As a result of monitoring of causative agents of diseases of vegetable crops and studying of its species specification, the genus and species of fungi and bacteria, were found. Previously unknown in the Central region of Russia pathogens of carrot were identified: Sclerotinia nevales, Gleocladium roseum, Verticillium spp, Trichotecium roseum, Streptomyces scabies, F. nivale, F. chlamidosporum, F. equiseti, F. proliferatum, Chaetomium spp., Erysiphe umbelliferum, Erwinia carotovora. Main causative agents of diseases  of carrot during storage were also described: Alternaria infectoria, A. alternatа, A. arborescens, A. radicina, A. cheiranthi, A. corotiincultae, A. cinerariae, Embellisia spp., Nimbia spp., Cladosporium spp. It was found new pathogen for onion (Aspergillus niger), garlic (Fusarium semitectum, F. subglutinans, F. proliferatum, F.avenacium), red beet (Typhula ishikariensis), and radish (Drechslera Bondartseva).

Contributions of main factors and their interaction effects on development of the allelopathic activity of seeds have been shown. The specificity of distribution of factor influence portion has been revealed depending on extract concentration.

Relevance. Evaluation of nutritional value of seeds of agricultural crops is considered to be highly significant for revealing new sources of antioxidants for humans.Material. The aim of the present investigation was antioxidant status and selenium accumulation levels by chicory seeds (13 cultivars) and comparison of the results with antioxidants status of seeds of other root vegetables: celery (5 cultivars), parsley (2 cultivars), parsnip (3 cultivars) and carrot (7 cultivars).Results. Among agricultural crops studied chicory was characterized by 3-4 higher levels of selenium accumulation by seeds and relatively low total antioxidant activity and polyphenol content. Anomalously high protein content in chicory seeds may explain the efficiency of selenium accumulation while relatively low antioxidant activity may be connected with lower levels of essential oil. Direct correlations between polyphenol content and total antioxidant activity were demonstrated for carrot (r=+0.924; P<0.01) and chicory (r= 0.803; P<0.01) seeds.

The two varieties of parsnip, «Krugliy» and «Beliy aist», were estimated for micro-and macronutrients. The differences in accumulation of 25 micro-and macro-elements between two varieties were revealed. It was found that parsnip is the source of phosphorus, potassium, magnesium, ferrum, calcium, silicon, cobalt, chrome. The cultivar «Krugliy» is able to accumulate the high concentration of iodine.