Growth and yield of corn grain and green ear in competition with weeds

Abstract

Studies on plant growth are interesting because they provide explanations for the factors that influence yield in various crops. The objective of this work was to evaluate growth and yield in corn cultivar AG1051, when in competition with weeds. Cultivar AG 1051 was submitted to two groups of treatments: weed control, and sampling periods for dry biomass evaluation. The weed control treatments consisted of hoeing (two hoeings performed at 20 and 40 days after sowing) and no hoeing. Sampling periods consisted of collecting the above-ground part and roots of corn every fifteen days, until 105 days after sowing (DAS); the first sampling was performed 30 DAS. A completely randomized block design with ten replicates was used. For the characteristics evaluated in a single season, statistical analyses were carried out as a random block experiment. For the characteristics evaluated in several periods, statistical analyses were carried out as random blocks with split-plots (weed control assigned to plots). Fourteen weed species, unevenly distributed throughout the experimental area, were the most important. The growth observed for the above-ground part and root system of corn was 30% smaller in the non-hoed plots, compared to the hoed plots. Lack of weed control increased dry matter of the above-ground part of the weeds and reduced the number of unhusked and husked marketable green ears by 23% and 49%, respectively. Grain yield reduction caused by lack of weed control reached 38%.

Weed control in corn via intercropping with gliricidia sown by broadcasting

“…This may have occurred due to corn competition with weeds for water, light, and nutrients (Carruthers et al, 1998), but also or mainly because weeds cause reductions in the corn root system and leaf area (Silva et al, 2009c) and may produce allelopathic substances that may be harmful to corn (Rajcan & Swanton, 2001). For similar reasons, gliricidia may have benefited corn, negatively influencing the weeds.…”

Controle de plantas daninhas na cultura do milho com gliricídia em consorciação

“…Além disso, há indícios de que ocorre o "pegamento" de algumas plantas daninhas após as capinas (Silva et al, 2010a). Resultados semelhantes a esses foram observados por outros autores (Linhares et al, 2009;Silva et al, 2009b), que também estudaram o consórcio milho-gliricídia visando ao controle de plantas daninhas.…”

“…Entretanto, mesmo que não sombreiem as plantas de milho, as plantas daninhas influenciam o crescimento dessa cultura, por meio da radiação que elas refletem. Adicionalmente, as plantas daninhas influenciariam a atividade fotossintética do milho, via redução da área foliar, observada por alguns autores (Silva et al, 2009b), provocada provavelmente pela interferência das raízes das plantas daninhas sobre as raízes do milho. Uma outra maneira de as plantas daninhas influenciarem o crescimento da parte aérea do milho seria por meio da emissão de compostos orgânicos voláteis biogê-nicos.…”

Effect of weeding management on the performance of local maize populations

“…Indeed, there are different practical reasons for removing weeds, but the most important is the competition for water, nutrients and sunlight. Also, weeds induce reductions of the maize root system and leaf area (Silva et al, 2009), thus diminishing yield (Tollenaar et al, 1997). Effective control of weeds in cereals must rely on both preventive (such as placement of fertilisers and crop rotation) and curative methods (i.e.…”