Weed suppression ability of three winter wheat varieties at different row spacing under organic farming conditions

Abstract

For three seasons, six field trials were conducted in winter wheat (Triticum aestivum) at different sites in North Rhine-Westphalia, Germany. The aim was to evaluate the performance of three varieties, which differ in their shading behaviour, in suppressing weeds under organic farming (Ö kologischer Landbau) conditions and grown at three row spacings. The experimental factors were cultivar, row width and row orientation. Key parameters of crop and weed development, including ground cover and biomass, were assessed at different growth stages and analysed with ANOVA. Growth of the site-specific weed vegetation was significantly affected in five of six trials. Weed growth was reduced by cvs Astron and Pegassos compared with cv. Greif, and was lower at 12 cm compared with 24 cm row spacing. No effect of row orientation (East-West, North-South) on weed growth was observed. The more competitive cultivars Astron and Pegassos were taller than the less competitive cv. Greif and had higher ground cover and light interception, presumably induced by planophile leaf inclination and partly, in the case of cv. Astron, because of higher leaf area index (LAI). Narrow row spacing (12 cm), resulting in a more even spatial plant distribution, increased crop ground cover, LAI, dry matter and light interception. In two trials, the variety with planophile leaf inclination performed better at wider row spacing, suggesting that planophile wheat cultivars may be advantageous in wider row stands.

Weed Suppression and Tolerance in Winter Oats

“…No significant differences in weed tolerance were found among naked oat varieties (b). Drews et al 2009;Gooding et al 1993). However, it was not found to have a direct suppressive effect on post-harvest weed cover in the current study.…”

Papéis do arranjo de plantas e do cultivar de soja no resultado da interferência com plantas competidoras

“…Alocação preferencial de fotoassimilados para folhas, em detrimento da alocação para as raízes, é uma estratégia utilizada pelas plantas para superar a competição por luz (Gibson et al, 2004). Em arroz, a redução da radiação solar, aumentou a proporção de maté-ria seca foliar em relação a planta inteira (raízes e parte aérea), passando de 0,18 (100% de radiação solar) para 0,28 (50% de radiação solar) (Gibson et al, 2004 Incremento no sombreamento do solo decorrente da redução do espaçamento entre fileiras suprime o crescimento de plantas daninhas (Drews et al, 2009). Em soja, a redução do espaçamento melhora a eficiência de herbicidas (Young et al, 2001) e viabiliza a redução da dose herbicida (Pires et al, 2001 1/ Redução na produtividade de grãos de soja devido à presença do competidor.…”

“…Várias características da planta relacionam-se diretamente com a competitividade superior da cultura em relação às plantas daninhas, dentre as quais podem-se citar: matéria seca da parte aérea (Wortmann, 1993;Olesen et al, 2004), estatura (Fleck, 1980;McDonald, 2003;Drews et al, 2009), tamanho das folhas (Wortmann, 1993), índice de área foliar (Wortmann, 1993) e cobertura do solo (Callaway, 1992;Drews et al, 2009). Essa diversidade de características permite selecionar cultura com uma ou mais delas e, desse modo, obter cultivar mais competitivo com plantas daninhas.…”

Calibration of Soil Test Based Balance Fertilizer Doses with FYM for Wheat under High Density Planting System in Midland Alfisols of Chhattisgarh Plateau

“…In this case farmers generally increases seed rate to counter the ill effects of late sowing. Several workers have reported benefits of high density planting of wheat in terms of yield, nutrient uptake and nutrient use efficiencies under late sown conditions (Hiltbrunner et al, 2007;Drews et al, 2009, Chen et al, 2010.…”