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The purpose of this research is to investigate the impact of variety and irrigation on three cotton types, and to study the effectiveness of irrigation on the productivity of these cotton types which were fed by different norms of mineral nutrition. To assess the impact of soil humidity and fertilizer amount, we set up a field trial with three varieties of cotton. The field experiment was carried out within the Faculty of Agriculture, Trakia University, Stara Zagora, Bulgaria between 2018-2019. A two way factorial ANOVA (with variety and irritation as factors) suggested a significant main effect of irrigation (p< .001). Variety showed the strongest impact on the differences in "flowering" of cotton which were 64% in 2018 and 41% for 2019 respectively. We established an efficiency coefficient (KEF) representing the ratio of the additional harvest and the actual irrigation rate. The KEF of irrigation water varied depending on the cotton varieties and the levels of fertilization. The highest values of KEF were recorded after fertilization by N8 as given by units of cultivar Helius (EF = 0.67).  The effect of irrigation, expressed as a harvest per unit of irrigation water considerably varied over years. It was established as a ratio between the irrigation rate and the additional cotton  produce. At zero fertilization Helius, each cubic meter of water carried an average 2.24 kilograms of cotton harvest over two years. Optimizing the water supply and fertilizing with N16 provided 2.83 kilograms. On average, the Darmi variety irrigation effect ranged from 0.63 kilograms (N24) to 2.43 kilograms per cubic meter (N16) during the given period.

Editors and Sections Genetics and Breeding Atanas Atanasov (Bulgaria)Svetlana IntroductionRye belongs to Poaceae family, Pooideae subfamily, Secale genus (Kiryakov, 1999). The significance of rye in Bulgarian agriculture is not appreciated properly and its resources are not used. This crop is cultivated more successfully than wheat in the low mountain regions, in more acid soils. Rye has good self-endurance and keeps down the weeds strongly.Various plant resources are used as initial materials in the selection of the cultural plants: old and new varieties, populations, different forms and types of a given specimen, etc. They are carefully selected, maintained and preserved. Therefore, gene banks (like the Institute of Plant Genetic Resources in Sadovo) are of great importance for preserving the plant genetic resources, as well as for protecting the specimens threatened by extinction. The rye collection in IPGR -Sadovo ranks fourth in Europe. According to Knüpffer (2011), the Bulgarian collection ranks seventh in the world. The national basic rye collection includes around 1300 specimens and it is placed after the collections of Russia, Poland, Germany, the USA and Canada.The contemporary selection is directed to creating economically advantageous varieties. The initial material is necessary to be of a wide genetic base. The constant expansion of the existent collections, as well as the accumulation, addition and systematizing of the received data help for higher effectiveness of the selective-improving activity. Rye Millenium variety is created on the basis of an inter-population changeability of a set of qualitative characteristics (Аntonova, 2003;Mangova and Antonova, 2003). Such evaluation has been made for rye specimens in the phase of ear formation in the study (Kuneva and Valchinova, 2016).The current study aims to evaluate comprehensively the rye collection and the possibilities for the specimen usage in selection on the basis of mathematical approaches. Material and methodsThe scientific research was conducted in the period [2009][2010][2011][2012] in the experimental field of IPGR -Sadovo on cinnamon-forest soils with examined 54 specimens collected, of which 16 specimens collected from expeditions around the country and 38 specimens collected from abroad ( Figure 1). The Bulgarian rye variety Millenium was used as a standard (a current standard in IASAS). Danae variety was used as a former 30-year-old standard for the country. 21* e-mail: kuneva@au-plovdiv.bg The experiment was set in a block method at 1.2 m area under review, in three repetitions. The sowing norm was calculated at 500 2 horse power/m . In maturity phase 10 specimens were marked in advance and were measured in three repetitions. Evaluation of the impact of the examined specimens was made on the basis of the following biometrical indicators: ear length (cm); awn length (cm); tillering -productive and non-productive tillering; plant weight (g); ears weight (g); weight of the main ear (g); mass of the main ear`s grain (g); number of spike...

The present research aims at assessing the influence of leaf fertilizers on the two common wheat varieties. Study results show that the crude protein content ranges from 128.50-143.94 g/kg DM in the Enola variety and from 115.93 to 127.34 g/kg DM in the Illico variety. The introduction of Wuxal Grano slurry increased the crude protein content by 9.1 and 12.0 % relative to the control. The applied leaf fertilizers do not affect the contents of FUM, FUG and PDI. As a result of the correlation analysis, a very high correlation (r = 0.947-0.993) was found between CP and PDI for both common wheat varieties.

The purpose of this study is to determine the impact of controlled permanent water deficiency and three levels of fertilization on earliness and total yield of tomatoes, greenhouse production using different mathematical approaches. In order to evaluate the morphological manifestations, the early harvest and the total yield under the influence of different irrigation and nutritional regimes, a tomatoes variety "Vitelio" was used. The irrigation is done with a drip irrigation system. Against the background of the same fertilizing rates in the variants with different irrigation norms there is a decrease in the early stage with an increase of the irrigation norms. A high correlation between plant height and total yield, with correlation coefficient (r = 0.899) and between sheet count and total yield r = 0.824 was found. There was a negative correlation between the first and third harvests and the total yield, respectively with correlation coefficients r = -0.724 and r = -0.704. The nature of the linear relationship between plant height and total yield is determined by the coefficient R2 = 0.8. Based on a two-factor analysis, it was found that irrigation regime had a dominant influence on the two parameters considered: height and yield, which was statistically proven with a very high degree of confidence (p ≤ 0.001).