Genetic Variance and Selective Value of Ear Number in Corn ( Zea mays L.) 1

Crop Science ◽  
1968 ◽  
Vol 8 (5) ◽  
pp. 540-543 ◽  
Author(s):  
Charles A. Laible ◽  
V. A. Dirks
Irriga ◽  
2020 ◽  
Vol 25 (4) ◽  
pp. 670-676
Author(s):  
Walber Cesar Vieira Filho ◽  
Vanessa de Fátima Grah Ponciano ◽  
Sihelio Julio Silva Cruz ◽  
Isaac de Matos Ponciano ◽  
Silvia Sanielle Costa de Oliveira ◽  
...  

EFEITOS DOS ADUBOS VERDES NO MILHO IRRIGADO SOB PLANTIO DIRETO     WALBER CESAR VIEIRA FILHO ¹; VANESSA DE FÁTIMA GRAH PONCIANO 2; SIHÉLIO JULIO SILVA CRUZ 3; ISAAC DE MATOS PONCIANO 4; SILVIA SANIELLE COSTA DE OLIVEIRA 5 E UELITON SOUSA FERREIRA6   1 Discente do curso de Agronomia, IF Goiano Campus Iporá, Av. Oeste, 350, Parque União, Iporá, Goiás, Brasil. [email protected] 2 Professora, IF Goiano Campus Iporá, Av. Oeste, 350, Parque União, Iporá, Goiás, Brasil. [email protected] 3 Professor, IF Goiano Campus Iporá, Av. Oeste, 350, Parque União, Iporá, Goiás, Brasil. [email protected] 4 Professor, Faculdade de Iporá, R. Serra Cana Brava, 512, Boa Vista, Iporá, Goiás, Brasil. [email protected] 5 Professora, IF Goiano Campus Iporá, Av. Oeste, 350, Parque União, Iporá, GO. [email protected] 6 Engenheiro Agrônomo, R. José Bonifácio, Centro, Amorinópolis, Goiás, Brasil. [email protected]     1 RESUMO   O objetivo do trabalho foi avaliar o efeito de diferentes coberturas vegetais sobre o crescimento e produção de biomassa de milho para produção de silagem em sistema de cultivo irrigado por gotejamento. O experimento foi conduzido durante o ano agrícola de 2019, em um Neossolo quartzarênico argiloso, na área experimental da Fazenda Escola da IF Goiano Campos-Iporá. O delineamento experimental utilizado foi o de blocos casualizados, sendo cinco tratamentos e quatro repetições. Os tratamentos empregados foram: T1) Área em pousio, T2) Crotalária, T3) Mavuno, T4) Lab-lab, T5) Aries. Aos 88 dias após a semeadura, quando as plantas de milho atingiram o ponto de corte para produção de silagem, foram avaliados diâmetro de colmo, altura de inserção da primeira espiga, número de espigas, diâmetro e comprimento das espigas. Os resultados foram submetidos a análise de variância e ao teste de Tukey a 5% de significância. Os adubos verdes apresentaram diferença no desenvolvimento do milho quando comparados com área em pousio, os adubos verdes que apresentaram maiores efeitos foram o capim Mavuno e a Crotalária.   Keywords: Zea mays L., Capim Mavuno, Crotalaria spectabilis     VIEIRA FILHO, W. C.; GRAH PONCIANO, V. F.; CRUZ, S. J. S.; PONCIANO, I. M.; OLIVEIRA, S. S. C.; FERREIRA, U. S. EFFECTS OF GREEN MANURES IN IRRIGATED CORN UNDER NO-TILLAGE     2 ABSTRACT   The work aimed to evaluate the effect of different green manure on the growth and production of corn biomass for silage production in the drip-irrigated cultivation system. The experiment was conducted during the 2019 agricultural year, in a Neossolo quartzarênico argiloso in the experimental area at Farm School of IF Goiano Campos-Iporá. The experimental plot used was randomized blocks, with five treatments and four replications. The treatments used were T1) Fallow, T2) Crotalária, T3) Mavuno, T4) Lab-lab, T5) Aries. Field evaluations were made 88 days after emergence: height of insertion of the first ear, number of ears, stem diameter. The results were subjected to analysis of variance and Tukey's test at 5% significance. The green manure difference in the development of the corn when compared with fallow area, the green manures that dissipate the greatest effects were Mavuno grass and Crotalária.   Keywords: Zea mays L., Capim Mavuno, Crotalaria spectabilis


Genetika ◽  
2010 ◽  
Vol 42 (3) ◽  
pp. 455-464
Author(s):  
Nenad Delic ◽  
Jovan Pavlov ◽  
Vojka Babic ◽  
Gordana Surlan-Momirovic ◽  
Tomislav Zivanovic

The objective of the present study was to observe differences among four sizes of the F2 populations (100, 200, 300 and 500 plants) on the basis of test-crosses for grain yield according to the average values of the populations, genetic and phenotypic variances, genotypic and phenotypic coefficients of variations and broad-sense heritability. The values of genetic variance did not significantly differ over population sizes according to all possible comparisons, including the comparison of values obtained for the phenotypic variance. Furthermore, the values of broadsense heritability (67.8%-69%) did not significantly vary over different F2 population sizes. Genetic variability of the observed progenies, as a principal prerequisite of successful selection, was at the satisfactory level in all population sizes.


2021 ◽  
Vol 186 (2) ◽  
pp. 183-199
Author(s):  
Sevda KILINÇ ◽  
Şehmus ATAKUL ◽  
Şerif KAHRAMAN ◽  
Hüsnü AKTAŞ ◽  
İrfan ERDEMCİ ◽  
...  

This study was carried out to investigate the effects of different sowing times on duration of tasselling, plant height, first ear height, ear length, ear diameter, number of ears per plant, fresh ear yield with husk, fresh ear yield unhusked, and marketable number of ears of different sweet corn (Zea mays L. saccharata Sturt.) varieties in Diyarbakır between the years of 2010-2012. The trial was conducted as split plots in randomised complete blocks with three replications. The main plots were sowing times, and the sub-plots were varieties. The trials were carried out at eight different sowing times (1 April, 15 April, 1 May, 15 May, 1 June, 15 June, 1 July and 15 July) with ‘Merit’, ‘Jubilee’, ‘Lumina’, ‘Vega’ and ‘Sakarya’ composite sweet corn varieties. From the variance analysis of the three-year combined average, the duration of tasselling, plant height, first ear height, ear length, ear diameter, number of ears per plant, fresh husked ear yield, fresh unhusked ear yield and marketable ear number were statistically significant for sowing times and varieties. According to the sowing time × variety interaction, except ears per plant and first ear height values, all other traits were significant. The fresh husked and unhusked ear yields varied between 8541.7-19396.8 kg ha-1 and 5065.0-13485.7 kg ha-1, respectively. The highest fresh husked and fresh unhusked ear yields were obtained from the 15 April sowing time of ‘Vega’ variety. The results state that optimal sowing dates for different varieties of sweet corn could be from 1 April to 1 May, and the most suitable variety to be planted is ‘Vega’ in Diyarbakır conditions.


2018 ◽  
Vol 17 (1) ◽  
pp. 76
Author(s):  
EDUARDO DE PAULA SIMAO ◽  
ÁLVARO VILELA RESENDE ◽  
MIGUEL MARQUES GONTIJO NETO ◽  
EMERSON BORGHI ◽  
ÀLISSON VANIN

RESUMO - Neste trabalho, objetivou-se avaliar a resposta do milho à adubação NPK, em semeadura realizada nos meses de janeiro e fevereiro, sucedendo a cultura da soja, em Rio Verde-GO. O experimento foi conduzido em delineamento de blocos casualizados, num esquema fatorial 4x2, constituído por quatro opções de adubação NPK na semeadura, com ou sem adubação nitrogenada de cobertura. Foram cultivados os híbridos P 30F53 YH e DKB 310 PRO, no primeiro e segundo anos, respectivamente, e coletados os dados de altura de plantas e de espigas, número de espigas, de fileiras por espiga, de grãos por fileira, massa de 1.000 grãos e produtividade. A produtividade de grãos do milho safrinha é influenciada pelas épocas de semeadura que definem as condições de disponibilidade hídrica, e pela adubação nitrogenada em cobertura, sem expressar resposta à adubação NPK na semeadura, que, em janeiro, favorece a produtividade, por conciliar melhor a distribuição de chuvas no final da fase de desenvolvimento vegetativo e na fase reprodutiva, etapas críticas para o potencial produtivo do milho. Independentemente da época de cultivo e da adubação NPK na semeadura, a aplicação de N em cobertura promove ganho significativo de produtividade da cultura. Palavras-chave: sucessão de culturas, adubação de manutenção, veranico, Zea mays L. SECOND-SEASON CORN RESPONSE TO FERTILIZATION IN TWO SEEDING TIMES ABSTRACT - This study aimed to evaluate the response of maize to NPK fertilization in sowing in January and February, succeeding soybean crop, in Rio Verde, State of Goiás, Brazil. The experiment was conducted in a randomized block design in a 4x2 factorial scheme, and it consisted of four NPK options in seeding time, with or without nitrogen topdressing. Hybrids P 30F53 YH and DKB 310 PRO were grown in the first and second year, respectively. We collected the data of plant height, ears height, number of ears, number of rows per ear, number of grains by row, thousand kernel weight and productivity. The productivity of second-season maize grain is influenced by sowing time, which defines the conditions of water availability, and the nitrogen fertilization, without expressing response to NPK fertilizer at sowing. Seeding in January favors productivity to reconcile better distribution of rainfall at the end of the vegetative growth phase and reproductive phase, critical steps for the production of maize potential. Regardless of the growing season and NPK fertilization at sowing, application of N topdressing promotes significant productivity gain.Keywords: crop succession, fertilization, nutrient requirements, dry spell, Zea mays L.


2016 ◽  
Vol 7 (1) ◽  
pp. 47
Author(s):  
Gaspar Martínez ◽  
Humberto De León-Castillo

This study report genetic effects for lodging, uncovered ears and ear rot, of 42 single cross hybrids made with seven lines developed in the humid tropic of México, and six lines developed in the dry tropic, using a North Caroline II mating design. Hybrid variation was mainly due to GCA variance, and scanty to SCA variance for all the three attributes, although for ear rot, SCA variance had a considerable role, too. Partitioning GCA variance, revealed humid tropic lines had highest contribution to lodging and ear covering variance, and dry tropic lines the highest contribution to ear rot variance. In addition, humid tropic lines had higher GCAxEnvironment interaction variance than dry tropic lines. In conclusion, GCA effects, which reveal additive genetic variance, were the main effects for all the three attributes, and that GCA effects were higher in humid tropic lines than those of the dry tropic, maybe due to their mobilization in a more ample and diverse region.


1998 ◽  
Vol 21 (4) ◽  
pp. 537-544 ◽  
Author(s):  
Carlos Alberto Arrabal Arias ◽  
Cláudio Lopes de Souza Júnior

New genetic variance and covariance components related to intra- and interpopulational recurrent selection methods have been theoretically developed by Souza Jr. (Rev. Bras. Genet. 16: 91-105, 1993) to explain the failure of these methods to concomitantly develop hybrid and per se populations. Intra- and interpopulation half-sib progenies of 100 genotypes were sampled from maize (Zea mays L.) populations BR-106 and BR-105 to estimate variance and covariance components and to compare the expected responses to reciprocal (RRS), intrapopulational (HSS), and modified (MRS) recurrent selection in interpopulation hybrid, populations per se, and to determine heterosis. Four sets of 100 progenies, two intra- and two interpopulational, were evaluated in partially balanced 10 x 10 lattices arranged in split-blocks with two replications in two years (1991/92 and 1992/93) and two locations in Piracicaba, SP. Data for ear weight, plant and ear height, and ear by plant height ratio were recorded. Populations and interpopulation crosses were high yielding and showed high breeding potential for production of hybrids from inbred lines. Mid parent and the highest parent heterosis were relatively high, but lower than values reported for these populations under other environmental conditions. Additive variance estimates of populations per se and interpopulation crosses confirmed the high potential of these materials. The magnitude of the variance estimates for the deviations from intra- and interpopulation additive effects (<img src="http:/img/fbpe/gmb/v21n4/1918f1.jpg" alt="1918f1.jpg (1262 bytes)" align="middle"> for BR-106 and <img src="http:/img/fbpe/gmb/v21n4/1918f3.jpg" alt="1918f3.jpg (1259 bytes)" align="middle">for BR-105) and covariance between additive effects with these deviations (<img src="http:/img/fbpe/gmb/v21n4/1918f2.jpg" alt="1918f2.jpg (2022 bytes)" align="middle"> for BR-106 and <img src="http:/img/fbpe/gmb/v21n4/1918f4.jpg" alt="1918f4.jpg (1995 bytes)" align="middle"> for BR-105) indicated that these new components can significantly influence the effectiveness of breeding methods. Genetic component estimates for BR-105 had relatively small errors, with <img src="http:/img/fbpe/gmb/v21n4/1918f4.jpg" alt="1918f4.jpg (1995 bytes)" align="middle"> negative for all traits. Estimates of <img src="http:/img/fbpe/gmb/v21n4/1918f1.jpg" alt="1918f1.jpg (1262 bytes)" align="middle">and <img src="http:/img/fbpe/gmb/v21n4/1918f2.jpg" alt="1918f2.jpg (2022 bytes)" align="middle"> had relatively larger errors for BR-106. The MRS method was more effective than the RRS and HSS methods in producing hybrids from inbred lines. The choice of a population tester for the MRS method based on population means per se may be incorrect. The additional use, when possible, of intra- and interpopulation additive genetic variances from each population would be more appropriate.


2017 ◽  
Vol 9 (4) ◽  
pp. 2496-2501
Author(s):  
R. Pavan ◽  
E. Gangappa ◽  
S. Ramesh ◽  
A. Mohan Rao ◽  
Hittalmani Shailaja

The present study was carried out to detect the epistasis present in two cross of maize through triple test cross (TTC) analysis. The mean squares due to total epistasis was highly significant at P≤0.01 for all the characters in both C-I and C-II, except for ear length in C-I. The i type of epistasis was highly significant for the traits such as days totasseling, days to silking, earlength, ear circumference, kernels row-1,100 grain weight and shelling percentage in C-I and in C-II, ‘i’ type was non-significant for ASI, ear length, kernels row-1and grain yield plot-1. Both j type and l type of epistasis were significant for all characters in both C-I and C-II, except for ear length in C-I and days to silking in C-II. The estimate of additive genetic component (D) was highly significant for all characters in both C-I and C-II. Epistasis played a significant role in the inheritance of all the characters in both C-I and C-II except for ear length in C-I. Both additive and dominance components of genetic variance with a predominance of dominance genetic variance played an important role in the inheritance of all the quantitative traits except ear length in C-I and kernel rows ear-1 in C-II.


Author(s):  
Luiz Leonardo Ferreira ◽  
Hiago Zanon Barbosa ◽  
Ivan Ricardo Carvalho ◽  
Roselaine Lages Fonseca Prado ◽  
Carmen Rosa da Silva Curvêlo ◽  
...  

Seed treatment has as its main feature the prevention of pest entry in cultivated areas, besides being of great importance in the development of vigorous and healthy plants. The objective of this work was to evaluate the performance of corn genotypes with biostimulant in seed treatment under water stress environment. The experimental design was randomized blocks in a 3x3 factorial scheme, corresponding to three corn genotypes (P3707, P30S31 and P30F35) and three seed treatments with the biostimulants (ConrSeeds, Stimulate and Água). The experiment was carried out at Luiz Eduardo de Oliveira Sales Experimental Farm, located in the municipality of Mineiros, Goiás, from March 2018 to August 2018. Plant height, stem diameter, ear insertion height, number of rows per ear, number of grains per row, number of grains per ear and yield were evaluated. The obtained data was submitted to the assumptions of the statistical model, verifying the normality and homogeneity of the residual variances, as well as the additivity of the model, testing univariate and multivariate analyzes. Analysis of variance revealed significance only for the main genotype effect. Seed treatments did not improve yield components of corn genotypes. The genotypes differed, where the variables number of rows per ear, number of grains per row and number of grains per ear directly influenced the grain yield.


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