Beet Production for Ethanol in Waikato: Yields and Problems Encountered in Growing the Crop

Sugar and fodder beet were grown in three years to assess the potential sugar yield for ethanol production in the region. Fresh weight root yields ranged from 70-85 t/ha for sugar beet and 55-136 t/ha for fodder beet. Sugar contents averaged 15% for sugar beet and 10117o for fodder beet resulting in sugar yields of 10-12 t/ha and 5-12 t/ha respectively. Consistently higher sugar yield from sugar beet and a 4% higher root dry matter favoured its use over fodder beet. These sugar beet yields were considered to be below the environmental potential because of erratic, below optimum density plant stands of 40 000-80 000/ha resulting from establishment problems. The herbicide lenacil at 2 kg ai/ha and the insecticides carbofuran or disulfoton at 1.75 kg ailha were found to reduce plant stands by 21-27% with disulfoton being increasingly phytotoxic when used with lenacil or starter fertiliser. Without lenacil or insecticide, stand survival was 40-60% and further problems with soil fungi or nematodes were suggested. Though field establishment was improved 50% by methyl bromide soil fumigation, the use of fungicides and nematicides failed to identify the problem's cause. It was concluded that a 60-70 t/ha sugar beet yield giving 10-11 t/ha of sugar would be a reasonable commercial expectation for the region provided uniform stands of adequate density could be established. Additional