Browsing by Author "Calha, I. M."
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- Cover crops effect on floristic community and yield of maizePublication . Santos, J.; Grifo, Anabela; Amaral, A.; Calha, I. M.Innovative methods of weed management, such as cover crops, are becoming increasingly necessary. However, despite the objectives set out in the European Green Deal, their adoption by farmers has been gradual, regardless of the advantages they offer in terms of maintaining soil organic matter, preventing erosion and, in particular, reducing the abundance and biomass of weeds. In order to assess the impact of mixtures of Poaceae and Fabaceae as cover crops on the structure of the floristic community of the maize crop, a trial was set up in Ribatejo region comparing the use of cover crops with soil tillage and a control as reference. During the autumn-winter period, the biomass of the cover crop was assessed on five periodic dates accompanied by observations using satellite images. The NDVI (Normalised Difference Vegetation Index) and the amount of biomass were used to assess the effects of cover crops on the floristic community. In spring, the effect of these cultural methods on the abundance and frequency of weeds and on maize productivity was assessed. By the middle of the crop cycle, the NDVI values made it possible to detect significant differences between treatments. At 1.5 months from harvest these differences were not significant, which can be attributed to the development of the crop, which attenuates the effect of weed competition. Cover crops could provide a new opportunity for farmers to increase the sustainability of cropping systems, reducing dependence on herbicides and improving soil quality.
- O efeito das culturas de cobertura no controlo de infestantesPublication . Calha, I. M.; Amaral, A.As culturas de cobertura são plantas introduzidas como culturas intercalares na rotação/sucessão cultural que podem fornecer diferentes serviços dos ecossistemas. Podem contribuir para reduzir a biomassa das infestantes e a sua abundância nas culturas de primavera, particularmente no início do ciclo cultural. No entanto, a eficiência desta tecnologia depende de vários fatores sendo um dos principais a cuidadosa seleção de espécies que melhor se enquadram no sistema cultural.
- Effect of cover crops on the weed flora of processing tomatoes in a regenerative agriculture system with underground irrigationPublication . Amaral, A.; Calha, I. M.Cover crops (CC) are plants grown to provide regulating, supporting, and cultural ecosystem services in managed environments. Numerous studies have investigated the impact of cover crops on weeds. Winter cover crops suppressed both weed biomass and weed population density in spring crops, particularly early in the cash crop growing season. However, to effectively use weed suppression services from cover crops, farmers must carefully select species that fit within their rotations and suppress their problematic weeds. Field experiments investigated the weed suppression potential of winter CCs and their effects on processing-tomato grown with underground irrigation in non-tillage system. Treatments were: Lolium multiflorum -A, pea (Pisum sativum) - E; faba bean (Vicia faba) – F; wheat (Triticum aestivum) – T, Control No CC+ No tillage - Tsm; Control No CC+ tillage - Tcm. CC aboveground biomass ranged from 580 kg ha−1 (T. aestivum) to 2393 kg ha−1 (Vicia faba). Main weeds in tomato crop ranked in importance Cyperus rotundus, Setaria verticillata, Digitaria sanguinalis, Portulaca oleracea and Heliotropium europaeum. Weed density was reduced between 44 % and 70 % with cover crop relative to tillage. Lolium multiflorum and Vicia faba were also more effective in reducing the weed biomass. Tomato productivity ranged from 84 t ha-1 (T) to 123 t ha-1 (F). Contrary to expectations, Poaceae cover crops were not the most effective in suppressing weeds, compared to Fabaceae. The Vicia faba species had the greatest effect on weed population density compared to the control in bare soil and also contributed to greater productivity of processed tomatoes.
- Estratégia de controlo do rabo-de-raposa na cultura do tomate - oportunidade de intervençãoPublication . Calha, I. M.; Amaral, A.; Santos, J.; Cachado, J.; Nunes, A. P.
- Estratégias de prevenção e controlo da planta parasita rabo-de-raposa na cultura do tomate de indústriaPublication . Romão, I.; Calha, I. M.; Amaral, A.; Santos, João; Godinho, Maria; Cachado, J.; Nunes, A. P.
- Impacto das práticas culturais na flora infestante das culturas hortoindustriais: validação por inquéritoPublication . Pinto, A. S.; Nunes, A. P.; Amaral, A.; Valério, E.; Santos, João; Cachado, J.; Godinho, Maria; Matos, S.; Calha, I. M.O aumento dos prejuízos associados a uma flora infestante e parasita é um problema real das culturas hortoindustriais da região do Vale do Tejo. Os resultados de um inquérito aos produtores confirmaram que a escolha das práticas culturais condiciona o aparecimento e o controlo dessa flora.