18 WEEVIL-RESISTIXG ADAPTATIONS OF COTTOX. 



have attended the introduction into Texas of Mexican varieties of 

 corn. The plants grew 14 feet high the first year and bore very little 

 seed: in the following season:- they became smaller, earlier, and more 

 productive. 



The probability that the Kekchi cotton can be grown even at the 

 northern limits of cotton cultivation is strongly indicated by the 

 result> of an experiment at Lanham. Md. (1905). In favorable sea- 

 sons cotton can be grown to maturity a- far north as Washington, but 

 the present year has been very unfavorable, the summer month- being 

 for the most part cool and rainy, and with several interval- of 

 unusually low temperature. The cotton, which was planted intention- 

 ally in rather poor -oil. to avoid too great luxuriance of growth, ger- 

 minated very badly and remained small and stunted until August. 

 The Kekchi row- have, however, produced more plants, and more of 

 the^e have grown to maturity than with any of the domestic or for- 

 eign varieties included in the test. The Kekchi type has also remained 

 more constant in Maryland than did the King variety when grown in 

 Guatemala, though there are obvious differences between individual 

 plants. Two plant- in particular were found to have numerous bud-. 

 >ome ready to blossom before any of the other- had begun to -how 

 signs of productive maturity. 



It might be feared that a variety newly introduced from a tropical 

 country would be likely to suffer more from low temperatures than 

 our United States varieties, but this seems not to be the ca>e with the 

 Kekchi cotton, even when the cold i> carried down to the freezing- 

 point. There were light frosts in Lanham about the end of Septem- 

 ber, ju-t sufficient, a- it happened, to-do appreciable damage to cotton 

 m low ground. The Kekchi plants did not suffer more than the 

 American Upland varieties. The difference, if any. was in favor of 

 the Kekchi cotton, perhaps on account of the closer foliage. 



Many annual plants, even those of tropical origin, are most vigor- 

 ous and productive at their northern limits of growth, not. as has been 

 supposed, because this is the coldest part of their range, but because 

 the heat and sunlight, necessary to plant growth, are greater during 

 our summer month- than can be secured in a similar time in the 

 Tropics, owing to the much longer days of our northern latitude-." 



The Pachon cotton from western Guatemala, though it has grown 

 taller at Victoria. Tex. (52-79 inches), than at Lanham. Md. (30-40 

 inches), has produced numerous buds in Maryland, but none in 

 Texas. The Kekchi cotton also appears to have been more productive 

 at Lanham than at Victoria, to judge from a recent partial report 

 from Mr. Argyle McLachlan. 



a Cook. O. F.. 1902. Agriculture iu the Tropical Islands of the United States, 

 Yearbook of the United States Department of Agriculture for 1901, p. 367. 



