Vol. IX. No. 21.3. 



THE AGKICULTUKAL NEWS. 



205 



STUDENTS' CORNER. 



JULY. 



First Pkuiod. 

 Seasonal Notes. 



The end of .June, or tlie lieginiiiiig of .July, is a suitable 

 time for sowing J.cngal beans as a green dressing crop, or as 

 a covering for lime trees, with the object of lessening the 

 number of scale insects on those which are badly infested. 

 Why is the Bengal bean, together with many other plants of 

 the same kind, expecially suitable for the purpose of pro- 

 ducing green dressings? What are the special uses of such 

 dressings, in the soil? Tin you know of any. way in which 

 similar provision is made in nature for plants that are to 

 occupy the soil? Examine carefullj", from time to time, lime 

 trees badly infested with scale insects, and over which Bengal 

 beans are growing, for the purpose of getting indications, if 

 possible, of the way, or ways, in which the Bengal beans are 

 helping to effect a reduction in the numbers of the .scale insects. 

 In order to give assistance in the making of such observations, 

 the statement is made here that this action of the beans may 

 or may not be due, wholly or partly to one of the following 

 causes: (1) the improvement of the conditions under which 

 the fungi attacking the scale insects may grow: (2) the pro- 

 tection given to the insects that are parasitic on the scale 

 insects: (,3) the possession of some property by the Bengal 

 bean plant, itself, by which it is enabled to set up condi- 

 tions which make it difficult, or impossible, for the scale 

 insects to exist in its near presence. In giving these, there 

 is no suggestion that the lines of observation should be 

 confined to them. They are presented merely for the purpose 

 of indicating the way in which a subject of inquiry that 

 rccjuires careful investigation may be approached. 



As has been indicated already, a careful watch sliould 

 be maintained for fungi that are living on scale insects, and 

 thus helping to reduce their numbers. U.seful assistance in 

 finding and identifying such fungi is given in an article in 

 the A(/rn-ii/tii>-al A'eivs, Vol. VIII, p. 299. It must be 

 remembered, in reading the descriptions presented there, that 

 the part of the fungus which is most [)lainly seen, and which 

 offers the most definite characters for the [lurpose of identi- 

 fication is the part of ten called the fruiting body. Those who 

 have read carefully the two .series of articles in the A</ri- 

 cultural JVeii's, entitled The Life History of the Fungi and 

 The Chief Groups of Fungi that have appeared in Vol VIII, 

 pp. 251, 267 and 283, and in Vol. IX, pp. 78, 94, 110, 126, 

 142, 158, 174 and 190, will be entirelj' cognizant of the fact 

 that this fruiting body is merely the spore-producing part of 

 the fungus, and not the fungus itself. The real work of 

 feeding on the attacked scale insects is being done by the 

 vegetative part of the fungus, or mycelium, which is often 

 not easily seen by the unaided eye: the fruiting bod}- 

 possesses importance in that it bears the spores, which 

 become scattered abroad, and thus spread the fungus. This 

 ditticulty of seeing the mycelium must have account taken 

 of it when attempts are being made to find out whether, 

 or not, the scale insects are being attacked by fungi. 

 It may be, that, although the fruiting body cannot be found, 

 the fungus is present and doing some of its best work in 

 destroying the scale insects. The fruiting bodies are, as 

 a matter of fact, a sign, rather, that the work of the fungus 

 is nearly done, for they are always most likely to arise, when 

 the food- supply is getting siiiall, or when the conditions are 

 unfavourable to the fungus in some other way. 



Cotton seed, for planting, should be selected carefully, 

 either at the factory where it is bought, or on the estate, 

 where it has been chosen already from the most likely plants. 

 In making this .selection, the following kinds of seed will be 

 rejected: (I) all those which have not grown to their full 

 size and proper shape (that is, aborted seeds): (2) all those 

 which are smooth and black, and not in'possession of a tuft 

 of green fuzz. .See Island cotton seeds that do not possess 

 this fuzz, to a greater or smaller extent, produce plants that 

 bear seeds having lint of inferior quality. 



Questions for Candidates. 



PRELIMINARY QUESTIONS. 



(1) Give some explanation of the fact that, while the 

 leaves of most plants are green, their flowers are of some 

 other colour. 



(2) How would you perform seed selection for corn 

 planting ? 



(3) Give an account of the methods for conserving soil 

 moisture in your district. 



INTERMEDIATE QUESTIONS. 



(1) How is the deterioration of cane-sugar, on storage, 

 brought about? What precautions would obviate this ( 



(2) Which is the more economical: a basic slag contain- 

 ing 14 per cent. phos])horic acid, and costing £4 per ton, or 

 one containing 45 per cent, of phosphoric aaid and costing 

 £5 per ton. 



(3) Give an account of the use of chlorophyll in plants. 

 What is chlorosis ? 



THE MAINTENANCE OF THE PRODUCT- 

 IVITY OF SOILS. 



The Bureau of Plant Industry of the United States 

 Department of Agriculture has issued recently, as its 

 fifty-seventh bulletin, A Study of Crop Yields and 

 Soil (.'ompositlon in Relation to Soil Productii^ity. 

 This contains the results of investigations conducted 

 with a large number of the soils of Europe and the 

 Uniteil States, and the following summary of these is 

 given at the end of the bulletin: — 



A careful study of the data which have been presented 

 appears to justify two conclusions. 



(1) That the productivity of the newer agricultural soils 

 of the United States and of the older agricultural soils of 

 Europe, taken as a whole and for a nation, are not declining, 

 as is popularly supposed. Individual farms deteriorate, 

 and soils wear out, as they have always done, but, as 

 a whole, it seems probable that we are producing more crops 

 per acre than formerly. This is undoubtedly due to many 

 factors: to better and more intelligent cultivation, more and 

 better .systems of rotation of crop.s, and, in later years, to 

 intelligent use of fertilizers — three methods of control in the 

 hands of every individual farmer. In addition, we must 

 recognize the increase in farm animals and stock, the improve- 

 ment in .seed by selection and breeding, and the increasing 

 density in population, which is forcing attention to more 

 intensive methods. 



(2) That, so far as our information goes, there is appar- 

 ently no significant ditt'erence at the present time between 

 the composition of the older agricultural .soils of Europe and 

 the newer agricultural soils of the United States with re.spect 

 to potash, phosphoric acid, lime and magnesia. 



