Predacion de semillas de Amaranthus quitensis H.B.K. en un cultivo de soja: influencia del sistema de siembra

Nisensohn, Luisa; Faccini, Delma; Montero, Guillermo; Lietti, Marcela

doi:10.1590/s0100-204x1999000300008

Cited by 12 publications

(9 citation statements)

References 29 publications

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“…Moreover, in our paper we excluded seed predators. Predation has been recorded for A. quitensis and has proved to be more important with respect to seed losses in conventional compared with non‐tillage systems (Nisensohn et al. , 1999).…”

Section: Discussionmentioning

confidence: 99%

Germination characteristics of Amaranthus quitensis as affected by seed production date and duration of burial

Faccini¹,

Vitta

2005

Weed Research

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Summary Thermal requirements for the germination of Amaranthus quitensis, a common annual weed in Argentina, were studied. In addition, temporal changes in dormancy from seeds produced at different times during the growing season were examined. For this second objective, thermal and light requirements for germination were tested in seeds buried at different depths, with or without crop residues. Base and optimum temperatures for germination rates were 12.8°C and 37°C respectively. At dispersal time, maximum percentage germination was 60–70% and this was generally recorded at 35°C/25°C in a 14‐h photoperiod. Seed germination tended to increase in later seed collection dates. Seeds of A. quitensis showed seasonal changes in germinability in the soil. In winter, germination of retrieved seeds increased to over 90% until summer, after which there was a decrease until the following winter when germination was close to 40%. There were no differences in germinability between burial depths and crop residue levels. Germination requirements for alternating temperatures and light tended to disappear after burial. Initial viability was 99% and declined slightly during burial. Soil temperature seems to play a crucial role not only by regulating seasonal changes in dormancy, but also by defining the percentage and the germination rate in non‐dormant seeds.

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Section: Discussionmentioning

confidence: 99%

Germination characteristics of Amaranthus quitensis as affected by seed production date and duration of burial

Faccini¹,

Vitta

2005

Weed Research

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“…Predator species for A. cristata were not determined, but for many other weeds, seed predators are rodents (Scopel et al. , 1988; Dellafiore & Polop, 1994), birds (Askew & Wilcut, 2001), carabid beetles (House & Stinner, 1983; Nisensohn et al. , 1999) and ants (Risch & Carroll, 2001).…”

Section: Discussionmentioning

confidence: 99%

Seed survival and predation of Anoda cristata in soyabean crops

et al. 2005

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Anoda cristata is a troublesome annual broad-leaved weed in summer crops in the rolling Pampa in Argentina; seeds are the only source of regeneration of this species. Seed persistence or depletion is the result of survival and loss processes, including predation. The objective of this study was to determine survival at two burial depths in undisturbed soil and predation rates of A. cristata seeds in soyabean crops in different rotations and tillage systems. Survival was discontinuous and decreased to 25% after 35 months, after which no further reduction in survival was observed to the end of the experiment at 96 months. No differences in seed survival between seeds placed on the soil surface and buried 5 cm below the soil surface were found at 80 months, but at later times survival was lower for seeds placed on the soil surface. Predation rates ranged between 0.3% day )1 and 6.7% day )1 . Of the models tested, a polynomial regression of the rate of predation with time gave the best representation of seed predation. From January to July, predation was higher in nontillage plots in the wheat/soyabean rotation. There was no significant difference in predation rates between tillage systems in the soyabean monoculture and no difference between planting densities. Higher crop residue levels in non-tillage plots in the wheat/soyabean rotation was the dominant factor influencing seed predation, probably because such habitat favours the presence of seed predators.

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“…El consumo de semillas de A. quitensis fue mayor a la temperatura correspondiente al mes de marzo que al mes de abril. Estos resultados coinciden con las tasas de predación obtenidas en el campo por Nisensohn et al (1999), las cuales alcanzan los máximos valores entre el 15 y el 30 de marzo, para luego disminuir a partir del mes de abril. CONCLUSIONES 1.…”

Section: Consumo De Semillas De a Quitensisunclassified

“…En la República Argentina, adultos de N. cupripennis han sido observados por Bosq (1942) alimentándo-se de granos recién maduros de cebada y centeno y por Ahmad (1974) atacando a la larva del gorgojo de la alfalfa Graphognatus leucoloma (Boh.). Nisensohn et al (1999) evaluaron indirectamente la predación en el campo de semillas de Amaranthus quitensis L. (H.B.K.)…”

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Evaluación del consumo de semillas de malezas por Notiobia (Anisotarsus) cupripennis (Germ.) (Coleoptera: Carabidae)

Lietti¹,

Montero²,

Faccini³

et al. 2000

Pesq. agropec. bras.

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RESUMEN -En este trabajo se estimó la preferencia alimentaria de Notiobia cupripennis por semillas de ocho especies de malezas primavero-estivales (Pr-Es) y de seis especies otoño-invernales (Ot-In) más comunes en los agroecosistemas del Sur de la provincia de Santa Fe, Argentina. Las semillas de las especies de cada grupo fueron ofrecidas en conjunto y de a pares a adultos confinados individualmente. La relación (semillas dañadas/semillas disponibles) x 100 de cada especie fue considerada como índice de preferencia alimentaria. Los resultados fueron analizados mediante análisis de la variancia y test de rangos múltiples de Duncan y mediante un test de diferencia de medias, previa transformación arcoseno de los datos. Las semillas de las especies Ot-In fueron más dañadas (27,65%) que las Pr-Es (10,40%). Se encontraron diferencias altamente significativas en el porcentaje de semillas dañadas entre las diferentes especies; las dicotiledóneas fueron más preferidas que las gramíneas. El orden de preferencia alimentaria se mantuvo cuando los insectos fueron obligados a elegir entre semillas de dos especies de malezas. La preferencia alimentaria se atribuiría a diferencias en el tamaño, la consistencia del tegumento y la composición química de las semillas en relación con la habilidad de manipulación de las mismas y los requerimientos nutricionales del insecto.Términos para índice: predación de semillas, preferencia alimentaria, carábidos, agroecosistemas, Amaranthus quitensis. CONSUMPTION EVALUATION OF WEED SEEDS BY NOTIOBIA (ANISOTARSUS) CUPRIPENNIS (GERM.) (COLEOPTERA: CARABIDAE)ABSTRACT -The food preference of Notiobia cupripennis among seeds of eight weedy spring-summer species (Sp-Su) and six autumn-winter (Av-Wi) species more common in the agroecosystems of the South of Santa Fe Province, Argentina, was estimated in this study. The seeds of the species of each group were offered simultaneously and in pairs to adults individually placed. The relation (damaged seeds/available seeds) x 100 of each species was considered as a food preference index. The data were analysed by analysis of variance and Duncans Multiple Range Test and by a paired difference test, previous arcsine-square-root transformation. The seeds of the Av-Wi species were more damaged (27.65%) than the Sp-Su ones (10.40%). Highly significative differences in the percentage of damaged seeds among the different species were found; dicotyledones were preferred over gramines. The food preference ranking was maintained when the insects were forced to choose between the seeds of two weed species. The food preference would be attributed to differences in seed size, tegument toughness and chemical composition of the seeds in relation to the ability of handling the seeds and the nutritional requirements of the insect.

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Predacion de semillas de Amaranthus quitensis H.B.K. en un cultivo de soja: influencia del sistema de siembra

Cited by 12 publications

References 29 publications

Germination characteristics of Amaranthus quitensis as affected by seed production date and duration of burial

Germination characteristics of Amaranthus quitensis as affected by seed production date and duration of burial

Seed survival and predation of Anoda cristata in soyabean crops

Evaluación del consumo de semillas de malezas por Notiobia (Anisotarsus) cupripennis (Germ.) (Coleoptera: Carabidae)

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