Effectiveness of Oxalis bee and Ecostop for prophylaxis and control of varroosis in honey bees (Apis mellifera L.)

I. Zhelyazkova*, S. Lazarov
Department of Animal husbandry – Non-ruminants and other animals, Faculty of Agriculture, Trakia University, 6000 Stara Zagora, Bulgaria

(Manuscript received 24 August 2018; accepted for publication 26 October 2018)

Abstract. The objective of the present study is to determine the effectiveness of Ecostop (plates) and Oxalis Bee – plant-based products for the prevention and control of varroosis in bees (Apis mellifera L.).The study was conducted at the end of the 2017 Beekeeping Season of the Beekeeping Experimental Training Center at the Faculty of Agriculture, Trakia University, Stara Zagora. Two products were used: Ecostop containing peppermint oil (2 ml/plate) and timol (5 g/plate), and Oxalis Bee – zootechnical feed additive for bees, including plant extracts, organic acids and invert solution from bio-sugar. The dosing of the products is in accordance with the instructions of the producers Primavet-Sofia Ltd., Bulgaria and the company Vechni pcheli Ltd., Bulgaria. The development and extensinvasion of bee colonies at the beginning and the end of the study and the effectiveness of the applied products were determined. It has been established that the development of bee colonies is normal for the end of the beekeeping season. The comparative analysis of the acaricidal effect of the test products against Varroa destructor shows 98.55±0.30% for Ecostop and 78.15±8.76% for Oxalis Bee. The reported difference in efficacy of both preparations is reliable at p≤0.05.

Biological activity of plant protection products against Tuta absoluta (Meyrick) in tomato grown in greenhouses

N. Valchev, V. Yankova, D. Markova
Abstract. Tomato leaf miner Tuta absoluta (Meyrick) (Lepidoptera:Gelechiidae) is a dangerous pest in tomato grown in greenhouses. The control of this pest is difficult because of the latent way of life of the larvae in the mines, high reproductive potential, polyvoltine development and manifestation of resistance to great part of applied insecticides. Integrated Plant Protection programmes including a complex of measures are developed for successful control of the pest. The most frequently used practice for control on T. absoluta is still the application of chemical insecticides. During the period 2011-2012 experiments were performed for determination of the effectiveness of some insecticides in tomato variety Velocity grown in heated greenhouses. A very good biological activity towards the larvae (L1-L4) of tomato leaf miner (Tuta absoluta Meyrick) was established in the products Avant 150 ЕC 250 ml/ha (E=79.38% 14th day after treatment) and Coragen 20 SC 0.018% (E=79.18% 14th day after treatment).


Screening of plant protection products against downy mildew on cucumbers (Pseudoperonospora Cubensis (Berkeley & M. A. Curtis) Rostovzev) in cultivation facilities

S. Masheva, N. Velkov, N. Valchev, V. Yankova
Abstract. Screening of plant protection products (PPP) against downy mildew in cucumbers Pseudoperonospora cubensis (Berkeley & M. A. Curtis) Rostovzev was carried out during the period 2006-2011 in the “Maritsa” Vegetable Crops Research Institute, Plovdiv. Their toxicity to the imago of the bioagent Encarsia formosa Gah. were studied. High effectiveness (over 85.00 %) of the PPP with active ingredients: dimethomorph (Zampro SC, Acrobat paplus SC); symoxanil (Korsate Pro WG, Korsate R DF), strobilurins (Eclair 49 WG, Quadris 25 SC) was established. With the lowest effectiveness to the agent of downy mildew is Timorex 66 EC. All studied products are suitable for including in the systems for control of this disease. A non-toxic product to E. formosa is the botanical fungicide Timorex 66 EC, medium toxic products are those containing a.i. strobilurin and propamocarb-hydrochloride. The remaining PPP are slightly or medium toxic to the bioagent. Therefore E. fоrmosa could be applied parallel with slightly toxic fungicides against P. cubensis.

Bioproducts against diseases and pest in tomato production in cultivation facilities

S. Masheva, N. Valchev, V. Yankova

Abstract. Effectiveness of the botanical products for plant protection Timorex 66 EC and Timorex Gold against late blight (Phytophthora infestans) and early blight (Alternaria solani), of the products Pyros, Pyrethrum FS EC and NeemAzal T/S against greenhouse whitefly (Trialeurodes vaporariorum), tobacco thrips (Thrips tabaci) and twospotted spider mite (Tetranychus urticae) on tomato in cultivation facilities was studied in the period 2008-2010. Products included as a standard were: Ridomil Gold MZ 68 WG, Horus Top, Skore 250 EC, Vaztak new 100 EC, Mospilan 20 SP and Omit 57 Е. Timorex Gold 0,75 % demonstrates god effectiveness against late blight (68,66 %) and early blight (59,52 %). Pyros is described with good biological activity against greenhouse whitefly (against adults – 84,36 % and against larvae – 66,75 %). Phytopesticide Pyrethrum FS EC is with high effectiveness (89,29 %) against tobacco thrips while NeemAzal T/S was with good acaricide activity (92,57 %). In the laboratory tests that were conducted for determination of the secondary action of the botanical products was establishes that Timorex 66 EC, Timorex Gold and NeemAzal T/S are slightly toxic to the bioagent Encarsia formosa and they could be applied in the integrated and biological systems for vegetable production.


Plant species screening for biofumigant activity against soil-borne pathogens and root-knot nematodes

S. Masheva, V. Yankova, G. Toskov
Abstract. During the period 2009-2010 in the Maritsa Vegetable Crops Research Institute, Plovdiv in pot experiments screening was conducted for biofumigation activity of five plant species (chrysanthemum, broccoli, tagetes, basil and marigolds in the rate of 4 kg/m2). Herbage (50 days) was introduced in August in soil infested with Verticillium dahliae and Meloidogyne arenaria. The containers were covered with polyethylene film. The maintained humidity is 75- 80% and soil temperature – 37,8º C – 45,5º C. On the following year pepper plants (variety Kurtovska kapiya1619) were planted in pots with pathogen and tomatoes (variety Ideal) in pots with nematode. All testing plants species showed activity towards the verticillium wilt and nematodes. The Neal highest efficacy against Verticillium dahliae Kleb. is reported in variants with plant residues of chrysanthemum (E=76,11%) and broccoli (E=71,99%), and against Meloidogyne arenaria – with broccoli (E=71,23%), chrysanthemum (E=67,68%) and tagetes (E=64,79%).


Effectiveness of the Insecticide “MIDO 20 SL” in the Fight with the Green Rose Aphids Populations /Macrosiphum Rosae L./

The study was carried out in the period 2008 – 2009 in the Institute of roses and aromatic plants – Kazanlak. The preparation was used against Macrosiphum rosae L. in a plantation with Rosa damascena Mill. at a dose of 500 ml/ha. Observations were made in the following continuity: preliminary treatment, on the 3rd, 7th and 14th day. The effectiveness of the insecticide “Mido 20 SL” was calculated according to the formula of Henderson and Tilton – in the range between 99.80 – 94.50 % for the period. “Mido 20 SL” is effective against Macrosiphum rosae L., but it has a toxic effect on useful insects in the plantation.

Effectiveness of the Insecticide “MIDO 20 SL” in the Fight with the Green Rose Aphids Populations /Macrosiphum Rosae L./

H. Lambev