Oilseed rape harvesting

As calcareous soils can be found at fairly high altitudes and the fields are often exposed, great care should be taken when growing crops which shed their seed easily, e.g. oilseed rape. Harvesting must be carried out carefully to minimise yield loss. 

Up to Harvest. Oilseed rape and field beans are used as break crops for winter wheat on a variety of soils, and potatoes are used on the lighter soils. Sugar beet may also be grown, but this depends not only on the soil but also on the proximity of a sugar beet processing factor. Four Rothamsted-based experiments compared the effectiveness of winter wheat and winter oilseed rape in their use of labelled nitrogen fertilizer. Potatoes were included in two of these experiments and sugar beet and field beans in one experiment each. Two criteria based on the... 

After Flarvest. How do the memory effects shown by the other crops compare with those of winter wheat Winter wheat did not show a memory effect after one year, but oilseed rape does seem to do so. Researchers of the Agricultural Development and Advisory Service found that nitrate production by microbes in the soil after a rape crop increased with the amount of fertilizer given to the crop (R. Sylvester-Bradley, personal communication). One reason may lie in this crop s habit of shedding its leaves as harvest approaches, which means that the microbes in the soil get early access to these residues. This habit might contribute to the apparently smaller efficiency of this crop in using nitrogen fertilizer. The crop may be just as efficient as winter wheat at taking up the fertilizer but drops... 

Winter barley is an ideal entry for oilseed rape because the earlier harvest allows early drilling of rape. It has been shown on organic farms that building up fertility by using a green manure crop, such as red clover, has paid off financially, with the subsequent boost in yield of the following cereal crop. 

According to FAO statistics, the average field harvest of oilseed rape in Europe is 2500 kg ha-1 [8] and based on our own experiments, 3000 kg ha-1 yields can be obtained in the greenhouse. This translates into an annual harvest potential of 9000 kg ha-1, based on the fact that three harvests each of 3000 kg ha 1can be obtained in a year. The desired protein is produced predominantly in the sprout. The developing seeds do not accumulate recombinant protein. 

Organic farmers, unlike conventional farmers who may use herbicides, are unable to control volunteer plants from contaminated plants in the field (e.g. in oilseed rape) or volunteers which may originate from field-to-field transfer by machinery (e.g. combine, harvester). 

Destroy remains of harvested over wintered brassica crops by beginning of May. Several insecticides approved for use in oilseed rape. Some EAMU recoimnendations in other brassica crops. 

The harvest index of wheat has been substantially increased by the breeding of semi-dwarf varieties, and a closely related trait, improved resistance to lodging, has resulted in improvements both to yield and crop quality. Improved yields have been an important trait in all of the other major crops. In some cases improvements have been obtained by plant breeders selecting for winter hardy types which can be autumn sown. Oilseed rape is an important example, others, less successful, have included linseed, peas and lupins. 

The disease Sclerotinia sclerotiorum is important in oilseed rape and a number of other crops as well. It infects the stems of crops during flowering and has a substantial effect on yields. During combining, fragments of the sclerotia of this fungus often break away from infected stems and become mixed in with the harvested seed. There are no field standards for the incidence of this disease but the permissible number of sclerotia in a lOOg certified seed sample is 10 (5 in a 70 g sample for turnip rape varieties). 

Abstract This chapter opens with an introduction to the concept of world markets for oilseeds and proteins and how this affects farmers decisions to grow break crops. It then tackles the agronomy of the main combinable break crops including oilseed rape, linseed, field peas and field beans. It briefly covers more esoteric crops such as flax, lupins, navy beans and sunflowers. Each crop is dealt with by describing the variety choice, tire establishment, crop nutrition, crop protection, and harvesting and storage, as well as a brief discussion of their markets and quality aspects requited. 

Peas do not compete well with weeds and efficient weed control is essential to avoid yield loss. Pereimial weeds should be dealt with before planting and thistles, oilseed rape and groundkeeper potatoes can be a particular problem. Nettles and thistles can interfere with hand picking and, in machine-harvested crops, weeds can lead to crop rejection from the processor. Inter-row cultivations may be effective when the peas are between the second and fifth node growth stage. 

Oilseed rape embryos (average fresh weight = 2.5 mg) were harvested, removed from their... 

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