Increasing maize productivity by presowing usage of biologies Mycofriend, Mikovital and Florobacillin

The aim is to study how presowing usage of biologies Mycofriend, Mikovital and Florobacillin influences on biometric indicators of maize, its productivity and soil moisture holding capacity. Using mycorrhizal fungi and nitrogen-fixing bacteria, we have received positive results about their influence on plant growth and development and maize yield forming. Leaf surface area in variants with fungi Trichoderma harzianum Rifai (Mycofriend bio-based product), and Tuber melanosporum Vittad (Mikovital bio-based product) and bacteria Bacillus subtilis Cohn. (Florobacillin bio-based product) was counted on 30th, 60th, 90th and 120th days of vegetation and was estimated by 11.2–90.0% higher compared to the control. Leaf mass and root system mass exceeded control indicators by 24.0–48.9%, respectively. Plants height in these accounted periods was higher by 4.0–31.5% compared to the control. In addition, in these variants, soil moisture holding capacity increased by 7.3–38.1%, share of soil lumps smaller than 0.25 mm decreased by 2.8–7.2%. Grain yield of Maize in variants with mycorrhizal fungi and nitrogen-fixing bacteria was 1.64–2.68 t/ha higher than in the control. It should be noted that presowing usage of fungus Trichoderma harzianum Rifai on plants seeds, provides better efficiency on plants’ growth and development and their productivity.


Introduction
Biological and agricultural researches dedicated to improving stability of agricultural production and reducing its losses have become important over recent years [1,2]. The problem of providing plants with moisture has become of even greater importance.
Water content decrease causes a number of biochemical processes in a plant, which negatively affects photosynthesis process [3].
The plant begins to expend moisture from the moment of seeds germination. However, moisture losses at this stage are insignificant. Maize begins to absorb a lot of moisture after emergence, and almost all moisture is used for evaporation (transpiration) [4].
Lack of moisture slows down chlorophyll biosynthesis. In drought, chlorophyll is often destroyed. Leaves yellowing during severe droughts is a common external mark of water deficit [5].
Drought stress and insufficient soil aeration induce water content decrease in plant tissues, which leads to slowing down or stopping their growth, browning, drying and leaf fall. At the same time, there is a mass dying-off of small roots and growth inhibition both during and after the drought [6].
Soil moisture has a significant effect on roots activity for water absorption. However, its significant part in the soil is unavailable for plants. Difference between available and unavailable moisture of soil with different mechanical composition defines its moisture supply.
Fungi of arbuscular mycorrhiza (AM), which have a multifunctional effect on plants, facilitate growth of root system's absorptive capacity, which increases intensity of nutrient absorption and reduces negative effects of drought and soil salinity [7]. This is because water is an indispensable resource and condition for plants' existence. Water environment is necessary for all types of biochemical reactions that take place in plants [8].
Mycorrhiza can affect integrity of membranes, which is proved by higher concentration of electrolytes in plants roots inoculated with arbuscular mycorrhiza (AM) fungi and lower level of their yield [9].
For efficient growth and development of maize plants we have used symbiotic microorganisms with different dominant function: mycorrhizal, nitrogen fixation, phosphate mobilization, protection against phytopathogens, etc., which improves nutrition and reduces pesticide load on agrocenosis [10].
Obtained results confirm many researchers' conclusions, that using mycorrhizal fungi and nitrogen-fixing bacteria contributes to better moisture supply of plants, and hence nutrients. In particular, V. V. Volkohon, O. V. Nadkernychna, T. M. Kavalevska et al. [11] claim that this will allow plants to improve moisture supply.

Materials and research methods
Research was conducted at the Institute of Bioenergy Crops and Sugar Beets of National Academy of Sciences of Ukraine on the basis of Veselopodilsk Research and Breeding Station (VPDSS), which is located on the Left-Bank Forest-Steppe of Ukraine. Soil cover is marked by diversity of colours. Alkaline and weakly-alkalinized chernozems predominate.
Researches were conducted in the field crop rotation repeated 4 times, size of accounting area was 25 m 2 . For our research we have used fungi of vesicular-arbuscular mycorrhization Tuber melanosporum VITTAD (Mikovital bio-based product) and Trichoderma harzianum RIFAI (Mycofriend bio-based product) and bacteria Bacillus subtilis Cohn. (Florobacillin bio-based product).
According to research program we have defined water content and mass of leaves and root system, leaf surface area for 30th, 60th, 90th and 120th days of vegetation, soil moisture holding capacity and its physical state and yield.
In particular, to define root system mass of maize plants, we have selected 10 plants on protective strip in each repetition in the same period. Root system was dug out at 30 cm depth and cut to root collar, cleaned from the ground, washed with water, dried for 1 hour, weighed on laboratory scales.
To establish leaf water content of maize plants by determining their mass, collection was carried out after 30th, 60th, 90th and 120th days of vegetation. 100 leaves in each variant (25 leaves from each repetition) were selected and weighed on laboratory scales no later than an hour. Obtained data were processed using statistical calculation methods [12,13,14].
Plants height was also determined at the same period. To do this, 10 plants were selected in each repetition and measured with a ruler.

Research results
Obtained data for 2017-2019 years show that mycorrhizal fungi and nitrogen-fixing bacteria in symbiosis with root system of maize plants provide increase of all indicators that were studied compared to the control. In particular, in these variants there is a significant increase of maize leaf water content during all four calculations compared to the control (Table 1).
Thus, mass of 100 leaves of zea mays after 30 days of vegetation in variants with fungi Trichoderma harzianum RIFAI.
A similar trend is observed concerning mass of maize plants root system. According to the data in Figures 1 and 2, this indicator exceeds the control by 13.6-112.0% in all periods of accounting. Increase in leaf mass and root mass is happening due to symbiosis of microorganisms with root system, formation of a new cluster of roots fibrilla from fungi hyphae, which facilitate better nutrients absorption, namely phosphorus and water.  (Table 1).  Similarly, in variants with Mycofriend, Mikovital and Florobacillin biologies, plant height indicators prevail in comparison with control. In particular, when using bio-based product Mycofriend plant height was in the range from 48 to 220 cm, bio-based product Mikovital -47-204 cm and bio-based product Florobacillin -46-200 cm. Exceedance of control indicators in these variants was 4.0-28.8% (Table 2).  Apart from researching impact of mycorrhizal fungi and nitrogen-fixing bacteria usage on the growth and development of maize plants, we have also determined soil moisture holding capacity and physical state of maize crops. It was found that in the variants with these organisms, moisture holding capacity of soil was 7.3-38.1% higher than in the control, and proportion of lumps smaller than 1 mm was 2.8-7.2% lower (Figs. 3, 4). These indicators prove that symbiosis between fungi and plants root system changes soil physical state and its moisture holding capacity. It is known from literature references [19,20] that these changes, first of all, occur by means of creating mycelial network and forming adhesive component of glucoprotein-glomatin.
Enhancement of nutrients for plant growth and development and soil quality using mycorrhizal fungi and nitrogen-fixing bacteria improved maize grain yield, which in these variants was 1.65-2.68 t/ha higher than the control (Table 3). Results of our research coincide with conclusions of Z. Guralchuk [21] that increasing rhizosphere soil volume occurs due to symbiosis of living organisms with plants root system, which further significantly affects their leaf surface area and height, moisture holding capacity and soil physical state.

Conclusions
Presowing usage of biologies Mycofriend, Mikovital and Florobacillin on maize seeds contributes to enhancement of such bioenergy indicates of growth and development as root and leaves mass, plant's height and leaf surface area by 4,0-112,0% compared to control.
Due to symbiosis between mycorrhizal fungi and nitrogen-fixing bacteria with maize plants' root system, moisture holding capacity of soil and its physical state has increased by 2,8-38,1%. Maize grain yield in variants with Mycofriend, Mikovital and Florobacillin biologies was higher by 1,65-2,68 t/ha compared to control.