BUREAU OF PLANT INDUSTRY. 283 



Cultural possibilities of halata. — The balata gum of Guiana, Vene- 

 zuela, and adjacent regions has been known for many years as an 

 acceptable substitute for rubber or gutta-percha, or even superior for 

 some purposes, but little attention has been given to its cultural 

 possibilities because the growth of the trees was supposed to be very 

 slow. Recent observations in the Canal Zone and in Haiti indicate 

 that the young balata trees develop rapidly and need to be studied 

 from the standpoint of commercial production or for planting in 

 rubber reserves. 



Planting of Ceara ruhher in Nicaragua. — Several plantations of 

 the Ceara rubber tree {Manihot glaziovii) in the district of La Paz, 

 Nicaragua, were visited in June, 1923. More than 100,000 trees had 

 been planted about 20 years before, including one estate of 60,000 

 trees planted in 1901. In the more favorable places the trees had 

 attained a height of about 40 feet and a diameter of 12 to 14 inches, 

 but the returns from tapping did not pay the cost of the operation, 

 and the hope of profit was abandoned several years ago. Much of 

 the rubber had been cut down to make room for pastures of Guinea 

 grass. Also the plantations of Ceara rubber had suffered from the 

 attacks of termites, which destroy the wood of the trees, leaving a 

 weak outer shell which may break down. No plantations of thf^ 

 Hevea or Para rubber tree were found in Nicaragua, but the Ceara 

 rubber is also a native of Brazil and has been confused with Hevea. 

 On account of the long dry seasons in this part of Nicaragua the 

 planting of Hevea would not be recommended, but Ceara rubber 

 was considered promising for dry regions. 



Exhaustion of native nibher in Central America. — It might be 

 supposed that the most favorable conditions for rubber culture would 

 be found in districts where wild rubber trees are most abundant in 

 the forests. Rubber-planting enterprises in Mexico and Central 

 America have been projected on this assumption regarding the native 

 rubber, overlooking the fact that the native Central American rub- 

 ber tree is well-nigh exterminated in many districts that formerly 

 produced large quantities of rubber. The native method of tapping 

 is destructive, so that with intensive rubber gathering all the trees 

 of seed-bearing age may be killed, and the forest growth of rubber 

 is reduced or brought to an end. This has occurred notably in the 

 Canal Zone and adjacent districts of Panama that formerly pro- 

 duced commercial quantities of rubber, where the rubber tree is now 

 very rare and in some districts completely extinct. Protection of 

 seed-bearing trees would be necessary in order to maintain the 

 growth of rubber under the natural forest conditions. Merely with 

 precautions for seeding, large quantities of rubber undoubtedlj^ could 

 be grown without other expense in waste lands of Central America 

 and the "West Indies. 



Ruhher reserves in tropical America. — ^^^^lether it is practicable to- 

 establish in any part of tropical America the same system of pro- 

 duction that has been developed on the East Indian rubber planta- 

 tions is one of the important questions, but other possibilities of 

 increasing the production of rubber in tropical America need also 

 to be considered. Some of the difficulties of the plantation system 

 might be avoided if measures could be developed for encouraging 

 the production of rubber by native farmers in tropical America, as 

 in some parts of the East Indies. Also it might be possible to provide 



