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Cyperus esculentus L. is known as chufa, yellow nutsedge or tiger nut. lt grows wild as a weed, but also is grown as a crop; sometimes it is also called rush-nut. Although it can be found in cold regions, as Alaska (Holm et al. 1977: 125), it is considered a plant of warm areas, widespread in tropical and temperate zones around the globe (de Vries 1991). It is most troublesome in eastem and southem Africa and in North and Central America. Recently it has also spread to sorne European countries with colder climates such as the Netherlands (Rotteveel 1993;de Vries 1991), Switzerland (Gerhold 1992Schmitt 1995; Schmitt and Sahli 1992), Germany and Austria (Gerhold 1992) and Hungary (Dancza 1994). Kükenthal (1936) distinguished eight botanical varieties of Cyperus esculentus. Recently three of these varieties were rejected and only four wild varieties (esculentus, leptostachyus, macrostachyus, and hermanii) and the cultivated variety sativus are recognized today (ter Borg and Schippers 1992). This can explain the existence of two distinct groups of plants which have a similar morphology but differ widely in application and which are known by the same name: one is a weed and the other, a crop.Since ancient times the chufa tuber has been considered a foodstuff; it was an

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This study analyses the effects of seven treatments for removing hardseededness and four for breaking physiological dormancy in caper seeds. Seeds were germinated in a growth chamber and the maximum germination percentage, the time to reach 50% of final germination and the mean relative cumulative rate were calculated. The logistic function was suitable for analysing caper seed germination. Acid scarification followed by the addition of a GA 3 solution to the germination substrate was the best, efficient and cost effective method for ensuring satisfactory seed germination. Acid scarification can be substituted by mechanical scarification with ultrasound, hot water scarification or soaking, but these procedures require longer germination periods to reach satisfactory germination levels. The soaking method proved useful enough to remove hardseededness and it is also the most simple among the assayed treatments.

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