Grain yield response of some agronomy practices on contemporary common winter wheat cultivars (Triticum aestivum L.)

M. Nankova*, A. Atanasov
Dobrudzha Agricultural Institute, 9520 General Toshevo, Bulgaria
(Manuscript received 28 June 2018; accepted for publication 5 September 2018)

Abstract. During2014–2017,theinfluenceofsomemainagronomyfactorsonthesizeoftheresultantagronomiceffectfromtheirapplicationtocontemporary common winter wheat cultivars was investigated. The study was carried out in the experimental field (Haplic Chernozems soil type) of Dobrudzha Agricultural Institute – General Toshevo. The trial was designed by the split plot method, in four replications, on harvest area of 12m2. Cultivars Sadovo 1, Pryaspa, Kami, Kalina, Kiara, Kossara and Katarjina were grown after winter oilseed rape, spring pea, sunflower and grain maize at four levels of nutrition regime. The nutrition regime was differentiated depending on the previous crop. After spring pea, 30, 60 and 90 kg N/ha were used, and after the rest of the previous crops – 60, 120 and 180 kg N/ha. With the exception of the check variant all fertilizer variants were against background fertilization with 60 kg P2O5/ha and 60 kg K2O/ha. The positive reaction from the complex interaction of the tested agronomy factors was best expressed in 2015 – 2409.2 kg/ha, while during the extremely unfavorable year 2016, the effect was only 628.2 kg/ha. The independent and combined action of the mineral fertilization and the year conditions had determining influence on the size of the agronomic effect (AE). The positive effect from the mineral fertilization on the values of AE was accompanied by slight differentiation between the tested fertilization norms. Within this study, the highest mean value of AE was determined after fertilization with N180P60K60 – 2274.2 kg/ha. The variation in the mean size of AE depending on the type of previous crop was high – from 900.6 kg/ha (pea) to 2031.2 kg/ha (oilseed rape). The applied agronomy practices caused differentiation in the mean values of AE according to the type of cultivar. The cultivars Kiara (1796.1 kg/ha) and Kalina (1704.5 kg/ha) were with the highest size of AE. They exceeded the AE values of the two standard cultivars Sadovo 1 and Pryaspa by 30.26% and 23.62%, respectively. Averaged for the research, it was found that AE was in positive statistically significant correlation with grain yield and its physical properties.

Productivity of durum wheat cultivar Predel at nitrogen-phosphorous fertilization

L. Plescuta*

Department of Plant Production, Faculty of Agriculture, Trakia University, 6000 Stara Zagora, Bulgaria (Manuscript received 30 June 2017; accepted for publication 10 October 2017)

Abstract. The effect of nitrogen-phosphorus fertilization at nitrogen rates 0, 80, 120 and 160 kg.ha-1 and 0, 80 and 120 kg.ha-1 for phosphorus has been studied in durum wheat Predel cultivar, grown on leached vertisol soil type during the period 2012-2014 in the field of the Field Crops Institute – Chirpan. The results show that at alone nitrogen fertilization grain yield reaches 3,75 t.ha-1 at moderate N120, while at alone phosphorus fertilization the increase compared to the non- fertilized control (2,50 t.ha-1) is insignificant. At combined N120P120 the highest grain yield was obtained during the period – 4.50 t.ha-1, with 57.41% above the control. The harvest index of durum wheat grain variety Predel is 0.353 on average. Good HI results are formed at fertilization with P120 and N80P80.


Plastid pigments quantity and some physiological parameters related to photosyntetic processes in triticale grown for green biomass

H. Nedeva*, R. Ivanova, H. Yancheva

Crop Science Department, Faculty of Agronomy, Agricultural University, 12 Mendeleev, 4000 Plovdiv, Bulgaria
(Manuscript received 20 May 2016; accepted for publication 6 June 2016)

Abstract. The aim of the study was to establish the amount of plastid pigments and some physiological parameters related to photosynthetic processes in two triticale cultivars, grown for biomass under different nitrogen fertilization rates and harvesting stages in the region of Southern Bulgaria. The research was carried out in the field of Crop Science Department at the Agricultural University, Plovdiv, during the period 2013 – 2015. The experiment was set after the block method with four replications, and 20m2 for each experimental plot. Two triticale cultivars – Musala and Attila grown for green biomass at different fertilizer rates (N , N , N , N , N ) have been tested. The two cultivars are harvested in heading formation and milk maturity stages. The physiological parameters – 0 120 160 200 240 intensity of transpiration, photosynthesis rate and the amount of plastid pigments (Chlorophyll A, Chlorophyll B, Carotene) have been observed at different cultivars and harvesting stages. In both tested cultivars in heading stage the transpiration intensity was higher when rates of N were used, while in milk 200 maturity stage the highest values were in variant with N . The photosynthesis rate at both cultivars in heading stage was increased with increase of the 240 nitrogen rate. In the stage of milk maturity the values of some indices decreased in both cultivars. The lowest content of plastid pigments in leaves of Musala cultivar was received in the control variant. It was observed that the increase of the nitrogen rate leads to increasing the pigments content. The highest content of pigments in Attila cultivar was received when N was applied.

Strategies for durum wheat fertilization

L. Plescuta, G. Panayotova*

Department of Plant Production, Faculty of Agriculture, Trakia University, 6000 Stara Zagora, Bulgaria
(Manuscript received 11 November 2015; accepted for publication 19 May 2016)

Abstract. Durum wheat (Tr. durum Desf.) ranks second in the world cereal production after common wheat. It differs from the other species with its high grain
protein content, especially with gluten quality, which makes it suitable for producing spaghetti, macaroni, semolina flour and other products for the food industry. The purpose of this review was to summarize the results obtained in Bulgaria and in the world on the impact of mineral fertilization on yield and quality of durum wheat. All authors confirm that a significant increase of the grain yield in the last decades was achieved by both using new varieties and through optimal fertilization. Nitrogen as a nutrient is of great importance for wheat productivity. Nitrogen fertilization leads to stronger increase of leaf area, dry matter
accumulation, content of protein and gluten. Accumulated nitrogen and phosphorus depend mainly on the formed dry matter. At low nitrogen rates yield
increased at higher phosphorus level. Suppressant effect of high nitrogen and phosphorus rates on growth and development is emphasized in richer soil. A
number of authors have found genotypic specificity regarding grain yield in dependence on the level of fertilization. Problems of genetically determined and
improved grain quality under different durum wheat varieties are the subject of extensive research. The opinions of all authors are one-way for the positive
influence of fertilization and in particular nitrogen on the technological quality parameters – protein content, wet and dry gluten, vitreoussness, carotenoids
pigment, although the values vary significantly. The influence of fertilization is insignificant on the test weight.


Effects of irrigation and fertilization on soil microorganisms

T. Dinev1*, I. Gospodinov2, A. Stoyanova3, G. Beev1, D. Dermendzhieva4, D. Pavlov3

1Department of Biochemistry, Microbiology and Physics, Faculty of Agriculture, Trakia University, 6000 Stara Zagora, Bulgaria 2Agricultural Institute, 6000 Stara Zagora, Bulgaria
3Department of Plant Production, Faculty of Agriculture, Trakia University, 6000 Stara Zagora, Bulgaria
4Department of Applied Ecology and Animal Hygiene, Faculty of Agriculture, Trakia University, 6000 Stara Zagora, Bulgaria

(Manuscript received 8 January 2016; accepted for publication 29 February 2016)

Abstract. The purpose of this study is to determine the influence of nitrogen fertilization and irrigation on the total count of aerobic mesophilic microorganisms, moulds and yeasts in the soil. The experiment was conducted in three variants and samples were taken as follows: from irrigated and fertilized furrow; from irrigated non-fertilized furrow and from furrow without irrigation and fertilization. For determination of total number of mesophilic aerobic microorganisms, moulds and yeasts the samples were diluted and cultivated on medium sheets coated with culture medium according to the requirements of the microorganisms. Data analysis shows that fertilization has the strongest multiplication effect on the number of aerobic mesophilic microorganisms in soil (their number increases from 10.522 x 106 to 12.8 x 106 cfu/g), whereas the irrigation does not have any statistically significant impact. The multiplication of moulds and yeasts in this trial is stimulated mainly by the increased humidity. When irrigation is applied the number of moulds and yeasts increases from 1.158 x 105 to 1.407 x 105 cfu/g, while fertilization does not affect their quantity in a statistically significant way.


Influence of sowing and fertilization rates on the yield and plant health of einkorn wheat (Triticum Monococcum L.)

V. Maneva*, D. Atanasova, T. Nedelcheva, M. Stoyanova, V. Stoyanova

Institute of Agriculture, 8400 Karnobat, Bulgaria

Abstract. In the period of 2012 – 2014, on the experimental field of the Institute of Agriculture in Karnobat, Bulgaria, was conducted a field trial of various sowing and fertilization rates of einkorn. There were four sowing variants: 100% − optimal sowing rate, accepted as control (420 seeds/m2), 125% (525 seeds/m2), 150% (630 seeds/m2) and 175% (735 seeds/m2). The fertilization rates were also four: unfertilized control − N0, N40, N80 and N120 kg/ha. All the trial variants were investigated for insects, diseases and weeds. The highest einkorn yield was obtained after increasing the sowing rate by 50% above the optimal, followed by 25%. The differences in yield after the various fertilization rates were insignificant, which supported the view that it is not necessary to fertilize einkorn. There is greater lodging of einkorn when the fertilization rate is increased. During the studied period no diseases were found on einkorn. As for the pests, there was found the harmful effect of three types of cereal flies − Phorbia securis T., Chlorops pumilionis Bjerk. and Oscinella frit L. and the cicada Philaenus spumarius. The highest density of 6.5 nb/m2 for the cereal flies was established for the optimal sowing rate and the unfertilized variant, probably due to the sparser crops. During the einkorn spring vegetation period, the cicada Philaenus spumarius was found in its highest density for the optimal sowing rate, probably due to the sparser crops and in the variant with N80 fertilization. The least attacked variants were 175% and N120, due to the greater crop density. With the increase of sowing rate of einkorn the weed density and fresh mass were reduced. The increasing rates of nitrogen fertilization increased the competitiveness of einkorn, which led to reducing the weed density, but the fresh mass per weed plant increased proportionally with increasing the fertilization rates. The weeds in all the trial variants had low density, below the economic threshold of harmfulness.


Influence of fertilization and sowing density on grain production of Sorghum bicolor L., in the climatic conditions of Central Moldavia, Romania

S. Pochişcanu*, T. Robu, A. Gherasim, M. Zaharia

Department of Plant Science, Faculty of Agriculture, University of Agricultural Sciences and Veterinary Medicine, 3 Mihail Sadoveanu Alley, 700490 Iaşi, Romania

Abstract. Specialists in the USA, European Union, Japan, Australia, China, etc., Investigating industrial exploitation of biomass used in all forms and all adequate technologies. In this context appeared “stars biomass”, of which emerges, first, to the temperate continental sorghum, known and used for many years in the USA, China, Italy and France. Improvement of some technological sequences cultivation of sorghum, is a matter of great importance to our country, in order to obtain high yields, to provide the necessary food, feed raw material in the production of bioethanol, considered a fuel of the future. Experiences has been located in the specific climatic conditions of Secuieni, Central Moldavia, bifactorial type. The biological matherial used were hybrids F32, Armida, Alize, Quebec and KSH2G06. Mineral fertilizers applied to grain sorghum crop, increased grain production. Variation in grain production in grain sorghum varys depending on hybrid and the influence of fertilization. Using higher seeding densities cause significant production increases in grain sorghum, and the production level depends of cultivated hybrid and climatic conditions. The results of this study are part of a doctoral program, funded by the Ministry of Education Youth and Sports research, the IOSUD USAMV Iaşi.


Tolerance and own tolerance of wheat under conditions of permanent and long-term rotation

N. Nankov, G. Milev, A. Ivanova, I. Iliev, M. Nankova*

Dobrudzha Agricultural Institute, 9520 General Toshevo, Bulgaria

Abstract. The investigations on the long-term growing of wheat without rotation as well as its two-field rotation with maize in Dobrudzha Agricultural Institute date back to 1957. In a stationary field trial carried out during 2011 – 2013, cultivar Enola was grown at planting density 500 germinating seeds/m2. Four levels of nutrition regime were tested, which were formed by systematic introduction of the following fertilizer norms: N0P0K0, N60P50K30, N120P100K60 and N180P150K90. The long-term growing of wheat in two-field crop rotation increased the productivity of the crop with 16.8 % in comparison to its cultivation without rotation. The yield from cultivar Enola under long-term non-rotation growing was influenced to a much higher degree by the meteorological conditions of the year (1.6 times) as compared to two-field rotation with maize. The systematic mineral fertilization increased wheat productivity under the two forms of rotation. Under two-field crop rotation, the increase of yield according to the non-rotation growing was with 20.9%. Averaged for the investigated period, wheat had higher productivity after mineral fertilization with N120P100K60 (N:P:K=1:0.8:0.5). The intensive nitrogen fertilization, even when preserving the ratio with the other main macro elements, led to lower productivity, especially of the wheat grown without rotation. The factor determining wheat productivity under two-field rotation was mineral fertilization; its strength of effect was 1.9 times higher than its effect on long-term growing without rotation. The meteorological conditions during wheat growing influenced the physical indices of grain, and were especially well expressed on test weight. Under low nutrition regime (the check variant and N60P50K30), the grain in the monoculture was smaller in comparison to the two-field crop rotation. Under the higher levels of fertilization and in the monoculture a tendency was observed toward larger grain. The test weight in both crop rotations decreased with the higher fertilization norms. No significant correlations were found between productivity and the physical properties of grain under both types of growing. Under long-term growing of wheat in two-field rotation, there was a high positive correlation between absolute and test weight of grain.


Comparative evaluation of triticale cultivars grown in the region of Dobrudzha

A. Ivanova1*, N. Tsenov2

1Dobrudzha Agricultural Institute, 9520 General Toshevo, Bulgaria 2Agronom I Holding, 9300 Dobrich, Bulgaria

Abstract. The productive potential of the new triticale cultivars Irnik and Boomerang was investigated in a three-year field experiment (2011 – 2013) carried out at the trial field of Dobrudzha Agricultural Institute, General Toshevo. The experiment was designed by the split plot method in four replications, the size of the trial area being 12 m2. The investigation involved four previous crops: oilseed rape, peas, sunflower and maize, and three norms of mineral fertilization, each according to the type of the respective previous crop. Fertilization with phosphorus and potassium was used as a background (Р6К6), and nitrogen was tested at the following fertilization norms: N6, N12 and N18 after previous crops oilseed rape, sunflower and maize, and N3, N6 and N9 after spring peas, with check variant N0P0K0. The effect of some agronomy factors on the formation of the yield from triticale was analyzed: the year conditions, the type of previous crop and the norm of mineral fertilization. The new genotypes were compared to the standard cultivar Rakita. The new triticale cultivars demonstrated marked responsiveness to fertilization and increased their productivity with the higher fertilization norms. Irnik and Boomerang are new genotypes of triticale with higher productive potential than the standard cultivar Rakita.


Production potential of new triticale varieties grown in the region of Dobrudzha

Abstract. The production potential of the new triticale varieties Kolorit, Accord and Respect were investigated in a three-year field experiment (2009 – 2011) carried out in the trial field of Dobrudzha Agricultural Institute, General Toshevo (DAI). The experiment was designed by the split plot method in 4 replications, the size of the trial plot being 12 m2. The investigation involved four predecessors – oilseed rape, pea, sunflower and maize, and three fertilization norms according to the type of predecessor. The effect of some agronomy factors: the year conditions, the type of predecessor and the norm of fertilization, on the formation of yield, test weight, and 1000 grain weight of the new triticale varieties was analyzed. It was found that the year conditions and the level of mineral fertilization were the decisive factors for the formation of the yield of these varieties. Test weight was influenced to the highest degree by the year conditions and the genotype. The environment was determining for 1000 grain weight, while the genotype and the fertilization norm of mineral fertilization had similar effect. The new genotypes were responsive to fertilization, the tiered increase of the nitrogen fertilization norm leading to analogous higher productivity. During the years of investigation all three varieties gave high yields; varieties Accord and Respect had the highest test weight, and varieties Kolorit and Accord – the fullest grain with the largest size.