Show t- t 1 TO BREED RESISTANT PLANTS PLANT rp r tt f Crops Proof Against Insects or Disease Can f Be Grown Gro by the Farmer a W t Y GUY ELLIOTT LLIOTT MITCHELL The farmers farmer's too greatest foes are insects and plant diseases He can canby by a proper rotation of at crops and fertilization convert a poor Into a rich soil and he can stimulate plant growth by plenty of ot fertilization By the same process he can keep down the weeds which rob his crops craps of at nourish nourish- nourishment ment went and moisture He can to a great extent overcome with but little trouble all the various smaller hin hin- hindrances hindrances hindrances to crop growing growing all all but the bugs and the blight These twain are hard to handle None is so arrogant as to profess Indifferent to their at tacks Not many years ago they were expected not the less dreaded especially especially espe espo- the blights and the rots and the mildews they were the natural visitations visita visita- of providence There was no use trying to combat them If It they I came they came The farmer prayed that they might not come that year Now science has shown us that tha they can in mOst cases be overcome If It not overcome they can be prevented Ye Yet the process Is often fraught with I great trouble and expense to the farmer Now suppose a a. man could develop a strain of at plants so hardy that blights and rust would pass them by In disgust and so bitter and unsavory for a bug that the hymenoptera the and the other toughs of ot the Insect trust wd Ild pass by and prefer to eat oak and hickory leaves It would be a cinch for that man would it not He could sit in the shade and hire myrmidons to do his work directing those close at hand handIn In person and those at a distance by telephone Such a condition may be possible The man who gets in first would be the one to sit In the shade and reap the advantage Eventually we would all get on to the scheme and unless the population of the world Increased with accelerated rapidity there would be an production over-production of ot food products and prices would eventually eventually eventually ally get back to their present level so that we would all have to work again The Department of ot Agriculture and some of ot the experiment stations have been working along this line Une of selecting selecting se se- letting resistant plants with the Idea of at least giving the enterprising American farmer a good big start In the aggregate enormous crop losses millions losses millions and millions millions are are caused by the attacks of Insects and plant diseases In dry weather insects insects in in- sects are particularly abundant andin and andin andin in wet weather plant diseases flour flour- ish while In average weather both do dothe dothe the best they can to gather the crop ahead of ot the farmer Many plant diseases diseases dis dis- dis eases and insects can be controlled by bythe bythe the various poisons sprays and cultural cultural cul cuI cul- cul tural methods already discovered but for some some some-as as for tor example the rust of at wheat peach yellows seed clover-seed fly etc satisfactory satisfactory remedies have not yet fet been discovered vered Some Instances may be cited to show Just what Is meant by resistant or immune immune immune im im- mune varieties and their value Grapes furnish a striking example European European European Euro Euro- grapes planted in this country fail fall wherever the American root grape-root louse Is present because the louse Isable is isable isable able to attack and destroy the roots of these varieties The roots of native na Live tive American grapes are also attacked by the same louse but are so hard and wiry that the louse can not destro them In other words they are re rc resistant Distant The unusual resistance of the Keiffer Keiffer Keif- Keif fer pear to blight has made it pos possible Bible sible to grow this pear In the Southern Southern South ern States where most other varieties varieties varie vane ties fall fail because of blight The variety variety va va- of ot cowpea known as Little Iron has proved so resistant to wilt disease that in some fields it has survived when all aU other varieties have been killed American gooseberries are but little subject to the mildew which seriously se r affects the larger English varieties Varieties va Va- when grown here With nearly every crop grown some of Its varieties varieties vari van are more resistant or Immune to some disease or insect attack than others Some varieties of the same plant are but little affected by a disease while others are badly Injured Variations Variations Variations Va Va- In this respect also extend to Individual plants of a given variety These Thee facts have been utilized to some extent In the origination of the various so called proof disease proof varieties varieties va va- pieties which have been Introduced into culture culture as as for example the rust proof varieties of wheat oats etc ete As a a. rule however these vane varie varieties ties have not been developed ped by any systematic scientific methods of selection se so- lection and breeding and although a afew few tew show merit most of them have not measured up to the claims made madei madet t i for far them They They have have however served 5 t a very useful purpose In thought of at turning th the e scientific and as well in the direction practical of at tS the me men S d on e n of ot disease disease resistant resistant varieties with results which promise to prove of ot great practical utility POTATOES During recent years the disease r resistance re re- o- o of ot potatoes SS especially has r received re- re attention by several of ot th the S e agricultural experiment stations in the United States notably those of Maine Minnesota and Vermont A recent bulletin of ot the Bureau of ot Plant Industry In In- of at the Department of ture tore prepared by L. L R. R Jones of the Vermont Station summarizes and dig dis cusses this work and that along aim sim liar ilar lines abroad as well as the ex of ot practical growers Sum the results Professor Jones draws the following tentative ci con elusions Disease resistance in potatoes is relative not abs absolute lute no variety known being wholly proof against late blight and rot It seems related to general vegetative vigor and Is is therefore there there- fore In a measure dependent upon upon cultural and developmental conditions and tends to decrease with the age age of the variety It can be restored by originating new varieties from seed especially of ot hybrid origin Not all seedlings show superior disease re re- S Early varieties may escape the disease dis dis- disease ease by maturing before it becomes epidemic but when similarly exposed they are as a class less resistant than late varieties The source of seed tubers Is Is' a matter matter mat mat- ter of importance northern-grown northern seed giving plants the superior disease resistance In Europe Seed from a a crop that was not too highly fertilized Is probably preferable Possibly tubera tub tubers tubers ers era are better for seed purposes If ft dug before Defore they reach full tull maturity High fertilization especially with nitrogenous nitrogenous nitro nitro- genous jenous manures lowers the power of the plant to resist both blight and rot So far as skin characteristics are an Index the red varieties with ith thick and rough skin seem more more resistant as a class than the thin-skinned thin white varieties So far as as stem and foliage characters are concerned the evidence evidence evi evl dence favors the stem that Is hard bard rough and rath rather r woody at the base and the leaf that Is small somewhat rough and dark colored In America trials as to disease resistance resistance resistance re re- have been conducted at some of ot the experiment stations notably In Ct i I L I f rF e I JACKSON COTTON ON THE LEFT DRAKE ON THE RIGHT Comparative Resistance to Wilt DIs Disease ase Vermont where experiments in breeding breeding breeding breed breed- ing and selection for increased resistance resistance resistance re re- are under way These results have been correlated with information recently secured by a circular of inquiry inquiry in in- addressed to a large number of potato specialists in the Northeastern States and in Canada From these it appears that a wide variation Is shown In disease resistance among the varieties varieties varieties varie varie- ties now in cultivation in America but that no one variety Is preeminent Among those which have been widely widely wide wide- ly tested the following deserve mention mention men men- tion as of ot the resistant class Red Red Rustproof Irish Cobbler Sir Walter Raleigh Doe Pride and White Beauty In tests made at the Vermont station station sta sta- sta tion In 1905 the following varieties o i smooth flabby leaves and decumbent I stems t J I IThe The evidence at hand seems to Justify the tho hope that the combined efforts ef et- efforts forts of ot potato specialists working from both the practical and the scientific scientific standpoints may soon result inthey Inthe in inthe they the development of varieties of ot potatoes potatoes pota pata to toes s combining general excellence with witha a high degree of at disease resistance CANTALOUPES s. s A recent bulletin of ot the Colorado Station reports th the discovery by a local grower of ot a rust resisting cantaloupe canto canta loupe which promises to be of at Immense immense im Im- mense mouse value to the Rockyford cantaloupe cantaloupe canta canta- loupe Industry In this case seed atthe of at the Rockyford variety was purchased from five different They were planted and cultivated under similar aim sim ilar liar conditions When rust attacked the field just before the melons began to 0 ripen It developed rapidly and soon destroyed all the vines except those V f J I i sl I 4 u r L t r I I aylor iron Black IRON COWPEA VS BLACK AND TAYLOR I Showing Comparative Resistance to Wilt and Root Knot grown from the seed of at one Many of ot the hills from this strain of at Rockyford seed remained green throughout the season and produced a good crop of melons Further observations observations In the muskmelon fields of ot that n neighborhood also showed that I wherever this strain of ot Rockyford seed had been used many hills were were unaffected unaffected with rust while with other strains of seed of the same variety the vines were all dead The Investigator selected a quantity of seed from the rust-resistant rust hillsand hills hillsand hillsand and planted them In comparison with ordinary seed On the rust-resisting rust hills the melons were hidden under a healthy growth of vines and were large solidly netted with thick firm flesh small seed cavity completely filled with seed On the rusted hills the plants were almost devoid of leaves and the small melons were prematurely premature premature- ly ripe with thin watery flesh open large seed cavity and practically of ot no market value In tracIng back the history of this strain of ol seed f It was J found that i some years before a seeds man had saved the first lot from a single healthy melon taken from a field of ot rusted vines It had therefore been teen developed by the simple process of ot saving seed from the best melons produced by plants which withstood attacks of rust when surrounding plants were destroyed by this disease What was thus accomplished plashed by one farmer with one crop can probably be accomplished by other farmers with the same or with other crops if it they will be alert while the crops are growing to select and mark individual plants which show exceptional exceptional exceptional merit along the lines of prolific prolific pro pro- life yield early maturity resistance to disease or other desirable quality and save seed separately front froni the plant showing such qualities Marked variations variations va va- va which may be profitably utilIzed utilized utilized util util- In this way are constantly occurring occurring occur occur- ring and are plainly evident on all farms The point to be emphasized is that Improvements In farm tarm crop varieties nearly always trace back to individual plants No one is in better position to o notice these exceptional plants than the farmer He Is In his fields garden garden gar gar- den or orchard every day where these exceptional plants are produced If one plant in a rust-infected rust wheatfield wheat wheatfield wheatfield field stands up green and free from the disease that Is a plant to save seed from as the basis of a rust re strain If It one hill of potatoes potatoes potatoes pota pota- toes in a blighted field remains unaffected by disease seed from that hillmay hill hillmay may produce a resistant blight-resistant variety It If if a squash Is found that Is die tasteful to the squash bug seed from that hill may produce squash vines which the bugs will not molest The Important fact Is that some plants are much more resistant to disease dis- dis disease ease ase and Insect attacks than others It t is a question of ot seeing the resistant 1 4 f fi f t M i V l I t r 1 Roots of ot Iron Cowpen Resistant Roots of ot Wonderful Cowpea Attacked Atto At to Root Knot tacked by Root Knot showed marked resistance to blight on both sandy loam and clay loam soils Keeper American Wonder Red Reds Doe Pride and Late Varieties having an upright habit of growth moderately branched with firm hairy sized medium-sized leaves are much more likely to prove prove resistant to late blight than are those with large f plant and propagating from It The I farmer has as great opportunity for this as as the |