Za intenzivno gajenje hibrida kukuruza neophodno je, pored komponenti prinosa i drugih agronomski važnih osobina biljke, za objektivnu ocenu njihovih. Ministri Evropske unije odobrili su gajenje kontroverznog genetski modifikovanog novog roda kukuruza, TC američke kompanije DuPont Pioneer. S druge strane, domaće životinje troše tokom uzgoja velike količine semena kukuruza, što sa obzirom na ograničen zemljišni fond obično znači učestalo gajenje.
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Skip to main content. Log In Sign Up. Parametri stabilnosti prinosa zrna i komponenti prinosa hibrida kukuruza razlicitih FAO grupa zrenja.
Journal of Central European Agriculture,15 4p. Grain yield and its ,ukuruza were assessed in 11 maize hybrids with different lengths of growing season FAO maturity groups using analysis of variance and regression analysis at three different locations in Western Serbia.
The kuouruza hybrids and locations showed significant differences in grain yield, grain moisture content at maturity, 1,kernel weight and ear length. A significant interaction was observed between all traits and the environment.
OPLEMENJIVANJE KUKURUZA NA PRINOS I KVALITET.
The hybrids with higher mean values of the traits, regardless of maturity group, generally exhibited sensitivity i. Regression coefficient bi values for grain yield mostly suggested no significant differences relative to the mean. The medium-season hybrid gave high yields and less favourable values of stability parameters at most locations and in most years, as compared to medium- late hybrids.
As compared to medium-early hybrids, medium-late hybrids FAO and mostly exhibited unfavourable values of stability parameters i.
Apart from producing lower average yields, FAO and hybrids showed higher yield stability as compared to the other hybrids tested. Medium-late hybrids had higher yields and showed a better response to favourable environmental conditions compared to early-maturing hybrids. Therefore, they can be recommended for intensive cultural practices and low-stress environments.
Due to their more favourable stability parameter values, medium-early hybrids can be recommended for low-intensity cultural practices and stressful environments. Nepovoljne vrednosti patrametara stabilnosti registrovane su kod hibrida kasnijih grupa zrenja u odnosu na ranije grupe zrenja to jest FAO vs FAO Setve je obavljena u provoj polovini aprila u obe godne na svim lokalitetima.
Introduction Identification of genotypes with a high potential for yield and stability across environments is an essential task in plant breeding. Identifying stable genotypes is often complicated by the presence of genotype x environment interaction GEI.
Significant GEI results from changes in the relative ranking of genotype performance across environments, and it affects breeding progress Pham and Kang, Moreover, the high value of GEI is often associated with a low correlation between genotypic and phenotypic values, thereby reducing the selection progress.
A genotype is considered stable if its performances are relatively constant across environments. Becker and Leon established a biological or static concept of stability under which a stable genotype displays a minimal variance for yield, for instance across different environments. However, this concept is of less importance to breeders and agronomists, who prefer genotypes with high yields and the potential to respond positively to agronomic inputs and favourable environmental conditions Becker, Under dynamic stability, a genotype or cultivar attains a constant high yield response to changes in the environment.
A number of stability analyses using GEI have been proposed to identify genotypes exhibiting good performance or high yields under different environmental conditions. Stability measures are based either on regression analysis or on principal component analysis Bernardo, The model proposed by Eberhart and Russell has been widely employed in the last several decades mostly due to the classification of variation in genotype performance into predictable regression and unpredictable deviation from regression components.
In this model, a regression coefficient greater than 1. However, Alwala et al. Moreover, if the regression coefficient does not show significant differences across genotypes, regression lines can be grouped, with only deviation from regression being used as a stability parameter for genotype classification.
Using this criterion, Flores et al. However, the fact that the independent variable environmental index in this model can be used before the experiment may be considered a limitation to interpreting deviations from regression as being a measure of cultivar stability. Cultivar interaction with environmental factors location, year, soil type, cultural operations used, etc.
The statistically non-additive genotype x environment interaction suggests dependence of yield differences among cultivars on the environment Yue et al. A strategy to reduce GEI involves selecting cultivars with a better stability across a wide range of environments in order to better predict their behaviour Eberhart and Russell, ; Tai, The model proposed by Eberhart and Russell interprets the variance of deviations from regression as a measure of cultivar stability and the linear regression coefficient bi as a measure of cultivar adaptability.
An objective evaluation of maize hybrids in intensive cropping systems requires identification not only of yield components and other agronomically important traits but also of stability parameters. The objective of this study was to evaluate grain yield and its components in maize hybrids with different lengths of growing season FAO kukuruzw groups using analysis of variance and regression analysis.
Short-season hybrids generally have a lower genetic potential for yield as compared to medium-late hybrids, but show more favourable values of stability parameters. The results obtained should point to the possibility of using short-season hybrids instead of medium-late ones, given the balance between yield, yield components and other agronomically important traits, on the one hand, and values of stability parameters, on the other.
Materials and methods Eleven double-way maize hybrids developed at the Zemun Polje Maize Research Institute were assessed. The hybrids belong to different maturity groups, viz. The hybrids were tested in parallel field experiments during and at three locations in West Serbia: Given the relatively narrow geographic area, kkuuruza locations selected for the gajene are representative of the major types of soils used for maize production in this region.
The soils at these locations differed in type and general fertility. The soil in Mojsinje is a heavy-textured vertisol acid in reaction pHH2O 5. Monthly rainfall Figure 1 showed variations across growing season in experimental years, April-September particularly in year.
The experiments were laid out in a randomised block design with four replications.
Each hybrid was sown in four rows per replication with 17 hills each with two plants per row at a spacing of 57 cm, making up a plant density of 50, plants ha Sowing was conducted in the first half of April in both years at all locations. Upon plant emergence, the crop was thinned to obtain the planned plant number.
During the growing season, in both years, standard cultural practices without irrigation were used. The results obtained were subjected to the factorial analysis of variance using F and LSD tests, and stability parameters were evaluated by regression analysis Eberhart and Russell, Results and discussion The analysis of variance revealed significant differences in grain yield, grain moisture content at harvest, 1,kernel weight and ear length between hybrids belonging to different maturity groups and between locations Table 1.
The lowest average yield was produced by HY01, and the highest by HY No significant differences were found between the regression coefficients for all hybrids in the first year and the average value. The regression coefficient bi was highest in medium-season HY06, and lowest in medium-early HY The regression coefficient of HY07 was closest to the mean value 1. The highest and significant deviation from regression was exhibited by HY08 1.
Half of the other hybrids showed significant values, whereas the other half showed negative values Table 2.
The highest regression coefficient was determined in HY06 and the lowest in HY The regression coefficient of HY05 was closest to the mean. Similarly to the previous year, coefficients of determination were largely uniform and high. The values of the standard error of the mean of the regression coefficients suggest identical heterogeneity of bi in both years.
Grain moisture content at harvest was highest in medium-late hybrids HY10 and HY11, with HY11 having the highest average value for the trait.
At all locations, the lowest value was found in HY01 Table 3. In the first year, the linear regression coefficient was significantly lower in HY07, whereas no significant differences from the mean value were observed in the other hybrids. The value for this parameter was highest in HY09, and that of HY06 was closest to the average.
In contrast, the values for the other hybrids were negative or significant. The regression coefficient in the second year was lowest in HY06, highest in HY04, and closest to the average value in HY Individual values were not significantly different from the average value in any hybrid. Most hybrids in the second year showed significant deviations from regression for grain moisture content. Significant differences in the trait were observed between hybrids as well as between locations.
The highest and highly significant regression coefficient in the first year, relative to the average, was found in medium-late HY10, whereas medium-season HY08 and HY05 had significant values.
The lowest highly significant bi value was detected in HY02, and the value closest to the average in HY The hybrids HY09 and HY01 showed highly significant deviations from regression, whereas the other hybrids had negative values Table 4.
S di R 1,k. S di R weight weight 0.
SCIndeks – Članak
With the exception of HY08 and HY10, the other hybrids showed negative values. The highest average value for ear length in the first year was found in HY08, and the lowest in HY The regression coefficient values in all hybrids did not significantly differ from the mean, with the hybrid HY09 being the closest to the average value. Most hybrids showed significant deviations from regression Table 5.
The medium-early hybrids HY03 and HY01 showed significant deviations from regression, and negative values were observed in most other hybrids. Discussion Genotype adaptability and stability are useful parameters for recommending hybrids for known cultivation conditions. Eberhart and Russell proposed an assessment of cultivar response to environmental changes using a linear regression coefficient and variances of regression deviations.
Cultivars are classified according to the value of their linear regression coefficients into those having bi less than, equal to, or greater than unity, as well as according to the value of the variance of regression deviations equal to or different from zero.
Namely, cultivars that have regression coefficients greater than unity would be more adapted to favourable growing conditions, those with regression coefficients less than unity would be adapted to unfavourable environmental conditions, and those with regression coefficients equal to unity would have an average adaptation to all environments. Furthermore, genotypes with variances in regression ganenje equal to zero would have highly predictable behaviour, whereas those with regression deviation different from zero would have low predictability.
The regression coefficient for grain yield for all hybrids except HY02 in was not significantly different from the mean, indicating adaptability of the test hybrids to the environment.
The significantly different value of bi in HY02 in the first year suggests greater-than-average stability of this kukuduza as compared to the other hybrids tested. Among medium-early hybrids, HY06 gave higher grain yields as compared to medium-late hybrids in almost all trials in both years, but also had higher values of the regression coefficient and showed mostly significant deviations from regression.
The stability parameters indicate that this hybrid exhibits a specific response to the particular agroenvironmental conditions i. In terms of stability parameters, HY05 was comparable to the medium-early hybrids, fajenje its grain yields at certain locations corresponding gaienje those of late-season hybrids. Most medium-early hybrids give low yields, along with generally favourable values of stability parameters i.
The results of kykuruza authors suggest that hybrids with higher average yields have better adaptation to favourable agroenvironmental conditions, with no linear trend observed due to significant regression deviations i. The hybrids belonging to low maturity groups have higher adaptability, but show a low response to the environment and, hence, frequent inability to make use of favourable conditions Troyer Likewise, genotypes having a high value of S2di are considered highly unstable, whereas those with low values as kukuruaz stable.
The same authors underlined that regression analysis, although widely used in the previous period, provides useful information on genotype stability.