Effects of plastic mulch, sowing date and cultivar on the yield and maturity of forage maize grown under marginal climatic conditions in Northern Ireland

Abstract

The effects of growing forage maize (Zea mays) with or without plastic mulching treatments on the dry‐matter (DM) yield, cob yield, DM content and starch content was investigated in Northern Ireland in 1996 and 1997. Cultivars differing in maturity characteristics were sown in spring at a range of dates in three replicated plot experiments and were used to compare the effects of two plastic mulches and an untreated control: one plastic mulch completely covered the rows (floating); the other had holes punched in the plastic, through which the plants grew (punch). Between April and October in 1996 and 1997, the Ontario heat units (OU) received were above average at 2489 and 2660 respectively; in those years without plastic mulches, the earliest maturing cultivar, Melody, yielded 11·0 and 13·6 t DM ha–1, with dry‐matter contents of 214 and 215 g kg–1 respectively. Mean daily increases in soil and air temperature under plastic mulches of up to 6°C and 11°C, respectively, were closely related to solar radiation. Under plastic mulches, 15% fewer OU were required to reach silking, and 33% more OU were available between silking and harvest. Meaned over three experiments, two years and three cultivars, plastic mulches, when compared with the unmulched control, increased maize yield from 12·0 to 14·7 t DM ha–1, cob yield from 3·7 to 6·8 t DM ha–1, dry‐matter content from 230 to 270 g kg–1 and starch content from 198 to 272 g kg–1. The effect of plastic mulch on the maturation of the crop was greatest at earlier sowings. In 1997, plants from an early sowing date (10 April) that had recently emerged through the punch plastic mulch were damaged by frost, whereas those in the floating plastic mulch plots were unaffected. When the floating plastic mulch was left on after the six‐ to eight‐leaf stage of the first‐early maize cultivar Hudson, the plants were physically damaged and the yield reduced, but DM and starch contents continued to increase. The increases in yield and dry‐matter content under the plastic mulch were greater in Diamant (second‐early cultivar) than in Melody (first‐early cultivar). It was concluded that, under marginal climatic conditions, plastic mulches ought to be used to improve the reliability of early cultivars rather than growing later maturing cultivars.

Effect of plastic mulch on growth and yield of chilli (Capsicum annuum L.)

“…The plant without mulch had the smallest base diameter at all growth stages. This result was in conformity with the report of Easson and Fearnehough (2000) on forage maize.…”

“…Increased air temperature at the canopy level at mid-day might be due to stomatal closure resulting in reduced transpirational cooling allowing the heat to escape. Similar results were obtained by Easson and Fearnehough (2000) who reported that plastic mulches increased daily air temperature compared to the control. …”

Agronomic factors affecting the yield and quality of forage maize in Ireland: effect of sowing date and plastic film treatment

“…Digestibility of the whole plant (as estimated by NIRS) at maturity was not affected by sowing date in 1995. Easson and Fearnehough (2000) found that plastic advanced the silking date and, thus, prolonged the period between silking and harvest date, thereby increasing the number of heat units available and improving grain fill. However, this effect occurs at temperatures considerably higher than those experienced under field conditions in Ireland.…”

Assessing seed priming, sowing date, and mulch film to improve the germination and survival of direct‐sown Miscanthus sinensis in the United Kingdom

“…In semiarid or cooler climates that are less favourable for growing maize, mulch films, made from a clear or coloured starch that is degraded by light or microbes, have been used to increase soil temperature and retain soil moisture (van der Werf, ) and significantly increase maize yields in either semiarid (Zhou, Li, Jin, & Song, ) or cooler climates (Farrell & Gilliland, ). The increase in yield is achieved by reducing evaporation from the soil and increasing the soil temperature (Easson & Fearnehough, ). The mulch film creates a “greenhouse effect” by which incoming solar radiation passes through the film, trapping warmed air between the soil and the film and warming the soil surface (Zhou et al., ).…”