scholarly journals EVALUATION OF MAIZE HYBRIDS TOLERANT TO PHAEOSPHAERIA LEAF SPOT, GRAY LEAF SPOT AND COMMON RUST AND YIELD

2017 ◽  
Vol 16 (1) ◽  
pp. 72
Author(s):  
RENATO BARBOSA CAMARGOS ◽  
JOÃO CANDIDO DE SOUZA ◽  
EDUARDO ALVES ◽  
CARLOS EDUARDO CAIXETA DE CASTRO ◽  
PAULO EDUARDO RODRIGUES PRADO ◽  
...  

 ABSTRACT - The objectives of this study were to identify maize hybrids which have high grain yield and resistance to Phaeosphaeria leaf spot, gray leaf spot and common rust, as well as to estimate the most efficient period for measuring the reaction of the hybrids to the pathogens. Two experiments were set up in Lavras, MG, Brazil, assessing 30 hybrids in the season of 2011/2012. The experimental design was a 6 x 5 lattice arrangement with three replications. Grain yield was evaluated and five assessments of disease severity were performed at ten-day intervals as of 60 days after maize emergence. After that, the area under the disease progress curve (AUDPC) and the Spearman correlations between the diseases and the various assessment periods for each disease were estimated. It was found that the hybrids GNZ9626 PRO and GNZ9501 PRO have high grain yield and a satisfactory level of resistance to Phaeosphaeria leaf spot, gray leaf and common rust, and that assessment of the level of resistance to these diseases should be performed in the period from 80 to 100 days after plant emergence, which provides results similar to AUDPC.Keywords: Zea mays L., Leaf diseases, Genetic resistance.AVALIAÇÃO DE HÍBRIDOS DE MILHO À MANCHA BRANCA, CERCOSPORIOSE E FERRUGEM COMUM E À PRODUTIVIDADERESUMO - Os objetivos deste trabalho foram identificar híbridos de milho que apresentem alta produtividade de grãos e resistência à mancha-branca, cercosporiose e ferrugem comum, bem como estimar a época de avaliação mais eficiente para mensurar a reação dos híbridos aos patógenos causadores dessas doenças. Para isso, foram instalados dois experimentos no município de Lavras, MG e avaliados 30 híbridos no ano agrícola de 2011/2012. O delineamento experimental utilizado foi o látice 6 x 5 com três repetições. Foi avaliada a produtividade de grãos e realizadas cinco avaliações da severidade dessas enfermidades, em intervalos de 10 dias, a partir de 60 dias da emergência das plantas. Posteriormente, estimou-se a área abaixo da curva de progresso das doenças (AACPD) e a correlação de Sperman entre as mesmas com as diversas épocas de avaliação de cada doença. Constatou-se que os híbridos GNZ9501 PRO e GNZ9626 PRO apresentam alta produtividade de grãos e satisfatório nível de resistência à mancha-branca, cercosporiose e ferrugem comum e que para a avaliação do nível de resistência a essas enfermidades deve-se optar pela avaliação no período que compreende 80 a 100 dias após a emergência das plantas, o qual fornece resultados semelhantes à AACPD.Palavras-chave: Zea mays L., Doenças foliares, Resistência genética.

2014 ◽  
Vol 2 (2-3) ◽  
pp. 132-143 ◽  
Author(s):  
Liyu Shi ◽  
Xiangling Lv ◽  
Jianfeng Weng ◽  
Hanyong Zhu ◽  
Changlin Liu ◽  
...  

1991 ◽  
Vol 71 (4) ◽  
pp. 1021-1027 ◽  
Author(s):  
M. Tollenaar ◽  
M. Mihajlovic

Genetic grain yield improvement of maize (Zea mays L.) in Ontario during the past three decades can be attributed, in part, to increased tolerance to environmental stresses. We have observed a differential response of field-grown old and new hybrids after application of the photosystem II inhibiting herbicide bromoxynil (4-hydroxy-3,5-dibromobenzonitrile). Studies were conducted to test whether tolerance to bromoxynil is associated with stress tolerance and grain yield in maize hybrids representing three decades of yield improvement in Ontario. Experiments were carried out with seedlings of eight maize hybrids grown in pots in controlled-environment growth cabinets and, in one experiment, with seedlings grown in pots outside during the months of July and August at Guelph, Ontario. Bromoxynil was applied to the youngest fully-expanded leaf of plants at the 6- to 8-leaf stage and chlorophyll fluorescence of the treated leaves was measured in the 2- to 24-h period after bomoxynil application. Results showed that the chlorophyll fluorescence ratio Fv/Fm, an indicator of photosynthetic efficiency, declined after bromoxynil application until 4 h after application and, subsequently, recovered slightly during the next 20 h. Large differences in the Fv/Fm ratio were apparent among hybrids in the response to bromoxynil. The Fv/Fm ratio was significantly higher for hybrids released in the 1980s than for hybrids released in the 1970s, and the Fv/Fm ratio of the latter group was significantly higher than that of the four oldest hybrids. Chlorophyll fluorescence ratios Fv/Fm after bromoxynil application in the seedling phase were highly correlated with grain yield of the hybrids in field experiments conducted during 1987 and 1988 (r = 0.91). Results of this study support the contention that maize genotypes that are less sensitive to bromoxynil are less susceptible to environmental stresses. Key words: Zea mays L., stress tolerance, bromoxynil, chlorophyll fluorescence, Fv/Fm ratio, detoxifying agents


Scientifica ◽  
2021 ◽  
Vol 2021 ◽  
pp. 1-9
Author(s):  
Seyed Habib Shojaei ◽  
Khodadad Mostafavi ◽  
Ali Omrani ◽  
Saeed Omrani ◽  
Seyed Mohammad Nasir Mousavi ◽  
...  

The present study investigated the stability and adaptability of maize (Zea mays L.) hybrids. In this study, 12 maize hybrids were planted and examined considering the grain yield. The experiment was arranged in a randomized complete block design (RCBD) with three replications in four research stations in Iran during two crop years. The combined analysis of variance showed that genotype-environment interactions were significant at one percent probability level. The grain yield can stabilize, and hybrids with specific adaptability are recommended to each environment. Hybrids with specific adaptability can be recommended to all types of the environment. Means comparison yield of the genotypes identified DC370 as a high-yield genotype. Regarding AMMI analysis, genotype × environment interactions (GEIs) and two first components were found significant. The SC647 genotype was identified as the most stable genotype. Regarding the stability parameters, SC647 and KSC705 genotypes were selected as the most stable genotypes. From AMMI1 and AMMI2 graphs, the SC647 genotype was identified as the most stable genotype compared with other hybrids.


2010 ◽  
Vol 61 (9) ◽  
pp. 700 ◽  
Author(s):  
Saeed Safari Dolatabad ◽  
Rajab Choukan ◽  
Eslam Majidi Hervan ◽  
Hamid Dehghani

Adapted maize (Zea mays L.) hybrids should be identified and chosen based on multi-environment trials analysing several traits. The objectives of this study were to identify mega-environments and suitable adapted maize hybrids based on both mean grain yield and grain yield stability and were to evaluate the 14 maize hybrids based on several desirable traits. Biplot analysis determined one mega-environment and two sectors that consist of one location in each sector for maize in Iran. The mega-environment included Kerman (KRM), Kermanshah (KSH), Moghan (MGN), Dezfol A (DZF A), Karaj (KRJ), Darab (DRB), Dezfol B (DZF B), Shiraz B (SHZ B), and Esfahan (ESF), where hybrid OSSK 602 was the best performing hybrid. The first sector included Khoramabad (KHM) where BC 678 was the best hybrid, and the second sector included Shiraz A (SHZ A) where ZP 599 was the hybrid with the highest performance. OSSK 602 was the best hybrid among all of the studied hybrids followed by ZP 677 and ZP 684. The genotype × trait biplot indicated that ZP 677 and OSSK 602 had greater thousand-kernel weight and grain number, whereas ZP 684 had longer day to maturity and larger cob diameter. KSC 700, KSC 704, and BC 678 had higher ear height and more days to tasseling than other hybrids. The genotype × trait biplot graphically displayed the interrelationships among traits and it was used in identifying hybrids that are good for some particular traits.


2017 ◽  
Vol 130 (6) ◽  
pp. 1285-1295 ◽  
Author(s):  
Xinye Zhang ◽  
Qin Yang ◽  
Elizabeth Rucker ◽  
Wade Thomason ◽  
Peter Balint-Kurti

Author(s):  
Ayse Gulgun Oktem ◽  
Abdullah Oktem

Aims: It was aimed to determine the effect of different levels of farmyard manure on yield and quality attributes of the popcorn (Zea mays L. everta Sturt) grown under second crop conditions. Study Design: The experiment was set up according to randomized complete blocks experimental design with 3 replicates. Place and Duration of Study: Research was conducted in 2018 under Harran Plain conditions as second crop, Sanliurfa, Turkey. Methodology: Antcin hybrid popcorn variety was used as a plant material. Farmyard manure (FYM) applications were 0 (control), 1 tone da-1 FYM, 2 tone da-1 FYM, 3 tone da-1 FYM, 4 tone da-1 FYM, 5 tone da-1 FYM and 6 tone da-1 FYM. In study, plant height, stem diameter, grain yield, 1000 kernel weight, popping volume and protein ratio values were researched. Results: Farmyard manure levels were significant in all tested characteristics. Farmyard manure levels effected positively on plant height (P≤0.05), stem diameter, grain yield, 1000 kernel weight, popping volume and protein ratio (P≤0.01). The highest plant height value was seen 6 tone da-1 application of FYM application whereas the lowest plant height value was found at control parcel. Stem diameter value ranged from 19.33 mm (control) to 23.87 mm (5 tone da-1 FYM). The highest grain yield value obtained from 6 tone da-1 FYM (489.71 kg da-1) while the lowest value was seen at control parcel (219.95 kg da-1). But 4, 5 and 6 tone da-1 FYM applications were found in same statistical groups. 1000 kernel weight values ranged from 159.60 g to 204.67 g. The highest popping volume value was seen 6 tone da-1 FYM treatment. Protein ratio (%) values ranged from % 9.27 to %14.01. The highest protein ratio was obtained from 6 tone da-1 FYM while the lowest protein ratio value was found at control parcel. Conclusion: All farmyard manure levels effected positively on plant height, stem diameter, grain yield, popping volume and protein ratio. The highest grain yield value was seen at 6 tone da-1 FYM. But, 4, 5 and 6 tone da-1 FYM treatments were in the same statistical groups. There was no statistically significant increase in grain yield after 4 tone da-1 farmyard application (478.57 kg da-1). According to research results, considering grain yield, popping volume and protein ratio values, 4 tone da-1 farmyard manure was seen sufficient in organic popcorn cultivation.


2021 ◽  
Vol 66 (3) ◽  
pp. 231-245
Author(s):  
Adesike Kolawole ◽  
Ibrahim Raji ◽  
Solomon Oyekale

Maize (Zea mays L.) is a staple food for millions of people across the globe, and it supplies more than 30% of total dietary calories. However, the normal endosperm lacks a sufficient quantity of the nutritive precursor of vitamin A. To achieve food security and avert malnutrition, there is a need to adopt the cultivation of the early multiple stress-tolerant pro-vitamin A maize hybrid. The objective of this study was to assess the agronomic performance and yield of the newly developed maize hybrids. Fifteen improved maize hybrids and one commercial hybrid used as a local check were evaluated in a randomized complete block design with two replications for two years at the Ladoke Akintola University of Technology Teaching and Research farm in Ogbomoso, Nigeria. Hybrids exhibited significant variation (P < 0.01) for grain yield, number of days to anthesis and silking, ear height and husk cover. Across the years, the grain yield of hybrids ranged between 4,780.8 kg ha?1 (PVAEH-19) and 7,886.9 kg ha?1 (PVAQEH-1), with a mean of 6,354.2 kg ha?1. PVAEH-15 ranks the best on the basis of superiority in grain yield, early flowering and tight husk cover. Fourteen hybrids out-yielded the local check (4,947.2 kg ha-1), and five hybrids had a significant (P < 0.05) yield advantage of > 26% over the local check. The consistent performance of PVAEH-15 and PVAEH-16 in the two years of evaluation indicates potential for the adaptability of the hybrids to the agro-ecology. Farmers? adoption of these maize hybrids will boost maize production and prevent malnutrition in the derived savanna agro-ecology of Nigeria.


BMC Genomics ◽  
2015 ◽  
Vol 16 (1) ◽  
Author(s):  
Jafar Mammadov ◽  
Xiaochun Sun ◽  
Yanxin Gao ◽  
Cherie Ochsenfeld ◽  
Erica Bakker ◽  
...  

Plant Disease ◽  
2002 ◽  
Vol 86 (8) ◽  
pp. 859-866 ◽  
Author(s):  
P. M. Caldwell ◽  
J. M. J. Ward ◽  
N. Miles ◽  
M. D. Laing

The effects of the application of 0, 60, and 120 kg N ha-1 and of 0, 25, 50, and 150 kg K ha-1 on final disease severity, standardized area under disease progress curve, and grain yield were investigated at Cedara, South Africa, on a maize (Zea mays) hybrid susceptible to gray leaf spot (GLS), caused by Cercospora zeae-maydis. The trial was a randomized 3 × 4 factor design, split for fungicide treatments, and replicated three times. With increased N and K levels, final percent leaf blighting and the standardized area under disease progress curve were higher. In fungicide-treated maize, grain yields increased with increasing levels of N and K, as expected. In non-fungicide-treated maize, grain yield increased significantly with increased levels of N, despite increased disease severity. This was in contrast to small increases in grain yields from non-fungicide-treated maize with increased K levels, which were not significant. This was probably because grain yield response, which should have occurred at higher K applications, was reduced by increased disease severity. The effect of N, P, and K on GLS wasinvestigated at Ahrens. Maize was grown in a 4 × 4 × 4 N-P-K factorial, in a randomized complete block design. Fertilizer was applied at 0, 60, 120, and 180 kg N ha-1, 0, 30, 60, and 120 kg P ha-1, and 0, 50, 100, and 150 kg K ha-1. No fungicides were applied. A single disease assessment at physiological maturity showed that final disease severity increased with increasing levels of N, P, and K. These results have implications for small-scale farmers who are encouraged to fertilize for increased grain yields but may not have the resources to apply fungicide sprays to control fungal diseases.


Sign in / Sign up

Export Citation Format

Share Document