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On a certified organic field a trial of the hull-less oat variety Mina was conducted, sown after peas-sunflower mixture, maize for silage, and fallow. The aim of this experiment was to evaluate the effect of predecessors on the productivity and phytosanitary condition of hull-less oats in organic farming. The study was conducted in the period 2012 – 2014 under field conditions on leached, moderately loamy to slightly clayey smolniza at the Institute of Agriculture in Karnobat, Bulgaria, on a field certified for organic farming. The trial was conducted with spring hull-less oat, variety Mina. Predecessors – peas-sunflower mixture, maize for silage and fallow. Phytosanitary monitoring was conducted. The insect reporting was performed through direct investigation for plant pests. The weed reporting – species composition and density of weed infestation by a quantity-weight method, at the end of tillering and beginning of ear formation stage. Disease infestation was determined by walking through the plots during crop vegetation, by the route method, by inspection of the plants. The best predecessor for hull-less oats was fallow, followed by peas-sunflower mixture. The yield was high and the level of weed infestation was comparatively lower than after maize for silage. During the studied period a tendency for the effect of predecessor on disease infestation was not formed. The predecessors did not affect the species composition but mainly their density

During the period 2012 – 2014 in the Institute of Agriculture, Karnobat a field experiment was conducted with winter malting barley varieties Emon, Vanessa and Vicky. The influence of broadleaf (dicotyledonous) herbicides alone and in their combination with wild oat (monocotyledonous) in tillering stage of the crop was studied in optimal and double doses. The herbicide selectiveness was assessed according to the EWRS scale. Yields were reported after harvest. In variety Vanessa during the treatment with Derby Super, Granstar Super, Sekator OD and combination of Puma Super 7.5 EW + Sekator OD in optimal doses, the yield does not differ from the weed control. Variety Vicky endures well the treatment with optimal doses in all of the tested herbicides, except Husar Max. In treatment with double doses, only Granstar Super does not affect negatively the yield of grain. Comparing the data from ANOVA about the role of herbicides and year conditions on the malting barley varieties it can be concluded that the yield of variety Emon is the most stable in regard to herbicides applied in optimal doses (5%), followed by Vanessa (17%) and Vicky (18%). At application of the herbicides in double doses, their influence is increased – in variety Emon up to 15%, and in varieties Vanessa and Vicky – up to 23%.

During the period of 2013 – 2015 the influence of farming types (organic and biodinamic) on the phytosanitary status and yield of kamut was studied. Kamut is resistant to diseases and they are not a problem for growing it in an organic and biodynamic way. In both kinds of farming single numbers of five types of pests on kamut were recorded. Two of them were from Order Homoptera (Sitobion avenae L. and Rhopalosiphum maidis (Fitch)) and three from Hemiptera (Philaenus spumarius (L.), Eurygaster integriceps Put. and Aelia acuminata L.).The species diversity of the weeds was greater in biodynamic farming. Kamut yield from biodynamic farming was proven to exceed the organic one. The strength of effect of the type of farming factor was 83.57%.

Until recently, Penthaleus major (Dugès) has not been recognized as an economically significant pest for the cereal crops. After climatic changes, its population began to grow and inflict damages around the world. The aim of this study was to investigate its distribution in Bulgaria and establish whether it presents a danger to the cereal crops. In the autumn of 2015 and the spring of 2016, a monitoring survey was conducted to establish Penthaleus major (Dugès) with the cereal crops in Bulgaria. Over 60 sowed fields were investigated from all around the country. Samples were taken to identify the pest. It was established that Penthaleus major (Dugès) inflicted harm to the wheat in north-eastern (12-14 mites per stem) and south-eastern Bulgaria (6-8 mites per stem). Its density was under the threshold of economic harm. There was not found infestation of barley, rye, oat and triticale. On the field boundaries bordering the areas attacked by the mite were reported the following weeds: Capsella bursa pastoris (L.) Medic, Descurania sophia (L.) Welb. et Berth, Senecio spp., Sisymbrium orientale Torn., Taraxsacum officinale Weber, Anthemis spp., Bromus arvensis L., Eragrostis pilosa (L.) P.B. Lolium temulentum L., which can be habitat for Penthaleus major (Dugès).