more organic matter for the next summer's crop. It is sometimes used in winter gardens and is a common nurse crop. Rye grows better than any other cereal in heavy clay and light sandy and infertile or drought-affected soils. It can tolerate pH between 4.5 and 8.0, but soils having pH 5.0 to 7.0 are best suited for rye cultivation. Rye grows best in fertile, well-drained loam or clay-loam soils. Frost resistance S. cereale can thrive in subzero environments. The leaves of winter rye produce various antifreeze polypeptides (different from the antifreeze polypeptides produced by some fish and insects). Ecology The nematode Ditylenchus dipsaci, leaf beetle, fruit fly, gout fly, cereal chafer, dart moth, cereal bug, Hessian fly, and rustic shoulder knot are among insects which can seriously affect rye health. Diseases Rye is highly susceptible to the ergot fungus. Consumption of ergot-infected rye by humans and animals results in a serious medical condition known as ergotism. Ergotism can cause both physical and mental harm, including convulsions, miscarriage, necrosis of digits, hallucinations and death. Historically, damp northern countries that have depended on rye as a staple crop were subject to periodic epidemics of this condition. Such epidemics have been found to correlate with periods of frequent witch trials, such as the Salem witch trials in Massachusetts in 1692. Modern grain-cleaning and milling methods have practically eliminated the disease, but contaminated flour may end up in bread and other food products if the ergot is not removed before milling. After an absence of 60 years, stem rust (Puccinia graminis f. sp. tritici) has returned to Europe. Areas affected include Germany, Russia (Western Siberia), Spain, and Sweden. Races PTGBH, PTGFH, RKBBK, SKGBC, SKGBH, SKGBR, TKDLK, TKGBK, TKGBR, and TKGDH are now present on rye in Spain. Invasiveness Rye is a common, unwanted invader of winter wheat fields. If allowed to grow and mature, it may cause substantially reduced prices (docking) for harvested wheat. Cultivation Since the Middle Ages, people have cultivated rye widely in Central and Eastern Europe. It serves as the main bread cereal in most areas east of the France–Germany border and north of Hungary. In Southern Europe, it was cultivated on marginal lands. Rye grows well in much poorer soils than those necessary for most cereal grains. Thus, it is an especially valuable crop in regions where the soil has sand or peat. Rye plants withstand cold better than