PESTS ON ANNUAL LEGUME CROPS AND POSSIBILITIES FOR CONTROL IN BIOLOGICAL PRODUCTION

Biological production of legume crops is becoming more widespread in many countries, with research aimed at increasing yields and improving product quality. Legumes are an important element of agrotechnical approaches in biological systems. They are a suitable precursor for a various vegetable crops and are actively involved in crop rotation. Annual legumes are attacked by many pests, which at high densities can compromise the yield. Experiments to determine the effectiveness of biological plant protection products to control the main pests on beans and peas grown in a certified organic field were conducted at the Maritsa Vegetable Crops Research Institute, Plovdiv during the period 2019-2020. The tested pests were: black bean aphid (Aphis fabae Scop.), pea aphid (Acyrthosiphon pisum Harris), bean weevil (Acanthoscelides obtectus Say), pea weevil (Bruchus pisi L.), pea moths (Laspeyresia nigricana Step. and Laspeyresia dorsana L.) and twospotted spider mite (Tetranychus urticae Koch.). Tested products are: Piretro Natura EC 75 ml/da (a. i. pyrethrins), Neem Azal T/C 0.3% (a.i. azadirachtin), Naturalis 100 ml/da (a. i. Beauveria bassiana), Dipel 2 X 100 g/da (a. i. Bacillus thuringiensis var. kurstaki strain ABTS) and Rapax 100 ml/da (a. i. Bacillus thuringiensis subsp. kurstaki, strain EG 2348)

Assessment of Balkan Pepper (<i>Capsicum annuum</i> L.) Accessions for Agronomic, Fruit Quality, and Pest Resistance Traits

To maintain the continuous genetic variation and increase the genetic gain, appreciable germplasm diversity and its comprehensive characterization is necessary to further utilize gene sources for pre-breeding. The diversity of pepper forms, cultivation traditions and diverse fruit usages are typical for Balkan countries. Considering this rich diversity, 21 pepper accessions from the Balkan region were evaluated for morphological, biochemical, and insect resistance traits during 2018 and 2019 at Maritsa Vegetable Crops Research Institute, Plovdiv, Bulgaria. Among the studied accessions, the highest productivity was observed in pumpkin shape K1115 and kapia type K1081 accessions, with 0.74 kg and 0.70 kg per plant, respectively. Concerning fruit quality, the highest total polyphenols and ferric reducing antioxidant power (FRAP) were observed in pumpkin shape K712 (203.44 mg GAE/100 g FW) and K1103A (11.49 µmol Fe2+/g FW) accessions, respectively. Concerning insect resistance, 38% of studied accessions showed no infestation of green peach aphid. The kapia type K697 accession was seen as the most reliable resistance source, as it was not infested by aphids and had the least thrips (20% on plants) and cotton bollworm (6.67% on plants and 8.34% on fruit) damage. Based on examined traits, accessions were identified for enhanced fruit quality and promising insect resistance and have been included in further pre-breeding efforts

Organic Production of Snap Bean in Bulgaria: Pests and Diseases Incidence and Control, Soil Fertility and Yield

Among factors affecting snap bean production in organic growing systems, pests and diseases are of paramount importance. The current study was aimed to determine the impact of organic production practices on snap bean pests and diseases infestation, soil fertility and yield. Five treatments of plants during the whole growing season with a Bordeaux mixture at a dose of 3000 g/ha, provided more than 50 percent protective effect against the development of the bacterial blight Xanthomonas axanopodis pv. phaseoli and anthracnose Colletotrichum lindemuthianum. In organic fields, commercial bioproducts containing pyrethrins or entomopathogenic fungi Beauveria bassiana can be successfully applied to control the black bean aphid (Aphis fabae Scop.). To limit the attack of bean weevil (Acanthoscelides obtectus Say), phytopesticide containing pyrethrins can also be used. Against the two-spotted spider mite (Tetranychus urticae Koch.), products containing the active ingredient azadirachtin were seen to be effective five days after treatment. Soil amendment with vermicompost at a dose of 2850 L/ha slightly increased the amounts of water-soluble nutrients; however, soil remained nutrient deficient across the growing season. Among the tested Bulgarian varieties, Evros possessed higher yield, and appear to be suitable for organic system than the Tangra variety