Swedes and turnips

Both swedes and turnips are sensitive to acidity and grow best at pH levels of 6.5. Like mangolds and fodder beet, the full-season turnips and swedes usually follow cereals in the rotation. Turnips can be grown from July to October, or they can be sown in July to provide autumn grazing before the frosts. 

Swede and turnip tops are safe for feeding and may have a crude protein content in the dry matter as high as 200 g/kg, the digestibility of the organic matter being about... 

Both swedes and turnips are liable to taint milk if given to dairy cows at or just before milking time. The volatile compound responsible for the taint is absorbed from the air by the milk and is not passed through the cow. 

Some varieties of swedes and turnips are more resistant than others... 

Spores over-winter on infected plants and are carried by air currents to infect the following year s crop. Particularly susceptible crops are Brussel sprouts, swedes and turnips. 

Swedes and turnips are grown for sale as a whole root or for further processing as prepared vegetables, for example for soups. 

Swedes and turnips require imcompacted well-drained loams, silts and light clay loams. The crops can be grown around the UK but are mainly grown in areas with cool surmners, such as the south-west, west and north of England, Wales and Scotland. 

Where clnb root is a problem, particularly on acid soils, swedes and turnips should be grown no more than one year in four or five after another brassica crop with a plarmed Uming pohcy before planting. 

Swedes and turnips can be hand pulled or lifted mechanically using a modified potato lifter and transported to the packhouse in crates or bulk boxes. Swedes are harvested from July to the following March. Late crops can be stored for several months in cold stores. Turnips store less well. 

Table 18.3 Fertiliser recommendations (kgdia) for maincrop forage swedes and turnips...

Lime is important as swedes and turnips are often grown on potentially acid soils. Soil pH should be above 6. Club root can be prevalent under acid conditions. However, over-liming is equally serious as it can induce boron deficiency symptoms (Table 6.2). 

Swedes and turnips are both brassicas in which the principal phytochemicals of interest are glucosinolates found throughout the plant but particularly in the root. Parsnip is a member of the Umbelliferae family and like many members of this family, including celery (Apium graveolens), contains psoralen (Figure 7.6) which in sensitive people can cause blistering on exposure to light (see Section 7.3.5 and Chapter 5). 

Turnips are generally lower in dry matter content than swedes and are divided into two main groups white-fleshed varieties (8% dry matter), often called stubble turnips, which are frost susceptible and prone to bruising, but grow very fast and make valuable catch crops which can be grazed in situ and yellow-fleshed varieties (8-10% dry matter) which are whole season crops and produce higher yields. 

In Britain the main root crops (turnips, swedes and fodder beet) were important feeds for ruminants in the eighteenth and nineteenth centuries. They gave high yields in unfavourable environments and could be stored for the duration of the winter. Increasing use of silages for winter feeding has reduced the importance of root crops. By 2007 the area in Britain devoted to these crops had declined to 140 000 ha 997 166 000 ha). 

Swedes Brassica napiis), which were introduced into Britain from Sweden about 200 years ago, and turnips Brassica campestris) are chemically very similar, although turnips generally contain less DM than swedes (see Table 21.1). Of the two types of turnip that are grown, the yellow-fleshed cultivars are of higher DM content than the white-fleshed cultivars. The ME value of swedes is usually higher than that of turnips, i.e. about 13 MJ/kg and 11 MJ/kg DM, respectively (seeTable 21.1). The main sugars present are glucose and fructose. 

Brown heart of swedes Boron and turnips (Raan) deficiency... 

Oilseed rape (sometimes also known as swede rape) and turnip oilseed rape are two very similar species. Breeders, Pre-Basic, Basic and certified (Cl) seed generations are available. There is no second generation (C2) of certified seed permitted. 

The growing of swedes and main crop turnips is similar. 

Swedes, like turnips, are very often grazed in situ in the field, but both crops can deteriorate under wet and frosty conditions. Varieties with globe-shaped roots, rather than tankard shaped, are less prone to damage when harvested by machine. In most districts they are lifted in late auturrm, before they are fully matured. It is advisable to allow the roots to ripen in a clamp to minimise scouring when fed to stock. In mild districts, swedes may be left to mature in the field for this purpose,... 

Swedes are slower growing than turnips and are grown as full-season crops. The very high dry matter varieties may be so hard that they require chopping before feeding to animals to ensure high intakes. 

Rapeseed/Canola belongs to the turnip rutabaga, cabbage, Brussels sprouts, and mustard family of crops that can be grown at low temperatures and moderate humidity. Three species have been grown as oilseeds Brassica napus, known in Europe as rape, oil rape, Swede rape, and Argentine rape B. campestris, known as rapeseed, oil turnip, turnip rape, and Polish rape and B. juncea, known as leaf mustard, brown mustard, Oriental mustard, and Indian mustard. B. campestris was grown in India as early as 2000-1500 BC. 

Other Whole Oilseeds. Various oilseeds have been fed whole, or dehulled, when available for feed at competitive prices or in grades substandard for extraction but still wholesome for feeding. Examples include safflower (Carthamus tinctorius), fat content 35%, dmb and oil-type sunflower seed fat content 44%, dmb. Currently, interest is high in feeding whole canola seed (41 6% oil) in Canada and northern European countries. Double-zero strains of Brassica napus (rapeseed, oilseed rape, swede rape, and Argentine rape) and Brassica campestris (turnip rape, oil... 

The genus Brassica comprises some 40 species, of which the following are of agricultural importance kales, cabbages, rapes, turnips and swedes. Some of the brassicas are grown primarily as root crops, and these will be discussed in Chapter 21. 

The rapes grown in Britain are usually swede-rapes (B. napus), although turnip-rapes (B. campestris) also occur. Rape may be included in seed mixtures for pastures, in order to provide forage until the grasses become established. The nutritive value of rapes is similar to that of the kales. A forage rape and kale hybrid (var. Swift) is valued for fast growth combined with winter hardiness. 

Recently numbers of this pest have increased in the UK. Mainly a problem in turnips, oilseed rape and swedes. 

For a soil with an index of 2, the fertiliser recormnendations for swede would be 70kg/ha N, lOOkg/ha of P Oj and 150-200kg/ha of K O. Small edible turnips require lower rates of N. 

There are limited numbers of swede varieties available some, such as Ruta Otofte, Marian and Airlie have been available for many years. More recent introductions are Siskin and Invitation (which have good resistance to club root disease), Brora and Gowrie. Massif is a recent introduction of a maincrop turnip and is higher yielding than the traditional Aberdeen Green Top Scotch. 

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