Application of herbicides on common winter wheat (Triticum aestivum L.) at different doses and their reflection on the structural elements of spike

  1. Z. Petrova, Nankova

 

Dobrudzha Agricultural Institute, 9520 General Toshevo, Bulgaria

 

DOI: 10.15547/ast.2018.03.046

(Manuscript received 13 June 2018; accepted for publication 25 July 2018)

 

Abstract. The aim of this investigation was to determine the effect of the application dose of herbicides on structural elements of spike in common winter wheat (Triticum aestivum L.). The investigations were carried out during 2015–2017 at Dobrudzha Agricultural Institute (DAI) – town of General Toshevo. The following herbicides were used: Derby super WG (33 g/ha; 66 g/ha; 132 g/ha), Secator ОD (100 mL/ha; 200 mL/ha; 400 mL/ha), Ergon WG (50 g/ha; 100 g/ha; 200 g/ha), Granstar super 50SG (40 g/ha; 80 g/ha; 160 g/ha), Lintur 70WG (150 g/ha; 300 g/ha; 600 g/ha) and Mustang 306.25 СК (800 mL/ha; 1600 mL/ha; 3200 mL/ha) from the group of sulfunylureas with various mechanism of action. The preparations were applied at three doses – optimal, double and quadruple, at stage 29 of common winter wheat cultivar Dragana, Zlatitsa and Kalina. The herbicide effect was determined by the quantitative weight method and evaluated by the EWRS scale. These were the traced structural elements of the wheat spike: length of spike (cm), number of spikelets per spike, number of grains per spike, weight of grain per spike (g) and weight of 1000 grains (g). Four-factor dispersion analysis was applied. The factors year conditions, cultivar, herbicide and dose were traced. The factors with the highest strength of effect were the year conditions (10-95%) and the used cultivar (2-87%). Significantly lower was the effect of the factors applied herbicide (2-4%) and dose (1-2%) on the investigated structural elements of spike.

 

Breeding programme for developing new sweet cherry cultivars in the Fruit Growing Institute, Plovdiv, Bulgaria

S. Malchev*, A. Zhivondov

Fruit Growing Institute, 12 Ostromila, 4004 Plovdiv, Bulgaria
(Manuscript received 2 June 2016; accepted for publication 21 September 2016)

Abstract. Sweet cherry is a major structural species in Bulgaria. According to the Ministry of Agriculture and Food, in 2010 it occupied 21% of the fruit tree areas, which defined it as a leading fruit crop. It represents 16% of the total fruit production in the country, as is the relative share of peach, being surpassed only by apple and plum production. The increased interest in establishing new cherry plantations necessitates the provision of new market-oriented cultivars with a better sensory profile of the fruits, resistant to biotic and abiotic stress factors, suitable for creating modern intensive cherry plantations. The Bulgarian sweet cherry cultivars are chronologically discussed and a thorough description of the development of the sweet cherry breeding programme, launched at the Fruit Growing Institute in Plovdiv in 1987, is presented. Current objectives comply with the world’s major breeding trends and the changing market requirements. The paper reflects the main objectives of the programme and the finalized products obtained in the last twenty years of the past century and first decade of the new millennium, i.e. the new cultivars ‘Kossara’, ‘Rosita’, ‘Rozalina’ and ‘Thrakiiska hrushtyalka’ and some promising hybrids.

Influence of environments on the amount and stability of grain yield in modern winter wheat cultivars I. Interaction and degree of variability

N. Tsenov, D. Atanasova
Abstract. Numerous common wheat varieties have been developed in Bulgaria, which when grown under variable environments, the magnitude of the grain yield is influenced by them. In order to determine the reasons for such variations the effect of the growing conditions on grain yield from the winter wheat cultivars with the highest distribution in production were investigated. The cultivars were investigated during four successive years at twelve different locations in Bulgaria with contrasting environmental components such as soil and climate. The phenotypic response of the cultivars was followed with a focus on the size of the yield and the direction of variation within the group of cultivars as a result of each factor: season, location of growing, genotype, and their complex interactions. The collected data were analyzed with the help of several well-known statistical software, (Statistica 7, Statgraphics XV, Jmp 10), which provided sufficient information on the genotype x environment interaction. Significant differences were found among the investigated cultivars by grain yield regardless of their specific response to the year conditions and the location. The genotype x environment interaction was significantly high and non-linear. This means that under changeable environments the different cultivars react differently and can therefore be grouped according to the grain yield stability and plasticity they demonstrated. This is very clear from the significantly high values of heterogeneity of variation. The principal component analysis showed that the dispersion of grain yield was of three-component type, PC1 being only about 1/3 of the total variation of the character, while PC2 and PC2 formed about 50 % from this variation. Within a wide ecological network of 12 locations in Bulgaria a significant genotype x environment interaction was established for grain yield in four successive years. The direct influence of the investigated factors, through their correlations with grain yield, showed the highest effect of the year (r=0. 476*), followed by the location (r=0.208*), the value of the genotype was the lowest and negative (r=-0. 194*). This normal distribution of the data on grain yield was combined with linear and non-linear type of interaction of the groups of cultivars with the year conditions, the location and their interaction as factors of influence; this made the analysis on the adaptability of each cultivar very difficult.

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Technological evaluation of new common winter wheat lines developed at Dobrudzha Agricultural Institute – General Toshevo

I. Stoeva

Abstract. This study investigated the changes in the technological properties of common winter wheat lines of the latest generation of DAI breeding during the period 2004 – 2008. The dynamics of meteorological factors during the years of investigation typical for the region of Dobrudzha allowed better evaluation of the quality of the cultivars under biotic and abiotic stress. The results from the investigation showed that cultivars Aglika, Dona, Enola, Bolyarka and Iveta were a contribution to the breeding reality of quality wheat in Bulgaria. The degree of modification of most of the technological indices of the investigated cultivars was significant and depended on the source of variation (genotype, environment and the genotype x environment interaction). The genotype effects were most important in determining glassiness, sedimentation, pharinograchic value and the characteristics of bread (>50%). The effect of the year was lower (<30%). The percent of the cultivar x year interaction was significant for wet gluten yield in 70 % flour and the pharinographic stability of dough (>70 %). The increase of the mean daily relative air humidity and the sum of rainfalls during the first decade of June had on the whole a negative effect on test weight, glassiness and partially – on wet gluten in 70 % flour of cultivars Karat, Aglika, and Iveta. The high mean daily air temperature during the first decade of June had a negative effect on bread volume, form resistance, crumb quality, dough stability and sedimentation of most of the investigated cultivars.

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Influence of some stimulators on the grain economic and sowing-seeds properties of two durum wheat cultivars

A two-factor experiment was carried out on pellic vertisol soil type in 2007-2009 on the experimental field of the Cotton and Durum Wheat Research Institute, Chirpan, Bulgaria. Factor A included 2 Bulgarian durum wheat cultivars – Vuzhod and Saturn, which belong to var. valenciae. Factor B included 6 rates – non-treated control and 3 stimulators: Tritimil – 300 ml/ha, Napsil – 300 and 500 ml/ha, Cemofol – 500 and 700 ml/ha. All stimulators were treated in the tillering stage of the durum wheat. Stimulators Tritimil, Napsil and Cemofol decreased less the 1-st and 2-nd overgrown internode length of cultivar Saturn compared with cultivar Vuzhod. Napsil and Cemofol increased grain yield by 9.0 % and 10.9 % in cultivar Vuzhod and by 10.3 % in cultivar Saturn. Both stimulators have equal or increased effectiveness compared with the standard Tritimil. The studied stimulators increased the vitreousness, protein content, wet and dry gluten contents. Stimulators Tritimil, Napsil and Cemofol increased germination energy and seed germination and decreased the waste grain quantity.

Influence of some stimulators on the grain economic and sowing-seeds properties of two durum wheat cultivars

G. Delchev, D. Nenkova, D. Stoychev