Cucurbit Genetics Cooperative Report 23:110-111 (article 36) 2000
John Burgmans
Future Resources, 633a Queen Stret, Levin, New Zealandl [email protected]
Abstract: Oil seed pumpkin, (Cucurbita pepo var. Styriaca), cv. Wies 371 was first evaluated in new Zealand in 1991 and subsequent trials indicated that the crop grew well in areas where traditional cucurbit crops are produced in both the North and South Islands. Commercial attempts to establish the crop failed initially through lack of interest and experience but were successful in 1999. Seed yields were very low but can be improved by using fresh seed stocks and by minimising the virus infections.
Introduction: For 30 years I did research for the Ministry of Agriculture and Fisheries, followed by 8 years working for the Crop & Food Research Institute concentrating on the introduction of new crops to New Zealand (1). Presently I work as a private consultant with an emphasis on new crop introduction.
New Zealand growing areas of squash and pumpkins are mainly in the northern and eastern parts of the North Island, with some squash produced also in the top and middle half of the South Island. Oil seed pumpkins could grow in any region where cucurbits are being grown successfully.
The oil seed pumpkin, (Cucurbita pepo var Styriaca), cv. Weis 371, was first evaluated as one of the 60 new crops introduced in 1991. As with numerous crops that are unfamiliar to the average New Zealander, it has taken many years for the oil seed pumpkin to become accepted. This slowness is often attributed to the patience required of growers while learning unfamiliar methods of growing or processing and the lack of consumer interest while the crop is being introduced. In addition, the harvesting and general processing methods for a new crop often prove to be very expensive and it is generally quicker to revert back to suppliers from well established areas so the costs can be kept down. Once these problems have been overcome, however, it is usually recognised that New Zealand is in an excellent position to offer a good quality products. Our market is also well suited for offering organically produced crops and well su8ited as a niche market situation, which is often the case for example in Japan,which has become more health conscious over recent years.
Last season was the first time that oil seed pumpkins were grown on a small commercial scale in Hawke’s Bay, on the east coast of the North Island. It was quite clear that there are still many problems associated with the harvesting and drying of the seed. Despite these problems, the crop’s products were very well received, which encourages ongoing development.
What was done with the crop? Crop & Food Research evaluated cv. Weis 371 for seed quality and spacing effects in Hawke’s Bay, Waikato and south of Aukland, all areas in the North Island. In 1991 some commercial firms showed interest but development was slow until last year, when the first serious commercial cropping started. Some of the seed stock was nearly seven years old and this resulted in a low germination and very uneven plant growth and fruit maturity, which in turn resulted in low seed yield and quality.
Last year ‘Weis 371’ was used in trials designed to improve the seed yield. Some pilot trials were done with composted rock phosphate compounds and fish oil as a nutrient to increase the seed yields and the seed size.
Results. Spacing trials. Plant densities varied from 1 to 2.5 plants/m2 , in rows 1.5 m apart. Mean fruit weight, seed weight/fruit and the individual seed size declined as the plant density was increased resulting in no increase in the seed yield/m2 There was a positive relationship between fruit weight and seed yield. It is recommended that the oil seed pumpkin crops for seed be planted at 1 to 1.5 plants/m2 rather than 1.5-2/2 plants/m2 as recommended for squash fruit production. Estimated seed yields varied from 1 to 1.4 t/ha/ The mean oil content of the pumpkin seed was 40.4% with over 90% of the oil comprising of three fatty acids, linoleic (52.7%), oleic (28/3%) and palmitic (12.7%) acids (2).
Virus infection levels cause concern. The high levels of virus infection in the seeds, caused by WMV2, (204%) and ZYMV, (0.6-1.4%) may have caused higher than normal visual field symptoms of around 20% to 25% in the plants during the growing season, which is considered too high for our normal squash and pumpkin crops. As further plantings may be planned for next season, it is important that the seed stock is free from viruses and imported seed should be verified virus free. The reason for this concern is simple: considerable amounts of money and effort have been expended by the present squash exporting industry to minimise the virus infection levels in their crops. Thus it would be highly irresponsible to introduce a known source of virus infected seed crop.
Fertiliser trials. The initial trials using the composted rockphosphate and fish nutrient showed that both the seed size and seed quality could be increased but further tests will be carried out during the 1999/2000 season to confirm this.
Discussion: Until last 1999 the commercial acceptable of oil seed pumpkins was very slow as the harvesting and drying techniques were still inadequate. The market awareness of the product is not yet strong enough to make oil pumpkin production viable. This is changing from the New Zealand perspective, the oil seed pumpkin products are better known now and there is also a growing awareness of organically produced crops. the processing technology still remain a serious problem but this can be overcome.
The trial results indicated that oil seed pumpkins can grow in areas in New Zealand which successfully grow cucurbits. Whether or not oil production is commercially viable remains unanswered but the oil composition is similar to the overseas oils which have been used as a culinary or medicinally product.
The market potential for dry seeds is very good and there is a growing market in the USA and Asia not only for the traditional seed uses but also for new products that can be developed, such as confectionary lines. We have also found interest in new culinary and medicinal uses. New Zealand should be seen by the Austrian traditional industry as a complementary rather than a competing market and we would like to encourage more research and commercial cooperation.
The virus infection was more serious than originally thought and it was higher in the oil seed crops than in the other cucurbit crops during the 1999 season, which may be entirely a seasonal coincidence and should not be regarded as a trend. The seed yields were too low and for the crop to be viable these yields need to be increased substantially. The fertilizer treatments applied last season may help to achieve this goal.
In conclusion note the following points:
- Variety evaluation of new (virus free) types are needed in New Zealand
- Efficient mobile harvesting and drying equipment is needed
- Virus infection needs to be minimised
- Explore and promote new products from the seed
Literature Cited
- Burgmans, J.L,, J.J.C. Scheffer and J. Follett. 1996. Naked oil seed pumpkin, Crop & Food Research broadsheet 70.
- Douglas, J.A., J.L. Burgmans, J. Follett, J.J.C. Scheffer and R.A. Littler. 2000. The seed yield of oil seed pumpkin at four plant populations and the oil composition of the seed (prepared for publication).