276 



THE TROPICAL AGRICULTURIST. 



[OCTOllER I, 1882. 



dustaiiis, under the name oi sliorosheyre shag 'B. , Idliee 



led sag H. 



Unilt-r tlie head "climate" we are told: — 



This plant is an annual, and prefers a temperate 

 climate. Being hardy it will succeed even in the 

 frigid zone (Biiron Mueller). Fiost does no in- 

 jury if irriga'.ed, nor any quantity of rain : westerly 

 winds of Upper India favours the he.-vlthy growth, 

 and long continued cloudy weather favours abhis, a 

 small Hy (H. mdhoo), which attacks this and all other 

 plants of N. 0. crucifrrece, more or less ; and within a few 

 days, nay, a few hours, generates in myriads, feeds 

 on all parts of the plant, especially the flowers, pods 

 and tender leaves, and ultimately destroys the crop 

 wholesale. There is no means of extirpation of this 

 formidable pest. 



So that we can grow nothing which has not its 

 fungoid or in-ect enemies, and it might be a serious 

 question whether in growing r<ipe we might not be 

 introducing a fresh insect foe to our regular cultiure. 

 To quote again :— 



Time of Sowing. — No time should be lost to sow 

 the seed just after the thorough cessation of the rains — 

 miildle to end of September ; and, if possible, a fort- 

 night earlier- Later sowing exposes the crop to attacks 

 from the abbis. 



Geographical Distribution.— A native of various 

 parts of Europe (Baron Mueller): also indigenous to 

 Northern India ; ascending as high as 15,000 feet in the 

 Himalayan mountiius (Sir W. Jackson Hooker). 



Soil. — The rape, like all other plants of the cab- 

 bage tribe, requires a very rich and heavy soil. 

 ArgiUacous soU of the r.alcarcoics order, 

 epecies not too poor in sand and liumiis. 



of 



BoO : — 

 Clay... 

 Lime 

 Humus 



hand 



and of the 

 Composition 



70 

 5 

 4 



21 



lUO 



parts. 



Chemistry of the Rape Plant.— The produce of 

 one acre— seed, pericarp, leaves, and stem (vide licad- 

 ivg yield) has : — 



Seed... ■■• 26-'Tl461h. of inorganic matter 



Do ... ... 5,844'541 ,, ,, organic „ 



Pericarp, leaves, and 



6,109 -(iSV 



stem . 

 Do. .. 



673 591 

 14,600-595 



of inorganic matter. 

 , „ organic ,, 



15,274 186 lb. 

 Chemical analyses of the inorganic portions of the 



above : — 



Seeci. 



Potash 



Soda 



Chloride of sodium. 



Lime 



nesia 

 Oxi^e of iron 

 Phosphoric acid 

 Sulphuric acid 

 Carbonic acid 

 Silica 



lb. 



43-483 



1.325 



2-651 



22-007 



23-333 



4772 



85-377 



, 14-317 



, 14-848 



. 53 029 



Leaves, stem, and 



pericarp. 



lb. 



113-836 



72074 



16-166 



142 SOI 



20-207 



8-756 



38 '394 



26-270 



155-599 



79-483 



Total 265-142 673-58(3 



From thf above tabl?, thr kinds and quantities of 

 elementary substam-e-j required are redundant, whicli 

 the soil on winch the plaut is to be raised mu~t con- 

 tain or must bo supplied as manure, otherwise the plant 

 will not grow, tinurish, and yield according to the 

 e-pectatiuus of the cultivator. 



More places of decimals have not been given, as the 

 differt nee of a grain or so in each elementary substance 

 in an acre, is immaterial for the application of m.inurc. 

 Where the decimal ligurcs are less than -.500, half a 

 pounrl, and more Ihun -500, one pound, sUouhl be 

 computed for munure. 



Eape plant belongs to the lime orde~. — (Lie''ig), 

 It will be seen that rape, allowed to seed, which 

 we do not contemplate, takes from the soil large 

 quantities nf potash, lime, and phos[ihoric acd. To 

 allow the plant to ripen its seed, therefore, would 

 seem to be, for the purpose we liavo in view, a fatal 

 mistake. It ought tn be buried in the sod when 

 green, and we should think caustic lime ought to be 

 added to ha.sten deconipositiou and prevent the form- 

 ation of fungi. About manure for rape, ploughing and 

 water channels for irrigation, we need not quote ; nor 

 need we cultivate in "ridges.'' But as the Indian 

 cultivation is for ridges with plauts a fnot apart, we 

 should prob.ably, tor thick, broadcust sowing us 3 double, 

 or treble the ludiau allowance of 1 seer or as we say in 

 Ceylon measure {.}., part of a bushel) of seed per acre. 

 Care should be taken to obtain clean, well sifted seed. 

 Hand-sowing will suffice for estate experimen's, but for 

 extensive cniture of this and other plants the Indian 

 writer recommends ilie "beet-sowing machine" re- 

 cently invented in France. Cultivated for .seed the 

 maximum yield obtained from rape by the writer of 

 the article was : — 



Seed ... ... ... (i,I09 11... 



Pericarp ... ... .. 3,054 ,, 



Leaves and stem ... ... 12,219 ,, 



Total ... 21,382 lb. 



The seed being tlius somewhat under one-third of the 

 whole. Sown thickly to be turned into the soil before 

 the appearance of floweis, we should think 20,000 lb 

 per acre could be calculateil on. Lime added at the 

 rate of at least 5 cwt. per acre would we should think 

 be beneficial. 



It is possible that from its pungency, mustard may 

 be pieferable, as inimical to insects instead of inviting 

 their attacks. We do not suppose there need be any 

 difference in the mode of cultivation - sown broad- 

 cast over forked soil. As in the c:ise of rape, we ought 

 probably to obtain seed of 1 he Indian vaiiety, which Is 

 very largely grown on the opposite coutineut for 

 lighting oil. The Indian mustard is distinguished as 

 Sinapis ramosa. The "hill mustard," which is said 

 to be a different genu^, Bunia.^, tnight suit our higher 

 altitudes. Seed of each oouhl be obtained for experi- 

 ments. Dr. Trimen ouuld obtain seed through 

 Dr. King of llowrah or Mr. Buck of the Indian 

 Agiicultural Department. 



NITEIFICATION OF AMMONIA AND LOSS OF 

 NITRATES : PIGS ON COFFEE ESTATES. 

 (2'o the. Editor of the Ceylon Obicrver.) . 



Udagama, August 18. 

 J'KAP. Sir. — I niu-'t I hank you for affording your 

 space to so h I'g a letter as my last in your i8^ue 

 of the 5th ins ::nt, and will not fuitlier ask to oc- 

 cui'V it now in attempting to correct a slight mix- 

 \\vi u|i of stop.s and capital letters — attnbutahlo 

 1 am free to admit to faulty writing — as my mean- 

 ing under all impoitant headings stands unaltered. 

 But I Honld wish to add that 1 h-td overlooked 

 suli.sei|nent letters in the Fhld commeniing on Mr. 

 WarinatiiuV led ores, and tliat appear in your August 

 numiiei of the 'fnijiirii/ Agriculturist — though I do not 

 see that they i'fford material to do more tluiii perhaps 

 S'linewl a' modify my conclusion. It is true that Messrs. 

 Lawes and Gilberi in their " practical conclusions " tell 

 us "the nitrogenous eompounds of the soil itself 



