An accession of L. hirsutum (L.A. 1363) from Alta Fortaleza at 3,100 m in Peru (Ancash) has proved useful for the study of various adaptations to cold. Unfortunately, like other accessions of L. hirsutum f. typicum, its flowers abort at an early stage of development unless the daylength is less than about 12 hours. This limits most experiments involving pollen and seed production to the winter months. In an attempt to produce dwarf plants which would be suitable for growing in controlled environment chambers, L.A. 1363 was grafted on 3-cm rootstocks of L. esculentum Tiny Tim. No dwarfing resulted, and most pldnts were discarded. A remaining plant is however, now flowering under natural daylength (currently 14.3 h in early December, 34 deg. S) next to a plant of the same clone on its own roots which carries only aborted flower trusses. This surprising result therefore suggests that grafting on suitable rootstocks may allow routine flowering of L. hirsutum f. typicum under natural daylength.