. Some diseases of Puerto Rican forage crops. Forage plants Diseases and pests Puerto Rico. cliocolate-brown at first and be- come ashen with a difftise gra\'- purplish surroimding area. Tiie spots are oval or angular to some- what irregular and elongated. They measure 4-8 mm. and may coalesce. The diseased areas shred with age and expose the imbedded sporangia (fig. 12, B). These are spherical, subspherical, or short cylindrical with rounded ends. They are golden-brown and smooth. Their measurements are 18-33m x 15-24^t. The wall is V to thick. {35, p. 524). Rust Rust of Paspalu7n plicat
. Some diseases of Puerto Rican forage crops. Forage plants Diseases and pests Puerto Rico. cliocolate-brown at first and be- come ashen with a difftise gra\'- purplish surroimding area. Tiie spots are oval or angular to some- what irregular and elongated. They measure 4-8 mm. and may coalesce. The diseased areas shred with age and expose the imbedded sporangia (fig. 12, B). These are spherical, subspherical, or short cylindrical with rounded ends. They are golden-brown and smooth. Their measurements are 18-33m x 15-24^t. The wall is V to thick. {35, p. 524). Rust Rust of Paspalu7n plicatulwn (brownseed paspalum, gTamalotillo) is caused by Puccinia leris (Sacc. & Bizz.) Magn. This disease has been found to some extent at all times of the year but was most prevalent during the dry winter months. Arthur {3, p. 230) re- ports that this rust is very com- mon in South America and extends as far north as Texas and Louisiana. The disease did not appear to cause much damage on gramalotillo in Puerto Eico. The chestnut-brown uredia (fig. 13, A) are found on both sides of the leaf and are eventually sur- rounded by a necrotic zone. The urediospores (fig. 13, B) are cin- namon-brown, globoid or ellipsoid, and measure 19-29m x 23-32^. The wall is ^1 to thick, echmulate, with two or thi^ee pores (sometimes four), located equatorially (4, p. 126). The pustules frequenth' are parasitized by Darluca jilum . (See reference to parasitism of Puccinia cynodontis on Cynodon dactylon for further discussion of rust infection, p. 4). Talquezal Tar spot Tar spot of Paspalum virgatum L. (talquezal, cortadero) is caused by Phyllachora cornispora Atk. This disease was found all months of the year. Though at times it was so abundant as to cause some defolia- 260443^—53 3 tion, it did not appear to be of any Figure ^4. Rust on Paspalum plica- tulum (brownseed paspalum) caused by Puccinia levis. X B, Spores of P. levis. X 528. The black fungus stroma (fig
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