Critical period for weed control: the concept and data analysis

Knežević, Stevan Z.; Evans, Sean P.; Blankenship, Erin E.; Acker, Rene C. Van; Lindquist, John L.

doi:10.1614/0043-1745(2002)050[0773:cpfwct]2.0.co;2

Cited by 387 publications

(527 citation statements)

References 34 publications

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“…The extent of interference periods depends on the competition between the crop and the weeds due to the specific differences among species in morphology, physiology and development. From this evaluation, the CPIP may be unique to each crop and it varies according to the composition and density of the weed population, as well as the time of onset compared to the crop (Knezevic et al, 2002). The cropping system and management practices also influence the extent of the interference periods (Carvalho et al, 2008b;, as well as edaphic climatic factors.…”

Section: Phytosociological Survey and Weed Interference In Eggplants mentioning

confidence: 99%

Phytosociological Survey and Weed Interference in Eggplants Cultivation1

et al. 2016

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-Eggplants are vegetables of great importance in the South and Southeast regions of Brazil, which are subject to interference from weeds. In order to collaborate with weed management in this vegetable, this study was carried out to determine the periods of weed interference in growing eggplants. The study was conducted in the Brazilian municipality of Jaboticabal, SP, at the Faculty of Agricultural and Veterinary Sciences, UNESP [Universidade Estadual Paulista "Júlio de Mesquita Filho" (São Paulo State University)], in the period from February to July 2013. The experiment was arranged in a randomized block design with 22 treatments, three replications divided in 11 periods of coexistence and weed control with eggplants: 14, 28, 42, 56, 70, 84, 98, 112, 126, 140 and 154 days after transplanting (DAT). In each treatment, a phytosociological study was carried out to identify the important species of weeds in eggplant crops. The main weeds were Eleusine indica, Nicandra physaloides, Portulaca oleracea and Cyperus rotundus due to their high relative importance. The interference of these weeds caused losses of up to 96% to the standard commercial fruit yield. The period before interference was 6 DAT and the total period of interference was 102 DAT. Therefore, it is concluded that after the initial six days after transplanting eggplants, the crop should be free of weeds within the next 96 days.Keywords: Solanum melongena, competition, productivity, weed community. Nápoli: 14, 28, 42, 56, 70, 84, 98, 112, 126, 140 Palavras-chave: Solanum melongena, competição, produtividade, comunidade infestante. RESUMO -A berinjela é uma hortaliça de grande importância nas regiões Sul e Sudeste e, que está sujeita a interferências das plantas daninhas. Com o intuito de colaborar com o manejo das plantas daninhas nessa hortaliça, objetivou-se determinar os períodos de interferência das plantas daninhas no cultivo de berinjela Nápoli. O estudo foi realizado no município de Jaboticabal, SP, na Faculdade de Ciências Agrárias e Veterinárias da UNESP, no período de fevereiro a julho de 2013, no delineamento em blocos ao acaso com 22 tratamentos e três repetições, divididos em 11 períodos de convivência e de controle das plantas daninhas com a berinjela

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Section: Phytosociological Survey and Weed Interference In Eggplants mentioning

confidence: 99%

Phytosociological Survey and Weed Interference in Eggplants Cultivation1

et al. 2016

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“…Early plant vigour is particularly important in annual crop production. Extensive research has identified the stage(s) in which crops are most susceptible to weed competition, the so-called critical weed-free period, and this is often during the crop establishment and early growth stages (Knezevic et al 2002;Seem et al 2003). …”

Section: Increasing Crop Competitivenessmentioning

confidence: 99%

Biotic interactions, ecological knowledge and agriculture

Shennan

2007

Phil. Trans. R. Soc. B

180

126

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This paper discusses biotic interactions in agroecosystems and how they may be manipulated to support crop productivity and environmental health by provision of ecosystem services such as weed, pest and disease management, nutrient cycling and biodiversity conservation. Important elements for understanding biotic interactions include consideration of the effects of diversity, species composition and food web structure on ecosystem processes; the impacts of timing, frequency and intensity of disturbance; and the importance of multitrophic interactions. All of these elements need to be considered at multiple scales that depend in part on the range of the movement of the organisms involved. These issues are first discussed in general, followed by an examination of the application of these concepts in agricultural management. The potential for a greater use of ecological management approaches is high; however, owing to the nature of complex interactions in ecosystems, there is some inherent unpredictability about responses to management interventions under different conditions. Such uncertainty needs to be accommodated in the development of recommendations for farm management. This requires an increased emphasis on the effective synthesis of complex and often apparently contradictory information and on field-based adaptive research, monitoring and social learning by farmer/researcher collaborations.

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“…No entanto, pesquisas evidenciam grande variabilidade nos períodos para a cultura do girassol. Tal fato reforça a ideia que há necessidade de repetir esses trabalhos em diversas condições, para que se garanta base de dados confiáveis sobre os efeitos da interferência de plantas daninhas (Brighenti et al, 2004;Knezevic et al, 2002;Silva et al, 2012).…”

Section: Introductionunclassified

Períodos de interferência de plantas daninhas na cultura do girassol

et al. 2013

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ResumoObjetivou-se neste trabalho determinar os períodos de interferência de plantas daninhas na cultura do girassol. Foram realizados dois experimentos com o girassol híbrido Helio 250, sendo um conduzido no verão e o outro, no inverno. Para ambos, o delineamento experimental utilizado foi em blocos casualizados, com quatro repetições, e cada unidade experimental foi constituída de cinco linhas de plantas com 6,0 m de comprimento, espaçadas por 0,7 m. No experimento de verão foram avaliados oito períodos de convivência e controle de plantas daninhas: 10, 20, 30, 40, 50, 60, 70 e 88 dias após a emergência (dae). No experimento de inverno, os períodos foram: 7, 14, 21, 28, 38, 48, 58 e 82 dae. Avaliaram-se a massa da matéria seca e a área foliar das plantas de girassol, produtividade, massa de mil aquênios e massa da matéria seca de plantas daninhas. Estimaram-se os períodos anteriores à interferência (PAI), períodos críticos de prevenção à interferência (PCPI) e períodos totais de prevenção à interferência (PTPI). Considerando-se a produtividade de aquênios no verão, o PAI foi de 16 dae da cultura, o PTPI, de 39 dae e o PCPI abrangeu 23 dias do ciclo da cultura. No inverno, o PAI foi de 12 dae, o PTPI estendeu-se até os 34 dae, resultando em um PCPI de 22 dias.Palavras-chave: Helianthus annuus L., competição, produtividade. Interference periods of weeds in sunflower crop AbstractThe objective of this work was to determine the periods of weed interference in sunflower crops. Two experiments were done with the sunflower hybrid Helio 250, one in the summer and the other in the winter. For both experiments, a randomized block design with four repetitions was used and each experimental unit was composed of plants in five lines, 6.0 m in length, spaced 0.7 m apart. In the summer experiment eight periods of cohabitation and weedy plant control were evaluated: 10, 20, 30, 40, 50, 60, 70 and 88 days after emergence (dae). In the winter experiment, the periods were 7, 14, 21, 28, 38, 48, 58 and 82 dae. The dry matter mass, leaf area of sunflower plants, yield, thousand achenes mass and weedy plant dry matter mass were evaluated. The periods prior to interference (PPI), the critical periods of preventing interference (CPPI), and the total periods of preventing interference (TPPI) were estimated. Considering the yield of achenes in the summer, the PPI was 16 dae of the crop, the CPPI was 39 dae and the TPPI lasted 23 days of the crop cycle. In winter, the PPI was 12 dae and the CPPI lasted for 34 dae, resulting in a TPPI of 22 days.Key words: Helianthus annuus L., competition, yield. INTRODUÇÃOO girassol (Helianthus annuus L.) é uma magnoliopsida (dicotiledônea) anual da família Asteraceae originária do continente norte-americano mas que é cultivada em todos os continentes, destaca-se mundialmente como importante cultura oleaginosa e apresenta ciclo curto e alta produção de óleo (Porto et al., 2007;Silva et al., 2007;Thomaz et al., 2012). Essa cultura tem crescimento inicial lento. A partir de 30 dias após a emergência, o c...

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Critical period for weed control: the concept and data analysis

Cited by 387 publications

References 34 publications

Phytosociological Survey and Weed Interference in Eggplants Cultivation1

Phytosociological Survey and Weed Interference in Eggplants Cultivation1

Biotic interactions, ecological knowledge and agriculture

Períodos de interferência de plantas daninhas na cultura do girassol

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