AGRICULTURAL SCIENCE.

New Zealand Herald, Volume XLVIII, Issue 14806, 9 October 1911, Page 3

AGRICULTURAL SCIENCE.

PLANT FOOD AND DISEASE, COMBATING FRUIT' PESTS.. There are still many men on the land . priding • themselves on being what they r 7 call practical farmers who ignore or condemn agricultural science, and therefore miss much which is marvellous and beautiful and valuable in life. To this class, of man soil is just soil—good, bad, or indifferent, loam, clay or alluvial. The quantity and quality of its. fertilising; elements; the reason why some crops fait and some succeed are not known. If the farmer had the proper training in agricultural science from his youth up he could possess such knowledge as would make him practically master of his soil, largely independent of seasons, and to a. large extent conqueror of pests and diseases. ; f . : Mr. C. B. Lipman, instructor in soil bacteriology to the University of California, speaking of one phas© of scientific agriculture which plays an important part classes of practical farming, says: We are just beginning to get an insight into the complex and profound reactions which go on in the soil in the preparation of plant food by bacteria, and other microorganisms. The presence of bacteria in soil is essential to plant life. Bacteria are plant cells so small that 200,000 of them would make a row not more than an inch nr ->\ but under favourable conditions they ' miJtiply by dividing themselves with in-< conceivable rapidity. One cell may have 200,000 descendant'? within 24 hours;, They are omnipresent not only in the soil but in the air, the water, and in all plant and animal life. . They are the agents, not only of life, but of decay. They exist in three forms — the round called the * coccus,' the rod shaped called the 'bacillus, and the corkscrew form called the ' spirelium.' " Ihe work of bacteria. in the soil, is 'as yet only imperfectly understood and most of the study given to the subject has been with respect to the bacteria which develop nitrogen and make it available to plants. Ihere are -;wo general - classes of these bacteria, of. which one causes the forma- / tion of ' nitrogenous compounds insoluble in water, and the other changes these compounds into forms available to the plant. , ' The Value of Knowlegde. It is not absolutely necessary that the . : average farmer should study soil organisms tiom the biological point 'of view bnt if he knows generally the conditions • vf.hich are favourable to the beneficial , bacteria, he will • be in : a position to materially affect the productiveness of his ; •soil. Koughly speaking, beneficial bac- : ' teria can thrive only in soil that is free from stagnant water, well cultivated, pos sessing an abundance of humus, and con-> ' taining the usual . essential fertilising -i elements, without injurious alkalis, acids, ■/■/;£■ or poisonous minerals. No doubt in some cases it may be necessary to introduce .'■■■■!• special . bacteria-... for particular crops. Lucerne, for instance, may xieed'lhifl assistance, and probably here and there red clover may bo made to . thrive when ■ its ■ own nitrogen-gathering ' bacteria are supplied to the soil, but averagely, speaking - if the- soil is worked - into good - condition and receives a fair proportion of all-round 'rVi fertilisers the soil organisms" will come - . sooner or later. ",. v v• , ,v',' , .1, What Science la Doing for ; the Farmer. : Science is doing a great deal for the far- v : mer in the way of helping him to combat; ; • insect and: fungoid•• pests: - It has brought chemistry to' bear on these -enemies,- and spraying formulas' now go' a.' long way to- ' ward checking potato and tomato blights, . leaf-curl in peaches, _ codlin' moth in apples . - ' " ?nd pears, and' e\ cry year L adds . new- ' " weapons tor the farmer's use. -- But.spraying, after all, is only a crude way of deal- ■ ing with fungoid diseases and other pests*. u:Prevention is' better ; than cure, and . the . idea should -be to 1 render',' plants and trees immune against disease. For ? some » years.">• we have been arguing. in v these icolumns • that if .the soil is provided with every- - r - thing necessary for the healthy sustenance of vegetable life there will be little or no ' tendency towards disease ,of any kind. As . human beings properly . fed and'■'-living : under thoroughly hygienic- conditions, largely escape the germs and spores and ' .*■ bacilli, which work havoc among the ill- : nourished denizens of slums,: so the plants ; and trees grown in well-drained, wellcultivated soils, and fed with all the ' " elements than go to produce, perfect wood and fruit, will be largely immune against the spores of blights,' and,; possibly against v the attacks of low forms of insect life. : ; r We have ample evidence to show in . all ' - classes of farm crops and farm ] animals that the properly balanced ration, whether bv of fertilisers or. food, makes ; for health, whilst the. ill-nourished specimens in both - classes are prey for every disease or pest that comes along. Doctoring Trees. ; - An ' investigator named Mokrzecki, has. . recently been experimenting : with disease ; >v ■' in trees by means of injections, which is only a way ot doctoring through the veins instead of through.' the mouth or roots. Apple, pear, "and cherry trees were, badly . affected with chlorosis, , and : presented » t.sickly and languishing ' appearance. I :'^He J injected into the trunk of .an apple tree a solution' containing 12 grains of iron ' V sulphate. In ten days there was no trace of chlorosis, and in three weeks the leaves were dark green and perfectly healthy. •He also tried the effects of sulphate ofiron on peaches affected with the, same . disease, but in this case applied it through the roots. The soil for a foot in i depth ' lover the roots was removed, and a solution of iron sulphate in the proportion of ...; |oz to five parts of warm water, was poured in, then the soil was replaced. Mokrzecki obtained satisfactory results in combating gummosis or gumming in peaches arid cherries by injecting into the trunks a solution of one per cent, of salicylic acid. The gumming was stopped, ' the wounds healed up, and all the trees ; • thus treated became healthy and -vigorous. • Prevention is Better Than Cure. : » These experiments are only quoted- to show what possibilities ;there are in the direction ;of * combating . diseases in : trees :r , by means of the sap, but it is-highly, probable that, diseases could have been pre- ( > vented in the first place by supplying the f soil with the class of food necessary - for the health of the tree." Trees and all" other, vegetation require certain wellknown ; elements > for 1 their - sustenance— nitrogen, potash, phosphoric acid, lime/; iron, magnesia," are the main constituents ', j of a fertile soil, and they must be in an available form and in proper proportions. ' , To know what a soil lack,, is knowledge which is - half - the i. battle in producing healthy plants. This knowledge the scientist can give. ■ It is remarkable that considering how important the products of ' the soil, are to man- how little attention has been given in' the "past to the condi- ■ tions under which they are produced. We loso millions of pounds worth of plant crops every year by disease, we lose more " f'P. million pounds by faulty methods of tillage.,,; " And besides , the . losses there are v the. possible gains through increased > pro-> . . duction due to better methods, and yet .jv - even in this so-called enlightened age how little real., attention is . given to this sub- . j :■ ject. Our educational authorities in the ; ' world still think a knowledge of • dead j languages, and biassed history, and theology and such like things of more; importance than agricultural science; and the ; greatest 6* all industries 'on , which the welfare of the world depends is left largely - J•■'»? to the untutored. ' The aim -of education is. to fit us for the battle of life;or:at any . , : rate it should be, and in no way, is the battle of life as strenuous , as: in raising food ; and clothing ' for ; : the •; millions; of human beings in the world. How much is , done even in this young country to educate - , our people in the science of agriculture, t v t how much is done to fit them to make the. best use of our soils; and genial climate? Unfortunately, singularly "little. ' But .the , time will »come. and 'is coming soon, when every 'lad in.New Zealand-who v wishes to go on to the land will« have the opportunity of obtaining special education r *>-*:« to fit-him'for : his work. -And the time will come, too, when the highest chairs m |ga /' our universities, the highest honours an our educational system, will be given to those who have and can teach the broadest ' ''*> and ; best .truths of agricultural science. < . ' '-V ':r 1 ■ < . - -r-c\H^,. jj