Muutamia havaintoja juolavehnän juurakoista ja juurista

In summer 1948, when making observations about the root relations of field crops (5), I acquired as by-product some data about the rhizomes and roots of couch grass, which is one of the most common and most detrimental weeds under the conditions in Finland. The method employed in these observations (5) made it possible to acquire a clear picture about the position of the rhizomes and roots, about their extent and about the depht of the roots. As we have not sufficient information about these things (2), I thought it desirable to publish the obtained facts, scarce as my observations are. The rhizomes of couch grass are confined to a very thin surface layer in the furrow slice, the maximum depth being usually 10 cm. Only in one of the cases I examined the maximum depth was 15 cm. Possibly a very airy soil and cultivation in spring contributed to this case. Some facts seem to indicate that rhizomes die, if they are deeper in the soil than 10 cm. In general couch grass is considered a very shallow-rooted plant (fig. 3, a quotation from Korsmo, 2), but my observations show that the root system of couch grass is very profuse and penetrates deep into the soil, the maximum depth being 60—90 cm., which is the same as the maximum depth of the roots of field crops