Vol. XVII. No. 41.5. 



THE AGRICULTURAL NEWS. 



83 



to produce far greater crops than their aucEstors. 

 St.udies which lead to such results can best be carried 

 on in botanic gardens, where there ought to be found 

 a greater amount of material and more scientific appli- 

 ances than are possible in most private establishments. 



Besides the scientific function of botanic gardens 

 there is their educational aspect. In an article on this 

 subject in Scimce, June 20, IMIT, it is well remarked 

 that the notion that knowledge can be acquired from 

 books is too prevalent; the idea that one can read about 

 nature, and thus acquire knowledge o/ nature is as mis- 

 leading as to suppose that one can acquire knowledge of 

 buisness byreading aViout business. We must distinguish 

 between information and knowledge. Information may 

 be obtained by reading, but knowledge can only be 

 acquired by contact with and experience of realities. 

 Hence botanic gardens open to the public a source of 

 real knowledge of plants: and there is no more pressing 

 problem to-day than to learn how to grow plants, and 

 how to grow them in increasing quantities and of 

 inci-eased value in eveij possible situation. If made with- 

 out insight into plant nature efforts in this direction 

 pass through a period in which knowledge is acquired 

 through painful I'xpcriencG ver\ often with failure as 

 the ultimate result. 



THE ORIGIN OF THE UBA CANE. 



The L'ba or ^'uba cane is best known as the only 

 variety of sugar cane grown to any large extent in Natal, 

 where, 'although it is not altogether a satisfactory type from 

 a milling point of view, it meets with great favour by ihe 

 planters, and is the only one which has hitherto stood 

 successfully the ravages of frost and drought, as well as 

 the various fungoid and animal pests met with in the sub- 

 tropical area.'* of that province.' 



The variety has several times been introduced into the 

 West Indies, and though it is hopelessly inferior to the West 

 Indian types, it has been found capable of useful application 

 in Trinidad and Antigua on soils physically unsuitable for 

 ordinary cane. 



The must likely theorj- regarding the origin of this 

 cane is that it was brought to Natal by a former Gover- 

 nor when returning from a voyage to India in 1884-5. 

 Dr. C A. Barber contributes a note on this point to the 

 Iiiieriiaiioiial Sugar [niiritni for January 1918. Having 

 grown Uba cane from Natal for a considerable number of 

 years alongside Indian varieties, Dr. i'.arber feels no doubt 

 whatever that it is a Gamui cane of the PunsaJii group of 

 Indian cane, a series which is grown in many places from 

 Assam to the Punjab, a distance of over 1,200 miles along 

 the Himalayas. The GaiiDii, i:ancs a-: a class are intermediate 

 between the thick tropical c:.nos and the slender indigenous 

 Indians one. The idea that the l'ba is an Indian cane is 

 therefore definitely confirmed. 



Dr. Barber has inet with a difficulty in the name. No- 

 word bearing any likely relation to uba ha.s been tound ia 

 any Indian language. But a recent visit to Burmi has 

 supplied a possible explanation. Noticing a .Moulmein cane 

 that was indistinguishable from Uba the question was asked 

 if there was any Hiumese word of that sound. The reply was 

 'Oh, j-es, of course, "uba" means "take it ' '. It is the 

 usual reply of the polite Burman (who will give yoa 

 anything) to any request made on going round his fields. So 

 that the suggestion follows that the Natal Governor, leaving 

 from a r^urtnese port, as was likely at that time, asked for 

 specimens of this cane, and mistook the inevitable reply for 

 its name. 



Dr. Barber further remarks that he has often wondered 

 at its being grown in Natal and Queensland. It is true that 

 it is very resistant to salt in the soil, moderately fibrous, very 

 luxuriant, and tillers well. It requires little water, and ig 

 much easier to grow on poor land than thicker canes. Oq 

 the other hand, it has a low sucrose content, and is subject to 

 red rot. It is not reckoned at all as among the best Indian 

 varieties. The Madras cane-breeding station has raised 

 a number of thin canes which possess the hardy qualities of 

 the group combined with a good sucrose content, and plants of 

 these are offered to the Natal growers for trial, with a good 

 prospect of their being found superior to the present stock. 



HUMUS CONTENT OF THE SOIL, AND 



FERTILITY. 



Experiments conducted at Purdue University using a. 

 surface clay soil very deficient in organic matter and differeot 

 organic manures, undertaken to prove whether the humus 

 content of the soil is a guide to fertility, are reported ia 

 Sail Science, 3 (1917). 



The results of the vegetation and humiCcation tests 

 seem to show that wherever there is rapid humification of 

 manure, the growth of the plant is greatly stimulated, 

 indicating 'that the decay of organic matter is desirable in 

 plant growth and not just its mere presence.' This w,*8 

 especially noticeable when green manures were rol'ed under 

 and limed, as compared with discing or mixing the manures 

 uniformly with the soil. 



Certain of the manures seemed to be as soluble in a 4-per 

 cent, ammonia sulution when just mixed with the soil as after 

 humification This was found to be true with alfalfa and steer 

 and somewhat with cow manures. Horse manure seemed to 

 humify slowly, and its plant food was largely unavail- 

 able to corn during the first year, but the humification 

 and vegetation tests showed it becomes more available ia 

 the second year. It was possible to increase the rate of 

 humification of horse manure in the first year by adding 

 dolomitic limestone, which resulted in a greater yield of 

 corn than where humification had not taken place. 



The organic residues left in the soil from manure 

 treatment were not very effective during the second year in 

 producing a growth of corn, probably because the most 

 available or valuable complexes had disappeared in the fir^t; 

 year. There is no apparent relationship between the 

 percentage of ash in humus and iho growth of corn. The- 

 humification and vegetation tests seemed to indicate 

 a rather close relationship between the amount of hum'is and' 

 the growth of corn. 



