.SECTION X.— METHODS OF CONTROL. 137 



Corn, As a preventative of insect pests corn is a very bad rotation 

 crop for Trinidad, as it is a host plant for both the froghoppcr and the 

 small moth borer. It is also capable of being infested with Mosaic 

 Disease. At the same time it is a valuable crop and might be grown as 

 part of a rotation on lands which do not suffer severely from insect 

 damage. 



Leguminous Crops. Alfalfa was tried at Caroni Estate, but, 

 according to Mr. Gilbert, it would not stand the damp climate and was 

 in addition banJly damaged by a weevil. 



Bengal Beans have been tried at Caroni and elsewhere. As they 

 are poisonous they are grown only as a green manure to be ploughed in 

 to improve the tilth and humus content of the soil. An illustration of 

 Bengal Beans being used as a cover crop for sugar is given by 

 Urich (1913 C. plate VI.). Gough (1911 C. p. 37) notes that they were a 

 great success at Caroni in 1910, but failed completely at Chaguanas 

 where they were sown without previous preparation of the soil. 



Goto Peas have been tried on a larger scale than any other legumi- 

 Jious plant and Waterloo Estate in 1918 had 1,400 acres of land under 

 this plant, afterwards to be planted in cane. According to Mr. Carlee 

 they cover the ground quicker and better than the Sword Bean. When 

 possible they are grown to seed, the seed picked and the haulm fed to 

 the cattle and returned to the ground as pen manure. If this cannot be 

 done they are ploughed in as green dressing. 



Sword Beans. The common species in use here is Canavalia 

 ensiformis, which in addition to being a good cover crop and stock feed 

 is to a small extent edible by man. It is widely used in other parts of 

 the West Indies. Another species, Canavalia gladiata, is of more 

 vigorous growth, and has been grown successfully by Mr. Connell at 

 Esperanza Estate and Dr, Shannon at Harmony Hall. 



Pigeon Peas have been tried on several estates, but unless thickly 

 planted are not such a good cover crop as the lower growing species. 

 On the other hand the more woody stalks of this plant when ploughed 

 in should help considerably in improving the drainage and aeration of 

 the soil. On some estates they were grown on ths bodies of the fields 

 with the idea of preventing the spread of the froghoppcr, but there is no 

 evidence of any results being obtained in this way. 



Woolly Pyrol was particularly recommended by Gough (1911 C. p. 34) 

 as a suitable cover crop for cane land, and Urich in 1913 mentions that 

 it has given good results, but it does not seem to have come much into 

 use in the last ten years. 



Non-leguminous Plants. Yams are one of the best non-leguminous 

 crops that can be grown on cane lands. They give a large yield of 

 a marketable food, necessitate deep tillage of the ground, and provide 

 a haulm to be ploughed in. 



In 1917 the Usine St. Madeleine planted a five acre field with yams 

 irnmediately after the cane was cut (about April). The yams were 

 removed in February 1918 and the field planted with crop plants a 

 month or two later. The canes grew rapidly as a result of the excellent 

 condition of the soil and were bigger at the end of the year than many 

 wet season plants, while the proceeds of the sale of the yams more than 

 paid for the whole cultivation of the field from the time the canes were 

 removed to the time when they were growing again. 



