Application of bacterial agents on sunflower

The study was aimed to examine the effects of bacterial agents combined with two variants mineral fertilization on sunflower yield.
 Materials and methods. main field experiments were carried out in Department Plant Production Variety Investigations Institute named after V.Ya. Yuriev NAAS Ukraine 2016−2018.
 soil deep granular slightly leached chernozem. It had following agrochemical parameters: humus content (Tyurin’s method) 5.8%; pH 5.8; hydrolytic acidity 3.29 mg/eq per 100 g soil. nutrient reserves control (no fertilizer): nitrogen – 132 mg/kg; phosphorus 104 potassium 128 mg/kg. amounts fertilizer (N30P30K30): 130-140 180−200 170−190 mg/kg soil.
 Data statistically processed by variance correlation analyses.
 Results discussion. In2016-2018, plants grew developed under very contrasting weather conditions compared multi-year averages. There a water deficit during critical periods (anthesis, seed setting filling), especially at elevated air temperatures.
 In study, biofertilizer GroundFix + agent HelpRost turned be most effective combination. When used dose 5 L/ha without fertilizer, yield increased 0.33 t/ha control; when it N30P30K30 as basic gain amounted 0.36 t/ha. ‘GroundFix HelpRost’ combination applied, 0.30 0.32 t/ha, respectively. efficiency 3 “5−6 leaf pair” phase crop -0.03 -0.04 respective fertilization. 8 L/ha, raised respectively; co-applied HelpRost, increment 0.42 0.58 respectively.
 strong positive effect April temperatures yield, coefficient 0.36− 0.72, June (r = 0.33−0.59), except for L/ha’ - 0.25 r 0.07, respectively).
 Conclusions. same N30P30K30, By combining we obtained increments Increasing gave 0.37−1.00) between precipitation amount growing period. We noted temperatures, 0.36−0.72, 0.33−0.59).