Weed dynamics in grain sorghum-grass intercropped systems

Abstract

The aim of this study was to assess the influence of short-season sorghum-grass intercropped systems on weed population dynamics. The integrated systems consisted of sorghum grown at two row spacings (0.50 m and 0.70 m), intercropped with palisade grass or Congo grass. We also used sole crops of sorghum, palisade grass, Congo grass and a fallow to serve as a reference for spontaneous vegetation. The experiment was conducted in 2010 and 2011 at Planaltina (Federal District) in Brazil. Weed populations and weed dry matter were assessed during the short season and during the succession soybean cycle. The weed soil seed bank was sampled in both years of the study. Sorghum at a row spacing of 0.50 m intercropped with Congo grass reduced the Ageratum conyzoides population. The Tridax procumbens seed bank in the soil was reduced by using sorghum at a the row spacing of 0.70 m, whether intercropped or not. Planting palisade grass during the short season reduced Digitaria sanguinalis in the soil seed bank. Planting palisade grass or Congo grass as a sole crop or intercropped reduced the number of weed seeds in the soil, showing that these species can be recommended for integrated weed management in intercropped systems.

Ecology, Biology, Environmental Impacts, and Management of an Agro-Environmental Weed Ageratum conyzoides

“…Palisade grass ( Urochloa brizantha ) cropping at regular intervals and sorghum intercropped with congo grass ( Brachiaria ruziziensis ) have also been reported to decrease the seed bank of A . conyzoides [ 111 ]. Growing sweet potato ( Ipomoea batatas ) varieties in fields dominated by A .…”

Intercropping sorghum and grasses during off-season in Brazilian Cerrado

“…The right combination of crops in intercropping systems does not affect these parameters (Borges et al, 2018;Santos et al, 2018b). Furthermore, even when certain Urochloa species may compete and become weeds to crops due to their high regrowth ability (Nakao et al, 2019), the use of an herbicide at the desiccation operation is effective to control palisade and Congo grasses before the summer crop (Sodré-Filho et al, 2014).…”

“…Sorghum's high seedling emergence due to the effective sowing time -middle of the rainy season -, enabled fast establishment of the plants (300,000 plants ha -1 ), which did not affect the development of the forage grasses, although the environmental conditions varied from year to year. In the Brazilian Cerrado region, the practice of cultivating sorghum after the main crop at the end of the rainy season is increasing among farmers, mainly due to its better adaptability to irregular rainfall regimes in comparison to other crops, such as maize (Sodré-Filho et al, 2014;Cordeiro et al, 2015). Compared to other crops, sorghum's advantages include drought tolerance and adaptability to low-fertility and acid soils, common characteristics of the Cerrado region (Borges et al, 2018).…”

Weed infestations in soybean grown in succession to cropping systems with sorghum and cover plants

“…The seedling emergence of weed species varies throughout the year in the Cerrado region, making it more difficult to propose control techniques (Concenço et al, 2015). The composition and population of a weed community are influenced by the soil management (Sodré Filho et al, 2014). An example of this effect on weed dynamics is the expansion of no-tillage system in Brazil, in recent years, which affected the prevalent species and the weed seed banks in the soil, due to the concentration of seeds on the soil surface (Ikeda et al, 2013).…”