scholarly journals Probing behavior of the corn leafhopper Dalbulus maidis on susceptible and resistant maize hybrids

2021 ◽  
Author(s):  
Pablo Carpane ◽  
María Inés Catalano
Keyword(s):  
Total Duration ◽  
Electrical Penetration Graph ◽  
Corn Hybrids ◽  
Dalbulus Maidis ◽  
Maize Hybrids ◽  
Probing Behavior ◽  
Corn Stunt ◽  
Corn Leafhopper ◽  
Old Females ◽  
Mesophyll Resistance

The corn leafhopper Dalbulus maidis is the main vector of the pathogens that cause corn stunt, a major disease of maize in the Americas. As host resistance is an efficient tool to control diseases, the findings of a previous report showed that some corn hybrids are resistant to D . maidis . In this work, we assessed the probing behavior of D . maidis on susceptible and resistant corn hybrids using EPG (Electrical Penetration Graph) technology. Fifteen-day-old females were monitored for 20 hours, with access to hybrids DK390, DK670, DK79-10, and DK72-10. Hybrids DK390 and DK72-10 showed resistance to D . maidis in phloem, since insects feeding on these hybrids presented more salivation events in phloem without subsequent ingestion, which are seen as failed attempts to ingest. A reduction of the total duration of phloem ingestion was observed, and accordingly of the time spent by insects with access to these hybrids on xylem ingestion. The hybrid DK390 also had mesophyll resistance, seen as less probing time and a higher number of probes of short duration. These findings support and are consistent with previous research, providing useful information to characterize maize hybrids resistant to D . maidis , and so to corn stunt.

EUDORYLAS (METADORYLAS) SP. (DIPTERA: PIPUNCULIDAE): A PREVIOUSLY UNREPORTED PARASITOID OF DALBULUS MAIDIS (DELONG AND WOLCOTT) AND DALBULUS ELIMATUS (BALL) (HOMOPTERA: CICADELLIDAE)

1991 ◽  
Vol 123 (1) ◽  
pp. 241-242 ◽  
Author(s):  
Fernando E. Vega ◽  
Pedro Barbosa ◽  
Alejandro Perez Panduro
Keyword(s):  
Latin America ◽  
Natural Enemies ◽  
Central Mexico ◽  
Dalbulus Maidis ◽  
Spiroplasma Kunkelii ◽  
Corn Stunt ◽  
Corn Stunt Spiroplasma ◽  
Maize Rayado Fino Virus ◽  
Corn Leafhopper

The genus Dalbulus (Homoptera: Cicadellidae) consists of 11 species, 10 of which can be found in México (Nault 1990). Some members in the genus, such as the corn leafhopper, Dalbulus maidis (DeLong and Wolcott), and the Mexican corn leafhopper, Dalbulus elimatus (Ball) are serious pests of maize due to their transmission of three corn stunting pathogens: corn stunt spiroplasma (CSS; Spiroplasma kunkelii Whitcomb et al.), maize bushy stunt mycoplasmalike organism (MBSM), and maize rayado fino virus (MRFV) (Nault 1990). Due to the widespread damage that these leafhopper-vectored pathogens cause in maize-growing regions in Latin America, a search for the leafhopper natural enemies was conducted in maize agroecosystems in central México.

scholarly journals The Reaction of some Maize Hybrids, Created at ARDS TURDA, to Fusarium spp. Infection

2017 ◽  
Vol 74 (1) ◽  
pp. 47
Author(s):  
Laura ȘOPTEREAN ◽  
Loredana SUCIU ◽  
Ana Maria VĂLEAN ◽  
Felicia MUREŞANU ◽  
Carmen PUIA
Keyword(s):  
Production Capacity ◽  
Climatic Conditions ◽  
Fusarium Ear Rot ◽  
Ear Rot ◽  
Artificial Infection ◽  
Fusarium Spp ◽  
Corn Hybrids ◽  
Maize Hybrids ◽  
Resistance Reaction

The most important disease of maize in Romania are stalk and ear rot, which caused yield losses in average of 20%. The resistant hibrids represent one of the most efficient solution for reducing the field loses caused by Fusarium spp. on the maize (Nagy et al., 2006). Diseases caused by Fusarium spp. can affect the yield and grain quality of maize because of contamination with numerous mycotoxins produced by these fungi (Czembor et al., 2015). The purpose of this paper was to know more about the reaction of different maize hybrids to Fusarium and the evaluating the effect of ear rot on the yield ability and mycotoxins accumulation. The experiments carried out at ARDS Turda, during four years (2012-2015). The biological material was represented by 8 hybrids, from different maturity groups, tested in two infection conditions with Fusarium spp. (natural and artificial infections). The temperature and rainfalls of the four years of experiments corresponding to the vegetation of maize (april-september) are influenced favourably the pathogenesis of stalk and ear rot caused by Fusarium spp. and a good discrimination of the resistance reaction of genotypes. Fusarium ear rot has significantly affected production capacity and chemical composition of corn hybrids tested. In conditions of artificial infection with Fusarium spp. was a decrease in the content of starch, fat and increased protein content compared with artificially inoculated variants. The quantity of fumonizin B1+B2 has reached to 5630 μg/kg in conditions of artificial infection. There are negative correlations between production capacity and degree of attack of fusarium ear rot; depending on the reacting genotypes tested increasing disease causes production decrease. The response of maize hybrids to Fusarium infection is influenced by infection and climatic conditions. These factors affect production both in terms of quantity and quality and accumulation of mycotoxins.

New insight into the behaviour modifying activity of two natural sesquiterpenoids farnesol and nerolidol towards Myzus persicae (Sulzer) (Homoptera: Aphididae)

2019 ◽  
Vol 110 (2) ◽  
pp. 249-258 ◽  
Author(s):  
Anna Wróblewska-Kurdyk ◽  
Katarzyna Dancewicz ◽  
Anna Gliszczyńska ◽  
Beata Gabryś
Keyword(s):  
Myzus Persicae ◽  
Total Duration ◽  
Host Plant Selection ◽  
Electrical Penetration Graph ◽  
Potato Aphid ◽  
Epg Technique ◽  
The Mean ◽  
Freely Moving ◽  
Peach Potato Aphid ◽  
Insight Into

AbstractThe effect of structurally related sesquiterpenoids (E,E)-farnesol and cis-nerolidol on the host-plant selection behaviour of the peach potato aphid Myzus persicae (Sulz.) was evaluated using electrical penetration graph (EPG) technique. No repellent effects of (E,E)-farnesol and (Z)-nerolidol to M. persicae were found but aphid probing activities on (E,E)-farnesol- and cis-nerolidol-treated plants were restrained. During non-phloem phases of probing, neither (E,E)-farnesol nor (Z)-nerolidol affected the cell puncture activity. On (E,E)-farnesol-treated plants, the total duration of phloem phase, the mean duration of individual sustained ingestion periods were significantly lower, and the proportion of phloem salivation was higher than on control plants. On (Z)-nerolidol-treated plants, the occurrence of the first phloem phase was delayed, and the frequency of the phloem phase was lower than on control plants. The freely moving aphids were reluctant to remain on (E,E)-farnesol- and (Z)-nerolidol-treated leaves for at least 24 h after exposure. (E,E)-Farnesol and (Z)-nerolidol show complementary deterrent properties, (E,E)-farnesol showing ingestive and post-ingestive activities and nerolidol showing pre-ingestive, ingestive, and post-ingestive deterrent activities.

Competitive Abilities of Six Corn (Zea maysL.) Hybrids with Four Weed Control Practices

1994 ◽  
Vol 8 (1) ◽  
pp. 124-128 ◽  
Author(s):  
Garry Tyron Ford ◽  
Jane Mt. Pleasant
Keyword(s):  
Weed Control ◽  
Dry Matter ◽  
Field Experiments ◽  
Leaf Angle ◽  
Corn Plant ◽  
Corn Hybrids ◽  
Area Index ◽  
Maize Hybrids ◽  
Grain Yields ◽  
Plant Characteristics

Six corn hybrids were studied in field experiments in 1989 and 1990 to identify hybrids and corn plant characteristics that may be valuable in systems using reduced levels of weed control. Four weed control treatments (no-control, cultivation-only, band herbicide-plus-cultivation, and broadcast herbicide) represented main plots and maize hybrids were subplots. Medium-season hybrids with differences in height, early-season vigor, and leafiness were used. There were significant differences among hybrids in leaf angle, leaf width, leaf number, plant height, leaf area index (LAI), plant dry matter (DM) and grain and stover yields. Lower yielding hybrids had grain yields that ranged from 87 to 91% of the highest yielding hybrid. Aboveground corn characteristics were not correlated with weed numbers, weed cover, or weed biomass. A significant interaction between hybrid and weed control for grain yields was observed in 1989, suggesting that some hybrids are more competitive when weed pressure is high.

scholarly journals Characterization and Correlation of New Electrical Penetration Graph Waveforms for the Corn Leafhopper (Hemiptera: Cicadellidae)

2011 ◽  
Vol 104 (3) ◽  
pp. 515-525 ◽  
Author(s):  
Pablo Carpane ◽  
Astri Wayadande ◽  
Elaine Backus ◽  
William Dolezal ◽  
Jacqueline Fletcher
Keyword(s):  
Electrical Penetration Graph ◽  
Corn Leafhopper

scholarly journals INFLUÊNCIA DE FORMAS DE ADUBAÇÃO DE SEMEADURA NA PRODUTIVIDADE DE GRÃOS DE HÍBRIDOS DE MILHO

2019 ◽  
Vol 18 (1) ◽  
pp. 88-98
Author(s):  
GUSTAVO DE CARVALHO PERON ◽  
RENZO GARCIA VON PINHO ◽  
LUIZ ANTONIO YANES BERNARDO JÚNIOR ◽  
VANDER FILLIPE DE SOUZA ◽  
FRANCIELLY DE CÁSSIA PEREIRA ◽  
...  
Keyword(s):  
Zea Mays ◽  
Grain Yield ◽  
Fertilizer Application ◽  
Minas Gerais ◽  
Climatic Conditions ◽  
Joint Analysis ◽  
Crop Season ◽  
Corn Hybrids ◽  
Maize Hybrids ◽  
Grain Productivity

RESUMO - Entender como o manejo de aplicação de fertilizantes interfere no sistema produtivo é primordial para amanutenção do máximo aproveitamento da produtividade dos híbridos. Desta forma, o objetivo com este trabalho foiverificar a influência da forma de adubação de semeadura, feita a lanço ou localizada, na produtividade de grãos de 33híbridos comerciais de milho, em quatro diferentes safras agrícolas. Foram conduzidos quatro experimentos no municípiode Serra do Salitre, em Minas Gerais (MG), nos meses de novembro de 2015 e de 2016, janeiro e fevereiro de 2017 efevereiro de 2017. O delineamento experimental utilizado foi o de blocos completos casualizados com três repetições,com os tratamentos dispostos em esquema fatorial de 33 x 2, sendo 33 híbridos de milho e dois sistemas de adubação desemeadura: a lanço e localizada. Na análise conjunta da produtividade de grãos, ocorreram interações significativas entrehíbridos e safras, e também entre formas de adubação e safras. Apesar da interação significativa, o sistema de adubaçãolocalizada foi superior em ambas as safras avaliadas, considerando nível de significância de 5% pelo teste de Tukey.Mesmo com as condições climáticas menos favoráveis na segunda safra, a adubação localizada mostrou-se mais eficiente.Palavras-chave: adubação localizada, adubação a lanço, segunda safra, Zea mays L.EFFECT OF SOWING FERTILIZATIONON GRAIN PRODUCTIVITY OF MAIZE HYBRIDSABSTRACT - Understanding how the management of fertilizer application affects the production system is essentialto maximize the productivity of the hybrids. The objective of this study was to verify the effect of broadcasting andbanding fertilization on grain yield of 33 commercial maize hybrids in four different crop seasons. Four experimentswere carried out in Serra do Salitre, state of Minas Gerais, Brazil, in November 2015, November 2016, January andFebruary 2017. The experimental design was a randomized complete block with three replications, with treatmentsarranged in a 33 x 2 factorial scheme, 33 corn hybrids and two sowing fertilization forms, broadcast and bandapplication. The joint analysis of grain yield showed significant interactions between hybrids and crop seasons, andalso between fertilization systems and crop seasons. The unfolding of the interaction between the fertilization formsand crop seasons showed that the yield of grains in the band fertilization was superior compared to the broadcastfertilization, regardless the crop season evaluated. Even with the less favourable climatic conditions in the secondharvest, the band fertilization showed to be more efficient when compared to the broadcast fertilization.Keywords: broadcast fertilizer, band fertilizer, second crop, Zea mays L.

scholarly journals RESULTS OF ENVIRONMENTAL TESTS OF NEW HYBRIDES OF CORN IN EXTREME CONDITIONS OF 2017

2018 ◽  
Vol 13 (4) ◽  
pp. 96-102
Author(s):  
Олег Шайтанов ◽  
Oleg Shaytanov ◽  
Марсель Тагиров ◽  
Marsel Tagirov ◽  
Ханиф Каримов ◽  
...  
Keyword(s):  
Air Temperature ◽  
Starch Content ◽  
Climatic Conditions ◽  
Corn Hybrids ◽  
Maize Hybrids ◽  
Russian Research Institute ◽  
Grain Moisture ◽  
Two Samples ◽  
Early Ripening ◽  
The Republic

Evaluation of new breeding samples of early ripening corn hybrids of All-Russian Research Institute was carried out on typical for the Republic of Tatarstan gray forest loamy soils. Unusual climatic conditions for the XXI century of the growing season of 2017 allowed us to make the most rigorous selection among the studied hybrids. At the time of harvesting a sample was detected with grain moisture 33.0 (control 34.6%), starch content in grain 58.8% (control 49.2%), grain productivity in terms of moisture 14.0% - 5.17 tons per hectare (control 4.73 tons per hectare). Also, two samples with grain moisture content of 38.4-38.7% were selected, which surpassed the control by 33.8-39.1%, with an equal starch content. The results of phenological observations of the growth and development of early maturing corn hybrids over 12 years were analyzed. A close negative correlation (r = -0.933) was established between the average daily air temperature and the duration of sprouting of the early ripe maize hybrids. A regression equation was derived, according to which a decrease in average daily air temperature by 1°C increases the duration of emergence of seedlings of early ripe maize hybrids in Tatarstan by 1 day.

Sign in / Sign up

Export Citation Format

Share Document