Variação da competição interespecífica em milho em função do controle de plantas daninhas em faixas

Merotto, Aldo; Vidal, Ribas Antônio; Fleck, Nilson Gilberto

doi:10.1590/s0100-83582001000200018

Cited by 6 publications

(4 citation statements)

References 19 publications

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“…In the corn experiment, the preemergent herbicide treatments resulted in a weed infestation that ranged from 0 to 230.2 g m -2 of dry matter at 25 DAE (data not shown). The effect of interspecific competition in corn observed in similar situations of weed infestation reduced corn grain yield by approximately 50% (Merotto Jr. et al, 2001). Thus, the number of weeds in the experimental area was satisfactory in regards to the extent required for assessment by different methods of analysis and to the amount that affects crop development.…”

Section: Resultsmentioning

confidence: 99%

Reflectance indices as a diagnostic tool for weed control performed by multipurpose equipment in precision agriculture

et al. 2012

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Several tools of precision agriculture have been developed for specific uses. However, this specificity may hinder the implementation of precision agriculture due to an increasing in costs and operational complexity. The use of vegetation index sensors which are traditionally developed for crop fertilization, for site-specific weed management can provide multiple utilizations of these sensors and result in the optimization of precision agriculture. The aim of this study was to evaluate the relationship between reflectance indices of weeds obtained by the GreenSeekerTM sensor and conventional parameters used for weed interference quantification. Two experiments were conducted with soybean and corn by establishing a gradient of weed interference through the use of pre- and post-emergence herbicides. The weed quantification was evaluated by the normalized difference vegetation index (NDVI) and the ratio of red to near infrared (Red/NIR) obtained using the GreenSeekerTM sensor, the visual weed control, the weed dry matter, and digital photographs, which supplied information about the leaf area coverage proportions of weed and straw. The weed leaf coverage obtained using digital photography was highly associated with the NDVI (r = 0.78) and the Red/NIR (r = -0.74). The weed dry matter also positively correlated with the NDVI obtained in 1 m linear (r = 0.66). The results indicated that the GreenSeekerTM sensor originally used for crop fertilization could also be used to obtain reflectance indices in the area between rows of crops to support decision-making programs for weed control.

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Section: Resultsmentioning

confidence: 99%

Reflectance indices as a diagnostic tool for weed control performed by multipurpose equipment in precision agriculture

et al. 2012

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“…A diminuição da massa de plantas daninhas traz uma série de benefícios para o desenvolvimento do sorgo, destacando-se entre os principais a menor capacidade competitiva da comunidade infestante com a cultura, devido às plantas infestantes se apresentarem menos vigorosas (CARVALHO et al 2011), e a facilidade na execução do controle químico por meio da aplicação de herbicidas em pós-emergência (MEROTTO JR. et al 2001).…”

Section: Resultsunclassified

Desempenho agronômico e supressão de plantas daninhas no sorgo em semeadura adensada

Braz

Machado

Carmo

et al. 2019

Rev. Ciênc. Agrovet.

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A semeadura do sorgo adensado pode influenciar no manejo cultural de plantas daninhas e desempenho produtivo da cultura. Sendo assim, o objetivo deste trabalho foi avaliar a influência do adensamento na semeadura do sorgo sobre o desenvolvimento agronômico da cultura e supressão de plantas daninhas. O experimento foi conduzido a campo no delineamento blocos casualizados. Os tratamentos foram dispostos em arranjo fatorial 2x2x2, adotando oito repetições. O primeiro fator consistiu em dois espaçamentos entre linhas, 0,50 e 0,25 m; o segundo fator foi composto por duas populações, 180.000 e 270.000 plantas ha-1 ; por fim, o terceiro fator correspondeu à convivência ou não com a comunidade infestante. Para o sorgo, foi avaliada a altura de plantas, comprimento e massa de panícula, massa de mil grãos e produtividade. Para as plantas daninhas, avaliou-se densidade e massa seca. O espaçamento entre linhas e a população de plantas influenciou os componentes de rendimento do sorgo, sem, contudo, apresentar efeito sobre a produtividade. A interferência das plantas daninhas durante todo o ciclo de desenvolvimento do sorgo promoveu redução na produtividade. O adensamento de plantas no cultivo do sorgo proporcionou redução da densidade de infestação e massa seca de plantas daninhas.

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“…Evans et al [2] observed that number of grains per ear Downloaded by [Cornell University Library] at 11:29 18 November 2014 Means within the same column followed by the same letter are not significantly different according to T test ( p≤ 0.05). [1,2,4,13] Merotto et al [9] observed yield losses when corn plants were kept under row or inter-row weed interference and these losses were similar to weedy plots until harvesting. * = significant at 99% level.…”

Section: Corn Measurementsmentioning

confidence: 99%

Effects of Hand Weeding Strip and Nitrogen Fertilizer on Corn Plants

Silva

Martins

Cardoso

et al. 2005

Journal of Environmental Science and Health, Part B: Pesticides

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The objective of the present research was to evaluate effects of different strip weed control associated with nitrogen fertilizer on corn applied after planting. The experiment was set and conducted in Botucatu, São Paulo State, Brazil, and the hybrid planted was Dekalb 333-B. A completely randomized block design with four replications was used. Experimental plots were disposed as a factorial scheme 2 x 2 x 4, constituted by two types of weeding on row (with or without manual hoeing), two types of weeding on inter-row (with or without manual hoeing), and four nitrogen levels applied after planting (00, 60, 90, and 120 kg ha(-1)). Plots were composed by six rows with 5 m length. Nitrogen fertilizer was applied at 35 days after emergence (d.a.e). For weed community it was evaluated: weed density, dominancy, frequency, and relative importance. The main weed species were: Brachiaria plantiginea, Amaranthus retroflexus, Bidens pilosa, Cyperus rotunds, Brachiaria decumbens, Euphorbia heterofila, Oxalis latifolia, Acanthospermum hispidum, Commelina benghalensis. It was evaluated corn height at 40 and 100 d.a.e., first ear insertion height at 100 d.a.e., and final grain yield at harvesting. Plants and first ear insertion height were affected when nitrogen fertilizer was not applied. Treatments without weed control showed that weed interfered negatively with plants height. There were no correlation between weeds and nitrogen fertilizer for all parameters evaluated. Parcels without weed showed the highest ear weights and final grain production. Treatments that received nitrogen fertilizer, independently of studied arrangement, provided higher yields.

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Variação da competição interespecífica em milho em função do controle de plantas daninhas em faixas

Cited by 6 publications

References 19 publications

Reflectance indices as a diagnostic tool for weed control performed by multipurpose equipment in precision agriculture

Reflectance indices as a diagnostic tool for weed control performed by multipurpose equipment in precision agriculture

Desempenho agronômico e supressão de plantas daninhas no sorgo em semeadura adensada

Effects of Hand Weeding Strip and Nitrogen Fertilizer on Corn Plants

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