Vol. IX No. 203. 



THE AGKICULTURAL NEWS. 



37 



The site for a plantation should always be selected 

 v.here there is a good natural main outlet for drainage waters. 



' Under draining' with pipe, rubble or a bush base is, 

 1 consider, utterly useless in cacao cultivation, as it stands to 

 reason that such drains must very early be filled by the roots 

 of the trees (both cacao and shade trees), and that the action 

 of the drains after the first few months will be stopped by 

 the roots finding their way into them in search of moisture. 

 The theory is good, but the practice is (juite unsound with 

 regard to cacao. It is ditt'erent in lands on which cereal 

 crops are annually cultivated, for there the roots seldom or 

 never reach to the drains during the period of growth, and 

 consequently, the drains themselves work from year to year 

 without let or hindrance; but the principle cannot be 

 effectively applied on cacao estates. The planter should 

 therefore trust entirely to his surface drainage, and make that 

 .system do the work to the best advantage. 



GREEN DRESSINGS IN ANTIGUA 

 AND DOMINICA. 



The following is ;id account of e.xperiments and 

 observations that have been conducted and made in 

 connexion with green dressings in Antigua and Domin- 

 ica by the Curator of the Botanic Station, in the former 

 island, and by the Assistant Curator, in Dominica: — 

 AXTii;u.\. 



At the present time, in Antigua, the problem is to find 

 out what kind of dressing should be grown. The ideal plant 

 for this purpose would be a quick-growing, ins3ct- and disease- 

 resisting leguminous plant. It is of importance that a (juickly 

 growing crop should be sought, for in some cases the time 

 between the planting of the dressing and the final preparation 

 of the land for the planting of sugar-cane is not great, often 

 not more than three or four months. On some of the larger 

 estates, however, a certain proportion of the land is rested for 

 nine to twelve months. When the term of fallow is for .-such 

 a period the importance of using a quickly growing dressing is 

 not so great. It is evident, however, that if such a practice 

 were to be adopted in all cases, it would be a great factor in 

 minimizing the severity of the attacks of pests of the sugar- 

 cane, probably more especially those of a fungoid nature, 

 which are of vital importance. 



A point that is .sometimes not taken into account is that 

 the quantity of green material yielded by a dressing does not 

 represent the amount of solid material returned to the soil. 

 It is well known that the greater part of the weight of 

 a plant is made up of water. The following figures, which 

 give an approximate idea as to the amount of moisture 

 contained in some plants used for this purpose, may therefore 

 be of interest : — 



Loss after drying in air, 

 per cent. 

 Woolly pyrol 7G-3 



Barbuda bean 73'5 



Ground nut 7I"1 



Lima beam 73*5 



Soy bean 3r6 



All the above, with the exception of the soy bean, were 

 wt/ighed five days after cutting, the .soy bean being weighed 

 seven days afterwards. The great difference between the 

 amount of water contained in the soy bean, when compared 

 with that of the others, is explained bj' the numerous seeds 

 formed by this plant. 



It was thought that it might be interesting if the lengths 

 of the roots of the different plants used for green dressings 

 were taken. It is known that the roots of plants which use 

 different layers of soil for the obtaining of their plant food 



flourish better when grown together than when grown with 

 those which utilize the same layer for this purpose; it is thus 

 ])robable that deeply rooting plants would be of value in 

 placing at the disposal of the subsequent crop, plant food in 

 an assimilable form, which otherwise would not be within its 

 reach. This would perhaps be the case when the subsequent 

 crop is one similar to the sugar-cane, most of the roots of 

 which form a dense mass in the top -1 or 5 inches of soil. 



Measurements of the main roots which were actually 

 made gave the following results: — • 



Days after Length of root, 



planting. inches. 



Java Crotalaria {Crutnlarin 



striata) 240 19^ 



Barbuda bean (Phant'o/us 



luwitua) 66 16 



Qo'vrpea, {Viynn ung-uiculata) 80 \Z\ 



Lima bean {I'/mseolu.t lunatii.'i) 66 13 



Woolly pyrol (P/iaseolus Mungo) 66 11^ 



Ciround nut {Arachi!< hyjmjani) 66 8| 



The approximate areas of land in different green dress- 

 ings in Antigua, during 1909, are given in the following 

 table. The larger figures must not be taken as representing 

 the crops most popular in Antigua for the purpose in 

 question, but as showing to a great extent the amount of 

 seed available for planting purposes, at the time of sowing. 

 This is especially so in the case of the soy bean. 



Area, acres. 

 I'igeon pea {Cajanus iiidii-us) 199 



Soy bean {(ilycine hispida) 138J 



Cowpea {Viyna unguiculata) 132 



Barbuda bean (Phaseolus luiiatus) 112 



A\'oolly pyrol (I'/iaseolus ilungo) 42 



Wina {Ttnimnus jxirvijlora) 4 



^Miscellaneous leguminous plants 7 



,, non-leguminous plants 7J 



Total 641f 



DOMINICA. 



Early in May of this year, a few seeds of Canavalia 

 '/ladiata were received at the Agricultural School, to be 

 grown for comparison with the horse bean, C. ensiforiuis. 



The seeds in both cases were sown in rows on the flat, 

 4 feet apart each way. The horse beans germinated in six 

 days; C. <jladi<ita took twelve days. A few weeks later, the 

 difference in habit of growth was very marked: the horse 

 beans were very compact, about 8 inches high, bearing seven 

 large compound leaves to every 1 2 inches of stem. C. [/ladi- 

 ata, on the other hand, had long twining stems bearing 

 two leaves on 3 feet of stem, the leaves being nuich smaller 

 than those of the horse bean. 



Ten weeks after sowing, the horse bean was in flower, and 

 five of the best plants were uprooted and carefully weighed. 

 They were then put to dry in the shade for three weeks and 

 again weighed; at this time the plants of C. ^/ladiata were 

 creeping slowly, and giving growth to many lateral shoots. 



Four weeks later, the last-named plants were in liowerj 

 they had an average spread of 3 feet. Five of the best 

 plants were uprooted, weighed, dried and reweighed. 



There was no difference in the weight of each set of five 

 plants. They both weighed, when green, 10 lb. — an average 

 of 2 H). per plant, and both lost on drying, 6 ft). 



It would appear that if the green dressing is required as 

 a catch crop, the horse bean is more useful. If, however, 

 the time the crop occupies the land is of little or no conse- 

 quence, and if the chief object is to keep down weeds, then 

 C. (jladiata would probably be found to be serviceable. 



