scholarly journals Bees Occurring in Corn Production Fields Treated with Atoxigenic Aspergillus flavus (Texas, USA)

Agronomy ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 571
Author(s):  
Krishna B. Bhandari ◽  
Scott D. Longing ◽  
Charles P. West

A saprophytic soil fungus, Aspergillus flavus, produces aflatoxin (toxigenic strains) in the kernels of corn (Zea mays L.) and seeds of many other crops. Many strains of A. flavus do not produce toxigenic aflatoxin, and soil application of these atoxigenic strains is a suppressive control tactic to assist in controlling toxigenic conspecifics. Effects of atoxigenic A. flavus applications on honey bees (Apis mellifera L.) and other bees are unknown, and basic information on bee occurrences in cornfields treated with and without this biological agent is needed to inform integrated pest management in corn. Fields receiving atoxigenic A. flavus applications of FourSureTM were compared to nearby control fields in three counties in corn production regions in eastern Texas. In each cornfield, 20 bee bowl traps were deployed along four equal transects located between corn rows, with contents of the bowls (i.e., bees) retrieved after 24 h. Eleven bee genera from four families were collected from cornfields, with only two honey bees collected and zero honey bees observed in transects. The sweat bee genus Agapostemon (primarily composed of the Texas striped sweat bee A. texanus) was most abundant in cornfields (44% of the total number of bees collected), followed by long-horned bees (Melissodes spp., 24%). The southernmost county (i.e., San Patricio) produced over 80% of the total number of bees collected. Bee numbers occurring in cornfields with applications of atoxigenic A. flavus applications were not significantly different from those of nearby control fields. Although not statistically significant, total numbers of bees tended to be lower in FourSure-treated fields than in control fields. More extensive research on bee abundances in relation to the effect of atoxigenic A. flavus is warranted.

Author(s):  
Krishna B. Bhandari ◽  
Scott D. Longing ◽  
Charles P. West

A saprophytic soil fungus, Aspergillus flavus, produces aflatoxin (toxigenic strains) in the kernels of corn (Zea mays L.) and seeds of many other crops. Many strains of A. flavus do not produce toxigenic aflatoxin, and soil application of these atoxigenic strains is a suppressive control tactic to assist in controlling toxigenic conspecifics. Effects of atoxigenic A. flavus applications on honey bees (Apis mellifera L.) and other bees are unknown, and basic information on bee occurrences in corn fields treated with and without this biological pesticide is needed to inform integrated pest management in corn. Fields with atoxigenic A. flavus applications were compared to nearby control fields in three counties in corn production regions in eastern Texas. In each corn field, twenty bee bowl traps were deployed along four equal transects located between corn rows, with contents of the bowls (i.e. bees) retrieved after 24 hours. Eleven bee genera from four families were collected from corn fields, with only two honey bees collected and zero honey bees observed in transects. The sweat bee genus Agapostemon (primarily composed of the Texas-striped sweat bee A. texanus) was most abundant in corn fields (44% of the total number of bees collected) followed by long-horned bees (Melissodes spp., 24%). The southernmost county (i.e. San Patricio) produced over 80% of the total number of bees collected. Bee communities occurring in corn production fields with applications of atoxigenic A. flavus applications were not significantly different from nearby control fields. While little is known of bee resource use in corn production systems in Texas, the abundant yet variable bee communities across latitudes in this study suggests a need to investigate the influence of farming practices on bee resources in regional corn production systems.


Author(s):  
Selene Yuliet Jacinto-Pimienta ◽  
José H. Rodolfo Mendoza-Hernández ◽  
Juan Manuel Zaldivar-Cruz ◽  
Ángel Sol-Sánchez ◽  
Luis Manuel Vargas-Villamil ◽  
...  

Se colectaron 38 muestras de miel de Apis mellifera L. en seis municipios, pertenecientes a las cinco subregiones del estado de Tabasco, se realizó el análisis melisopalinologico obteniendo 37 tipos polínicos de importancia (>10%). Bursera simaruba L. (Burseraceae), Spondiasmombin (Anacardiaceae), Diphysa sp. (Fabaceae), Erythrina sp., (Fabaceae), Mimosa orthocarpa (Fabaceae), Pipersp1, sp2, sp3 (Piperaceae), Machaerium sp., (Fabaceae), Cecropia obtussifolia (Moraceae), Psidium guajava (Myrtaceae), Acalypha sp., (Euphorbiaceae), Celtis sp., (Ulmaceae), Heliocarpus appendiculatus (Tiliaceae), Conocarpus sp., (Combretaceae), Haematoxy lumcampechianum (Fabaceae), Mimosa albida (Fabaceae), Zea mays L. (Gramineae), Diphysacarthagenensis (Fabaceae), Quercus sp., (Fagaceae), Citrus sp., (Rutaceae), Cocos nucifera (Arecaceae), Mimosa sp., (Fabaceae), Mimosa pigra var. Berlandieri (Fabaceae), Eleocharis sp., (Cyperaceae), Rumex sp., (Polygonaceae), Eragrostis sp., (Poaceae), Spondiasradlkoferi (Anacardiaceae), Muntingiacalabura (Elaeocarpaceae), Asteraceae sp1, (Asteraceae), Borreriaverticillata (Rubiaceae), Coccolobaaff. Diversifolia (Polygonaceae), Quercusoleoides (Fagaceae). En general se clasificaron 22 muestras de miel multifloral, 9 monof loral y 7 bif loral. Y al realizar el ACP, se obtuvieron dos componentes que explican 65% de la variación total, mostrando que Cárdenas y Huimanguillo tienen afinidad por Bursera simaruba L. (Burseraceae) y Cecropiaobtussifolia (Moraceae), en cambio Centro, Tacotalpa y Balancán comparten preferencia por Mimosa albida (Fabaceae), Psidiumguajava (Myrtaceae) y Rumex sp. (Polygonaceae) y Centla en cambio mostró una clara diferencia con los 5 municipios restantes.


1987 ◽  
Vol 22 (4) ◽  
pp. 307-310 ◽  
Author(s):  
W. W. McMillian ◽  
N. W. Widstrom ◽  
D. M. Wilson

The use of plants that resist insects has been suggested as a potential means of reducing aflatoxin contamination in some crops. Dent corn, Zea mays L., germplasm possessing the characteristic of a relatively tight, complete husk cover and germplasm possessing the characteristic of a relatively loose, incomplete husk cover on the ear were evaluated for 3 years at Tifton, GA, for aflatoxin contamination. In two of the three test years, corn ears with tight, complete husk cover sustained significantly lower mean amounts of aflatoxin than ears with loose, incomplete husk cover following artificial inoculation with Aspergillus flavus Link spores. Ears hand-infested with maize weevils, Sitophilus zeamais (Motschulsky), sustained significantly higher amounts of aflatoxin (329 ng·g−1) than ears infested with fall armyworms, Spodoptera frugiperda (J. E. Smith), (80 ng·g−1), European corn borers, Ostrinia nubilalis (Hübner), (71 ng·g−1), or corn earworms Heliothis zea (Boddie) (60 ng·g−1). Overall, ears in the check (inoculated with A. flavus only) sustained significantly lower aflatoxin (37 ng·g−1) amounts than ears from plots supplemented with insects. Although insects were not applied in the check plots, some damage was observed on the ears.


2010 ◽  
Vol 11 (1) ◽  
pp. 18 ◽  
Author(s):  
H. Arnold Bruns ◽  
Hamed K. Abbas

Aflatoxin research in corn (Zea mays L.) usually requires application of inoculum of Aspergillus flavus to soil or plant ears. The pin-bar vs. side-needle or spray vs. solid material inoculations using A. flavus isolate F3W4 (NRRL 30798) were compared in 2004, 2006, and 2007 using three hybrids in two irrigated experiments each year at Stoneville, MS. Both were planted on a silty clay soil in randomized complete block designs with four replications of treatments. Mature ears inoculated by the pin-bar, side-needle, or spray methods were analyzed for aflatoxin. Ears from controls and solid material inoculum treatments were sampled for analysis at plot harvest. Pin-bar inoculation had more aflatoxin in 2004 (551.9 ng/g) and 2006 (305.8 ng/g) than side-needle inoculation (342.2 ng/g and 151.1 ng/g for 2004 and 2006, respectively), which was greater than controls (76.8 ng/g and 21.6 ng/g for 2004 and 2006, respectively). Solid material inoculation did not differ in aflatoxin from controls. Spraying produced the most aflatoxin (344.1 ng/g) only in 2004. Aflatoxin was low in 2007 when timely rainfall, irrigation, and no temperatures ≥ 35°C resulted in only the pin-bar (20.8 ng/g) and solid material (20.6 ng/g) treatments having > 2.0 ng/g of aflatoxin. Accepted for publication 26 March 2010. Published 1 June 2010.


2018 ◽  
Vol 2 (6) ◽  
pp. 813-827
Author(s):  
Eva Guadalupe Lizárraga-Paulín ◽  
Irineo Torres-Pacheco ◽  
Ernesto Moreno-Martínez ◽  
Susana Patricia Miranda-Castro

El maíz (Zea mays L.) es un cultivo importante en México, que es a menudo afectado por la presencia de hongos patógenos. El objetivo de este estudio fue determinar el efecto protector del quitosán en plántulas de maíz sometidas a estrés biótico. El experimento se llevó a cabo en la Facultad de Estudios Superiores Cuautitlán, UNAM, durante 2008. Para cumplir el objetivo, después de algunas pruebas de calidad, tres grupos de semillas fueron sometidos por separado a los ataques de Aspergillus flavus y Fusarium moniliforme. Un primer grupo fue considerado como testigo positivo, otro fue recubierto con solución de quitosán y un último grupo fue dañado mecánicamente antes de la aplicación del biopolímero. Durante cinco semanas, el crecimiento de las plántulas se evaluó midiendo la longitud total, longitud de las hojas, de los tallos y el grosor de estos. No hubo incremento significativo en el tamaño de las plántulas, provenientes de semillas recubiertas con quitosán al compararse con el resto de los grupos; sin embargo, la ausencia de enfermedades en las plántulas tratadas con el biopolímero fue evidente. En la quinta semana de crecimiento, las estructuras foliares de las plántulas se sembraron en agar PDA, para determinar la presencia de los hongos estresantes. Se encontró que las hojas provenientes de las semillas tratadas con quitosán, desarrollaron carga fúngica nula, lo que sugiere que el quitosán actúa como un activador de mecanismos de defensa en plántulas de maíz, impidiendo la infección por los hongos patógenos utilizados.


Nucleus ◽  
2019 ◽  
Vol 16 (1) ◽  
pp. 337-345
Author(s):  
Fernando Belezini Vinha ◽  
Daniela Fagotti Soares ◽  
Darclet Teresinha Malerbo-Souza
Keyword(s):  
Zea Mays ◽  

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