<b>Performance of fall and winter crops in a no tillage system in west Paraná State

Abstract

ABSTRACT. The long-term exploitation of natural resources by agricultural activities has resulted in the need for alternative measures to restore degraded soil. The cultivation of cover crops can generate great benefits for agricultural systems, enabling the exploitation of natural resources, including water, light and nutrients, as well as the recovery of degraded soils. This work aimed to assess the coverage rate, fresh mass and dry mass of cover crops from fall and winter as well as the floristic composition of the weeds. The work was conducted in field conditions in soil classified as eutroferric Red Oxisol in the region of the city of Palotina, Paraná State, Brazil, using a random block experimental design with four replications. The treatments consisted of seven cover cultures: wild radish, linseed, triticale, rye, rapeseed, crambe, oats and fallow. The species with the highest coverage rates and fresh mass and dry mass values were wild radish, rapeseed and crambe. In the floristic and phytosociological data, the species with the highest incidence were Amaranthus retroflexus, Commelina benghalensis L., Brachiaria plantaginea and Gnaphalium spicatum.Keywords: natural resources, crop rotation, weeds.Desempenho de culturas de outono e inverno no sistema de plantio direto no oeste do Estado do Paraná RESUMO. A exploração dos recursos naturais, pelas atividades agrícolas ao longo do tempo resultou na necessidade de buscar medidas alternativas para recuperação do solo degradado. O cultivo de plantas de cobertura é uma alternativa que gera grandes benefícios aos sistemas agrícolas, viabilizando a exploração dos recursos naturais, água, luz e nutrientes e recuperação de solos degradados. O objetivo deste trabalho foi avaliar o percentual de taxa de cobertura, massa fresca e massa seca das culturas de cobertura de outono e inverno e a composição florística de plantas daninhas. O trabalho foi conduzido em condições de campo em solo classificado como Latossolo Vermelho eutroférrico, na região do município de Palotina, Estado do Paraná, Brasil. O delineamento experimental utilizado foi o de blocos ao acaso, com quatro repetições, os tratamentos foram constituidos por sete culturas de coberturas: nabo forrageiro, linhaça, triticale, centeio, canola, crambe, aveia; e área de pousio. As espécies que apresentaram os maiores valores de taxa de cobertura, massa fresca e massa seca foi o nabo forrageiro, canola e crambe. No levantamento florístico e fitossociológico, as espécies com maior incidência foram Amaranthus retroflexus, Commelina benghalensis L., Brachiaria plantaginea e Gnaphalium spicatum.Palavras-chave: recursos naturais, rotação de culturas, plantas daninhas.

Phytosociological survey of weeds in glyphosate resistant and susceptible soybean cultivation areas

“…According to Adegas et al (2010), the Asteraceae and Poaceae families represent great expressiveness among the weeds occurring in agricultural production areas in Brazil, as they are present in areas of grain crops, such as soybean and sunflower, and also appear predominantly in other systems in sugarcane fields (Oliveira & Freitas, 2008), in cassava cultivation (Cardoso et al, 2013), in maize crops (Teodoro et al, 2006), during off-season (Krenchinski et al, 2016) and after the cultivation of cover species (Albrecht et al, 2018).…”

“…This type of study should collect data in more than one harvest, as it may indicate variations in the importance of one species from one crop to another (Oliveira & Freitas, 2008). Albrecht et al (2018) emphasize that judicious phytosociological monitoring and study are essential in integrated weed management (IWM).…”

Plot size and replications number for triticale experiments

“…number were used, for example, plots of 6 m 2 to 16.8 m 2 , evaluation areas in plots from 0.25 m 2 to 1.2 m 2 and three to four repetitions (SuCu & ÇIfCI, 2016;ALBREChT et al, 2018). The lack of experimental protocols indicating the optimal plot size and number of replications, may result in experiments with low reliability or requiring excessive use of human, financial and time resources.…”