Sweet Corn Weed Control and Yields in Response to Sowing Date and Cropping Systems

Abstract

<jats:p>The high vulnerability of sweet corn (<jats:italic>Zea mays</jats:italic> L. var. saccharata) to weed competition and the urgent reduction of the dependence on chemical herbicides are major challenges facing the agricultural community. To investigate the effects of plastic mulches on weed control and yields in sweet corn under different sowing dates, a 2-year experiment was conducted at Varamin, Iran, in 2010 and 2011. The mulch treatments included black plastic mulch, semitransparent biodegradable mulch, an unmulched weeded control, and an unmulched unweeded control. The sowing dates were 5 June, 20 June, and 6 July. Results revealed that delayed sowing (6 July) reduced weed dry weight by 51% and 41% compared with the 5 June sowing date in 2010 and 2011, respectively, without reducing crop yield. The black plastic mulch treatment had the lowest weed biomass. The sowing date × mulch interactions on kernel number per ear, length of ear, percentage of unfilled ear tip, and yield of sweet corn were statistically significant (<jats:italic>P</jats:italic> &lt; 0.01) in both years. The maximum kernel number per ear (535) and the highest fresh ear yield (24,684 kg·ha<jats:sup>−1</jats:sup>) in 2010 were obtained on the 6 July sowing date under biodegradable mulch. The plants sown on 6 July produced the highest fresh kernel yield with the black plastic mulch (12,893 kg·ha<jats:sup>−1</jats:sup>) and unmulched weeded control (11,777 kg·ha<jats:sup>−1</jats:sup>) in 2010 and 2011, respectively. The highest percentage of unfilled ear tips in both years was observed in the unmulched unweeded plots sown on 5 June. According to our findings, to suppress the weeds and avoid the sweet corn yield loss in such a hot summer that we had, using the black plastic mulch and delayed sowing are recommended.</jats:p>

Coloured plastic mulches: impact on soil properties and crop productivity

“…But according to this report, the impact of plastic mulches on reducing weed infestations and yield of the plant were lower than organic mulches like coconut leaves [6]. Other reports found that plastic mulch reduced weed dry matter by 63.8% compared with an un-mulched land [71] and black plastic mulch showed decreased weed dry weights by 91.3% and 94.7% [61].…”

“…To modify the impact of these factors, various methods have been developed. Plastic mulches are ubiquitously utilized and are reported to enhance the growth and development of shrubs, vegetables, and other crops [45,47,[59][60][61][62].…”

“…Weed suppression is reported as one of the positive impacts of plastic mulching. Mulching by its effect on shading, which reduced germination and seedling growth of weeds; and by acting as a physical barrier reduced weeds' existence [61]. Weed control has been practiced in crop farming systems by temporary, impermeable, black plastic tarps, solarization plastic covers, and long use plastic mulches [60,92].…”

Growth of Sweet Corn and Weeds in Response to Colored Plastic Mulches

“…There was complete elimination of weeds under black and white/black plastic mulch, whereas in unmulched plots (control) weeding was done manually five times during of experimentation. The black plastic mulch reduced weed dry weights by 94.7% in sweet corn [12].…”