scholarly journals Resistance of popcorn hybrid (Zea mays) to multiple diseases and correlation between leaf disease intensity and agronomic traits

2020 ◽  
pp. 1800-1809
Author(s):  
Juliana Saltires Santos ◽  
Marcelo Vivas, Yure Pequeno de Souza ◽  
Antonio Teixeira do Amaral Júnior ◽  
Rafael Nunes de Almeida ◽  
Julio Cesar Gradice Saluci ◽  
...  

Grain yield and popcorn quality losses have become more common due to attacks by pathogens responsible for leaf diseases. Genetic resistance is the main control measure, as it is applicable in large areas and uses reduced costs and less environmental impact, compared to chemical control. In this context, the purpose was to select popcorn hybrids that meet resistance to Exserohilum turcicum, Bipolaris maydis, and Puccinia polysora and to have high levels of popping expansion and grain yield. We took into account two growing seasons (summer harvest - October 2014 to January 2015 - and winter harvest- April to July 2015). Twenty-eight hybrids from the complete diallel cross scheme were evaluated, among eight inbred lines (P8, P1, L55, L61, L70, L76, L77 and L88). For this purpose, we used a randomized block design with four replicates in two growing seasons. The traits investigated were the incidence of P. polysora (IPP), B. maydis (IBM), and E. turcicum (IET); severity of P. polysora (SPP), B. maydis (SBM), and E. turcicum (SET); grain yield (GY); and popping expansion (PE). Data from the experiments were submitted to the principal component analysis (PCA) through the R software. Results showed that the traits IET and IPP in the summer harvest, and IET and SET, in the winter harvest, were the most significant in the select of hybrids. The P8 x L76 and L70 x P8 hybrids were selected for summer harvest and the L77 x L61 hybrid, for winter harvest

2020 ◽  
Vol 38 (2) ◽  
pp. 280-286
Author(s):  
Anna Bárbara De Souza Cruz ◽  
José de Anchieta Alves de Albuquerque ◽  
Paulo Roberto Ribeiro Rocha ◽  
Leandro Torres de Souza ◽  
Diego Lima de Souza Cruz ◽  
...  

As a control measure against weeds, the use of herbicides is an effective and inexpensive alternative. However, there are no products recommended for the cultivation of cowpea in Brazil, making it necessary to search for alternative solutions. The objective of this study was to evaluate the effect of herbicides applied in the pre- and post-emergence on cowpea nodulation and production under conditions of the Amazonian savannah. Two experiments were carried out in a randomized block design with four replicates, using the cowpea cultivar BRS Aracê subjected to the pre-emergence herbicides: Metribuzin, Sulfentrazone, Smetolachlor, Pendimethalin, Oxadiazon, Alachlor, Metribuzin + Pendimethalin, Metribuzin + Alachlor and Quizalofop-p-ethyl, Bentazon, Fomesafen, Imazethapyr, Imazamox + Bentazon, Quizalofop-p-ethyl + Imazethapyr, Quizalofop-p-ethyl + Imazamox and Quizalofop-p-ethyl + Bentazon, and post-emergence herbicides: Quizalofop-p-ethyl, Bentazon, Fomesafen, Imazethapyr, Imazamox + Bentazon, Quizalofop-p-ethyl + Imazethapyr, Quizalofop-p-ethyl + Imazamox, and Quizalofop-p-ethyl + Bentazon. The number of nodules in each plant, the dry matter of nodules, dry matter of roots and the grain yield were evaluated. According to the results obtained, the management of weeds in pre- or post-emergence according to the herbicide used affects the nodulation and productivity of cowpea under the conditions of the Amazonian savannah. The herbicides Metribuzin in preemergence,and Fomesafen and the mixture of Quizalofop-pethyl + Imazethapyr in post-emergence are not recommended for weed control in cowpea. The application of Oxadiazon, Alachlor, and Pendimethalin in pre-emergence can be considered interesting because they do not inhibit the development of the root system or the nodulation of cowpea which provides agreater grain yield. Regarding weed control strategies at postemergence, the application of the herbicide Imazethapyr and the combination of the herbicides quizalofop-p-ethyl + imazamox, Quizalofop-p-ethyl + Bentazon and Imazamox + Bentazon allow satisfactory levels of grain yield, root system development and nodulation of cowpea.


2019 ◽  
Vol 2019 ◽  
pp. 1-7 ◽  
Author(s):  
Fiseha Baraki ◽  
Muez Berhe

Ethiopia is one of the famous and major producers of sesame in sub-Saharan Africa, and Ethiopian sesame is among the highest quality in the world. The experiment was conducted in Northern Ethiopia for three growing seasons (2013–2015) under a rain fed condition with the objective of identifying high-yielding genotypes and their agronomic traits. The experiment consisted of twelve genotypes laid down in randomized complete block design with three replications. The genotype, year, and genotype × year interaction components showed statistically highly significant variation (p<0.001) for most of the agronomic traits which clearly confirms the presence of genotype × year interaction in this study. The highest combined mean grain yield (906.3 kg/ha) was obtained from Hirhir followed by Serkamo white (756.5 kg/ha), and from the three growing seasons, the highest grain yield (1161.5 kg/ha) was recorded from Hirhir grown in the second growing season (2014). The growing seasons were different from one another in allowing the genotypes to have a different performance, and all of the agronomic traits, except thousand seed weight, were statistically different across the three growing seasons. In the ordination of the genotypes and agronomic traits, PCA1, which accounted for 38.3% of the variation, was positively associated with grain yield, branches per plant, length of the pod-bearing zone, plant height, number of pods per plant, number of seeds per pod, and thousand seed weight. On the contrary, PCA2, which accounted for 19.7% of the variation, was positively associated with days to 50% flowering and days to 50% maturity.


2020 ◽  
Vol 36 (5) ◽  
Author(s):  
Alan Mario Zuffo ◽  
Francisco de Alcântara Neto ◽  
Tiago Zoz ◽  
Rafael Felippe Ratke ◽  
Jorge González Aguilera ◽  
...  

 Stress events or leaf damage can alter the redistribution of photoassimilates and modify the morphological traits directly related to grain yield. This study aimed to evaluate the influence of agronomic traits on grain yield in soybean crop in function of leaf defoliation. The experiment consisted of a randomized block design with three replications, arranged in a 6 x 3 + 1 factorial scheme. The factors were composed by six reprodutive stages (R1, R2, R3, R4, R5, and R6) and three defoliation levels (33%, 66%, and 99%), and one additional treatment without defoliation (control). The following traits were evaluated: plant height, number of pods per plant, number of grains per pod, thousand grain weight, and grain yield. The magnitudes of the correlations between the same traits showed high oscillation according to the defoliation level. Results revealed the potential for the indirect selection for grain yield by the traits plant height and number of grains per pods under 0% of defoliation and by the trait number of pods per plant under 33% of defoliation.


2019 ◽  
Vol 11 (4) ◽  
pp. 142
Author(s):  
Alexsander Rigatti ◽  
Daniela Meira ◽  
Tiago Olivoto ◽  
Carine Meier ◽  
Maicon Nardino ◽  
...  

This study aimed to evaluate direct and indirect effects of agronomic traits importance on grain yield with focus in pre-harvest sprouting. Experiment was conducted in 2017 crop season, and conducted in a randomized block design, with three replications, with eight wheat cultivars (BRS S&aacute;bia, CD 105, CD 1104, CD 1440, Frontana, Jade&iacute;te 11, Mirante and ORS Vintecinco). Grain yield and its components were evaluated, as well as other important traits such as pre-harvest sprouting. Data were submitted to variance analysis; and phenotypic, genotypic and environmental correlations were estimated to understand grain yield expression, direct and indirect effects of its components were evaluated through path analysis. Cultivar BRS Sabi&aacute; showed shorter cycle, cultivar CD 1104 was highlighted in number of spikes per area, hectoliter weight and grain yield. And cultivars Frontana, CD 1440 and ORS Vintecinco presented the best tolerances pre-harvest sprouting. Grain yield showed high and positive phenotypic and genotypic correlations with number of ears per square meter. Furthermore, high positive direct effect of pre-harvest sprouting on grain yield, revels lower tolerance for cultivars with high grain yield. Number of spikes per square meter showed intermediate and positive direct effect and pre-harvest sprouting had the greatest direct effect on grain yield.


2019 ◽  
Vol 10 (1) ◽  
pp. 168-175
Author(s):  
Daniela Sarti Dvorjak ◽  
Sandra Helena Unêda-Trevisoli ◽  
Wallace De Sousa Leite ◽  
Alysson Jalles da Silva ◽  
Fabiana Mota da Silva ◽  
...  

Path analysis is an important study that slices the correlation coefficients between two variables to evaluate whether the relationship between them is of cause and effect. This study aimed to estimate the phenotypic and genotypic correlations between agronomic traits and perform a path analysis in order to identify variables for indirect selection aiming at a higher grain yield. Fourteen soybean F6 lines from the soybean breeding program of FCAV–UNESP, Jaboticabal, São Paulo, Brazil, were analyzed. The experimental design was a randomized block design with three replications. The agronomic traits plant height at maturity (PHM), first pod height (FPH), lodging (Ld), agronomic value (AV), number of pods per plant (NP), number of seeds per plant (NS), and grain yield (GY) were evaluated. Overall, the genotypic correlations were higher than their corresponding phenotypic correlations. The genotypic correlations between grain yield and the traits agronomic value, number of pods per plant, and number of seeds per plant were positive, significant, and of high magnitude. Path analysis showed that the trait number of seeds per plant had the highest direct effect on grain yield, while the trait number of pods per plant had the highest indirect effect through the number of seeds per plant on grain yield


Genetika ◽  
2020 ◽  
Vol 52 (1) ◽  
pp. 81-96
Author(s):  
Bekir Aktas

Yield and quality attributes of 13 bread wheat cultivars registered for Thrace region in 2018 and 5 standard bread wheat cultivars were determined and compared in this study. Tested cultivars are originated from Turkey, Bulgaria, Romania, Croatia, Austria and Ukraine. Experiments were conducted in 2015-2016 and 2016-2017 growing seasons. Since the locations were not equally distributed to growing seasons, statistical analyses for yield and other parameters were performed through assuming each location as an environment. Therefore, assessments were made over 7 environments. Environment (E) explained 54.9% of the total variation (E+G+GEI), genotype (G) and genotype ? environment interaction (GEI) generated 25.6% and 19.5%, respectively. GGE (Genotype + Genotype by environment interaction) biplot analysis was able to explain 78.51% of variation in grain yield. Trial environments gathered under 3 mega-environments. Of the cultivars registered in 2018, Adali, Bc Anica, Topkapi, FDL Miranda, Otilia, ZT Ziyade, Viktoria and Dragana had values larger than the average and thus they had the largest PC1 (Principal component 1) scores. Tested cultivars were also assessed based on vector lengths to average environment coordinate (AEC). Adali cultivar with a high PC1 score and the closest position to AEC apsis was found to be quite prominent for grain yield. In environment-focused assessments, E3, E4 and E5 had the closest position to ideal environment circle. With regard to physical quality attributes, Pehlivan, Bojana and Adali cultivars had high performance values. The cultivar Bojana, Topkapi and Iveta had protein contents above 15%. For Zeleny sedimentation values, Krasunia odes?ka had the best performance.


Author(s):  
TEGEGN BELETE ◽  
KEBEBEW ASSEFA ◽  
SENTAYEHU ALAMEREW

Objective: The objective of the study was to identify high yielding and stable tef varieties across different locations of South and Southwestern part of Ethiopia. Methods: The experiment was conducted using 21 tef varieties obtained from a tef breeding program based at Debre Zeit Agricultural Research Center. The trial was laid out using a randomized complete block design with three replications at six locations during the 2018 cropping season. Data for all relevant agronomic traits were collected, but only plot yield data converted to kg/ha was subjected to statistical analysis. Results: The results of combined analysis of variance for grain yield of 21 tef varieties across six locations revealed that there is a highly significant difference among the locations, genotypes, and interaction effects with the contributions of 67.4, 8.1, and 17.8% of sum of squares, respectively. Analysis of variance of AMMI model revealed the two interaction principal component analysis (IPCA1 and IPCA2) were highly significant according to Gollob’s test and accounted for 42.8 and 20.6% of variance, respectively. Conclusion: Based on AMMI Biplot analysis, Ambo location could be the representative area among tested locations to determine the tef varieties and the variety Heber-1 (G11) and Dukem (G15) were recommendable for broad adaptation since they were stable and high yielding across locations.


2020 ◽  
pp. 1328-1334
Author(s):  
Adaniel Sousa dos Santos ◽  
Leandro Pereira Pacheco ◽  
Rafael Felippe Ratke ◽  
Weverson Lima Fonseca ◽  
Alan Mario Zuffo ◽  
...  

In this study, the growth and productive characteristics of the soybean were investigated in no-till system after using limestone in a tropical soil of the Brazilian Cerrado. The study was conducted in a Typic Hapludox. The sources of limestone came from Piauí miners (C1, C2 and C3) and from a mining company in Ceará (C4) plus a control treatment (without limestone), with four replicates, during the 2013/2014 and 2014/2015 growing seasons, in a randomized block design. The limestone was applied in October 2012, using a gravity distribution. The limestone rate applied was 2.73 Mg ha-1 to raise the soil base saturation to 60%. The final plant stand, relative chlorophyll index, leaf area index, shoot dry matter, photosynthetically active radiation, the efficiency of photosynthetically active radiation, number of stems, pod number per plant, thousand-grain mass and grain yield of the soybean were evaluated. There were significant differences between the sources of limestone, with emphasis on the sources C1 and C4 due to the greater increases in plant growth and soybean grain yield (79% and 90%, respectively, in the 2014/2015 harvest). Soybean yield is correlated to the vegetative and reproductive development of the plant when cultivated in a tropical soil of the Cerrado corrected with limestone.


2020 ◽  
Vol 50 ◽  
Author(s):  
Adalin Cezar Moraes de Aguiar ◽  
Diecson Ruy Orsolin da Silva ◽  
Claudir José Basso ◽  
Bruna Dal’Pizol Novello ◽  
Álvaro André Alba da Silva

ABSTRACT Maize seeds lost during harvest may emerge and establish themselves during the cultivation of common bean, becoming a problematic weed in succession crops. This study aimed to evaluate the effect of the infestation level and interference period of volunteer maize on agronomic traits of common bean. The experiment was carried out in a randomized block design, with four replications, in a 2 x 8 factorial scheme consisting of two maize infestation levels (4 plants m-2 and 12 plants m-2) combined with eight coexistence periods between crop and weed (0, 7, 14, 21, 28, 35, 42 and 88 days after the emergence of the common bean). Variables related to the common bean vegetative growth (plant height, stem diameter, number of side branches and shoot dry matter) and to its grain production (number of pods per plant, grain yield and weight of 1,000 grains), as well as the period prior to interference, were assessed. The increase of the coexistence period and volunteer maize infestation level negatively affected the common bean growth and grain yield. The densities with 4 plants m-2 and 12 plants m-2 of volunteer maize reduced the common bean grain yield by 60 % and 84 %, respectively; while the periods prior to interference between crop and weed, for the respective infestation levels, were 15 and 8 days after the common bean emergence. In addition, the volunteer maize reduces the period prior to interference to very low values, indicating the need to anticipate the control of this weed.


2021 ◽  
Vol 12 (6) ◽  
pp. 725-730
Author(s):  
Guendouz Ali ◽  
◽  
Hannachi Abderrahmane ◽  
Fellahi Zine El Abidine ◽  
Benalia Frih ◽  
...  

Breeders are permanently looking for an efficient method of developing genotypes with improved yield. The aim of this study was to evaluate the performance of some durum wheat genotypes, the study of the correlations between traits and the direct effect of each trait on final grain yield. Twenty genotypes of durum wheat (Triticum durum Desf.) were planted in the experimental fields of INRAA, Setif, Algeria in (2016 –2017) crop season. The genotypes tested were grown in a randomized block design with three replications. The analyses of variance (ANOVA) demonstrate the existence of genetic diversity between genotypes tested. In addition, significant and positive correlations were registered between grain yield (GY) and days to heading (DH), number of spikes per square meter (NSM) and number of kernels per spike (NKS). The path analysis (PA) demonstrates positive and significant direct effects of the number of spikes per square meter (NSM), thousand kernels weight (TKW) and number of kernels per spike (NKS) on grain yield. Overall, the results proved that the genotypes Rezzak, Ofanto and BIDI 17 have the best ranking with the highest grain yield, and these can be recommended as the best genotypes for some in this area. In addition, the Principal Component Analysis (PCA) proved that the genotypes Rezzak, Bidi17, Ofanto, Kebir and Adnan 2 are very suitable genotypes for growing under semi-arid conditions.


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