Acid Scarification of the Seed of Two Cuban Fiber Plants

U LOBATA L. of the mdllow family, widely used for fiber in the Tropics, and the related Triumfetta seraitriIoba Jacq. of the linden family are being planted in Cuba for the production of their jute-like bast fibers. In Cuba both.of these as well as several other plants are called "malva." Observations indicated that the germination of seeds of these two plants under field conditions was irregular, and it appeared esirable to test the value of sulfuric acid treatments in the scarification of the seed to hasten germination. The seed of both species is born in bur-fruits. In Urena the dehiscence of the five-carpeled fruit is septicidal, and each individual seed is completely enclosed in its portion of the capsular covering, part of which is copiously prickly. In Triumfe~Ia the fruits rarely dehisce, but when they do the dehiscence of the twoto five-cavity fruits is locullcidal, and the seed is entirely freed of the copiously prickly capsular covering. However, natural dehiscence is so rare that, for practical purposes, the "seed" of T. semiIriloba is in reality the twoto five-seeded fruit. Since these bur-fruits mass together forming clusters, good seed distribution at planting time is difficult, if not impossible. Acid scarification, therefore, has two objectives, first, to assure a good distribution of the seed at planting time by eliminating the bristles with which the capsule, s are beset, and second, to make germination prompt and even. Because of the impractical, tedious difficulty in hulling the seeds of T. semitriloba no hulled seeds of this species were included in the experiment. Two hundred seeds collected at random from wild plants