which were: field – to study the interaction of corn with biological and abiotic factors; measurement and weight – to establish the crop yield.
PURPOSE OF WORK
Study the effectiveness of herbicides in combination with the adjuvants on weeds in corn crops as well as their effect on the harvest structure elements.
CONDITIONS OF RESEARCH
The work was carried out on the research field of the educational-scientific centre of Dnipropetrovsk State Agrarian and Economic University. Soil cover of the experimental plot is represented by ordinary low-humus medium-loam full-profile chernozem. Agrotechnique of corn cultivation was in accordance with zonal recommendations.
RESULTS OF RESEARCH
The highest yield level was obtained in the variant where Tivitus + adjuvant ESTERLIP (260 ml) was used 22.4 centner/ha compared to Trend 90 – 14.4 centner/ha, Synergent – 15.0 centner/ha in absolute control 3.7 centner/ha and control 2 – 6.6 centner/ha.
ACTUALITY OF RESEARCH
High weed infestation of agricultural lands is due to weeds ability to adapt easily to environmental conditions. Based on long-term observations of research institutions of Ukraine (Institute of Agriculture UAAS, Plant Protection UAAS, sugar beet UAAS, grain farming UAAS, National Agrarian University) it was found that only 10% surveyed areas have insignificant weed infestation, 60% areas – medium (10-50 pcs./m2) and 30% arable land – heavy weed infestation (over 50 pcs./m2). The potential weed infestation of arable land is from 400-500 million pcs./ha to 1-2 billion pcs./ha. Harmfulness of weeds is their ability to cause harvest and product quality reduction.
Harvest reduction of individual crops can reach: winter wheat and rye – 55-60%, spring barley – 40-45%, potatoes – 40-55%, sugar beet – 50-80%, corn – 50-70%, flax – 35-45%. Calculations show that losses from weeds in Ukrainian agriculture on the whole arable land annually make millions of ton: grain – 8-10, sugar beet – 15-18, potatoes – 5-6, sunflower – 0,5-1,0 and significant amount of other agricultural products.
The herbocritical period of corn is 40-50 days and lasts from sprouts to the stage of panicle formation. Biological basis of long herbocritical period is slow growth of the plant at the beginning of vegetation and technological basis – wide-row method of sowing, which creates favorable conditions for germination of weed seeds. The peculiarity of corn growing is that all major actions to protect against weeds should be carried out before the crop sprouts, which involves the use of ground hybrids and the use of the safety herbicides.
Adjuvants are of great importance as they reduce the cost and increase the effectiveness of crop protection agents, adjuvants help to fix the working solution of plant protection agents on the leaf surface and seeds, as well as to prevent their flocking and prolong their action.
SECTION 1. WEATHER CONDITIONS AND RESEARCH METHODS
Characteristic feature of early spring is rather big fluctuations of above zero (during the day) and below zero (at night) air temperatures, which delayed the physical ripening of the soil. Night frosts lasted until 31 March. However, from April the 1st rapid increase of average daily values was recorded, exceeding the long-term monthly norm by 1,8 °C. Spring temperatures reached their absolute maximum (+32 + 36 °C) during the second and third decades of May (Table 1).
TABLE 1. METEOROLOGICAL CONDITIONS OF CORN VEGETATION PERIOD IN 2020 YEAR (AMST., DNEPR CITY)
|Decade||Month of the year||For period|
|Air temperature, ºС|
|The multi-year norm||9,4||16,0||19,6||21,3||20,6||17,4|
March 2020 was moderately rainy. During the month 10 days with precipitation from 0.1 to 12.3 mm were documented, but their total did not exceed 23 mm (the long-term mark is 34 mm). The next spring months were marked by extremely uneven rainfall. So, in the first and third decades of April they fell 12.3 and 14.5 mm, respectively, in the second decade 9.2 mm. May was marked by rather favorable moisture, on average 54.2 mm fell per month (46 mm of the average long-term precipitation). Starting from June, the amount of precipitation until August dropped to almost zero. This phenomenon had impact, first of all, on the growth and development in late spring crops (corn, sunflower), however, with decrease in relative air humidity to 28-30% a decrease in leaf turgor and inhibition of assimilation processes were observed.
Total precipitation during summer (147.3 mm) was 30% from the norm, while terms of precipitaion did not coincide with the formation of corn reproductive organs, which had negative impact on its yield. The air temperature regime in summer exceeded the multi-year values by 1.9° С. In general, weather conditions during the growing season should be considered unfavourable for field crops (Table 1).
Abnormally hot, dry weather was maintained during August. Average daily air temperatures exceeded the long-term average by 8 °C and were +30 °C. Such hot and dry conditions were recorded in early September, and temperatures decreased by 5 °C to +25 °C only at the end of the first decade.
Abnormally hot, dry weather prevailed in the first decade of September. Rains of different intensity, thunderstorms, strong winds and temperatures decrease were recorded in the region at the end of the decade. Average daily air temperatures mostly exceeded by 3-7°C most of the time and were in the range 21-27 °C, while at the end of the decade they were close to normal or 1-2 °C below norm and reached 15-18 °C. Precipitation was of a torrential nature. The rainfall was 43 mm during the decade.
The field studies were carried out on the research field of the DDAEU (Dnipro National Agrarian-Economic University) Research and Training Centre. Soils of the experimental plots are presented by ordinary low-humus medium-loam chernozem.
Thickness of the humus horizon is about 75 cm. Content of Nitrogen in the upper part of humus horizon is 0,19%, Phosphorus – 0,14%, Potassium – 2,2%, humus – 3,9%. The soil type is common medium-loamy low-humus chernozem on loess.
Agronomic techniques for corn cultivation corresponded to zonal recommendations. Winter wheat was a predecessor; 23-25 cm deep was ploughed and the fallow land was levelled in spring with tooth harrows.
Corn (mid-early hybrid Poltava) was sown using the seeder SPCH-6, May 14, 2020. The experiment was one-factor. Placement of plots in the experiment is systematic. Repeatability – three times.
SCHEME OF THE EXPERIENCE
|Variants||Repeat / Plot №|
|Control 2 (herbicide without adjuvant)||4||5||6|
|Tivitus + adjuvant Trend 90||7||8||9|
|Tivitus + adjuvant Synergent||10||11||12|
|Tivitus + adjuvant ESTERLIP (140 ml)||22||23||24|
|Tivitus + adjuvant ESTERLIP (200 ml)||25||26||27|
|Tivitus + adjuvant ESTERLIP (260 ml)||28||29||30|
Potential infestation of the soil in the places of experiments by vegetative organs of reproduction of perennial root-sprout weeds was: 100-120 thousand pcs./m² (i.e. average) and by seeds of the juvenile: 800-900 million pcs./ha in the arable layer (high).
Herbicide with adjuvants was applied in the phase of 4-6 real leaves of weeds by a compact sprayer OM-4. (Photo 1).
Photo 1. Small sprayer, working width - 4 m (OM-4).
Plant height was determined by plots during the phase of full corn panicle emergence.
Corn infestation was determined by overlapping along the diagonal of plots in 10 points of the accounting frames (0.25 m2) with determination of their quantitative and species composition and subsequent recalculation of abundance per 1 m2 of the field. Weed infestation was determined before herbicide application and after 25 days after application.
Corn harvest was determined manually by breaking the cobs in two non-adjacent lines at a length of 14.3 m, followed by structure analysis and determination of grain yield and its moisture content, respectively, in terms of 14%.
SECTION 2. RESEARCH RESULTS
2.1 TECHNICAL EFFICIENCY OF HERBICIDE APPLICATION
The spring of 2020 year crops were characterised in the experiment by a very high weed infestation, mostly by the quarantine weed – wormwood ambrosia and also white orach. Namely these weeds created potentially the greatest threat to grain yield and therefore needed to be destroyd as a matter of priority. In addition to them, another 4-5 species of early weeds occurred sporadically in the crops.
As a whole the problem of effective protection of corn crops from weeds after not pair predecessors comes down to the solution of two main problems: prevention of seed bearing of their minor species and vegetative regeneration of perennial rootstocks.
For the above-mentioned species of weeds the answer to these questions is given by records of weed infestation before herbicide application and in 25 days after spraying.
TECHNICAL EFFICIENCY OF HERBICIDE APPLICATION TOGETHER WITH THE ADJUVANT,%
|Control 2 (herbicide without adjuvant)||75||31||74||51|
|Tivitus + adjuvant Trend 90||50||81||82||48|
|Tivitus + adjuvant Synergent||50||88||80||51|
|Tivitus + adjuvant ESTERLIP (140 ml)||75||75||80||78|
|Tivitus + adjuvant ESTERLIP (200 ml)||75||88||83||86|
|Tivitus + adjuvant ESTERLIP (260 ml)||75||94||83||91|
Analyzing the technical efficiency data, it should be noted that the application of the adjuvant had a positive effect on increasing the efficiency of the herbicide. If we consider the absolute control (without herbicide application) and the herbicide control without adjuvant, they have significant differences from the variants where both branded adjuvants and new research ones were used.
The highest technical efficiency for wormwood ambrosia was noted in areas where we applied ESTERLIP – 75% in comparison with Trend 90 -50%, Synergent – 50%; for white pigweed ESTERLIP – 75-94% in comparison with Trend 90-81%, Synergent – 88%.
2.2 PLANTS HEIGHT
Determining plants height as an important morphological indicator shows that corn reacts on changes in growing conditions.
||Avarage||% to control
|Control 2 (herbicide without adjuvant)||135||170||155||155||165||155||160||160||160||165||158||15,3|
|Tivitus + adjuvant Trend 90||185||190||160||165||175||190||175||190||175||160||177||28,8|
|Tivitus + adjuvant Synergent||180||185||190||185||185||195||180||165||175||180||182||32,8|
|Tivitus + adjuvant ESTERLIP (140 ml)||180||175||180||180||175||175||180||175||180||180||178||29,9|
|Tivitus + adjuvant ESTERLIP (200 ml)||200||200||195||195||205||195||205||200||195||200||199||45,3|
|Tivitus + adjuvant ESTERLIP (260 ml)||205||195||200||195||200||195||195||200||195||195||198||44,2|
When determining the height of plants in the flowering phase it was found that the most intensive growth was observed in the variant with the herbicide Tivitus in combination with the adjuvant ESTERLIP – 178-198 cm, compared with Trend 90 – 177 cm, Synergent – 182 cm, control 1 – 137 cm, control 2 -158 cm.
2.3 CORN HARVEST
Studies on the technology of corn growing for grain show that the formation of maximum grain yield is possible only when the factors of life support are optimized at all stages of crop organogenesis. Under the existing amplitude development of climatic elements during the crop vegetation, the effectiveness of technological methods is determined by the extent to which they can optimize agro-ecological regimes in agrocenoses.
Development of weeds leads to redistribution of nutrients and moisture in their favor, and this, in turn, causes a decrease in corn yield in the most depressed regime.
CORN GRAIN YIELD DEPENDING ON THE FACTORS STUDIED, CENTNER/HA
|Options||Repetitions||Average||+/- to control 1||+/- to control 2|
|Контроль 2 (herbicide without adjuvant)||6,6||6,4||6,8||6,6||2,9|
|Tivitus + adjuvant Trend 90||14,3||14,5||14,4||14,4||10,7||7,8|
|Tivitus + adjuvant Synergent||14,9||14,9||15,3||15,0||11,4||8,4|
|Tivitus + adjuvant ESTERLIP (140 ml)||12,8||13,5||12,7||13,0||9,3||6,4|
|Tivitus + adjuvant ESTERLIP (200 ml)||17,9||18,3||18,1||18,1||14,4||11,5|
|Tivitus + adjuvant ESTERLIP (260 ml)||22,9||22,7||21,6||22,4||18,7||15,8|
Weather conditions of the growing season were heterogeneous, that significantly affected the corn yield, which was low. Table, Photo So in average by variants it was from 3.7 to 22.4 centner/ha.
The highest yield was obtained in the variant where Tivitus + adjuvant ESTERLIP (260 ml) was used – 22.4 centner/ha compared to Trend 90 – 14.4 centner/ha, Synergent – 15.0 centner/ha in the absolute control 3.7 centner/ha and in the control 2 – 6.6 centner/ha.
- The highest technical efficiency for ambrosia wormwood was noted on the plots, where we applied ESTERLIP – 75% in comparison with Trend 90-50%, Synergent – 50%; for white pigweed ESTERLIP – 75-94% in comparison with Trend 90-81%, Synergent – 88%.
- The most intensive growth was observed on the variant with application of herbicide Tivitus in combination with ESTERLIP – 178-198 cm in comparison with Trend 90 – 177 cm, Synergent – 182 cm, control 1 – 137 cm, control 2 – 158 cm.
- The highest level of yield was obtained in the variant where Tivitus + adjuvant ESTERLIP (260 ml) 22.4 centner/ha in comparison with Trend 90 – 14.4 centner/ha, Synergent – 15.0 centner/ha in absolute control 3.7 centner/ha and on the control 2 – 6.6 centner/ha, adjuvant ESTERLIP provided yield depending on the concentration 14.3 – 15.6 centner/ha.
You can also see the results of the ESTERLIP application:
1. Influence of ESTERLIP on the enhanced effect of Rimsulforon herbicide;
2. Effect of ESTERLIP on raising the effectiveness of the microfertilizers.