Autumn-sown crops

Wilson, B.J. and H.M. Lawson (1992). Seedbank persistence and seedling emergence of seven weed species in autumn-sown crops following a single year s seeding. Ann. ofAppl. Bio. 120 105-116. 

The fungus mainly attacks wheat though there are distinct forms that attack barley and oats. Initial primary foci may be found in early spring. From the pustules, spores are carried by the wind to infect healthy plants. During winter, spores are normally dormant on autumn-sown crops. Cool, humid conditions favour disease. Temperatures above 25 °C inhibit growth. 

Norsworthy, J.K., Malik, M.S., Jha, P. and Riley, M.B. (2007) Suppression of Digitaria sanguinalis and Amaranthus palmeri using autumn-sown glucosinolate-producing cover crops in organically grown bell pepper. Need Res., 47, 425-32. 

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. 

At normal application rates trifluralin gives 4-6 months of weed control, so that after its application in spring other crops can be sown in the autumn. In cold soils a persistence of longer than 12 months must be taken into account (Menges and Hubbard, 1970). 

Continuous cropping of the same crop, sown at the same time each year, will tend to encourage those weeds that germinate at the same time. Examples include autumn-germinating bromes and black-grass in winter cereals, and late spring/... 

The range of crops, often with autumn- and spring-sown varieties, offers an option for most soil types, pH and crop rotations. Seasonal weather may adversely influence crop establishment, harvesting and sample quality. Home-saved seed has been an option for some of the crops but with specific quality requirements for the harvested product, and a trend to lower seed rates/plant populations, high quality seed with an appropriate treatment is advisable. 

On livestock farms kale is often direct drilled into an old ley after glyphosate spraying. This may be after an early grazing or a silage cut has been taken. Kale can also follow a catch crop sown after cereals in the previous autumn. Club root disease (Table 6.2) can be a problem and kale should not be grown in the same field more often than one year in three. 

Forage catch cropping is the practice of taking a quick growing crop between two main crops. The term is usually applied to crops of quick growing white turnips, or rape, or mixtures of the two, sown for autumn or early winter grazing after an early harvested cereal (usually winter barley) or any crop taken early for wholecrop silage. 

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