338 



THE AGRICULTURAL NEWS. 



OcToiiEU 24, 19U. 



FRUIT AND FRUIT TREES. 



THE MANURING OF BANANAS. 



On tliis important subject, tlie Qiieeyisland A</ricultuml 

 Journal for August 1914, has an article from the pen of 

 Mr. J. C Briinnicli, F.I C, Chemist to the Department of 

 Agriculture, Queensland. Tlie writer points (3ut that in 

 most publications on lianana culture, very little space is 

 given to the ijuestion of nianru-es, and that very few experi- 

 ments in tliis line have been reported. In tlie Aiiriculturnl 

 Newsoi August 191-t, there was a note on some experiments 

 made in manuring bananas also in Queen.sland. 



When one considers that until recent years the culture 

 of the banana in all banana-growing countries was of 

 the most reckless nature — large areas of land under bananas 

 being simply cropped for years and years, until owing to 

 complete .soil exhaustion the crop became unprofitable — 

 the want of any reliable information as to the value of 

 manuring, or as to the most suitable manure, is not surpris- 

 ing. The fact that in Qiieenslaiid the yearly crop of 

 4,500,000 bunches in 1898 had dropped to a little more 

 than 1,000,000 in the last few years, led the Department of 

 Agriculture there to investigate the matter, and to institute 

 a series of experiments under the direction of Mr. Brunnich, 

 the results of which he gives in the paper referred to aliove. 



In the first place he thinks that the manurial experi- 

 ments carried out show beyond doubt that exhausted banana 

 lands, provided the soil be in good physical conditiijn and 

 contains a fair amount of humus, may be made by cultivation 

 and the application of heavy dressings of artificial fertilizers, 

 to produce crops equal to those from virgin lands. 



After stating that from . all the evidence oljtainable, 

 there can be no doubt liut that bananas require a well- 

 drained, loamy soil, containing a fair amount of humus, and 

 good quantities of potash, lime and phosphoric acid in 

 a readily available form, he notes some evidence as to 

 fertilizers in other places. 



In Tenerift'e the banana culture has made great progress, 

 due to irrigation. The land is also heavily manured with 

 stable compost and guano. 



Potash manures especially have given good results in 

 India. 



Experiments in Panama liave proved the great benefits 

 of liming soil in the culti\ation of bananas. Tliis is als(3 

 proved Viy the experiments in Queensland. 



Pliosphorie acid is of great value, but more particularly 

 potasli must be supplied in liberal amounts. A number of 

 experiments carried out in Fiji and in Queensland by J. il. 

 Hattrick fully l)ear this out, and he states: 'that for every Is. 

 spent on potasli, the phvnter received 6s. in return.' 



A good deal of humus is returned to the soil by tlie 

 stalks of the plant when the fruit has been reaped. The 

 plan of cutting the stalk into pieces is better than leaving it 

 to rot whole. The growing of green crops of legumin(jus 

 plants is also strongly to be recommended, so long as the 

 cover crop is not allowed to grow too near tii the banana 

 stools, and so rob tlieni of necessary moisture. 



Sender's statement 'tliat no otlier cultivated plant 

 exhausts the soil to such an extent as liananas,' is borne out 

 by the comparison of soils from virgin land and exhausted 

 banana land. The analyses sliow tliat the total amount of 

 potasli present is reduced by nearly one-lialf, and the amount 

 of available potash remaining is less than one-tenth of that 

 found originally. Now, by an investigation of the actual 

 food requirements of the banana plant, it has been ascer- 



tained that a fair crop of bananas remo\es from the ground 

 per acre 123 lb. of potash, 12i lb. of phosphoric acitl, and 

 43'7 tti. of nitrogen, whereas the stalks left on the ground 

 contain 1-50 lb. of potash, (i lb. of phosphoric acid, and 

 41-4 lb. of nitrogen. Evidently, therefore. 273 lb. of potasli, 

 or about a cwt. of sulphate of potash, per acre, must 

 be available to the banana plant in a readily available 

 form to produce its next crop in a few months. 



After some preliminary experiments the standard fer- 

 tilizer was fixed per acre at 160 ft. of potash (applied as 

 320 ft. potassium sulphate), 80 ft. of phospliorio acid (applied 

 as 470 ft. superphosphate), and 40 ft. of nitrogen (applied a-s 

 290 ft. dried blood, or 290 ft. nitrate of lime, or 200 ft. 

 ammonium sulphate). This was applied twice a year to 

 normal crops, and in double quantities to 'rops on exhausted 

 lands. Of course a similar plot was left without manure. The 

 land was first ploughed shallow, and all weeds removed. ()ne 

 month before planting it was ploughed deeply down to 

 a depth of 18 to 24 'Jiiches. Cavendish bananas were used, 

 planted 1 2 feet apart, giving 302 stools to the acre. The 

 first lot of manure was applied in the plant hole, well mixed 

 with the soil, and subsequent applications were made as top 

 dressings, and slightly hoed under. It might be well, 

 liowever, in old banana plantations, to apply a part of the 

 fertilizer in holes made with a crow-bar to a depth of 18 to 

 24 inches round the stool, at a distance of from 3 to b feet, 

 and the rest as a top dresssing. 



The cost of this heavy application nf artificial fertilizers 

 is very great, but the results justify it, at least in Queens- 

 land. The average yield for three years of plots treated with 

 the standard fertilizer was 3,03-'i dozens of bananas per acre, 

 at a value of, say, £38, the fertilizer costing annually about 

 £12 10s. In the experiments with double the amount of 

 fertilizer, the average was 4,330 dozen, at a value of £54, 

 and at a cost of £25. 



Near this experimental block of land, similar manurial 

 experiments were carried out liy the head teacher of the State 

 School, with even more striking results as to the value of the 

 standard fertilizer. His unmanured land gave a crop worth 

 £28 lis. M. per acre; that treated with the standard fertilizer 

 yielded £67 2s. M. at a cost of £12 6s. 6d. while that 

 treated with the double dose yielded £55 15s. id. at double 

 the cost. It may be mentioned that this experiment is 

 referred to in the chapter of fertilizers, in 'The Banana', by 

 W. Fawcett, B.Sc, who also refers appreciatively to the work 

 of the author, whose article is under review. 



In conclusion it is stated that the soil after such treat- 

 ment is improved both in its physical and chemical condition. 

 The application of these (irinciples may well lead to the 

 lirofitable replanting of banana lands, abandoned as exhausted 



THE CULTIVATION OF GROUND NUTS. 



As a staple crop for exportation, the groun<l nut 

 (Arachi.1 hyjw/'fa) has made great advance in the last four 

 years in Rhodesia, and very interesting information as regards 

 this crop is contained in an article in tlie Rhudesia Agricul- 

 tural Journal for Aiigust 1914. 



The writer, Mr. H, Godfrey ]Muudy,F.L.S..}ioints out that 

 the advance in the po]iulai-ity of this crop among Rhodesian 

 planters is due, to a great extent, to the introduction by the 

 Department of Agriculture of sui)erior \arieties. In the 

 West Indies, in tho-iie islands where the soil seems suited 

 to the plant, as in St. Kitts and Montserrat, the Imperial 

 Department of Agricultuie has also been experimenting with 

 superior varieties imported 



