December, 1911] 



553 



Miscellaneous. 



producing good crops of a useful qual- 

 ity, The agriculturist cannot afford to 

 ignore these two most important aspect? 

 of the employment of shelter for plants 

 against the wind. 



The presence of belts of plants of a 

 kind other than those which form the 

 principal cultivation is of much use in 

 the checking of epidemics of disease. 

 These start in a certain place or places, 

 and, often travelling with the wind, 

 spread easily, because tbey can pass 

 through an uninterrupted area of the 

 very plant that is the object of their 

 attack. If, however, a wiud-break com- 

 posed of a plant Or plants on which a 

 disease has little or no effect occurs in 

 its paths, its course is interrupted, and 

 the changes of safety of the plantations 

 on the other side of the shelter belt are 

 increased to a useful degree. This circum- 

 stance makes it important that wind- 

 breaks should be chosen in consideration 

 of their power to resist disease, and of 

 the diseases to which they are most 

 subject, a matter to which further re- 

 ference will be made below. 



One of the subsidiary results of the 

 presence of the plants which form a 

 permanent wind-break is that the exist- 

 ence of these in the soil lessens the 

 washing that takes place at times of 

 heavy rain, so that they possess a use- 

 ful forest effect. The importance of 

 this cannot be over-estimated, particu- 

 larly where permanent crops are being 

 grown on steep slopes in regions of 

 heavy rainfall. 



Not the least among the advantages 

 of the existence of wind-breaks is the 

 assistance that this gives in conserv- 

 ing the water in the soil, and in decreas- 

 ing transpiration from the leaves of 

 plants. Where shelter belts are found, 

 the force of the air currents is lessened, 

 so that the rate at which moisture is 

 carried away from the areas over 

 which they travel are diminished 

 to useful degree. Wind-breaks serve 

 also to temper the chilling effect of cool 

 winds ; this result is, however, of no 

 great importance in the West Indies 

 except in the more mountanious islands. 

 A minor matter, but one worthy of 

 mention, is that they are said to 

 encourage the presence of birds ; though 

 whether this is of advantage or not 

 will depend on the circumstances of 

 the special case. 



Reverting to suitable wind-breaks for 

 crops of one season, it seems that more 

 attention may well be given to the 

 feasibility of providing those which are 

 of a permanent nature. Where such 

 provision can be made, as will have been 

 seen from what is said above, special 

 70 



advantages will accrue, in that the pro- 

 tective effect of belts of this kind will 

 extend over a far larger area than that 

 which can be sheltered by a temporary 

 wind-break, and that such protective 

 effect will be available during storms 

 in which the temporary belts, from 

 their very nature, would cease to do 

 the work that is required of them. It 

 is recognized that there is little incent- 

 ive when ground is being opened for 

 the growing of one-season crops to plant 

 permanent wind-breaks. Nevertheless 

 this course is followed in some districts 

 in the French West Indian islands, and 

 the suggestion is made that its further 

 adoption would be of advantage, and 

 would make for its justification. 



A final matter is to point out that care 

 is required in the choice and planting 

 of wind-breaks, The plants employed 

 in them are often leguminous, because 

 of their known property of assisting in 

 adding nitrogen to the soil, and because 

 the prunings from them are likely to be 

 richer in nitrogen than those from 

 ordinary plants. There should be the 

 assurance that they are not subject to 

 the diseases and pests that are most 

 likely to attack the plants which they 

 are designed to protect, and in planting 

 them due regard must be had to the 

 conditions of the estate on which they 

 are in use, or it may be found that they 

 have been placed in such a position in 

 regard to the prevailing winds as to 

 render inadequate the protection from 

 them. Care in these matters will give 

 the agriculturist an asset which at once 

 increases the living energy of his plants, 

 protects them irom disease, and con- 

 serves the soil and the water that are 

 required for their needs. 



A DICTIONARY OF TERMS USED 

 IN AGRICULTURE, BOTANY, 

 CHEMISTRY, AND ALLIED 

 SCIENCES : 

 For the use op Planters and Others. 



By J. C. Willis and M. Willis. 



(Continued from page 1^63.) 



Hemp, Bow- 

 string ... Sansevieria zeylanica, 

 &c. 



Hemp, Madras ... Crotalaria juncea 

 Hemp, Manila ... Musa textilis 

 Hemp, Mauritius. Furerea gigantea 

 Hemp, Raj mahal Marsdenia tenacissima 

 Hemp, sisal ... Agave rigida var. sisal- 

 ana 



Hemp, sun ... Crotalada juncea 

 Henequen ... Sisal Hemp 



