We study the phenomenology of light scalar quarks and the properties of a new family of hadrons containing such quarks in the framework of QCD taking into account non-perturbative effects caused by a possible existence of the condensate of the colored scalar fields. We suggest that 1-- bound state of scalar quark and antiquark may lie in the already accessible region {Mathematical expression} and be observable as resonance in PETRA e+e- collisions. © 1984 Springer-Verlag.