August, 1909.] 



166 



Miscellaneous. 



to grow in the intervening spaces. This 

 method is a compromise between clean 

 weeding and cutlassing solely. The fork- 

 ing around the trees must cause some 

 injury to the roots, but this may be 

 offset by the fact that the roots of the 

 trees are kept free from the injurious 

 effects of weeds, and if the grass that is 

 cutlassed down is applied as a mulch on 

 these cleaned circles, loss of moisture by 

 evaporation is prevented aud the general 

 tilth of the soil is improved. This mulch 

 should not be placed immediately around 

 the trunk of the tree, for such a practice 

 has been shown to be injurious, but it 

 should be spread evenly in a circle 

 commencing at least 18 inches or 2 feet 

 from the trunk, and as the trees grow 

 this circle should be enlarged. On the 

 other hand, care must be taken that a 

 hollow is not left around the tree, in 

 which water may accumulate. 



(c) Cutlassing. — On many estates, 

 where the rainfall is heavy and the 

 growth of weeds luxuriant, the weeds 

 and grass are allowed to grow, and 

 they are cutlassed down at periodical 

 intervals, and either used as mulch 

 around the trees or allowed to rot on the 

 ground where cut down. This system is 

 adopted in many young cacao planta- 

 tions, and in a very large number of 

 the Dominica lime cultivation?. By this 

 surface covering of weeds, the soil is 

 prevented from being " washed," and it 

 is protected from the harmful effects of 

 the sun. The conditions are also favour- 

 able to the bacterial action for the 

 liberation of plant food, for the moisture 

 content and temperature of the surface 

 soil are favourable to bacterial growth. 

 Against this, it is urged that the soil 

 will suffer in tilth from lack of proper 

 tillage, and that the soil will be im- 

 properly aerated. The cutting down of 

 the weeds, however, causes some of 

 them to die, and the drainage and aera- 

 tion that results from the death of the 

 roots is a matter that must receive 

 consideration. The weeds and grass use 

 up some of the plant food that should 

 be available for the trees, but it is 



NOT PERMANENTLY REMOVED 



from the soil, as the grass and weeds are 

 cut and left on the soil to increase the 

 humus in the soil. Again, they evaporate 

 directly from their leaves a large 

 quantity of soil water, and thereby 

 cause a loss of moisture directly from 

 the soil. It has, therefore, practically 

 to be decided whether the benefit derived 

 from the surface covering, sufficiently 

 offsets the loss of moisture and plant 

 food through the weeds and grass ; 

 particularly when the reduction of the 

 expenses over the clean weeding method 

 is borne in mind. 



On many of the lime and cacao estates 

 in Dominica this from of culture has 

 been practised for a considerable time, 

 and the results have during the last ten 

 years been closely investigated by 

 Dr. Watts, now Imperial Commissioner 

 of Agriculture, and it has been found 

 that the physical condition of the soil 

 generally remains good. The permanent 

 crops grow well under this system, and 

 " wash " of the soil is prevented, even on 

 the steepest slopes. The application of 

 the cut grass and weeds as a mulch 

 around the roots of the tree is probably 

 better than allowing them to rot where 

 cut down, as it affords direct protection 

 and good addition where the feeding 

 roots of the permanent trees are situated. 

 This system is practised in the coffee 

 cultivation at Onderneeming School 

 farm, under the direction of the Depart- 

 ment of Science and Agriculture, and on 

 some sections is assisted by bringing in 

 additional material for mulching pur- 

 poses. It has been quite satisfactory, 

 and increased crop returns have been 

 obtained. The weeds or mulch must 

 not, however, be packed too close to the 

 trunks, or otherwise they keep the 

 trunks too damp and favour the growth 

 of fungus diseases and the presence of 

 insect pests. 



It is well here to add a 



WORD OF WARNING 



in regard to this system. Para grass 

 should on no account be allowed to grow 

 in permanent cultivations. It should 

 always be dug out and burnt, or other- 

 wise it is likely to become a troublesome 

 pest. It was once observed on a cacao 

 plantation in St. Lucia that the removal 

 of Para grass was not properly done 

 from the beginning, with the result that 

 larger expenditure was incurred in doing 

 it at a later date, when its injurious 

 effects were being felt by the cacao trees, 

 The difficulty of getting rid of this pest 

 when once established is well known in 

 this colony, and care should therefore be 

 taken with it. 



(d) Green mulch.— This system con- 

 sists of growing cover crops, preferably 

 of leguminous plants, to smother out the 

 weeds. These crops are cut down just 

 as they commence to flower, and allowed 

 to remain on the soil as a mulch. The 

 advantages of this system over the 

 cutlassing of weeds is that control is 

 kept of the growth between the per- 

 manent crops, that the leguminous crops 

 benefit the soil by their root nodules, 

 and that a larger amount of material is 

 available for mulching purposes. Less 

 cutting down is needed, and the expenses 

 thereby reduced, but against this reduc- 

 tion must be placed the cost of the seed 

 and the cost of establishing the cover 

 crops. For cover crops purposes a 



