The Immediate Effect of Crossine

Varieties of 'orn dn Size of Seed Produced. ----- -- --- -- --- -- --- -----A Ti SIS PRESENTED TO THE GR.ADU .. TE UO~!t.TITTEE OF TttE VL_GINIA

by

Thomas Kennerly Wolfe, B. s. ""[ay 1915.

Outline.

I. Introduction.

11. 3tatement of Problem.

III. Materials and Methods Used.

IV. Description of the LJars.

V. Results.

VI. Discussion.

VII. Conclusions.

TH~ lI,tJIED IATL ~:B1 l!1.r~ C T OF CROSSING VARI2T 1~3 OF CORN

ON SIZE · OF S~BD PTIODUCED .

I ntroCluction .

It has been the seneral opin~on that the immediate ef-

feet of crossing varieties of cJrn is to increase the yield .

Corn differs fron most other plants in that the effoct of cross-

ing oay be seen the current yeCJ.r cllle to the hybriaization of the

end~sperm as well as the embryo .

~here have been many experi~entc to prove that cross

breedine cJrn increases the yield. Collins1 found when pollen

was mixed and used to pollinate the same ear that t nere w~s an

increaoe of the c rossed seed over the uncroBsed , varying froQ

3 to 21 per cent. I n an ezperiment at the Vir~inia Experiment 2 ut&tion , the re:::ml ts show t ~ilat in all crosses tho immec1-iate ef-

feet was to incre&se the yield . When different strains of Boone

aunty White were crossed there was an increase of 31 . 7%. Col -

lins3 also fJund that the immediate effect was to increhse the 4 yield. llcCluer shows that yields obtained fron planting c1ossed

seed were more important than those of the immediate cross. Uont -5 gomery finds that corn is restored at once to its full vigor by

crosslng, but the yield seems to decrease in the second genera-6

ti~n . Hattley found th~t cross 9ollinated seed proved 20% more

productlve than either parent .

Owin~ to Jendelian splltting, it cannot be e~pected ~~

tnut the yield. of hybrid"'\"'.rill continue to increase in future zen-

erations , therefore , it ls best to cross corn every year fJr next

year ' s ple1Ht in;5 , that L-) , :progeny from the aame cross should not

be used for more than Jne ~eneration.

- 2-

Statement bf ?toblem.

Ti.le :purpose of this experiment is to determine the imr.:ediate

effect of crossing varieties of corn on the size of the seed pro-

duccd ana to determine whether thi~ oeth~d of cross pollination

is advisaole from a practical standpoint . Mixed pJllen was uGed -«.~ to pollinate eac~ so as to ' eliminate error as far as 11ossible .

Material and Ifothocls Used_ .

Eight varieties of corn were used in this work : namely ,

Collier 1 s E1::celsior , Cb.soy ' s Pun~ Bred , -300110 C~:mnty Special , Col,...,

um::,ian Boaut27 , 11ickory King , Gold Standard , Improved Golden Dent,

and Im_Drovec1 LeaL'.1ing . I1he firnt five fare vrhi te dents and the last

three yellow dents . Due tJ the dominance of yellow over white and

double fertilization in maize , called xenia , ~hon white corn is

crossea yJi th pollen from .a ;Tell ow variety , the ,:;rellovr color a~Ypoars white

t he current year . Thus in each case when both/and yellow pollen

are used , we can detect the crossed seed .

I n crossinB yellow varieties with pJllen from white var-

icties, at least in sane varieties , the yel l ow color is diluted a&d

the kern~ls produced leave a paler cJlor than those fertilized wlfu

pollen from a yellow variety.

In making the c rosses , paraffinAd mani i a paper bags were

used for covering tassels and silks. The ears were bagged before

or as s,rn.n as the silks &.p:;)ea.red, ana the tassels bagged before

any of the pollen had begun t:i shed ..

The ears were pollinated when the silks were aoout three

inches long and the pollinatiofl was repeatea in one to three days

afterV'lards . Jlach e&.r w- . s po11inc..ted with pJllen from an·Jther

plant of the sar;ie variAty as v;eJl as pollen from the VF..,rj ety to

be crossed on it , the pollen bein~ mixed in application. The

2-b

bags were left on the ears until all d~ng0r of ollination was

over.

t.J:he crosses obt:iined are E'j ven .i.n tne descri ti on of

the ears and in the tbbles.

-3-

Descri )t_i_op __ of .Jars.

Hickor~r ing (white dent) - Im11rovea_ Lea~:iing

(yellov dent). Grains shallJw, characteristic Hickory hing type;

evitence of cross in ~olor. Length, 6i inches; circumJ eren·e,

6 inches; dia~eter, 2 inches. Number of crossed prGins , 91;

nuL'lber of uncro~sed g·rains, 2;-31. '~rnll filled. Cob, d1i te. ~:ros -

sea .)rains yello .. vii th white caps, uncrossed gruins rm re vd i. te.

E.ar No. 2. Hickorv Lin~ (white dent) Improved Leaming ., .._,

(c.,rellow dent). Grains shallow, Sc;.me as ear No . 1. lumber of

crosser'" ,t-:rai s , :~45 . 'umber of uncrossed grains, 62. Length,

inc he 8 ; ct iame t er' 1 ~ incr1es.

~o.r No. 3. Hickor~r Ling h-:.1.ite dent) J - Gold :3tanna.rd. (Yello·~

dent}. Grains medi1:i.:n, tJpicaJly Hi~kory in?", evidence of cross

in color. Lcn~th, 6 incnes; diameter ,2 inches. :Number of crosser1

grain;-3 , 3; number of uncrossec1 ?."rain .. 3, ~~00 . :ell filled , coo -

white. Uncrn:ssed grnins lJU:Ce v1hi to, crosse . ,e-ra.ins pale :~e1 o ~ ..

~ar no . 4. Boone County Special (white dent) Improved

Lea.min, (yellow dent). Gr&ins medit.t.X. , shows evidence of 1JroE.S in

gr~in u.nd valor. .Length, 6~ incl1eo; diameter, 2 in0hes. Numoer of

c r OBse t1 t:rb,L1s, 484; number of un . r ossed grai.ns, 3.

filled, cob - ~hite. rossed gL~ins yello~ with ~hito caps, ana

uncro~3ed grains pure ~hlte.

______ o,.;.....;_•_....;:..5_. .t3.)one our.ty 0pec ic:i,l ( YJhi tc dent) X Im~ roved

Golden lDent (ynllow de11t).. Grains meciiwn , chara0teristic of 3oone

C ' 1 · :'I f . 1 L th 6 3

.i· n ' e c• • aunty 0reciu , eviaence o c ~ oss in co )r. en~ - , 4 1-.> ,.) ,

dia.:netor, 2 1/8 inc!hes. :Num er of uncr)ssed gra·ns , 416; number of

crOHdP.d grains , 108. .Voll filled o:.ce}t 2- i ich at the tip. Cob-

white. Uncrossed ~rains ~ure white, crossed _rains yellow ·ith

-4-

~ar No. 6. Boone County 0pecial (white dent) X Gold Stand -

ard (yellow dent)~ Grains long, characteristic of Boone County

Special. ~vidence of cross in color. .Length, 5 inches; diametef, 9.l • ' ...... ..,. incnes. .Num1Jer of un 1..;rossed grains, 20; number of crossed

' grains, 351. Well fillea, cob, white. Crossed grains are yellow

with white caps, uncrossed grains are pure white .

Zar No. 7. Casey's.Pure Bred (white dent) X Gold Standard

(yellow dent). Grhins de~p, rows irregular, evidence of croas in

color .. Length, 5t inehes; diameter, 2 1/8 inches .. Number of

crossed 5rains, 24; number of uncrossed gr&ins, 325 ~ \'/ell filled,

cob - v.rhi te. ~rossed grains yell ow anc.l uncrossed f;rains pure whj te

~ar Ko. 8._ Boone County Special (white dent) X Gold Stand-

ara (yellow dent). Grains mediur1, characteristic of Boone County

Special ty1Je, evidence of cross in c ,)l or. .Length, 5 inches; diam-

eter, 2 1/8 in13hes. Hum'1er of uncrossed grains, 258; number of

crossed ~rains, 196. Well filled except one side, grains irregu-

lar., Cob, white .. · Grossed grains are yellow w.ith whitish caps, and

the uncrossed grains are pure white.

~ar No. 9. Casey's Eure Bred (white dent) X Gold Jtandard

(yellow dent). Grains medium, characteristic of Casey's Pure Bred.

Length, 4 inches; diameter, 1/5/8 inches. Numoer of crossed

grains, 1, number mf uncrossed grains, 171. Not filled on one

side, curved, evidence Jf cross in color. Cob - white, crossed

grains are yellow, uncrossed grair:.s _pure white.

..;.5_

~ar Ho. 10. Ooliier's ~xcelsior (white dent) X Gold 0tandara.

(yellow dentJ. Grains short, characteristic of Collier Excelsior,

e~ridence of c · ass in color. Lengt.h., 7 inches; diameter, 1 ? /8

inches. Number of crossed grairis, 68; number oi uncrossed gr&i11s,

169. Not well filled on one side or above middle,Qurved. Crossed

grains are yellow with white caps and uncrossed grttins are pure

yi>JJow~-~ar Ho. 11. Collier's ~:J:celsior (white dent) X Gold ~tand.ard

(yellovv dent). Grains meriium, characteristic of Collier 1 s ~xcel-

sior. Length, •;)

5~ inches. Number of crossed Diameter, l~ inc~es.

grains , 21. !~umber of uncrossed grains, 163. .Not well filled

on one side, rows irregul~r, tip not filled for i of an inch, ear

curved. Cob, white. Crossed grai~s ~re ycllaw with whitish caps,

and uncrossed grains are pure white. Evidence of cross ir: color.

Ear ~o. 12. Columbian 3eauty (white dent) X Improved .Leam-

ing (yellow dent). Grains ~eep, characteristic of Columbian

Jeauty.. Length, 6 inches. Diameter, 2 inches. Number of crossed

grains, 219. Number of uncrossed grai11s, 83. Hot vvell filled on

one side, curved. Cob red. Un.:;rossed f;rai.r .. s are wh.L te, crossed

yellow with whitish caps. ~vidence of cross in color.

~ar Ho. 13. HL~kory King (white dent) ;~ Improved Leaming

(yellow dent). Grains shallow, characteristic of Hickory King.

Length, 5{t inches.. Diameter, 2 inches. l~umoer of crossed grair.s,

31. lJumber of uncrossed grains, 14-2# Well fil1ed. Cob Vihit;e,

crossed grains are yellov with whitish caps, and uncrossed are

pure white. ~vidence of cross in color.

,. -o-

Ear .No. 14 •. B )One {Joun ty Special (white dent) X Gold

Standard (yellow dent). Grains shnllow. Length, 7 incnes. Diam-

eter, 2 1/8 inches. ~victP-nce of cross in color. Humber of cros-

sed grains, 23. Number of uncrossed grains, 219. Rows lrreguJar ...

~ar fairly well filled except 11 inches ht tip. Cob white eras-~

se(l grains are yellow 'vi th white caps. Uncrossecl aro pure :;rell~w .

.Gar Ifo. 15. Casey's .Pure Bred (white dent) X Gold stand-

ard. (yellow dent). GraLis mediw...1.. Length 7 inches. Diameter "1

2~ inches. Evidence of Cl oss in color. Number of crossed grains,

115, nur:iber of uncrossed, J64. Well fil1ea_, rows irregular. Cob

white. Crossed erains are yellow with white caps, and uncrossed

are pure white.

~ar Ib. 16. Hickory King (white dent) X Improved .Lenm-

ing (yellow dent). Grains sh&llbw, characteristic of Hickory

King. Length 6~ incnes, diameter 2 inches. ~vidence of cross

in color. Humber of crossed grains, 249. lfomber of uncrossed

erains, 37. Well filled. Crossed graics are yellow with white

caps. Uncrossed grains are nure white. - ·'-

Ear No. 17. Collier 1 s ~xcelsior (white dent) X Gold

Standard (yellow dent). Grairs pointed, Length, 8 inches. Diam-

eter 2 1/8 inches. ~via.enc e of cross in c 1)1 or. Hmn.ber of crosGed

grains , 157. Number of uncrossed grains , 15. Grains scattering,

~t tip 3 inches not filled. Uncrossed grains are pure white.

Crossed gr&ins are yell 1w \ri'i th white caps.

~ar No. 18. Gold Standard (yellow dent) X Hickory King

(;hite dent). Grains deep , characteristic of Gold Standard .

Length, 6} inches.. Diameter 2-i inches. Number of crossed grains ,

~~--388. N"L.mber of uncrossed grains, 32. Well filleo.. Cob - red,

-7-

Crossed grains are yellow with white cap. Uncr~ssed grains are

pure yellow.

£ar No. 19]. Gold Standard (yellow dent) ~ Hickory

King (white dentJ- Grains medium. Ch~racteristic of Gold

8tandard.. Lene;th 9 inches, diameter 2 1/8 inches. Numbe rp:f

crossed grains , 487; number of unc.1-~ ossed grains , 226.. Vvell filled ,

cob red. Grossed grains are yellow an~ white capped. Uncrossed I .,_..

gralfis are pure yellow.

Ear No. 20. Gold St2ndard (yellow dent) A Colliers

~xcelsior (white dent). Grains deep, characteristic of Cold Stand-

ard. LenE"th, 6! inches, diameter, 1 7/8 inche ::-~ . Number of eras-

sed grains, 342. Numbe~ of uncrossed erains , 210. Well filled,

cob - red. Crossecl grains sre yellow v'lith w·hitj sh caps. Uncros-

sea. grains are pure yell ow.

~ar No. 21. Improved Golden JJent (yellow dent} ""~

Collier Excelsior (white dent). Grains thick, narrow, and deep.

Characteristic of Improved Golden Dent. Length 5c inches. Diam-

eter 2 1/8 inches. ~vidence of ·c r oos in color Well filled . Cob

red. Crossed ~rains are yellow with whitish caps~ Uncrossed ~raim

are pure yellow. l:Jrunbcr of c i Jssed grains 350. Number of uncrosse

grains , 228 . Dent

~ar l~o. 22. film:proved Golclen.i X 6olliers Z:>celsior

(white dent). Grains aeep, characteristic of Improvea Golden

Dent. Length, 6 inches. Diameter, 2 inches. Evidence o.:' c1oss

in color. Well filled. Coo red. Crosse a. grains yellow with

whitish caps. Uncrossed grains are pure yellow.. l~ur:11)er of cross-

ed r.rains 319~. Number of uncrossed grains , 76.

-8-

Ear Io. 23. Improved Leaming fyellow dent) X ..doonc County

Special (white dent)* Grains deep, characteristic of Improved

1 Paming.. .Len~ th, 6{· inches. Diameter 2i inches. Evidence of

cross in color.. Well filled. Cob red. Num i)e r of crossed grains

75, Humber of uncrossed grains , 421.. CrosBed grains are yellow

with whitish cap, anfl uncrossed grains are pure yellow.

~ar Ho. 24. ID~proved Goloen Dent (yellow dent) X Collier's

~xcelsior (white dentJ .. Grains deep, characteristic of Improved

Golden Dent. Lenpth, 5i inches. Diameter 2 1/8 inches.. ~vidence

of crass in color. Well fil l ed. Cob red. Crossed grains are yel-

low with whitish cap~-3, and uncrossed erains are pure yellov:i. num-

ber of crossed grains 127. Number of uncrossed grains 265.

~ar No. 25. Improved Golden Dent X Collier's Excelisor (white

dent). Grains medium , characteristic of Improved ~olden Dent.

Length 6 inches, diameter 2 inc rrn s .. .8viden.;e of cross in .:;olor.

\,ell filled except a.t tip.. Cob red.. Crossed gr&ins are yellow

with white caps .. Uncrosseo grains fi re puro yellow. IJumber of cros~

sea grains , 23. Number of uncrossed grains , 342.

~ar No. 26. Gold Standard (yellow dentl X Casey's Pure Bred

(whito dent). Grains medium, characteristic of Gola Stanaard .

Length, 5! inches. Diameter, 1 7/8 inches. ~vidence of cross

in color. Well filled. Cob red~ Crossed grains are yellow with

whitish caps. Uncrossed grains are rmrc yellow.. Number of crossed

grhiDs, 54. tlumber of uncrossed grains, 321~

.Gar No . 27. Improved Les.aing (Yellow dent} " ... .D 0 one County

Special (white aent ). Grains medium, characteristic of Improved

Le ~~1ing. Length 6 in ches, diameter 2 inc~es. ~vidence of cross

in c8lor- Cob red. Crossed grains are yellow with whitish caps.

,

-9-

Uncrossed grains pu.re yellJw. .Number of crosser grains, 210.

Number of uncrossed · 32 O 1 f · 1 grains, · ~· n y air y well fiJled, missinf

on one side.

Ear No. 28. Improved Leaming (yellow dent) X Boone County

Special (·vVhite dent). Grains medium, characteristic of Improved

Learning. Length, 6 inches. Diameter, 2i inches. ~vidence of

cross in the color. ~ob red~ Crossed grains are yellow with

whitish caps. Uncrossed grains are yellow • .Number o ~~· crossed

gral.ns 217. Number 8f uncrossed grains, 33 .. Well filled near

tip, scattering ~ram middle to butt.

~ar No~ 29. Improved Leaming (yellow dent) X Columbian

Beauty (white dent). Grains deep. Length 5% inchesr Diameter

2 lnches. ~vidence of cross in colnr. Cob red. Crossed grains

are yellow with white caps. Uncro:rned grains are pure yellow.

Not well filled on one siae. Hwnber 'Jf crossed grains 172, Nurn-

ber of uncrossed grains, 50.

~ar No. 30. Improved Leaming (yellow dent) X 3oone County

111ecial. Grains medium. .r:.vidence of cross in color Length 7

inches. Diameter 2 inches. Cob red. No grains for ' 4 inches at

tip, scattering on one side. Crossed grains are yellow with whit-

ish caps. Uncrossed grains are pure yellow. Number of crossed

grains, 160. Nunber of uncrossed grains, 89/

~ar No. 31. Improved Golden Dent X Collier 1 s Excelsior

l white dent} • Grains deep. i:!videnc e of c r JSS in col .)r. Length

4 7/8 inches. Diameter, 2t inc~es. Cob red. it inches at tip

not filled, grains scattering. Crossed grains yellow with whitish

tips. Uncrossed ~rains are pure yellow. Number of crossed grains,

147. Humber of uncrossed grains, 15.

-10-

~ar bo. 32. Gold Standard (yellJw dent) X Casey 1 s ~ure

3red (white dent). Grains medium, characteristic of Gold .-Jtand-

ard. ...jvidence of cross in color.. Length 8 inches. Diameter 2 1/8

inches. Color red. 2~ inches at tip not filled, grains scatter-

ing. Urossed grains are yellow with whitinh caps. Uncrossed

are pure yellow. !{umber of uncrossed grains, 87. :Number of crosoE?l

grain;:;, 160,

~ar No. 33. Improved Golden Dent X Collier's Excelsior

(white dent). Grains medium. ~vidence of cross in color. Length

5{ inches. Diameter 1 7/8 inches. Cob red. Vell filled. Crossed

grains are yell 1)W with whitish c&.ps. · Uncrossed. gralns are pure

yellow. Number of crossed grains, 25. ~umber of uncrossed grains,

322.

~ar No. 34. Ic~rovea Leaming, (yellow dent) X Boone County

Special (white dent). Grains mmall. ~vidence of cxo8s in colnr.

Length, 6 inches. Diameter, 1 7/8 ilnches. '_.Poorly filled and cur-

ved. Crossed grains are yellow with whitish caps. Uncrossed

grains are pure yellow. i~unber of crossed ~rains , 110. Humber of

uncrossed gralns, 11?.

~ar No. 35. Improved Leaming lyellow dent) X Boone County

Special X Columbian 3eauty (white dents). Gr&ins narrow and deep.

~vidence of cross in color. Length, 6 inches. Diameter 2 inches.

~ e 11 f i 11 e cl • C r :rn s e c1 ~~ r ~n n s are ye 11 o v.,r l'i; i t .:1 Yih i t i sh c a p s . Un -

crossed~ 3rc:~ln8 ar8 pure :rellww. lJumber of crossed gr&lns, 244.

Nu_ .. ·Jor of uncrossed grains, 128.

-11-

~ar No. 36. Improved Leaming (yellow dont) X Caseyfa

Pure ~red. Grains medium broad. Bvidence of cross in color.

Length 6 inches. D ieJne te r 1 7 /8 j nche s. Well filled ::mt rows

~ide apart. Crossed vrains are yello~ with whitish caps Un-

crossed 3'reiins H.re pure yello1N. rurnber of uncrossed grairrn, 197.

Humber of crossed grb.ins, 191. zvidence of cross in ciJlor,

11ar No. 37. Golcl :Jtanclard (yellJw dent ) X Boone County

Special, (Vhite dent) . Grains roundish, evidence of cross in

color. J..Jen8'th, 6{- inches.. Diameter, lt inches. Grains are scat-

tered. :·one at all on the t ir> for one inch. urossecl grains are

yellow with whitish caps. Uncress~d are pure yellow. Bumber of

crossed gnains, 29. Nu~her of uncrossed ~rains, 117.

Results.

Table I. .

~esults of Crossing Corn •. ·Female p~ren~. white; M le paren~ yel-low.

~ar Cross 1 o. · Fetml e Male

Kind of Seed

Ho . of Seed.

1 Hickory King X Imp.Leaming pure hybrid

231 91

2 Hickory King A Imp . ~caming pure 62 hybrid 245

3 Hickory King X Gold Stand. pure 300 h~brid 3

4 Boone Co . Spec. X Imp .Learn. pure 3 h brid 484

5 rloone Co . Spec.X Imp.Gold D. pure 416 hvbrid 108

6 3oone Co.Spe·c-.X Gold Stand. pure 20 hybrid 351

7 Casey's 2ure Jred X Sold St . pure 325 hybrid 24

8 Boone Co.Spec.X Gold.Stano. pure 258 hybrid 196

1'~~------~~~----~~--------~~~~~171 9 Casey s 2ure Jred X Gold St. pure hybrid 1

10 Uollier's Lxcel. X Gold Std.pure 169 ~~~~~~~~~-~-h~v~_b_r_i_·a·~~~- 68

Avg . wt. Increase per sec-=d-·~R~m~·~~f~o~-~~

.492

.505

.473 • 546 .495 .513 .293 .. 340 .342 .357 .450 .428 ;431 . 381 .343 .367 ·----.376 .425 .400 .448

2.64

15 .. 43

3.63

l b .04

4.38

.. 5 . 4

• 12. 53

6.99 --------13.03

12.00

.::ar No.

11

12

13

14

15

16

17

-12-

Table I (Comcluded)

Cross Feniale Itlale

Kind of Seed.

Collier'9 ~xcel.X Gold Std. pure hybrid

Columbian Beauty X Imp.Learn.pure h~tbrid

Hickory King £. Imp. Learning pure hybrid

Boone Co.Spec. X Gold Stand.pure hybrid

asey 1 s Pure rlred X Gold 0t.pure bybrjd

Hickory King X Imp. Leamin~ pure h¥hria

~ollier's ~xc. X Gold Std. pure hyhrid

No. of Seed.

163 21 83

219 142

31 219 _: 23 164 115

317 250 15

157

Avg. Wt per seed in gms.

.460

.437

.471

.502

.582 .. 613 .. 478 .506 .391 .437 .596 • 649 .291 .329

Incre-ase ~

-5.26

6.58

-13.45

5.85

11.. 76

9.22

13.05

The evidence of crossing was clearly visibl~as would be ezpectdJ

because of the dominance of yellow over whlte and of xenia in

maize. It w~~l be noted in the above table that in 13 of the

17 crosses there is an increase in yield, this increase varying

from 2.64 per cent to 16.04 pe r cent. In the four cases where

th~re is a ~ecrease, the deerease ran~ed from 5.14 per cent

to 13.45 per cent.

In all crosses producing an incre&se yield the

increase is large enough to be of importance from a practical

standr.oint , uncl the same is true of the crosses showing a

decrease. It will be noted that in the above table the var-

ieties which show decreased yieJds in one ~lsce also ~ive increas-ed yields in other inst~nces. Due to thi s fact, these v~rietles should probably be left out of a ccount ~nd then a11 of the remain-ing varieties show an increase ylel~ in~ every case.

In three ~f the four crosses where there is a de-creaBe in yield, Gol:-l ...,Standara is the male parent. However, in othor cases where Gold Standard is used as the . male )Urent , large increases were obtained.

. -13-

Tu.ble II.

~~esul ts of Crossin~ Lorn. '.h,em le p rent yellOYP, Male puren.t white.

18 Gold Stc.nc .X Hickory King pure 32 .478 ~·~~-=-~~~_,_~-h~brid 388 .427

Gold Jtand.X Hickory Ling pure 226 .25~7--· -11. 9

19 hybrid 487 . 277

20 Gold ~tand. ] Coll. ~xcel. pure 210 . 351 7.78

hybrid 342 . 344 21

- .02 Imp.Gold. 'eritT-Co11 . ~xae1 . hu~e 228 . 346

y rid 350 .331 Imp.Gold~Dent X Coll.~xcel.pure 76 .413

- 4,.53 22

------~---- hybrid 3l<J .41~ Imp .Leaming X Boone Co.Spe . pure 421 .364 23

002 -- - - ...!..--: __ _

~~~---==-~-,,.,~~.,,,..._~~~~~~~~~l~1y~b~r=-=-id;;:_~ 75 .371 Imp.Gold.Dent X Coll.~xcel.pure -265 . 406

1. 92 24 ----~----- _ -.,--=, .. hybri_9. ___ __1_?1_ _____ _!~99 ____ ___::1~_J_p __ _ 25 Imp.Gold.Dent X t.;oll.-62:cel.Tmre 342 .41-:3

·---=hy_P.rid_ __ _..?p .4.?0 1.69 Gold 0tand. A Casey's P.3. pure 321 . 376 -26

-.003 hybJid ~- 54 • 375 27 Imp.Leaning ~ 3oone Co.upe.pure 32 .444

35

36

37

hybrid 210 .446 .005

. 007

.007

3.66 Imp.Leaming X Boone ~o.~~e.pure 128 .414

__ ,. _____ hxbriiL_~ 244 .. 41_7_ __.!:_007 Ir:1 p • Leaming X Casey s P . B. pure 1 9 7 • 3 9 8 - - - - -

hybrid 19 .432 a;64 Gola Stand.X Boone Uo . Spe. pure 117 . 488

hvbrid 29 .507 3.89

In the above table, as in Table I, those varietieG which show a decreased yield in one place likev:ise give~ increased vieJds in other crosses. ~ In the six crosses where there is a decrease in yield, Gold Standard is tne female parent in three and Collier 1 s Bxc e lsior is the male ,arent in three of them.

-14-

The evidence of crossing w~ s shown by the yellow g r a ins

being capped with white or oeing a ~aler yellow than tne pure

seed. In re.any crosses the y)ure and hybrid seed were difficult

to d.Lstinguish , but all doubtful seed_ nere wei~hed with thn hy-

brids.. Rowever, these results cannot he T8LLed U '"' OYJ to c.s ~Heat

an oYtent as those in Table I.

In six out of t~enty crosses there is a decrease in yiel d

varyinf) from .003 of a per cent to 11.9 :per cent. ln 0ig;ht in-

stcncc s , the difference is so smal l that we may say tha t cros ~ ing

had no effect on the yield in those cases.

In ei~ht crosses there are subst~ntial increas~s in

yield , while in four there are rather large decreases.

Selective 2ollination and Crowding out of Soea.

It might be th~ught that the increase in slze of hy-

bria seed on the same ear \"'i'ith ll Ure seed coulc1 be s.ttr:i.buted to

the stimulus given by cross fertilization~ By thj_s stimu.L.1tj on

tho hybrid ;:.:eecl may be able t :) become fertilized more rapidly

and then &evelop sooner and crowd out t~e pure seed. However, ).\_._:l'-

this "~'asAthe case. On ear Ho . 2 , Hickory Kin::;: X Improved I,eaning,

there was only one yell.Jw grain in the lhst tvrn inches at the ti ~- ,

the others being uncrossed (pure v;hite). The rernalr.lder of the ear

showed all hybrid sefH1 with the exception of tvrel vo grains 4 The

hybrid seed_ avera3o(l .G46 of a gram per seed, t11e pure se (; d t"..t

tip .473 of · ~ ~r~n, those intermixed with crossed ~ rains aver~~od

.476 of a ::i::ram. The grains at the e:xtrene ti9 were excluded 1.Jlnce

they ~ re usually sr.'.1al let than the other crrairn.3 .Jn the eur ..

Collins1 founfl in u case of c Hir1ilar nature tha t the

hybrict seed 1neighi,d. 292.f? grams !1er 1000 seec1 , pure seca f~83 z-rams. w e mvst conclude irom t~1s data that increased size of hybrid s e e tl i s no t au e t o c r ow d u1g out th e DU re 8 e e c1

u ,:C ~· l:i.':.::; t \;8Jl8l.'c1t i I) I ------ --------- .. --

, le rosnl -s

Iler L;O L ,':o cur.re it .. ~C'ar; Carri ~r2 31. 7 rier '~e it;; Etn ~n ir -

cent

r/ I

,)_!_' thA .3 ln the

;ith an av ra~, J' 53: r ~ent incrca~o for ·J tltP Cl"J S.S.

11 L er cent i -i t,·,-; ~, :I onorat Loi ....

ecnt in

In 1 ~ r~T 1 t 1: ., : t 'i or r-- -· i. ._ an j_ DC! ... c '""'f' c o · 5 t 1 . e r

the '1

1 o f t 1 , 1-... y b r ~ · ~ e rl 0 Te r t, • (' Jvtter

7 ~ust obtiirca ircroasos ~r)m ~f-3 to 134 er ;0nt

-15-

The results of t h i s eJ periment ~o t o sho~ t ha t t his method

of cross pJllination is profitable both ~o th8 f&r~er apd seed

~rower . The following method of corn brecdin~ will likAly prove

to be very efficient in produ:;ing pure and hybrit seea corn i;·;hen

properly carried out .

- . ...;. -----·~

•1 I - -I:' I

.. -11" 1

I I _/ :z 'I s 11 ,; ~ 1J · ~ ' ' ... 4 ' f if 10 fj ~

I

DiG.grarn of field. Ve r tical lineB represent rows of corn ..

Row l~o . 1 may be planted with a pure bred v"lhi te variety

an~ row No . 2 ~ith a pure brei yellow varJety , the varieties al -

ternating· across the field. Different strains of the m~.me variety

-·Y be used instead of eistinct varieties.

en one side of the fielcl a certain nm11ber of ro ~1s of the

vvhite variety nu.y be detasseled. ~ Thus the o&rs on the yellow or

those .=.;talk:J not r etasseled wil l bo pnre , while tn Jse ears on the ·.

v;hite or cletasseled rows will be hybrid . On the .other uiae of

the field , a certLin number of rows of the yellow variety may be

de t<.1~rnel ea . .1.. hus i n this c ase , the ears on the v; 1L~- t e or those

stulkG not cletasscled will be pure , v;hile t: ose ears on t!rn yellow

or detusseled r1ws ~ill be h ybrid. I r the field is large , it is

not necessary to dnthss~l a l ternate ro~s acrosb the entire ~ield.

Ho·t over , a ::mfficient nu::nber of rows sJuulcl be Clett:sse1ed on co.ch

Attention Patron:

Page 16 omitted from numbering

- 1'7 -

.... id e of the fielc1 to mr:lJ~e suye t1rn.t tho rows no.- reut e uctI e ~

u,re not close enou~h to the. re .mir.1.CT.er of the corn i the !'ielC.

which has no t been Cletasselecl to be i'Jollinatecl by i.t ..

Eure soec corn c a n bP obtc~- i rrnd fr ) Ill tl1e r vs ne v. rest

the ed;r~s "7hich have n0t been a etasseled , c .. nd hy' rid. ~;eed from

the d.etusseled r ,w:s on each side· Jd also from to corn ne~1r the

center f the field ~aere none ~ the rows have · eeL detasseled .

I n this ~ay , ne can sAcure , at small e x pen0e , b0th hybrid &nd

pure seed corn fror~ the same ~ield for l1e:·t yc·.:. r ' s l &ntin~ ..

-18-

C :Jnc lusi ons ..

1 . In the crosses obtfiined , 56.8 per cent produced

profitable increaseo in yield , a nd in 16.2 per cent the in-

crease i s D 1 i?; ht . In 21 • 6 ·per cent of the c r J s s es , the ., e -

crease is marked ; in 5.4 ~er cent the decre ase is sli3ht. The

larz,est increase is 16.04 rier cent and the c~re ;.:._ test d.ecrease

13.45 per cent.

2 . The farmer or aeea grower c an make prof itable ap-

pli~ation of these results by mixjng aced ut planting time . tie

will not only get an increase the current year , but will ontain

6.. lurger one the foll_owinf( year .

3. The increases and clecreases are not confined to any

certain varieties. However , Gold Jtsndar(t and Collier's ~xcel-

sior gr.i.ve decreasecl yielfls in & larger nu:nber of cre$ee than any

of the other varieties used.

4. All croGses were made between djstirct varieties

and not bet?een strains of the same variety. In a previ0us ex-

periment at thia station2 , larger increases in yield were ob-

tainecl in the latter case than were obtained in this e:;_pcriment.

Bi bl; O""ranhv.

1 .. U . ~ .. :Jo t . of ....... r :r i cu 1 Lu r 0 • 3 . -• I.. G i r n J ~ r /f 1 A ..

..Jffects of Cr ss ..':"Ollination Jf Size :1 3,3ecl j_n I' ize.

G .. l'. Collins cc J. H Yo. pt n.

V .i. r ~ i r. La Ju.1 1 e t i n .. ~ 0 ~ ( l 91 ;:> ) • .., he lm11c R L at n feet

on Y io 1 fl o

3. 3ureau J?l~nt In ustr 3nll{'tin 141~ c.rt IV. (19 C).

r Ir , 1ree j n ')' in C 0rn.

. • I . C )11 ir.s.

rr P 0b .. :--n Cr p.. D· l ' • ti • ~:on t ~ o c ry .

'D . ... art..,n .

7.. k re au ::21...,.,r ... t Ind 1 lS try .rlnJ J o t L... r o. 191 ( l 9J O ) . '11110

Va_n~ )~· .ti'.Lrst Ger: rt..tion Hybrids in Corn.

G • ... J. ollins.

8. Illinois 3nl lot in :fo U5. (1()92). 11'iclel ....:,, YJCrL.( n s

9.. 3uro....,u ?::!_ t fr:" 1lS tr: l·llet ir n . "1~3. (] Jl ',)

c.