Vol. XIII. No. .3.'s. 



THE AGRICULTURAL NEWS. 



379 



STUDENTS' CORNER. 



SEASONAL NOTES. 



Ill the Leeward Islands where sugarcane i.s largely 

 grown, there has been unt'ortniiately for the planter a rather 

 severe drought during the latter half of the year. Such 

 times of drought jircsent special o]jportunities of making 

 valuable ob.servations for future consideration. In the last 

 number of the Agricultural Nen's it was suggested that this 

 period of growth was a good one for making observations on 

 varieties of cane w-ith regard to their characteristics. In 

 A paper contributed to Vol. XIII of the West Indian Bulletin 

 by Mr. W. R. Dunlop, on stomatal characteristics of 

 varieties of sugar-cane, the writer expresses the opinion that 

 in the future selection of the sugar-cane for drought resis- 

 tance, more attention should be paid to the habits of the 

 leaves, and their stoinatal characteristics. The latter, (jf 

 course, can only be observed under the microscope, but any- 

 one can observe and note the habits of the leaves referred to 

 by Mr. Dunlop, and in connexion with this, how each habit 

 is correlated with aliility to withstand drought, or otherwise. 

 In some varieties of cane the haliit of the growing leaves is 

 to curl involutely, to jirotect the upper surface, while in some 

 few the habit i.s to curl revoUitely. to protect the under 

 surface. But in all ;a.ses, when the leaves are cut from the 

 plant, they proceed to curl up involutel}' before completely 

 drying. 



The student will see, by referring to the paper mentioneil 

 above, that the ([uestion as to the correlation of leaf charac- 

 teristics and drought-resisting qualities in varieties of sugar- 

 cane, has not yet been thoroughly worked out. Observations 

 carefully made and recordefl <m tlicsf points may be submitteil 

 to the officers of the Agricultural 1 )epartments. They will 

 be very likely of use in future investigations. 



Another point, which a period of drought must bring 

 into prominence, is the supply of fodder for the live stock of 

 an estate. Experiments might well be made in hay-making. 

 Some of the gra.sses in the West Indies possess the qualities 

 which tend to produce good hay, such as Andropogon caricosm, 

 which has so largely taken [josession of the pastures in Antigua, 

 and And ropogon pertusu', the sour grass of Barbados. If cut 

 at the prf)per period, and well cured and stacked, a cro]3 of 

 these grasses might prove, as hay, a great resource in times of 

 drought. Some of the wild leguminosae, such as Clitoria 

 ternatea known as 'wina' in Antigua, and as 'blue bell' in 

 Barbados, and Desiiiodinm tortuosuin, kiifiwii in some of the 

 islands as 'lieggar weeil', are go<id fodder in their green state, 

 and might prove worth while growing as a hay croj). They 

 cover the ground i|uickly, and do good to the soil. On the 

 subject of West Indian gi-asses and their value, reference may 

 be made to a paper liy Dr. Watts in the West Indian Bulletin, 

 Vol. I, p. 410, on the care of pastures in Antigua, and another 

 paper, also by Dr. Watts, in the same periodical. Vol. Ill, 

 p. 3.53, entitled Additional Notes on West Indian Fodder. 

 Favourable notice is given in this latter paper to another 

 native leguminous plant as a hay producer, Stylosanihes 

 procumhens, known as 'clover' in ( henada, 'creeping trefoil' 

 in Barbados, and in xVntigua as 'ilother Siegel'. 



At this season many fields of Indian corn will be approach- 

 ing maturity, and the etiects of attacks of insects are 

 likely to be evident. The caterpillars of the boll worm and 

 of the corn ear worm will have attacked the leaves and ears, 

 while aphis ir.ay be present on the leaves. In Antigua, the 

 gnibs of the brown hard back {Lachnosterna sp.) are likely 

 to be found at the roots of Indian coin. 



Students would do well to examine this crop, and observe 

 the presence of insec^'ts, and endeavour to estimate the extent 

 of injury cau.sed by them; also the amount of control exer- 

 cised over the pests by their natural enemies. 



In the case of the aphids, where these occur, the natural 

 enemies, the lady-birds, lacewing flies, etc., should be easily 

 found; the caterpillars are likely to be attacked by internal 

 parasites, and eaten by .Jack Spaniards: the hard back grubs 

 are not known to be attacked by parasites; and observations 

 are needed- on these points. In this connexion. Pamphlets 

 Nos. 73 and 7.5 may usefully be consulted. 



The insect pests and diseases of sugar-cane are also likely 

 t<5 be more noticeable as the crop reaches maturity. The 

 root borer (E.roplulialmus esuriens), the hard back grubs, and 

 the root disease should be ob.served where these occur, and 

 a lookout kept for the appearance of the rind fungus or 

 stem disease. 



In the ca.se of limes and of cacao, the root borer grubs 

 are also likely to be present, feeding on the roots. Limes 

 should be watched for any increase of scale insects, and 

 observations made as to the abundance of the parasitic fungi 

 which attack these pests. 



Precautionary Measures against the Spread 



of Plant Diseases. In referring to tlie discussions on 

 cacao cultivation which took place at the Third International 

 Congress of Tropical Agriculture, Trojiical Life (September 

 1911) takes occasion to make some remarks on the sub- 

 ject of legislation against plant diseases and pests. The 

 writer considers that certificates as to the freedom of plants 

 from diseases or pests are only of value when officially issued 

 at the importing centre, for he contends that plants or pri>- 

 duce may easily contract disease en route. Of course, 

 exporting centres known to be infected ought to be placed 

 Under quarantine, and exports of plants or seeds prohibited 

 from such centres, until the cause of the (]uarantine ceases to 

 exist. Some such regulations are already in force, and are 

 likely to be made more stringent. This question then 

 naturally ari.ses — How are planters to make and keep their 

 properties a clean centre of export? It is suggested that 

 definite areas of not more than 300 to 500 acres should 

 have isolating belt.s, preferably a practically bare strip of 

 land like a road, right round them. Such a jirecaution 

 would enable the careful planter to control a disease or pest 

 more easilj-, and it w-ould tend to prevent its spreading far 

 and wide. Even when the most stringent measures had to 

 lie applied, such as burning out, thej- could be more efiec- 

 tually and economically carried out in such limited areas. 



The Water Hyacinth (Eichomia sp.) is known in 



the West Indies only as an ornamental water plant. In Florida 

 it is a pest, interfering with the navigation of some of the 

 streams. In the Journal of tlie Royal Society of Arts for 

 Augu.st 14, 1914, it is stated that as a result of the .sprea<i 

 i)f this plant in the waters of Cambodia and other parts <}f 

 Indo-China, there have been investigations made as to its 

 possible uses. Professor , Perrot has published the results 

 of his experiments with the water hyacinth as a fibre 

 producer. He finds that fibre is extracted from the stalk, 

 which can be made into .serviceable rope and twine, and it 

 is suggested that it may be woven into bags for use in place 

 (jf the jute bags for rice now imported. It jiroduces a strong 

 flexible cloth which takes dye easily, of about the same 

 ijuality as jute. Native workmen obtain nearly 10 B). of 

 fibre from 220 Jb. of green stems, as compared with 3-.5 

 to 4 )ier cent, of fibre from sisal. 



