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The efficiency of crop cultivation technologies, including potatoes, can decrease under the influence of pests, especially in the case of untimely or low-quality protective measures. Pathogens parasitizing the vegetative surface of plants have a significant impact on the quality and yield of potato tubers. Such pathogens are fungi Phytophthora infestans (Mont) de Bary, Alternaria solani Sorauer and Alternaria alternata Keis, which are the causative agents of late blight and early blight. Early manifestation and significant development of these diseases during the growing season can lead to losses, which are estimated at 4 billion euros per year. Studies by many scientists reveal a significant positive result from the use of fungicides during the growing season of plants, harvesting and storage of crops. This article investigated the efficacy of fungicides against late blight and early blight and their effects on yield and tuber quality of the early maturing potato variety Bellarosa. The research was conducted from 2018 to 2020 at the PE Zherm of the Zhytomyr region Ukraine. The experiment scheme consisted of the following variants: Control – spraying of plants with water; Variant 1. Ridomil Gold MC 68 WP, (mancozeb, 640 g kg–1 + metalaxyl M, 40 g kg–1) – 2.5 kg ha–1– the reference variant; Variant 2. Infinito 61 SC, 68.75% (fluopycolide, 62.5 g L–1 + propamocarb hydrochloride, 625 g L–1) – 1.5 L ha–1; Variant 3. Quadris TOP 325 SC, 32.5% (azoxystrobin, 200 g L–1 + difenoconazole, 125 g L–1) – 0.8 L ha–1. It has been established that the application of fungicides in the potato plantings against late blight and early blight reduces the spread of the leaf spot by 1.4–2.0 times at the end of the vegetation period, and its development – by 1.8–2.9 times in comparison with the Control variant. An increase in yield of potato tubers of Bellarosa variety due to the application of fungicides against leaf spot disease was within 4.5–10.9 tha–1 in comparison with the Control variant. Among the studied preparations, the best indicators were obtained when using the fungicide Infinito 61 SC, 68.75% in potato plantings against late blight and early blight. Application of this preparation helped to reduce the spread of the studied diseases by 2.0 times, the development of diseases by 2.9 times, and increase the yield by 1.4 times compared to the variant without fungicides application. Application of fungicides also contributed to the improved quality of the tubers; in particular, we observed an increase of the dry matter content in tubers by 0.1–0.6%, ascorbic acid – by 0.2–1.1 mg% 100 g–1 compared to the variant without using the preparations. [ABSTRACT FROM AUTHOR]

This work purpose was to find the impact of Pistia stratiotes L., 1753 - a new species on the territory of Ukraine, on the vitality of other free-floating hydrophytes so-called pleuston - Salvinia natans (L.) All., 1785, S. laevigatum (Humb. and Bonpl. ex Willd.) Heine, 1968, to determine the degree of stability and competitiveness of these species for resources in natural ecosystems relatively to the undesirable species. To find out the influence of P. stratiotes on other free-floating on the water surface plant species which compete for elements of nutrition among each other, we have investigated changes in the content of photosynthetic pigments in S. laevigatum and S. natans, which were exhibited with P. stratiotes for 14 days. Besides changes in water indices, oxygen content, mineralization and pH, were measured. [ABSTRACT FROM AUTHOR]

Evaluation of Lactobacillus plantarum strains perspective for plant protection or fermentation of food of plant origin should include tests on abilities to attach to plant surfaces and to form biofilms. Comparing RAPD-profiles with these properties and also with geographical origin of the strains is necessary to find out the possibility of rapid selection of the strains and tracking their dissemination. Biofilm formation and RAPD-PCR profiles of 30 strains of L. plantarum isolated from grape must and pickles originated from France and Ukraine were compared. All isolates were able to attach to Lepidium sativum seedlings and form biofilms of different types. Amount of attached cells varied from (7.8 ± 0.2) x 104 to (2.1 ± 0.3) x 10³ CFU/cm² . The most developed biofilms were formed on shoots, leaves, seed coat shells. On roots this ability was strain dependent: the majority of French isolates (77.0%) formed separated microcolonies without developed matrix layer. Among Ukrainian isolates, 47.1% of the strains showed the same tendency, and in 41.2% of the strains individual attached cells without formation of microcolonies were observed. The level of initial attachment of bacterial cells to roots did not coincide with the level of subsequent formation of biofilms. Gene plnA was detected in 28.1% of isolates. All plnA possessing strains except the one formed microcolonies or biofilms with developed matrix. Lactobacilli could eliminate the biofilms of Agrobacterium tumefaciens pJZ from tomato roots in 75.0 – 100% of tested samples depending on a strain and method of inoculation. No clear association between the geographical origin of the L. plantarum strains and clustering by RAPD-PCR analysis was found. Two strains with high level of biofilm formation were grouped in one subcluster. [ABSTRACT FROM AUTHOR]

The article presents morpho-anatomical characteristic of Bidens connata in the valley of the Middle Dnieper. [ABSTRACT FROM AUTHOR]