Dependence of plant biometrics of cutting lettuce (<em>Lactuca sativa</em> L.) varietis on the concentration of microfertilizer Avatar-1

Purpose. To investigate the variability of plant biometrics of cutting lettuce (Lactuca sativa L.) varieties depending on the concentration of microfertilizer Avatar-1. Methods. Field study, biometric technique, comparative approach, statistical evaluation, generalization. Results. Dependence of the plant height, the diameter of the leaf rosette, the number of leaves per plant, the leaf area of plants on the concentration of microfertilizer Avatar-1 was defined. Investigations of cutting lettuce ‘Afitsyon’ and ‘Concord’ varieties by Dutch breeding were conducted in 2016–2017 in the collection sites of the department of vegetable growing in the scientific-experimental field  “Fruit and vegetable garden” of the National University of Life and Environmental Sciences of Ukraine. In order to determine dependence of plant biometrics of cutting lettuce varieties on the concentration of complex microfertilizer Avatar-1, the following scheme was used for the both varieties: variant 1 – water (control); variant 2 – 0,10% solution; variant 3 – 0,25% solution; variant 4 – 0,50% solution. Plants were treated with microfertilizer three times during the vegetative period. Alterations of plant biometrics of cutting lettuce ‘Afitsyon’ and ‘Concord’ varieties  depending on the concentration of complex microfertilizer Avatar-1 was studied. Conclusions. It was found that in case of three-time plant treatment with complex microfertilizer Avatar-1 at the time of harvesting, the best plant biometrics was registered in variant 3 (concentration 0,25%) for the both ‘Afitsyon’ and ‘Concord’ varie­ties of cutting lettuce. The height of plants of the cutting lettuce in ‘Afitsyon’ variety exceeded this figure in ‘Concord variety by 1,1–1,4 cm. The concentration of microfertilizer had no significant effect on the diameter of the leaf rosette of ‘Concord’ variety (25,1–25,9 см). The diame­ter of the leaf rosette of ‘Afitsyon’ variety was 26,0–28,7 cm. In cutting lettuce, the largest leaf area per plant was registered in ‘Afi­tsyon’ variety (3516.5 cm2/plant ) in case of plants  treatment with 0,25% solution of complex microfertilizer Avatar-1 that exceeded this figure in ‘Concord’ varie­ty by 660 cm2/plant. The best plant biometrics of cutting lettuce of the studied varieties and optimal concentration of complex microfertilizer Avatar-1 (0.25% solution) was defined that is important for improving agricultural cultivation techniques.