Seed production potatoes

October 1998 Potato blight control Organic vegetable seed production Companion cropping for organic field vegetables... 

In a genetically based series of experiments, seed production of the tall morning glory, Ipomoea purpurea, was used as a measure of fimess. No observable reduction in fitness was observed in the presence of the herbivore sweet potato flea beetle, Chaetocnema confinis (Siimns and Rausher, 1987). On the other hand, the magnitude of cost of production of furocoumarins in the wild parsnip, Pastinaca sativa, in terms of umbel production, is significant (Berenbaum et al., 1986). 

Legislation has been successful to date in the UK at stopping the introduction of Colorado beetle and potato flea beetle. Land growing potatoes for certified seed production must officially have no potato cyst nematodes. 

The majority of potato crops, however, are raised from replanted tubers known as seed potatoes. Seed production has traditionally been carried out in Scotland,... 

Northern Ireland and the hill areas of England and Wales where substantial seed potato enterprises still continue. The main advantages of these areas ate that the low temperatiues and strong winds keep aphid populations in check. This means that the severe virus diseases (leaf roll and the mosaics) which are spread from diseased to healthy plants by aphids, are less likely to occur. However, recent advances in aphid control and concerns over the quality of seed from some traditional areas have seen successful seed production extended to some of the English arable areas as a profitable break in predominantly cereal and break crop rotations. As with other forms of seed production the certifying authority in England and Wales is FERA, for Scotland SASA (Science and Advice for Scottish Agriculture) and DARD in Northern Ireland. In all cases the same basic Seed Potato Classification Scheme (SPCS) obtains. 

Dimethipin. 2,3-Dihydro-5,6-dimethyl-l,4-dithiin-l,l,4,4-tetraoxide [55290-64-7] (dimethipin, oxidimetbiin, UBI-N252, Harvard) (25) is used as a cotton defoHant and has been used as an experimental desiccant in potato vines. In addition, it defoHates nursery stock, grapes, dry beans, and natural mbber and is used as a desiccant for seed of canola, flax (l lnum usitatlssimum), rice, and sunflower (He/lanthus annuus) (10). The product has been available since the mid-1970s and the experimental work was first reported in 1974 (44). 

Starch is a polysaccharide found in many plants, where it is stored in roots and seeds. It is particularly abundant in corn and potatoes, the major sources of commercial starch. Perhaps as much as 50% of our food energy comes from starch, mostly in the form of wheat products. 

The food technologist may be especially interested in the fate of the carotenoids in the seed oil. Like red palm oil, the resulting carotenoid-pigmented canola oil may be more stable due to the antioxidant properties of carotenoids and may be more attractive to consumers. Alternatively, for food security concerns, transgenic soybean or canola oils and seed meals that are genetically modified for more efficient bio-diesel production may be bio-safety marked with lipid-soluble carotenoids and water-soluble anthocyanins, respectively. Potatoes are excellent potential sources of dietary carotenoids, and over-expression of CrtB in tubers led to the accumulation of P-carotene. Potatoes normally have low levels of leaf-type carotenoids, like canola cotyledons. 

Technically, the prospects for PHAs are very promising. If the price of these materials can be further reduced, application of biopolyesters will also become economically very attractive. At the moment, a worldwide effort is being made to produce PHAs from major crop plants, such as corn, potatoes and rape seed [9, 145-148]. This should ultimately provide cheaper technology for PHA production, leading to the implementation of PHA-based products in everyday life. 

In the first year, the maximum concentrations of sulfoxide and sulfone in soil, seed potatoes, and foliage were approximately 2, 2, and 6 times, respectively, the concentrations of those metabolites measured in the second and third year treatments. These results demonstrated that enhanced microbial degradation of relatively minor insecticidal compounds in the soil can significantly affect insecticide levels in the plant (when these degradation products are the major insecticidal component accumulated). As the sulfoxide and the sulfone metabolites are the major toxicants in the foliage of potato plants grown in disulfoton-treated soil, this reduction in toxicant residues overtime can be expected to reduce insecticide efficacy. 

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