Russell Method Research Articles

Yield plasticity of new varieties of soft winter wheat (Triticum aestivum L.) in different soil and climatic conditions of Ukraine

Purpose. To determine the level of productivity of new varieties of soft winter wheat, their stability and plasticity when grown in different soil and climatic conditions of Ukraine. Methods. The field trial was carried out in 2022–2023 under the conditions of the research stations of the Ukrainian Institute for Plant Variety Examination (UIPVE) in the Steppe, Forest Steppe and Polissia soilclimatic zones. The peculiarities of plant growth and development, the yield formation of 34 new varieties of soft winter wheat were studied. Plasticity and stability of yield formation were calculated and analyzed according to the Ebergard – Russell method, general homeostaticity and selection value according to Khangildin V.V. and Lytvynenko N.A. In the course of the research, computational and statistical methods were used. Analysis and synthesis were used to draw conclusions. Results. The yield varied from 5.4 to 8.4 t/ha, depending on the soil and climate zone and the location of the trial. The variety ‘LG Optimist’ had the highest average yield (8.1 t/ha) and ‘YUSON’ the lo west (6.0 t/ha). The most favorable conditions for the study of growth and development of genotypes in 2022 were in the Forest-Steppe (Ij = 0.9) and Polissia (Ij = 0.6) zones, in 2023 – Polissia (Ij = 0.2); the worst in 2022 – in the Steppe (Ij = –0.7), in 2023 – in the Steppe (Ij = –0.7) and ForestSteppe (Ij = –0.5) zones. In 2023, the best climatic conditions were in the Polissia zone (Ij = 0.2), the worst were in the points located in the Steppe (Ij = –0.7) and Forest Steppe (Ij = –0.5) zones. The theoretical yield values of the varieties at the research points did not differ from the actual values and averaged 7.1 t/ha, ranging from 6.0 to 8.1 t/ha. High homeostaticity and low level of variation (V ≤ 10.0%) were found in the varieties ‘Yevraziia’ (Hom = 15.6), ‘Dekaster’ (Hom = 15.2), ‘FORSAIT’ (Hom = 13.9) and ‘LG Optimist’ (Hom = 12.1). In addition, ‘LG Optimist’ (Sc = 6.9) and ‘Dekaster’ (Sc = 6.6) had the highest breeding value. The variety ‘FORSAIT’ (bi = 0.2; S2 di = 0.24), with an average yield of 7.4 t/ha, has a high plasticity, so it is recommended to grow it on extensive backgrounds and in unfavorable conditions. Varieties ‘Yevraziia’, ‘Nosivochka’, ‘SOLIFLOR CS’, ‘Mizynka’, ‘Troiana’, ‘LG Optimist’, ‘Biskvit’, ‘MIP Dovira’, ‘Etual’, ‘Tvorchist Odeska’, ‘Attribut’, ‘Epihraf’, ‘Dekaster’, ‘Epitet’, ‘Jannis’, ‘Pamiati Horlacha’, ‘Trembita Bilotserkivska’ and ‘Slava Unavy’ with a combined manifestation of high ecological plasticity bi = 1 and stability S2 di = 0 in average grain yield 7.2 t/ha, according to the genotype respond well to the improvement of growing conditions and are stable, are considered the most practically valuable. Conclusions. New varieties of soft winter wheat, when grown in different soil and climatic conditions, fully develop their genetic potential under significant changes in environmental conditions and produce the highest yield that can be obtained under ideal conditions.

Yield performance and stability analysis of three cultivars of Gayo Arabica coffee across six different environments

Abstract The three cultivars of Gayo Arabica coffee (GAC) are distributed widely in the Gayo Highlands, Aceh Province, Indonesia, between 900 and 1,700 m above sea level (masl). The difference in altitude affects the yield and quality of coffee, and Arabica coffee has biennial bearing characteristics, so there are always annual yield fluctuations. This study aimed to determine the yield performance and stability level of the three GAC cultivars, Gayo 1, Gayo 2, and Gayo 3 (G3), across six different environments. The study used a randomized complete block design with three replications. The six environmental conditions are the combinations of two altitudes (900 and 1,500 masl) and 3 years of production (2019, 2020, and 2021). The estimation of coffee yields is based on the fruit value, which is calculated by the number of productive branches per tree, nodes per branch, berries per node, and the weight of a single cherry. An investigation of the genotype-by-environmental interaction using a combined analysis of variance and the yield performance and stability analysis performed using the Eberhart and Russell method, AMMI (additive main effects and multiplicative interaction) and GGE (genotype + genotype × environment) biplot analysis. Results showed that the yield performance of GAC was significantly affected by the interaction between genotype and environment. G3 was an ideal cultivar because it had high yield performance, was stable, and could adapt to broader environments in Gayo Highland. Therefore, G3 deserves high priority for Arabica coffee development in that region.

Optimal value determination using traditional and newly developed method based on using initial basic feasible solution of a transportation problem using northwest and Russell method

Optimal value determination using traditional and newly developed method based on using initial basic feasible solution of a transportation problem using northwest and Russell method

Adaptabilidade e estabilidade da produtividade de grãos e de caracteres de pendão de milho

ABSTRACT: Due to the economic importance of maize, it is essential to evaluate the performance of genotypes under environmental variations (years, locations, and seasons). Consequently, researchers have scrutinized genotype-environment (G×E) interactions to ensure reliability in genotype recommendations. Furthermore, when a G×E interaction exists, adaptability and stability analysis can be performed. This analysis enables one to identify genotypes with predictable responses and adaptability to environmental variability. Hence, this study sought to determine if there is a G×E interaction and evaluate the response of 16 maize genotypes across seven environments through adaptability and stability analyses. Seven experiments were conducted with 16 maize genotypes using a randomized complete block design with three replications. Tassel length (TL), tassel branch number (TBN), tassel dry matter (TDM), and grain yield (GY) were evaluated. Individual and joint variance analyses were performed, along with the F-test at a 5% significance level. The complex parts of the interaction between genotypes and pairs of environments were estimated, followed by adaptability and stability analyses using the Eberhart and Russell method. A genotype-environment interaction was found for TL, TBN, TDM, and GY, indicating that genotypes respond differently in various environments. However, considering all four traits, there is no indication of the ideal genotype.

Genetic Stability of Different Genotypes of Bread Wheat (Triticum aestivum L.) Grown Under Levels of Nitrogen Fertilizer

Obtaining highly productive and stable varieties through different environments is one of the most important goals sought by plant breeders. A field experiment was carried out to investigate the effect of different nitrogen fertilizer levels on the stability of growth and grain yield in eight cultivars of bread wheat during two growing seasons (2020-2021 and 2021-2022), using split plot arrangement in randomized complete block design (RCBD) with three replications. The results showed that there was a significant response of some genotypes to the levels of nitrogen fertilizer for grain yield and its components during the two growing seasons. The Iba99 genotype was characterized by the highest mean of grain yield, number of grains. spike-1 and spike length, followed by the Baghdad2 genotype. The genotypes under study differed in the stability of traits in different environments. Baghdad2 showed the highest stability for important traits such as grain yield, weight of 1000 grains, number of grains spike-1 and spike length, while unstable and responded to different environments for plant height and a number of spikes.m-2. Whereas, Iba99 showed good stability for the spike length and the number of spikes.m-2, with its response to the environments for the other traits under study. Both stability phenotypic and genotypic resultant method and the stability triangle method showed very similar results with Eberhart and Russell method, therefore it is possible to rely on these two methods to estimate the stability of genotypes due to their lower complexity. Consequently, the stable genotypes traits in different environments can be selected and introduced directly into future breeding programs for the purpose of adopting new varieties. Although other genotypes showed superior characteristics of grain yield and its important components, they suffer by responding to different environments, thus they can be included in hybridization breeding programs with local varieties to transfer their desirable traits.

Assessment of yield performance and stability of hybrids and populations of tropical maize across multiple environments in Southeastern Brazil

AbstractThe identification of stable genotypes with high yield in diverse multiple‐stress environments is important to increase maize (Zea mays L.) grain yield under tropical environments. Our objective was to assess the yield performance and stability of experimental hybrids and broad‐based populations of tropical maize across diverse environments in Southeastern Brazil. We evaluated two sets of maize genotypes for grain yield: 190 experimental hybrids along with 6 commercial hybrids and 45 population hybrids along with their 10 parental populations across 8 environments in Southeastern Brazil. Multiple statistical methods were used and compared in the analyses. Combined analysis of variance indicated that genotypic main effect (G), environmental main effect (E), and genotype by environment interaction were highly significant (p < 0.0001) for grain yield. The E accounted for 42% of the total variation for both hybrids and populations, and they were more similar within the growing season than between seasons, mainly for populations. Low nitrogen (N) stress was a key factor in hybrid evaluation and recommendation, particularly under drought stress conditions. Among the environment classification methods, genotype main effect plus genotype × environment interaction (GGE) biplot provided more accurate information about environments grouping and selection of the genotypes than the Eberhart and Russell method. Harmonic mean of the relative performance of the predicted genetic values (HMRPGV) based on mixed models ranked the hybrids and populations according to mean grain yield and stability, penalizing hybrids, and populations with lower stability. Therefore, we recommend the GGE biplot and HMRPGV for genotype evaluation based on multi‐environment trials data. These methods identified 92V2144 and 92V2033 as the most promising hybrids for favorable and 92V2141, 92V2153, and 92V2137 as the most promising for unfavorable environments. 92VX033 and 92VX043 were identified as broadly adapted and stable populations across multiple environments in Southeastern Brazil.

Yield stability and agronomic performances of provitamin A maize (Zea mays L.) genotypes in South-East of DR Congo

Abstract Genotype assessment across various environments is a basic condition for developing stable and superior genotypes for sustainable maize production in the South-East of the DR Congo. Therefore, this research’s objectives were to identify the performance of newly developed provitamin A maize genotypes in various environments, and to recommend high-performing and stable genotypes for broader adaptation. Eight provitamin A maize genotypes, including one commercial variety, were planted at three sites during two consecutive cropping seasons (2020/2021 and 2021/2022) forming six environments. All genotypes in six environments were planted in a randomized complete block design containing three replications. Two stability analysis approaches, GGE biplot and Eberhart and Russell method are widely used to identify high yielding and stable genotypes. The combined analysis of variance revealed that G and E as well as their interaction (GEI) have significantly affected the emergence rate, cob’s insertion height, days to anthesis and silking, cob length, cob grain weight and grain yield. Average grain yield varied from 8.30 t/ha for PVAH-7L to 9.41 t/ha for PVAH-1L. The Eberhart and Russell method and the CV identified PVAH-1L, PVAH-4L, PVAH-7L and PVAH-6L as the most stable genotypes, but could not reliably identify the high yielding genotypes. On the other hand, the GGE biplot reliably and graphically showed the stable and high-yielding genotypes (PVAH-1L > PVAH-6L) as well as the low-yielding genotypes (PVAH-7 > PVAH-4L). In additional, the GGE biplot showed that L’shi21 was the best test environment for selecting high performing and stable provitamin A maize genotype. The results of this study indicate that PVAH-1L and PVAH-6L are the stable, high-yielding provitamin A maize genotypes in the South-East of the Democratic Republic of the Congo and should be disseminated in this region.

Validasi Intervensi Psikologis: “Positive Parenting Brief Family Therapy”

The parenting style applied by both parents has a big influence on the child's development. The low interaction between one or both parents in parenting has an impact on the poor attachment between parent and child. Dysfunctional parenting causes children to have low psychological well-being, less optimal and effective maternal care also has a significant impact on the child's mental and emotional development. Good parenting will reduce the damage to the child's social skills and he can be accepted by his peer environment. This study aims to increase information and knowledge about positive parenting through positive parenting education training. The training module is structured around the positive parenting principles coined by John Gray. The research module was prepared based on the Russell method with a focus on content and empirical validation tests. The content validation test resulted in Aiken V values moving between 0.71 to 0.94 with a mean of 0.78, while the empirical validation showed a decrease in the pretest and posttest scores on the dysfunctional parenting scale in the experimental group. Based on the legibility test, this module can be an alternative option to be given to parents in order to be able to implement positive parenting in the family.Keywords: Positive Parenting, Mother's Care, Mother's involvement

Identification and Registration for High-Yielding Strain through ST and MLT of Curcuma caesia Roxb. (Jor Lab KH-2): A High-Value Medicinal Plant.

(1) Background: Curcuma caesia Roxb. is a high valued crop which is extensively used in pharmaceuticals, flavour and fragrances. C. caesia is recognised as an endangered species due to its extensive collection from the wild through human intervention. Therefore, to prevent the species from extinction, it is very necessary to conserve and cultivate this plant species for the sustainable availability of the raw material. (2) Methods: In the present plant breeding programme, a multi-year study was performed for the identification of superior genotypes which will help in conservation. To fulfil this objective, a total of 135 accessions of C. caesia were collected from different regions of India and were set up for experimental selection trial for three years (2016–2018). After proper evaluation of the genotypes based on six agronomical traits, five high-yielding genotypes were identified which underwent multilocation trial for two years (2019 and 2020). The stability analysis using the Eberhart–Russell method, AMMI and GGE biplot were used to study the consistency of the genotypes in varied environments compared with the check variety. (3) Results: Analysis of variance indicated significant genotype and environment interaction for the yield traits, i.e., dry rhizome recovery, rhizome yield and essential oil yield. The coefficient of variation (CV) was highest for tillers per plant (21.76) and lowest for the plant height (4.93). All the results clearly demonstrated Jor Lab KH-2 as the highest yielding and stable genotype in varied environments compared with the check variety and other selected genotypes. (4) Conclusions: This genotype was then submitted to ICAR-NBPGR, New Delhi, for germplasm registration and received its confirmation vide registration number INGR 21159. This genotype will greatly benefit the breeders and will also help in the conservation of this endangered species. This is the first report on the identification and registration of a high-yielding variety of C. caesia.

Adaptive varieties of winter rye for cultivation in the arid zone of the north of the Astrakhan region

The purpose of the research is to study promising varieties of winter rye, as well as to assess their productive potential and adaptive properties when grown in arid conditions in the north of the Astrakhan region. The study included seven promising varieties of winter rye of Russian and Belarusian selection. Observations, counts and analyzes were carried out according to the methodology of the State Variety Testing, statistical processing - according to the method of B.A. Dospekhov. When calculating the coefficients of plasticity and stability, the S.A. Eberhart and W.A. Russell method presented by V.A. Zykin and others was used. As a result of three-year observations, varieties with high productivity, adapted to specific soil and climatic conditions, were identified. The highest yield has the varieties Yaselda, Zarnitsa and Zilant (1.09 t / ha, 1.31 t / ha and 1.46 t / ha, respectively), their excess over the standard was from 87.9 to 151.7%. The varieties Zarnitsa and Zilant with plasticity coefficients of 1.14 and 1.62, respectively, showed the highest degree of responsiveness to improving cultivation conditions. These varieties occupied an intermediate position among the varieties under study in terms of stability (?2d = 0.02). The most stable variety was Talovskaya 33 (?2d = 0.33).

Optimal value determination using traditional and newly developed method based on using initial basic feasible solution of a transportation problem using northwest and Russell method

Optimal value determination using traditional and newly developed method based on using initial basic feasible solution of a transportation problem using northwest and Russell method

Optimization of Crude Palm Oil Distribution Costs in PT. Perkebunan Nusantara III Using Vogel's Approximation Method, Russel Approximation Method and Stepping Stone Method

PT. Perkebunan Nusantara III is an Indonesian State-Owned Enterprise engaged in oil palm and rubber plantations. The company is headquartered in Medan, North Sumatra. In general, the distribution process of CPO is one of the most important aspects to be planned, because it will greatly affect the overall cost efficiency of the project. The increase in project costs is often caused by a CPO distribution process that is not optimal. The method used to solve the distribution optimization problem is Vogel's Approximation Method and Russell's Approximation Method to determine the initial solution and optimization test using the Stepping Stone method. From the results of the calculation of the Vogel's Approximation Method method for the initial completion and continued by using the Stepping Stone Method is the method that gives optimal results. For the final settlement, a minimum fee of Rp. 34,417.014,501.

Ecological plasticity and stability of common millet (Panicum miliaceum L.) productivity in different environmental conditions of Ukraine

Purpose. To estimate the ecological plasticity of common millet yield under conditions of Steppe, Forest-Steppe and Forest of Ukraine. Methods. Mathematical and statistical: determination of stability and plasticity by Eberhart & Russell method, correlation analysis. Results. As a result of correlation analysis of millet cultivated areas during the period of 2011–2020, it was revealed that cultivated areas in Ukraine depend on the world ones (r = 0.34). It was determined that a high level of common millet yield was obtained in the forest-steppe zone, namely in Poltava, Khmelnytskyi, Cherkasy, Sumy and Kharkiv regions (2.20–2.51 t/ha). Quite high rates of yield were obtained in Vinnytsia, Kyiv (Forest-Steppe zone) and Kirovohrad (Steppe zone) regions (1.86–2.02 t/ha). Low yield over 10 years was noted in Rivne, Zhytomyr and Volyn regions, which belong to the Forrest zone (1.09–1.34 t/ha). It is shown that during 2011–2015 high variability of millet yield was observed in Khmelnytskyi, Vinnytsia and Volyn regions. The coefficient of variation was 42.0–71.3%. During 2016–2020 significant variation was noted in Donetsk, Volyn and Odesa regions. The coefficient of variation was 31.8–43.9%. In the period from 2016 to 2020, high plasticity of the yield trait was noted in Vinnitsa, Kyiv, Kharkiv, Poltava, Cherkasy, Sumy and Khmelnitsky regions. During 2016–2020 high plasticity trait of millet yield was in Vinnytsia, Kyiv, Sumy, Kharkiv, Khmelnytskyi, Cherkasy and Poltava regions. Conclusions. According to the results of the studies, it was found that with a reduction in the area under millet in the world, the volume of its production in Ukraine increases. It was determined that the hig­hest yield of millet was obtained in the Forest-Steppe zone during the years of observation. According to the plasticity of millet yield, it was found that favorable conditions for realization of its biological potential were in Donetsk and Kirovohrad regions of Steppe zone, in Forest-Steppe zone of Vinnytsia, Poltava, Kyiv, Kharkiv, Khmelnytskyi, Cherkasy and Sumy regions.

A Comprehensive Method for Arriving at Initial Feasible Solution for Optimization Problems in Engineering with Illustrative Examples

Two methods have been used extensively for arriving at initial basic feasible solution (IBF). One of them is Northwest corner rule and the other on is Russell method (Hillier & Lieberman, 2005.) Both methods have drawbacks. The IBF obtained is either far from optimal solution or does not have adequate number of entries to initiate transportation simplex algorithm. The Northwest Corner rule gives an initial feasible solution that is far from optimal while the IBF solution obtained using Russell method doesn’t give enough number of entries to start the transportation simplex algorithm. Hence, there is a need for developing a method for arriving at initial basic feasible solution with adequate number of entries needed to initiate transportation simplex algorithm, which can then be used to get an optimal solution. A computer software has been developed based on the new proposed method for this purpose. The proposed new method has been validated through four simple but illustrative examples.

Environmental Plasticity and Stability of Introduced Euramerican Poplar Hybrids Depending on Climate Variation

Euramerican poplars are used in many countries of the world, but they are not always suitable for the cold climate of the northern regions. In particular, they are not winter-resistant enough for Russia’s conditions. Field testing of 23 clones from 10 varieties of these poplars in the forest steppe of the Central Black Earth Region of Russia allowed identifying varieties that are winter-resistant in these conditions. They have high survival and productivity. The study of them during various periods of growth, using the Eberhart and Russell method, made it possible to identify a number of varieties with not only high productivity and survival, but also with considerable environmental plasticity to the changing weather and climatic conditions of the region.

Optimasi OPTIMASI BIAYA TRANSPORTASI PADA UKM DI KOTA BATAM

This research was conducted at UKM Jovelyn in Batam city. Jovelyn's UKM produces various kinds of cakes and is marketed in markets in Batam City. The UKM opened 4 branches and marketed its products to 7 markets in the city of Batam. Product distribution is still random and not properly regulated. This resulted in a very large transportation cost, up to 1/3 of the total production cost. This shows that product transportation is still not carried out effectively and efficiently. The transportation problem is converted into a mathematical form so that the problem can be solved by the transportation method. The transportation method aims to minimize the objective function which is a function of transportation costs. The transportation method is basically the same as the linear program where at each iteration a selection is made to enter the basic variabel and leave the basic variabel. There are several iteration methods, namely the northwest corner method, minimum cost method, genetic algorithm, Vogel's approximation method, minimum row method, Russell's approximation method and column minimum method. Previous research has shown that the Vogel's approximation method, and Russell's approximation method are more efficient and accurate. This study uses both methods and a sensitivity analysis is performed to optimize the calculation results. The sensitivity analysis aims to determine the extent to which the objective function constants and the constraint function constants can change
 Keywords: Transportation, Sensitivity, SME

Breeding strategies in evaluation of forage barley

AbstractProducers on the Canadian Prairies grow barley (Hordeum vulgare L.) as a forage crop for ruminants, especially cattle. The purpose of our study was to determine methods to improve our selection of barley lines with superior forage value for ruminants. Data from the Western Cooperative Forage Barley Registration Test were used with permission of the Prairie Recommending Committee for Oat and Barley (PRCOB) and the breeders. Data were analyzed from 20 environments collected from 3 yr (2012–2014) and seven sites. We measured forage accumulation (FA) at the soft dough stage, five nutritive value traits, and three derived cow–calf variables. Although the variation in FA and forage nutritive value traits attributed to environment (E) was large, significant genotypic (G) effects were found for all traits measured. Whereas G× E effects were also significant, the mean square effect for G was up to 40 times higher than the mean squares for G×E. The proportion of variance attributed to G was greater for nutritive value traits than for FA. Significance of G means there was variability in the germplasm tested, and improvement through selection should be possible. The two parametric methods of stability analyses (Francis–Kannenberg method and Eberhart–Russell method) often identified the same lines as superior. Lines that were superior for FA and carrying capacity (cow on swath grazing, CC) were often different from those identified as superior for nutritive value, empty body weight gain (cow, EBWG) and average daily gain (backgrounding calf, ADG). A nonparametric method used to determine dynamic stability (Nassar–Hühn method) identified different lines as superior from the parametric methods. Breeders can use a combination of these selection criteria in breeding forage barley varieties with enhanced forage value for ruminants.

Адаптивная способность и стабильность селекционных популяций клевера лугового в условиях Кировской области

The results of the assessment of breeding populations of red clover according to the parameters of adaptive capacity and stability of the characteristic "yield of the dry mass" are presented. The experiments were laid on two types of soils, contrasting in the content of H+ ions и Al3+ ions. The meteorological conditions also significantly varied (drought in 2016 and over wetting in 2017). Parameters of adaptive capacity and stability of populations, environmental parameters as the base for the selection were counted according to A.V. Kilchevsky and L.V. Khotyleva method, regression coefficient of the genotype on the b1 environment was counted according to S.A. Eberhart and W.A. Russell method. Statistically high general adaptive capacity (GAAi = 3.10 t/ha), stability (σ2САСi = 0.64; Sgi = 6.68%) and the greatest breeding value (BVGi = 8.63) were identified in the tetraploid standard Kudesnik. Picked out, promising for adaptive breeding, diploid populations SGPA-53 and P-4/03, showing at an average GAAi (0.26 and –0.07 t/ha, respectively) the high stability (σ2CACi = 0.32–0.66; Sgi = 6.48–8.87%) and the breeding value (BVGi = 5.74–6.42). It is of interest to hybridize a low-productive (GAAi = –1.14 t/ha), but the most stable (σ2CACi = 0.08; Sgi = 3.62%, Kgi = 0.14) population P-15k. Correlation analysis revealed no significant relation between GAAi and stability parameters, which does not exclude the possibility of combining high productivity and environmental sustainability in one variety. A statistically high relation between the parameters Sgi and σ2CACi, Sgi and Kgi, (r = 0.86), bi and σ2CACi, bi and Kgi (r = 0.79) was established, indicating that these characteristics provide relatively close information on the population stability. The stress alumina background in 2017 and the medium acid ground (Sek – 40.88 and 35.33%; Pk – 0.37 and 0.32, respectively) were characterized by the highest differentiating ability and predictability.

Mean performance and stability parameters for comparing bread wheat cultivars under different environmental conditions

The present study was conducted to selecting wheat stable cultivars with high productivity across various environments using the models of Eberhart & Russell (1966) and Tai (1971). Fife wheat cultivars viz, Shandwell 1, Sids 1, Sids 12, Giza 168 and Misr 2 were grown in a randomized complete block design with four replications under sixteen environmental conditions (2 years x 2 locations x 4 sowing dates) on yield and yield components during two successive seasons of 2017/2018 and 2018/2019. Pooled analysis of variance for grain yield and its components revealed significant variance due to genotypes, environments, and their interactions, indicating that they varied in their responses to diverse environments. Highest significant grain yield across varied environments was found by Sids 12 (14.60 ardab/feddan) followed by Shandwell 1 (13.61 ardab/feddan). The results indicated that according to Eberhart & Russell and Tai, the cultivar Shandwell 1 was genetically stable across various environments because it showed high mean performance for grain yield over these environments when compared with grand mean beside acceptable stability parameters (bi near to one, S2di non-significant, α stability value not significantly differed from zero and the λ statistic was not significantly differed from one, also it appeared stable over environments for other traits according to both previous methods. Meanwhile, cultivar Sids 12 were stable over all the studied environments for grain yield, but only according to Eberhart & Russell method.

Оценка экологической пластичности и стабильности некоторых перспективных сортов тополей

When developing promising assortments of forest woody plants, it is important to take into account not only their growth and survival in some particular environment, but also their respond to change in growing conditions. In this regard, the purpose of this work is to evaluate the ecological plasticity and stability of some poplar varieties promising for the southeastern part of European Russia and Ukraine using the Eberhart and Russell method. The research was carried out on three testing sites: upland environment of the forest-steppe zone of the Voronezh region; floodplain environment of the dry steppe zone of the Volgograd region; and floodplain environment of the steppe zone of the Donetsk region. Five promising poplar varieties were identified and studied at each of the experimental sites. The indices of survival, growth in height and diameter, trunk volumes, and productivity by wood stocks and average increments are presented for each variety. Due to the average increments change with age, the ontogeny period from 21 to 30 years was chosen for the study, during which the average survival of poplars varies slightly. It was found that Regenerata, which is characterized by average plasticity and the lowest stability, was the most productive of the studied poplar varieties. It can perform high productivity only in the favorable environment. The poplar variety Pioneer demonstrated the least plasticity. Its productivity did not vary too much with change in growth conditions at average ecological stability. The highest plasticity at average ecological stability was observed in the Vernirubens variety. Average plasticity and stability were observed in poplar E.s.-38. The poplar variety Marilandica was also characterized by average plasticity, and high ecological stability. The research results allow using of the studied varieties more rational in different growing conditions, with regard to their environmental characteristics.