In this study was investigate the effect of vegetative treatment with the herbicides Basagran 480 SL, Pulsar 40 and Express 50 WG on the fat content of seeds of different Bulgarian cotton cultivars. The experiment was carried out with twelve Bulgarian cotton cultivars (Gossypium hirsutum L.) - Chirpan-539, Helius, Trakia, Vicky, Philipopolis, IPK-Veno, Boyana, Avangard, Natalia, Darmy, Dorina and Nelina. The herbicides were applied at the bud formation stage of cotton. Fat content in cotton seeds was determined by extraction - SR ISO 6492 method. For the first time in the world it has been established that in the vegetative treatment with herbicides the most valuable with regard to cotton seed fat content are all cultivars treated with Basagran 480 SL, except Chirpan-539 and Helius. It has been established that the treatment with the Express 50 WG herbicide less affected the cultivars Chirpan-539, Helius, Trakia, Vicky, Philipopolis, IPK-Veno, Boyana, Avangard, Natalia but all cultivars were negative influenced by the treatment with the herbicide Pulsar 40 with regard to fat content in seeds.

Compensations between yield components are important barriers to improve yield in wheat. Data about the number of spikes per m2 , the number of grains per spike and thousand of kernel weight (TKW) were obtained from 26 yield trials with winter wheat cultivars, performed in 10 locations in Romania, during 2016-2018. Grain yield showed most frequently positive correlations with the number of grains per spike. Correlation coefficients of grain yield with the number of spikes per unit area ranged from -0.3 to +0.7, with most of the trials showing low positive correlations. Most trials showed practically no correlation of grain yield with TKW. Most correlations among the yield components were negative, illustrating the difficulty of combining in the same cultivar high values of more than one component, because of compensation between yield components. The strongest negative correlation was found between the number of spikes per unit area and the number of grains per spike, and most correlations between number of grains/spike and TKW were also negative. Significant differences between cultivars were found in deviations from both regressions between negatively correlated yield components (number of spikes per m2 - number of grains per spike and number of grains per spike - TKW respectively). This suggests the existence of cultivar specificity in compensation between yield components. Cultivars showing positive or smaller negative deviations from the regressions between negatively correlated yield components might be useful in breeding for reducing compensations between yield components. Further studies are necessary to confirm if this could lead to genetic progress for yielding potential.

The present research paper aims at comparing the similarity and remoteness of influence of the features of eight common wheat varieties and their grouping on the base of important structural indicators through the use of a mathematical approach and a cluster analysis; studying of a relationships between the examined indicators in order to make more objective evaluation using the possibilities of the factor analysis; reducing the number of correlating indicators into new factors. Two-year data were used, obtained from the examination of eight common wheat varieties. The subject of the present research were seven seven foreign varieties of wheat - Ingenio, Bologna, Dalara, Moyson, Falado, Gabrio, Pibrak, and the eighth variety - Factor - was a local Bulgarian selection. The introduction of common wheat varieties is related to the study of their productivity and ecological plasticity. For this purpose there were reported and analised yield structural elements: plant height, wheat-ear length, number of ears, number of grains per ear, weight of grains per ear, grain yield from hectare. The cluster analysis showed that the influence of wheat variety on the qualitative indicators led to their grouping into two new clusters. There was established a strong positive correlation between the number of grains per ear and the hectoliter mass (r = 0.811) as well as between the number of ears and the weight of grains per ear (r = 0.771). The correlation coefficient between the number and weight of grains - (r = 0.649). The factor analysis established the influence of three main factors influencing the group formation of wheat varieties. The first factor was related basically to plant height, ear length, number of grains per ear and hectoliter mass. The second component was basically related to the number of ears and weight of grains. The third factor was related to the mass of 1000 grains.

This paper's aim is to identify new castor bean genotypes created at Agricultural Research and Development Station Teleorman in Southern Romania, with an improved productivity and adaptability to the area's environmental conditions. The study has dealt with 15 castor bean genotypes during three years' time (2013)(2014)(2015). The experiment was made according to the fully randomized block method, in three replications. The results of the variance analysis have shown that there was a significant difference between the castor bean genotypes regarding the grain yield. The three years' average yield has shown that both lines T 647/02 (2711 kg/ha) and T 2410 (2529 kg/ha) and the varieties Rivlas (2701 kg/ha) and Dragon (2451 kg/ha) have registered the highest productions, with significant production supplies (623-883 kg/ha) compare to the control variety Cristian (1828 kg/ha). The crops stability was estimated by the means of the variability coefficient. The correlations analysis showed that there are strong relationships between productions and productivity elements: the seeds' weight per primary raceme (r=0,992), the capsules' weight per primary raceme (r=0,925) and the number of seeds per primary raceme (r=0,841), as well as between the productivity elements: the capsules' weight and the seeds' weight per primary raceme (r=0,929), the weight and the number of seeds per primary raceme (r=0,832), the capsules' weight and the number of seeds per primary raceme (r=0,736). Also, there are significant positive correlations between the plant's height with the insertion height of the primary raceme (r=0,625) and the primary raceme length (r=0,625). There is a significant negative correlation between number of seeds per primary raceme and weight of a thousand seeds (r=0,586). The results achieved in the study suggest that the castor genotypes are productive and adapted to the weather conditions in South Romania, recommended to be grown in this agricultural area.

During the period 2018-2020 a field experiment has been carried out with the oil-bearing sunflower hybrid P64LЕ121 (Helianthus annuus L.). It is a sulfo tolerant hybrid by ExpressSun technology. A total of 25 variants were investigated. They included untreated control, 2 herbicides applied alone in addition with adjuvant Trend 90, 10 herbicide tank mixtures and 10 herbicide combinations. Soil-applied combined herbicides were performed during after sowing before emergence period of the sunflower. Foliar-applied herbicides were performed during 3-4 leaf sunflower stage. Full control of annual broadleaved weeds in ExpressSun oil-bearing is provided by a single treatment with herbicide Fluence at a dose of 40 g/ha or with herbicide Evorelle express at a dose of 60 g/ha applied during 3-4 leaf sunflower stage. Full controls of perennial broadleaved weeds is provided by two treatments with herbicide Fluence in doses of 20+20 g/ha or with herbicide Evorelle express in doses of 30+30 g/ha, applied during 3-4 leaf and 7-8 leaf sunflower stages. In the presence of annual and perennial broadleaved and graminaceous weeds, it is necessary to apply Fluence and Evorelle express as herbicide tank mixtures together with foliar-applied antigraminaceous herbicides Fusilade forte, Stratos ultra or Targa max. In the absence of perennial graminaceous weeds, it is necessary to apply herbicides Fluence and Evorelle express as herbicide combinations with soil-applied antigraminaceous herbicides Dual gold or Indipen. The highest seed yield is obtained by herbicide tank mixture Fluence + Fusilade forte, followed by herbicide tank mixture Evorelle express + Stratos ultra. High seed yields are also obtained by use of herbicide combinations Indipen + Evorelle express and Dual gold + Fluence.