534 



as -well-establislietl varieties or even subspecies, by otbers as distinct species. The 

 kinrls referred to the remaining group may possibly be different strains of a hybrid 

 of these two typi-s. These groups may, therefore, for convenience, be called the 

 long staple, the short staple, and the Rio Grande. The first will include strains or 

 subvarieties giving about 31 per cent of lint or under, its normal being about 30 

 per cent; the second, those giving about 32 to 3^1 per cent, its normal being about 

 32 per cent; and the third, those giving about 30 per cent or upwards, its normal 

 being about 374 P^r cent. 



The long staple group, with the lowest percentage of lint, shows the smallest 

 average yield of lint. 



The short staple group, with a medium percentage of lint, shows a somewhat 

 better average yield of lint than the long staple. 



The Rio Grande group, with the highest iiercentage of lint, shows the higliest 

 average yield of lint. * * *■ 



It seems to be established that thorough cultivation and careful selection of seed 

 for a number of years will improve the productiveness of any variety or increase its 

 percentage of lint. The limits of such possible improvement have not as yet been 

 determined. 



FertiUzcru for cotton (pp. 30-91). — The studies in this direction 

 included specnal nitrogen, j)hosplioric acid, and potash experiments; 

 experiments as to the amounts of these ingredients required; as to 

 the forms in which tliey are best api)lied; the best time for applying 

 nitrate of soda; methods of applying fertilizers (drilling r*'. sowing broad- 

 cast) ; and tests with marl and coi)peras. The results at the two farms 

 for 3 years seem to the author to warrant the following general con- 

 clusions: 



(1) Cotton requires nitrogtn, phosphoric acid, and potash. 



(2) Of the three, phosphoric acid is relatively tiie most importantnnd controls the 

 action of the other two. It can be used alone with some advantage to the crop, but 

 much more etlectively in connection witli jiotash and nitrogen. 



(3) Nitrogen is relatively more imjiortant than potash. It can be advanta- 

 geously used only in combination with phosphoric acid or phosphoric acid and 

 potash. 



(4) Potash, like nitrogen, is of little value to cotton when applied separately; it 

 must be combined with the otlier constituents. 



(5) Expressed in terms of the [recent] analyses, the proportion and amounts of 

 nitrogen, phosphoric aeiil, and potash r»'(iuire<l are as follows : Between } and 1 nitro' 

 gen, about 4^^ phosphoric acid, between ^ and \ potash. * * * In other words, 

 the required i)roi»ortion is: 1 nitrogen, 2^ i)hosphoric acid, and } potash; and the 

 amounts called for by a crop yielding 300 jjounds of lint per acre .ire, nitrogen 20 

 jiounds. phosjihoric acid 50 ])onnds, ])otasli 1.') ])ouiuls. 



(6) The amount of pliosphoric acid determines the amount of nitrogen and potash. 

 "With a given amount of t lie lirst, only certain amounts of the two last can be pofita- 

 bly used. 



(7) The amount of iihosjilioric acid and ])roportionate amounts of nitrogen and 

 Jiotash can not l)e iiuh linitely increased witli the ex]>e(tation of oV>taining a corre- 

 P])ouding increase in the crop. Tlie gain in cr<qi does not keej) pace witli increase of 

 fertilizers, and a point is speedily reached beyond which this gain is not sufficient to 

 meet the additional cost of the heavier applications. The soil can not be profitably 

 forced; the a]ipli(ation of fertilizers nuist be regulated by its mechanical as well as 

 chemical condition. 



(8) Potash can be as etlectively supplied by nniriate of potash or kainit as it can by 

 Buljihate of potash. This is o]»posed to the view which regards the chlorides of the 

 two former as injurious, and therefore holds that the higher-iiriccd potash of the 



