Botanic Gardens Singapore : diseases of economic plants

31

Diseases of Econ Pits

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botanic gardens.

Sir<" ATT ? 1 -: .

DISEASES rf E C 0 H 0 M I C

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PLANTS.

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F &i i

ParucuaO- -
G. B.DeuLnuk^.

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C0L0CA3IA. j^3C0L3i^A. ( ALUT O R Kh JD..L).

1

n V

Leaf

sort :—

it vras found to rale a

2 ■?> -T

— 4 - ». «w

there Mas

a 1

eaf shed to an er crr.ru

were

found to

be

av,tacked by the 1 e a 2 "

n. 1 extent. All varie

raTe

r cv.e ar* in their earlier stages sr.all roundish spots dark
H - " rlcnr * A ' 3 ' : ‘* 5 ■ - fungus develops its ti 331133 the spot gets

brownish appearance 'fit', concentric

T» r V r

j> *

0

i"i'.e enter

tin

A ■

s one is vrhi&i

& «s»d -hsi.

is the

reproductive part

of /.

fungus . The

src 1 3 coalec

* toget

e’ a■■ d t •. e 1 e a, f

cur 7 s

■ e 3 .=1 r>rr*oT ofl

After

3ore 11 r’ 3 t’ 1 0.1 f

sheds

"i v ■ft o *1 f

<^ 4 *^

fa ..

3 >

Ihe fup.<;u3 is Phythrhthspa Colocasia. mh® dpi®d leaf shows

*

t-any oPOiiaS cn. the epidermis. The frrguc i3 epe-de^intercellnr
¥i”J. snail slender unbranched hrsttrria as seen in the diaor»a?:',.

The spores geminate very rapidly In gelatine solution. and ^
i-.yp*.ea, .1 1 produced 2 rcie one end . It 3,3 nnsertate and tjrotorla
ca^e be se n tvj grated in the sar.e . np.e spore In solution 3Telia
up. ^ostcria are also seen in artificial culture of tp ... furors

Tf>r r>o ^ ~ r* > r ti v 1 o ^ -'• -a-. -« A • i _ _

- - -* w • - -p * -■ <*-.3 o , 3.1 se {rc^ie 1 ea2 « %i.e cno^c" of*°3

«rv 9 PSiP 2 fJ’-t through the sto»-.?.ta.

F^ib

Jk

Sv.j rldt.;i cr tie Xeav'es cf th ria*vE;3 /Gclreaaia. )

The syct begins a 3 a nr.Xe ‘Jr the r'ajrrfcty rf
bn* •.; i\ 3 rr-'.e eai-33 1 % get. .3 up f per. tte y

.1 ‘o -< ; -->(-v’ y , ->

"> p 'i :r p

r:' .j o,a x 0 r j r. 1. X e /. 2 *

► *

/ --

F;irrs tie ecbpe crets fcr a cert.-u 12 T siigS;!. yel* lev/. and

03ici>r :i rre£ 1 - 1 2•'* 3 yr 1 ; 3,

Sxsxxxkacx

0 :

tie

the it jt 3 r r -2 a d 3 i r 3J 1 '3

I*. ^ --

4 XX — c.ld and ycurr leaves a.3 ‘veil are at'•acted,
dr J 3d sr.rfaca raz % be serin t’e ray rrdr.etj ve yafct.3 rf tl, fianyi: 3
D a rb b X a 0 1 \ clr t. 3 . vJ 11 . sr. a 11 3 e t a 3.

th .3

f

*

5/^ -e (T^c - es^ed

■• j. rrr 3or- ■:• o -axar.

MV ’> ..

fay

aJbo

4 ^*-

iT^

iuM “ '

^6

In the drx^d

zcne

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^ •*. .

be

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,3 r - • a X 3 d r 1 3 *■■: /*? 11,

IT! * -> 1 t> N a **s a

. y * \ - • . * * „> ’ -- ✓

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:"p ?t *7

r n 3—

3 o 3 "' rv-"- ;p tl 3 '{! r‘f

r 0;. \i \ >; 1 .j, v. j r n. a

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3V-'\

r.f

*m ^

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P — ar»v ■?'p * ip

' t -J . . * 1 i ^ •

i ra.i.•• i. ■ £-. - ht.j!.c*:ad y v. fuujru't. Vera!cu?.aria otw.'!i.sig;’(i. tjtg

I’.'is i ruvfc on tie ore- iu ;:u\t3 haaltJiy but fcar ucsietlaoi.t

r j /"v'f" ■< -J,

J-LU i-J , iXXfi putC:lQ& 7, T Ill.Cjt t/lO.Vi GXtOlid LUid CC VO/'
l, * t •' i ... ;C.-^ ii • -;Iv 1 /'ll3. yc 311 0 - i /'C i" V».l,! r ’ lit i Cl '<“♦ "‘0 It "( t j *j i*

p u‘I; rx d raa * t a c f ret b 1 r •. y.

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( O.P. Butler, pp.

TllO

— F Is/

CC 5 -

rr r.T <■*

ob..

calyx 1 :■•*> al:;c feuud rettiuy

)

Rosxoay

r-luckiuf. frulv. arid da-itcylay tie

i :t f c u f i d tc b e o f f 3 e t i v o. 13 1 i :i d i j o a :i e

v -^ '■* '^abii3/’« uaC'. xt x/j prov.latoi.'. by 'olio

n T> -
—

tliebeax

x r j ‘taio. tc ontc

:s

x:s i cut id e
>!

d a a x 1 '. t;i 3

nans. bprayxuy
‘‘.proud xa

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i f i' 3 ■ v /a ‘a ‘'-In # <ai,

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CARICA

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TOPAYA.C

( PAPAYA , Pap ua. )

... .

Leif sect :

Saed! i ngs. : TI e^see&li ng i > n t] .3 bcxe 3 vrere
•1 3pp. The rid Ivs. dr3 the fir^st zc

"i ■n ^ ■'1

attacked by a C
catch tte inf ed tier*. drd ‘then it. spreads to t.J.3 yctinge? Ivs.

The seedlings in the:*r growth by thedise ase^ ’.ere va-s a
let of leaf shedding . The old Ivs. or being rerrved -rer ^

burn.edavray. Thits 3t 0*0031 the sore-ad .-

" *■ - *

0 ^ V L *

First, there > 3 di •330lon.rat.xort of the leaf in a particular
place and ti er it. turns gradually dull in colour and firallv
t.I.ere >.3 a reon!ar apet. vrit!. concentric ring3 of bro > rn colour

vr 11!. a c e r tre o f wl.i t.e 30r t. TI.i 3 ;i 3 tI.e ret*roduc t i ve r art.

* * *

of th fur.on3. The spots cealsce and tie le i curl3 and give3
"cle p ar c i . e d ap p 3 *a?*en. c e *

Grown up plant3.: he 3 re diseas is also observed in

“ * •' ,*■ ,-r

*•

thar. * The 1 v3• down below |r * attached first, and then th
fungus go 3 3 up if tie lv 3 . a re not cut and rereved.

e

1

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fertilised fls.

an.otl;

c» 11 . T 1 3 0 3 ,o

* k « 1

T V. 3 V

* ; ■ • •

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acted

tr.e buds

as vrel

.1 tl.iB

fi -*

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The buds

d-oodo' rn

and

30 al 3 t

hefr.

T ’.3

’I -* i o oT ' “1

it 1* • ‘ J 1

petals of the bud3 show tie sare di 33a3a. phe fungus ,

> t

enter3 tl.rough th er . Inside on the ovary , can be 3 eer
lepra3 33d cante 3 and t ^dropped down frsjf. there t ;i 3

f 3 l !M

distinct discolouration in the basal portion of the fr/.

TI ii 3 r e u t c ed t!. e err r an d s o r* i 1 3 t h c re 3 3 i n g e xp e r i r e n. 1 3.

• * ^ *

. /

RSMEOY 2 RIED.:— Sprayi!>n -rit!. 3 r?\l@anx mxtmrs. (nrrr.ilx,

Va

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hUet^rpc^/Uf. Cx

01 T&ty uaJ^

Ck*. fa>>

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U^C-7

<$n *

rCS sJ ^ , i ;.>?-
£ r-^V.

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»* jM ft

irtl.^i flcve ’-3 3r.r / cl4:3 cclrr.7*af«irn c* t.’e r.^i.3 ■?-? * n

.11-3.3 tlrim. II- fnr»ci!3 aJT’a.3t. t3 the c’ 9V9 lew-wnt £f t i. e <v ni
j^i.3 bn.y ur93 -^C •« oX5c?^ bn*'» I*3'L01, n !".6‘ CClru.T? cb-AP^^o ??*C T ■

r . At i^ 3 < 4' 9 tiKe , 4 . 1 ° r~X 1131.3 3

■■■rl-.tte tc dull ye Ur

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rf '•— rstal3 ciHs 33 111 e.uifcern. * The fruit. -V. * rct-z ->nd

The petill beccr.e

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*•'• - ?■‘ • 1r X 3 *', :t, 3 /?. 1 cr 3 3 3 y.IT f C m*

*^44

442

pa?' 5 l-.e 4 3rd 3J .r-r.- ; the fm- 3.

* v * r - -W.

®: rr *yr^3 rf ipri’ei.ii’e fcniiS c On 3 r s » leT-ti&e *"3 •;■; •= rtr
-J-j vl . p-rc 0 011 -

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JfJTjUf^ ^ 6 ux>p<H+ S’/ f***~JLr

TlfJuL. <V /4I fOu/^ ✓ jmJJAA O^Q^j.jxj^L, -

V ju 4 L'■ "*• -

X> - &>'**&*

itp -i«j i i o T : ’ 1 T ^ ^ ** *5"? p i v;« 3‘3 r3 ■’. *9 J ; "*1 J • •

x; .'3 X-’ j ■> ■-■> ■> ■ -‘-*J ■ ■* ■* •-* v. , '- • ^ ■ - ■■ 3

Ul-.o irrt.3 are rcr. ikI d. bh -i raided pciivh v is\ b T . ites a3

m?

tl.3 refmnc^V, r ari; cf <± f^. aJ** ,JJ<CT

ir Ant.]\r aone 3 ? c ■

vi.3 3*'.013 „

I f * ’ — I - Ar

itflXC Hc***f^ ***J*L»*M^) *tA

£j £/fs(<X4.t*. £ «£*»— C. c —» •■

Oil 3 plant, In. the J'.anpr plct j 3 attaote-cl by ,1 fi:r.£u- 3 .

C r 11 3 tC t r*;I 9 j .1 9 ‘ 3 r ' ■' ,/

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x • .<57*' ;» *j !'n>" t oc.er.

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rT■ *j r} % ?cr 'C .3 3 *■',’. 3 3"”.©!' *

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She tcv -j

i 3 V ;i 11 3 ,i * ‘ ■/ t *. 3 11: n f ■• /S 1 .3

2!io nbeve nctod disea so ueens to bo ,cc mneu , it haw destroyed in •,
three plant, a. It is no tod ±s bo that it. nakou it soli ccnspicucs

in the aidd?.e cf the atom. She yrcTrth stops and the trees succumb.

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She a. ^colouration due to the hyphen is noted ft up to the roots

• 4
.* »

( sent fc *' i d entif i aa hio n).

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T a 1 | =7

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Black runt cu the petioles.'( drying wad partially dried.)

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Papaya neadliac", rot. :

Papaya seeds ?rero scvrs «« £3cs i* tcer pets . The seeds did

*— % * . - -< , . +-

— ..f,

germinace but after a few days it was noticed that they were

r , '•, ; 'C ’\ t fc *

dying/Quiz retting at the bans. ) i& caa pot , the attack was

very severe out in the other , act to the sari© extent.

2?he magus attacks th e plants at the fcee&X cf t?e surface*
and as a consequence the seedlings die.

s ■• »

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Mi c re ex an*

Remedy :—

‘t

and se ds sewn.

‘•he soil was

diainfeotsd with »2S04( see gardens. Bui.)

ay a ( ccut.fi)

In the fruit plantation, a for of the grwcn up plants
vrere Tilting . In order to see the origin of the injury f the
5 ant ?;as submitted to thorough exam* Nothing ras acted on the
Ive* or the stem except at the sell levs?.. She stem was retting
at that ptcnfct and vras coal black, She root development 7?aa
abnormal. One thing I noticed ran that a let of rur manure
ran put underneath of the plant#

Micro# exam#:—•— Sections cut from the retting sheared fungous
mycelium peculiar to the B3iizocti.nla spp. ( clamp connections.)

Banana. ( suutr. Hapieaiuia)*

r - i 4 .

Bmu is subject t,c t.»c diseases. 1. leaf spot Besrtilczsiaspp.)

2. Macrcphcmaspr* saall bkick dots cu th leaver.

Leaf spot.. This is caused by a luagus very viral eat da theplaut

the riags

7

The spots are generally elongated aad axs An', to after the f&shioa
cf rotate starc?;. The spots vhea aiaay jcia to nether v.md cover the
?rhcle leaf i it being a na »s cf parched natter*

The colour cf the pet is first dull brovra a*d thsa.it xrx turms
dark brevra rith blkck dots e* the same. This is the spore mass
cf the fuagus. Old ivs. are no re subject tiaa the ycuag Ivs*

heaves cutting and bur*lag.

Spruyiag seems to check the di s ease * ( ^erdeaux*)

mo.'c. ex an.

> 1

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■

■»

»rr

n

2!ts stick*®'.! rips found in *sc®sPV3lii and raised cu stalks
jnjg iKsiatufes sperss airs unitfellulrar rith tcv* appenduagsu on «is tep

i

hile the nature -.cues have iksxefcur of no re cells , the mid cells

being brovm the top//cues colourless* with tew hairs on ••h.a,

/

fa'

jF

k

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9

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2 • Mac rev hen st nue .

Mh 5.*j ".aid to b3 £ umprcphviic

fungi** mad is feu ad cm Xvu. ( ms fmr meted here

E'ho small black -dots cu the

leaf

are the pycaidim cf the fungus*

•

*

■

Bean. ( P hasoc7.u n 7.anata *>.)

£his pl&at is subject. tfc<fc a 7.et cf> diseases. She fellcvriag are
Leaf spot. cclletctrichto liadenathiaaan .

this is found cn all parts cf t-ie plant/
di e bach, 3 • S cl e rc t i an.. * ir p .

acted .:

OS

* (_ •

V e rra < cal e r:\ a ipp

' V

Anthrocncse . f bean.- This i:i the worst scrt cf disease the
gardener has he fight .with. it attnekes all the parts cf theplnat

4

I

except, the rccts . Well selected beaus which showed nejf signs cf
any discoIcraticss develop this disease.This seems to ledge iu the
cctslec'cas aud iu the primary sh.cct.iji aud whence it Eiigr t.es up i.utc
the leaf aud pods ut especially nature pods, a.:.d pods cu old
plants. ( standing i.u the plot fer a long time. ) Compare the
eld plants aud the young newly pin ted beaus.

Gyr.pt.cus These are shewu by /sortacnetines eaakees( retting)
this is mere

Oh leaves sr.a

acticable iu rainy seasca. and wet Eixmaiaxer weather.

ceppe rcclca red

all white parchment like /spots(drying and.then shedding
are uct.icable. On pods they are observed as brownish specks.

This speck has a cushion .like rad dews iu the pcd. This i s due to
the vi go revs s growth cf the fungus. — stroma-—. shxx The fungus
develops its reproductive parts ere long if the weather is suitable
mcist weather, “lack apsis dots iu the spots shew the ascervuls
cf th.e fungus,,in which are found to be the spore sc f the disease.

The fungus eh ers the sod through this st ona -which makes a dwelli#
place cf the fungous spores.

This has done a great deal cf damage tc the crop and hence rigi/d
•election as regar ds seeds is easaatinl.

FiijS

Bordeaux gives* seed royalty. Burgundy nixr.uro Jian gi.Tr;>*. aa7-Hc

... „

3 at i !>f ac tc ry r s su 7. t :>.

k strain f coloured coated bean seems to bo lo f rj :uricepti.blo be

*

tMs fumgTOff* A C'.ty i nr ‘nay produce a reel sltrit variety.

Iviicrc. os an.

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ofarr*^ '

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jfu**o ***■ < r ^ cU - + */*r

plant ia found tc be a prey tc fuggiil

and second on flower.

Urcmyces appondiculatus? This is only t usd cu this plant
and act cu the allied species though they ..re growing node by side,
-he iuncus attncbe the 7-enves^the pods M^xneikxngxel&sxusxfnjcxxsL}

The leaves crumple and curl e* the sides, the fungus generally

is observe ca the lever side cf the leaf. First,pustules ~~

■

orange coloured and shining are acted and these burst and liberte.

the spores.

id

orange reorder. Thin found on the rods nine*

Dees much damage .

No remedy is tried.

Kirro exam.

fix

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k^cU. S’far**”'

/co 13 io

C

x

Groundnut, pie a aut.

Ground irt attacked by the fcl‘ owimg fungi:—-

% / JlC fc

Bhizecterda, spp.(rctj; Leaf 'spot. Cerccspera persona* a*

'T .

cbusrysd by ns.) 3 Ssptcglcsn arnohlde*.
pro. • *

RJii.zoct.enTa upp j-a*- This fungus attacks the. plant iu its

\ • i # * * " * *.

early an well an Idte stages. --it b -.oil fuagus first starts

from the recta upwards. She tissue at the noil level be cone

flaccid and papery atid acthiag renalns but a fevr tJire ads

cf tJe bant fibre. She cc a sequence is th*t the Ivu. dry and the

whole seedling or the plant an the cane nay be , 6 ten*

i:ic(rc.gex/iru shews t!ie fun cun ayceltua peculiar to the species.

Xoo^yJ-

s£)<rCL Ajtr&L

Leaf spot disease. :-r~

Thia neons to be the ccnna* leaf spot cn the plant.

She causal fuagus is Geptegleen ^rachidea. It produces large
round or a little eloagated spots which are brcwaish black i*
sellar : ia the centre and surrounded by a sharp blabk liao
aad thea a diffused yellow ring merging iatc the healthy tissu
Shey occur especially cathe lower aad older leaves, aad they

i a

drop before maturing.

^ ( A * fc. . • ■ ' ■ tf * ■ .*

There i*s a let Ivs. falling , diminishing the crop.

... . -u' »» ^ ^ »

fill ore. Exan.

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*

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mmm

E

Zen nt.y*i; ( Maize)***.

* - .

&X3e XS Cb8G3^*VGd CC KUbt®X 1) e a A X ©ftf 5]'c‘h filer'll’;

Relni. a tha.upcri.an. ; -Shin aeeny to be a very

, ^ ,w 4 ^ #“ «

% , ^ * 1 ' —- ,

daq ui $ e as j cr ••■Uu* crop* It produces lcu£ elca^a Gu gpct h v. r :ix cJi
fxrut besia snalX yellow cval cr round spots. They ihe« elongate

Aid run fclcag the side cf the veislets of the leaf. The nid Mb

. *•

limits the tip re ad . Thus they ceve r the whole leaf ifcmnthwi.ee.

- • f-

T!ie leaf is disccXcur©dxA*gxs52a»ttM*x first red ish and thn
y eXlc*?iaJn$xi£* 2 a whoa it dries up* The score mass cr& be feu ltd xa

Dreeaxsh powder ce the spot, observed only in suitable weather.

»

This shows the spores of the fuagus.

„ . 4 *

T:ie plaat is stuated and produces very snail cobs* as.cl
natures too early.

• Sfcfcippiaf. off the leaves,

Micro. exam

>

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Rico.

Heliai*tha, ^perium Bat.Iran? 1b fettad ch rice

:i *3 uc3aad ex the leaves . 2he black ponder ca the grata aaadcu
the sheathes shov: the spores* The fuaga •> seems to retard the
devsSbcrneat of tl* grata the basic.(He seed was observed).

Gr eci me a f rc m Mr X a ecu.

Micro exan.

Sfitrte^ .

£j*ov*- pesvyrvMaAntf

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7 fctJc a ' w -

,^e C ' •

i fare,

)/Lta<

l^bir*** (rjOu^eT) d^xryvxJ

Fujrs

i'~ Oo ccf.- ( C oCcr
S?ie cecca fruit is attacked by

a

*V

Ccf f 30.

• *•

S.

This estate crop cf the a&ny trc pi cal countries is subject tc the

following diseases*— ccf fee rust( henilia vastatrix), ccffeespct.

( pesilezzia coffee), p!ii7.7.csticta,

Ccffee rust

This

•

is the most

•

common disease

cf

.M. ~

1 * • r«*

’'» ;

pi a? it and d

fren a long tine

. This is the

*■

no T 1 1 *. vi. nil e ? < t

of

the

disaasaa cri

ccf fee, and is a

n^"> v y.hlA tr

J C vi 1. ' • 4 4 1 > J. '-»* '

great losses

to

the

planter.

The fungus as

/ '-4 iU U UVrfV*' »

on. the Ivs. b

ut i

t i

noted on

3 «-N

tips cf young branches and cn berries. She prime ry synp-fc*n of the

ai.t ;.ck is a ye?-lcvj spot cn the back cf the leaf, the colour is

/

intensified by the growth ci the fuu^u ; .i a ay 03- cay. 0**. i f *s tul.-.
development , the spot is covered with crania powder, the sreres cf
the fungus. On the upper surface there are nc signs cf the spots

i

first but latte cn brownish patches are observed . The spores a. re

net observed cn the upper surdace. . These spots grow wide by

*

by 3 o% ning , but thair srend is checked by t 1 a veins for r. time.

Vhen the attack is severe the whole turns brown a ad dry.

Ehis disease is net very virulent c the 3 states cn the Bet. ~arda
, only a few showing spots . ( checked by spraying.)

It is mere markedly observed cn the young Ivs. than cn the old Ivs.

Kenedy. :

of f active.

spraying is satisfactory but it is “.aid net tc be sc
Rust ra si sting varieties are these shd. be y rued *

K f

i c rc . ex an.

F 3 i/

MaMvu

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(2) PestilczrU. oef : -Thie; iu very cozaiicn on th 3 plants i.n

tdie Gardens. and causes vrhat may bo turned r.: af scjterch. Th3 p &&

fi.y'Ub iiheu its appearance cn the s upper surface and ' spr ..a

na^ 4 ly cn the 1 af * Gov oral 1 spots ji.cn and £ivo the leaf

>

tJt® appsa-a/uc^ cf W-.s scorch. 2 he rlvifia p®o«Ut'.r ofcsx tfn.K

*r»v* s» QS

v*un ‘'*u *» are no bed i.n t. 0 *rpcv. •» • v/. 1 *. 0 * 1 a;.

0 covered TP’.th snail GO’fcs

1 ** ^ •.

I ._*? t£, » fc*:

-;.;V3 uscervulii cf the fungus. She charaTfcerlsi.ic spores cf the

funyus are found &a the dots,

There i.s a yyeat

:* f

. » -y Kyi

v*«i** 1 ■ {■• 1 'r. t"( ia* r*n

I i .L ,. IU 1 •. > -•> v , . v- »• *•« t

riant i.s o’10deed tc a great extend.

Renedy tried.

The affected leaves ddi *r. v e baring bra

are burn*- I>c v, o.oau-i. i. s *peo.

IvII c re . ex an.

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