ON THE LAND.

New Zealand Herald, Volume XLV, Issue 13701, 18 March 1908, Page 3

ON THE LAND.

PLANT PATHOLOGY. Tiik nil';!, of making a, plant resident ** disease by supplying it with the chemical constituents necessary to its healthy condilion, in a form that is easily assimilated, i* as logical as the idea of supplying propyl? food to animals or men. If all the substances necessary to the. fullest development of a plant or tree are- present in tho soil in such form as to be readily assimilated by tho root system such plants or frees are immune against the attacks of fungoid pest« or the. lower forms of parasitic insects, audi less likely to ho affected than if they are deficient even in one constituent. Chlorosis, ' as all students of vegetable physiology are aware, is a yellowish colour in the ; chlorophyll or what- should bo the . green colour in tho leaves of plants, arid is duo to . unhealthy conditions, or to lack of proper plant food. The most important; constituents of plant life are phosphoric acid. iron, and nitrogen, the most difficult of "which to supply is iron, but in some eases it would bo found that not only is one or ; more food constituent missing, but the whole! chemistry of tlio plant was defective. The throe most necessary constituents for the healthy development of plants are nitrogen, potash, and phosphoric acid, and after" these come linn? and iron. livery agricultural chemist knows the effects' caused by the absence of even one of these constituents, but in a general way the farmer who has not studied the scientific side of agriculture! is unaware- of the actual condition of his soil; and it is only by noticing the failure of his crops through disease, that ha realises that anything is wrong. Then, instead of turning his attention to tho soil, ho satisfies himself with tho idea that tlia crops are suffering from some pest, or thafi tho climate has changed, or that tho Government is to blame. Many may .say that there is plenty of. iron in the soil for tho wants of all vegetable growth, and that may be; but it does not follow that, there is a normal quantity in the plant, iron in some forms is quite unassimilable; in others it is noxious to the plant. Then some plants have a distinct affinity for iron, while others can only assimilate it in small quantities. Further, wo cannot always consider these constituents in their raw state. It. has been proved by analysis that sugar-cane suffering from rust is deficient in silica on tho outer sheath. One wilL naturally ask, "How is it possible for the plant to assimilate such an insoluble substance as silica?" The ■ answer is, by keeping a good supply of humus ia tho soil, as it. is tho humic acid of tne humus that dissolves the silica, and! then tho plant; is able to take it up by tho roots iu a soluble form. It is important to notice that the innumerable fungoid growths that attack plant life contain no iron, and it has been proved in some cases that\a solution of iron will destroy these fungoid growths. As it is art axiom that no form of life can live for long on a food that is foreign to its own, it will be seen that the presence of iron in a plant would make it difficult for the lower fungoida to exist upon itor they could! not exist 'so ling as on plant food containing a normal chemical compospition, than ib seems likely that these fungoid growths will find more congenial food on chlorotic vegetable growth than on plant food containing & normal chlorophyll. Besides, wo know that tho juices of chlorotic plants are a (suitable food for many parasitic growths. We also know that other plants of the same species are immune to the same parasites. Hence it is not unlikely that the juices of tbo> normal plant act as poison to the parasites. No doubt there ar& those who ridicule the use of iron as a fertiliser, but that will not alter the fact that the percentage of iron iuj all e:s-"S varies considerably. For instance, in the potato, it ranges between g audi .04; in wheat between 3.3 and a trace;! and in oats between's.l and .1; with the important fact that tho potato ' containing the lew percentage was so diseased that it was unfit for food cither for man or beast. Fruit trees are greatly improved by a supply of iron and its manner of absorption, This is very easily explained by tho fad that it is through the chlorophyll tho plant takes up the carbon-dioxide from tho air, and this carbon is first turned into starch and then into sugar. From this it follows as a natural, corollary that as tho chlorophyll ranges between the normal and chlcw rotie so will the percentage of carbon taken, up vary, and as tho carbon varies so must the sugar, assuming that the rest of the chemistry of the plant is normal, ENGLISH FOOD IMPORTS, An extract' Steal tho annual compilation oS British imports and exports of animal food in? 1907 makes interesting reading. The esthnaW ed dead weight of cattle was 2,884,70&cwt5, and that of sheep was 55,500ewt, making a to., tal dead weight of 2,941,206cwt. Adding 19,458,098cwt of dead meat of all kinds, we have a total of 22,39& > 304cwt. This quantity has been exceeded twice only, namely* in 1906, where tlio total was 22,768,785cwt, and in 1905 when it was 22,4088810wt. Turning to values, that of live meat import* is £8,273,6-0, and that of' dead meat is £43,643,100. The value of dairy produce imported is £33,181,254. Adding for lard and eggs, we have a total of £96,724,065, for gross imports of animal food. Deducting £5,877,500 for exports, the net. amount is £92,846.565. This was exceeded only in 1902, when the net total was £95,209,196. For no earlier year was it as much aa £90,000,000. TUB PRICE OF WOOL. From the wool tables of tho Yorkshire Observer it appears that the average prices' ot English wool in 1907 were not nearly as' good as in 1906. Lincoln hog wool comes out at 12?-d per lb, and wether wool at Hid, as compared with 14id and 12|d for 1906. All other classes of English wool fell iu the course of tho year. Half-bred wool, for example, averaged barely 12d per lb in December, whereas it had been a minute: fraction under 14d in March. No year's average is given for any class of colonial wool, but only the price at the end of the' year, which was from id to id less than at the cad of 1906. Port Philip grease, is pud at 13d per lb, against 13id for 1906; Adelaide grease, at 9d, against 9|d; Cape* eastern average fleece, at lOd, against 10|d;j and Buenos Ayres at 6id, against bid. BREVITIES. Pure cold water is as good a wash as can be made for a horse with a sore back. Bathe it freely every time the saddle isi taken off. Graingrowera have learned that growing wheat continuously on the same land, burning the straw, and using light seed is nob conducive to large yields. Breeding from immature animals has a tendency to weaken the constitutions, and a weak constitutioued animal will contract disease mere readily than a strong one. It is a capital tiling, for chickens to give them no:Mo tea. This is made by boiling I stinging nettles, and giving the birds the j liquid in which they have been boiled. Rain water is the best for flowers, bui as this is not always available amateur gar-i doners should remember that hard watos is softened by tho action of sun and air. It is a. well-known fact that a good dairy, cow has tho -producing habit so firmly ! fixed that it is difficult to feed her in a way ' to make her lav 011 fat white she is giving ! mi!k: i The men who are studying and adopting ; modern methods and modern equipment; j lire crowding out the farmer who still goes ! on in tlio way he learned from his grandfather. I Owners of stallions in England are roalis- ! liif than in order to secure the King's preI miums of £150 each—2B of which aro offered—the animals exhibited must be of j very irood quality.