The potential of maize as a forage crop in Scotland

Abstract

SUMMARYBetween 1972 and 1976 a series of 15 trials was carried out at various climatically favoured sites throughout Scotland to assess the potential of new hybrid maize varieties of European origin under Scottish conditions. No meaningful differences were found between varieties in respect of dry-matter yield or maturity.Seed rates ranged from 100 to 200 × 103 seeds/ha giving final stands from 40 to 194 × 103 plants/ha. Regression analyses for the variety Dekalb 202 included in 54 treatments indicated that the relationship between plant population density and dry-matter yield was partly linear with an important quadratic function, suggesting an optimum of 179 × 103 (± 80 × 103) plants/ha. Plant population density accounted for 65·9% (P < 0·01) of the variance in dry-matter yield but was not significantly related to dry-matter content.Climatic variation between years had no overriding influence on growth and development. Dry-matter production for the variety Dekalb 202 sown in mid-May ranged from 2·86 (1972) to 14·54 t/ha (1975) with associated dry-matter contents of 15·1 and 24·1% respectively. In a few instances slightly higher dry-matter contents (maximum 28·6%) from mid-May sowings were associated with lower yields.Neither date of sowing nor accumulated temperature to harvest measured as Ontario Heat Units was significantly related to yield but date of sowing accounted for 29·5% (P < 0·01) of the variance in dry-matter content. Accumulated Ontario Units at harvest were not significantly related to dry-matter content.An interesting relationship between dry-matter yield and the date on which the crop had received 1379 Ontario Units was found. This relationship may be useful in selecting sites at which maize may be grown or to predict maximum potential final yield in any given season.

The ability of the Ontario heat unit system to model the growth and development of forage maize sown under plastic mulch

“…From silking onwards the development of the crop would not have been directly affected by the mulch in any of the treatments, resulting in the parallel development with the different sowing dates and mulch treatments in terms of DM yield (Figure 3) and DM content (Figure 5). Contrary to the findings of Potts et al. (1979) in Scotland, the accumulated OU from silking to harvest was able to provide a close fit for each of the variables relating to maturity of the crop confirming the conclusion that the OU system is an appropriate basis on which to model the development of forage maize grown under plastic mulch providing that adjustments are made to account for the higher temperatures experienced by the plants while under the mulch.…”

The effects of incorporating sugar beet pulp with forage maize at ensiling on silage fermentation and effluent output using drum silos

“…In the past, when the minimum thermal requirement was not received by the crop, this could result in crop failure ( Potts et al ., 1979 ). However, recent progress in the breeding of maize varieties with a reduced thermal requirement ( NIAB, 1998) has resulted in varieties that produce acceptable dry‐matter (DM) yields (10 t DM ha −1 ) even in poor years in terms of heat received ( Hameleers et al ., 1997 ).…”