Highly adapted obligate endoparasites of the root system, root-knot nematodes (Meloidogyne spp.), cause great damage to agricultural crops. Our research is aimed at the assessment of nematicidal activity and effectiveness of antagonist fungal and bacterial strains against the most common type of root-knot nematode in the south of Russia. By means of molecular genetic identification, it was found that in the south of Russia, the species Meloidogyne hapla Chitwood, 1949 and Meloidogyne incognita (Kofoid and White, 1919) Chitwood, 1949 cause galls on the roots of open-ground and greenhouse tomato. Screening of microbial agents against second-stage juvenile (J2) M. hapla was carried out in the laboratory. At the end of the experiment, two liquid fungal cultures of Paecilomyces lilacinus BK-6 and Metarhizium anisopliae BK-2 were isolated, the nematicidal activity of which reached 100.0 and 70.2%, and exceeded the values of the biological standard (Nemotafagin-Mikopro) by 38.4% and 8.8%. The highest biological efficacy was noted in the liquid cultures of P. lilacinus BK-6, M. anisopliae BK-2, and Arthrobotrys conoides BK-8 when introduced into the soil before planting tomato. The number of formed galls on the roots was lower in comparison with the control by 81.0%, 75.5%, and 74.4%.

Aim. Analysis of modern studies on the effectiveness of fungi and antagonist bacteria against Meloidogyne root‐knot nematodes on vegetable crops.Materials and Methods. Studies of Russian and foreign scientists on the use of biological agents and their metabolites to control Meloidogyne spp. when growing vegetables have been carefully analysed.Results. The harmfulness of gall nematodes on vegetable crops is described. Studies on the most pathogenic species of Meloidogyne, including those common in Russia, are summarised. Information is given regarding features of the relationship between the host plant and phytoparasites are highlighted. An analysis of the range of chemical and biological nematicides is presented. The problem of the lack of effective environmentally friendly products able to control root‐knot nematodes on vegetables, including the prospect of using biological agents, has been identified. The features of ongoing research on the study of the nematicidal activity of biological agents and their metabolites to control various stages of development of Meloidogyne species have been collected, analysed, systematised and described. The prospect of studying the mechanisms of action of microorganisms against root‐knot nematodes is substantiated in order to create new effective biological nematicides that allow the growth of high‐quality and healthy vegetable products.Conclusion. Gall nematodes (Meloidogyne spp.) remain a current pest of soil‐grown vegetables. Scientists are actively working on the study of nematophagous fungi and antagonist bacteria to create environmentally friendly biological nematicides. With proper use, biological agents and their metabolites can help protect plants from phytoparasites at the level of chemical nematicides and have an additional beneficial effect on the growth and development of vegetable crops.

An assessment of 27 mutant tomato lines from four countries (Germany, USA, Russia, Bulgaria) was carried out for resistance to five Alternaria alternata strains under conditions of the South of Russia. Five strains of the A. alternata fungus were isolated from naturally infected plants selected in five agroclimatic zones of Krasnodar Krai: Central - strain 1, Western - strain 6, North - strain 11, South Foothill - strain 12, Chernomorskaya - strain 13. The assessment was carried out in the field during 2018–2020, in a greenhouse and under the laboratory conditions three times for each studied strain. In the field, the plants were treated every year with a spore suspension of A. alternata strain 1. Mutant lines obtained from the United States: 868, 663, 533, 544 and 898 showed the greatest resistance to Alternaria in 2018–2020, the lesion of which averaged 4.5–8.0% over three years. 13 mutant lines: 17, 40, 688, 722 (Germany), 311, 394, 418, 542, 728, 743, 917 (USA), 322 (Russia), 159 (Bulgaria) showed average resistance with the development of the disease 10.2–24.9% over three years of the research. Mutant lines 743, 663, 868, 544 obtained from the USA possessed relatively high resistance to all the studied strains under greenhouse conditions; moreover, no signs of damage with strains 1 and 11 were observed on Mo 868, signs of damage by strain 11 of A. alternata were not observed on Mo 743. Under laboratory conditions, mutant lines 663, 743, 868, obtained from the United States, were most resistant. Mo 663 showed resistance to strains 1, 13; line 743 - to strains 11, 12; line 868 - to strains 1, 11. There was a predominantly positive correlation between the results of field, greenhouse and laboratory assessments, which indicates a strong connection between them and the possibility of using these methods to assess the resistance of tomato samples to Alternaria independently of each other.

Background: In the South of Russia, due to the large acreage of tomato crops (Solanum lycopersicum Mill.), there is an acute problem of plant protection against the obligate endoparasitic of the root system Meloidogyne hapla Chitwood 1949. The aim of this study was to assess the nematicidal activity of fungal strains isolated from the rhizosphere of tomato plants infected with root-knot nematodes (RKN) (Meloidogyne spp.). Results: After conducting route surveys, 10 soil samples were selected from the rhizosphere of tomato plants affected by RKN. Fifteen isolates of fungi belonging to different species were isolated from the soil samples. The species composition of the isolated fungal strains was determined: Metarhizium anisopliae IG01, Penicillium citrinum IG02, Trichoderma harzianum IG03, Aspergillus niger IG04, Trichoderma ghanense IG05, Trichoderma harzianum IG06, Trichoderma atroviride IG07, Aspergillus awamori IG08, Trichoderma atroviride IG09, Paramyrothecium roridum IG10, Trichoderma atroviride IG11, Trichoderma hamatum IG12, Beauveria bassiana IG13, Aspergillus ochraceus IG14, Purpureocillium lilacinum IG15. After initial screening in the laboratory, strains with the greatest nematicidal activity and safe for humans were selected: M. anisopliae ИГ01, T. harzianum IG03, T. ghanense IG05, T. atroviride IG07, T. atroviride IG09. The mortality rate of RKN when using these fungal strains varied from 79.4 ± 1.8 to 93.9 ± 3.1%. In the greenhouse, the fungal strains M. anisopliae IG01, T. harzianum IG03, T. ghanense IG05, T. atroviride IG07, T. atroviride IG09 showed high results in reducing the number of galls on the roots of tomato plants, and their biological efficacy was 71.4–83.0%. Conclusion: Work on the study of the nematicidal activity of fungi, in vitro and in vivo, allows us to conclude that strains isolated from the rhizosphere of plants can be effective in combating the north RKN (M. hapla). In the future, it is planned to establish the compatibility of M. anisopliae IG01, T. harzianum IG03, T. ghanense IG05, T. atroviride IG07, T. atroviride IG09 with each other and selecting the ratios of the studied strains to obtain mixtures to create an effective biological nematicide.

Исследование проводили с целью изучения влияния интегрированной и биологической систем защиты на состав почвенной микобиоты, фитопатогенные инфекции, биометрические показатели, урожайность и качество плодов растений арбуза. Испытания выполняли в условиях Анапо-Таманской агроклиматической зоны Краснодарского края. Почва - чернозем южный. Объект исследований - арбуз сорта Аватар. Варианты опыта: контроль (без обработок), интегрированная (эталон) и биологическая системы защиты. В варианте с биологической защитой отмечена лучшая эффективность, по сравнению с эталоном, в отношении Alternaria spp. (количество КОЕ ниже на 33,3 % в первый год исследований и в 2,3 раза - во второй), против Verticillium spp. (в первый год разница составила 63,3 %, во второй год Verticillium spp. не обнаружено). Против Fusarium spp. эффективность была ниже: количество КОЕ в первый год исследований выше на 25,8 %, во второй - в 2,75 раза. За период исследований в эталонном варианте опыта количество грибов Trichoderma spр. увеличилось с 0 до 2,06 тыс./г, в варианте с биологической системой защиты - с 0 до 4,13 тыс./г. Лучший результат отмечен при использовании биологической системы защиты: доля патогенов от общего количества микомицетов составила 9,5 %, супрессоров - 90,5 %. На растениях арбуза развития фитопатогенов не наблюдали. В варианте с биологической защитой вегетативная масса на 37,3 и 10,4 % превышала величины этих показателей в контроле и при использовании эталона; количество плодов с растения, по сравнению с эталоном, было меньше на 17,3 %, масса одного плода - больше на 2,4 %. Самая высокая в опыте урожайность отмечена в эталонном варианте - на 17,3 % больше, чем при биологической защите, наибольшая товарность (90,8 %) и наилучшие качественные характеристики плодов - в варианте с биологической защитой...

The primary aim of this research was to study the effectiveness of various strains of antagonist microorganisms and biological preparations against Meloidogyne hapla, in addition to their impact on the quality of tomato fruits and crop structure. Four microorganism strains and three registered environmentally safe nematicides were used in the experiment presented herein. The results showed that the strains Paecilomyces lilacinus F-22BK/6 and Arthrobotrys conoides F-22BK/4 had the greatest biological efficacy, reducing the number of galls on tomato plants by 91.8% and 88.4%, values comparable with the results of the chemical control Vydate 5G. The Metarhizium anisopliae F-22BK/2 and Arthrobotrys conoides F-22BK/4 treatments showed the best results, increasing the fruit weight by 8.6% and 9.9%, in addition to increasing the tomato yield by 5.0% and 13.3%. These strains contributed to an increase in sugar content, whereas the concentration of vitamin C was reduced in the Trichoderma viride F-294 and Fitoverm treatments, indicating a high level of oxidative stress in the latter treatments. The results of this study confirm the prospects of using biological nematicides against phytoparasitic nematodes, which will not only enable effective control of their population but also improve the quality of agricultural products, minimizing harm to the environment and human health.