3 research outputs found
Epidemiology and integrated control of Potato Late Blight in Europe
No full textPhytophthora infestans, the causal agent of late blight, is a major threat to potato production in northwestern Europe. Before 1980, the worldwide population of P. infestans outside Mexico appeared to be asexual and to consist of a single clonal lineage of A1 mating type characterized by a single genotype. It is widely believed that new strains migrated into Europe in 1976 and that this led to subsequent population changes including the introduction of the A2 mating type. The population characteristics of recently collected isolates in NW Europe show a diverse population including both mating types, sexual reproduction and oospores, although differences are observed between regions. Although it is difficult to find direct evidence that new strains are more aggressive, there are several indications from experiments and field epidemics that the aggressiveness of P. infestans has increased in the past 20 years. The relative importance of the different primary inoculum sources and specific measures for reducing their role, such as covering dumps with plastic and preventing seed tubers from becoming infected, is described for the different regions. In NW Europe, varieties with greater resistance tend not to be grown on a large scale. From the grower’s perspective, the savings in fungicide input that can be achieved with these varieties are not compensated by the higher (perceived) risk of blight. Fungicides play a crucial role in the integrated control of late blight. The spray strategies in NW Europe and a table of the specific attributes of the most important fungicides in Europe are presented. The development and use of decision support systems (DSSs) in NW Europe are described. In The Netherlands, it is estimated that almost 40% of potato growers use recommendations based on commercially available DSS. In the Nordic countries, a new DSS concept with a fixed 7-day spray interval and a variable dose rate is being tested. In the UK, commercially available DSSs are used for c. 8% of the area. The validity of Smith Periods for the new population of P. infestans in the UK is currently being evaluated
How sexual reproduction affects the population biology of Phytophthora infestans
No full textPhytophthora infestans is a rapidly evolving and highly adaptable pathogen. It is the cause of late blight, one of the most devastating diseases in potato production. Depending on whether both mating types are present or not, P. infestans can undergo both asexual and sexual reproduction. In most parts of the world the asexual part of the life cycle is the dominant reproduction system resulting in dominant clonal lineages. However, earlier reports indicate that sexual recombination of the late blight pathogen occurs in the Nordic countries. This thesis includes studies on how this will affect the population biology of P. infestans. The results show that the genotypic variation of P. infestans in the Nordic countries is high. The highest variation was observed within fields, and no dominating clonal lineages were found. In a field trial planted with artificially inoculated seed, the genotypes originating from the infected tubers had a minor impact on the population of P. infestans during the season. Immigrating genotypes, which probably originated from potato crops infected by oospores, proved to be more important for the epidemiology of the disease. The presence of the alternative host (hairy nightshade) was shown to result in an increased oospore production and a higher aggressiveness of late blight on potato. From the results it can be concluded that oospores play a major role in the population biology of the late blight pathogen in the Nordic countries. Furthermore, in a study of the variation in effector genes of P. infestans, indication of selection pressure towards losing intact Avr4 genes was found. In all studied isolates this frame shift mutation was observed which means that all isolates would be able to infect plants with the R4 resistance gene.
The population biology of the late blight pathogen in the Nordic countries is complex and differs from that in many other parts of the world. The difficulties to control this disease are numerous and the nature of the Nordic population of P. infestans threatens to further add to this problem
2
No full textTHE GITIZEN.
L. P. Hathaway,
Editor and Publisher.
Other? II! *..<- Pa
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Tekpr*ooc Msln III.
amfr-r*
ValSllicvU- 1
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wool■ I Mian, tl
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i afford
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Basaas ,t -d
hi -tr-n
;It pro'-i't tofjo
to cbunli mil.
ll.-B.b-l
>..| Will ,-Bt
minx* a* sit!
I'll! ■
ton ll -act Mas
a rliam-r.
* htam*-l t"i rvrrrthln-i;
it It* d<«*i ia ttu? damag*
Tb* "-t-ab"
Ho- tateel tat. I
to Ihe fruit
valley A sort of a (ungii* luut broken
Stray from Ih* » alt imi-ii and i- doing
a lKUe'-pr-tig-itm-''.«. it*..wnart*.-unl
In th? light of local -..mllllmt* ll as-
hard ly (air to take Assetnl.lrman Mil-
rh-dlr-**' tn "-a.-mmmif, |„ trlt wtiat It*
knew ala.nt a pceaaT gant.' ;n -ahirb onr
of thr l***11mg seualota t.Hik j-iii t.
Thorr an- a (••*■ pere-on* lu Palo Ut"
aho ran Naasai that Mit. I. "br*.** asa
card torn, ao"tt*er."
A young man at Muiuic. lu-I wa*
Hani Tit.--.tjt fur "carrving eigar*tir
pa pet*. ' bring tbr brat SsaffctM nnd. t
th? law probil-illr.g rigan-tlrw ami tbcit
maim tart lire -.-. .■nlly p***s-d tu lii.li-tmi
Tbr law author it!.--, would hart- trouble
in coerBlirag alt -4 Ihe rigarrtl* smoker,
in falitir.ua ami In fat-. All*. ?**s*ri*Uy
Hut at tli? Indiana rat? of ru-ai—in-*
lines it would mil lie l»ng until tlw
trraaurir* aerv all hill an-I o*r-airl->wii-g.
\(-w*i-*->nr read?-* can in-1 Is- i-x -■. !
UiremetiilK-r *-*-*-*tfatna "i.y read an,I
it i* Ihrrrforr BSSaSHIJ, *omrtimr*, to
retaiail Own ■'■ tliat which really -"-.-old
not It? lon-ott.ii
In viow of .-in-iiiii-tatti't- tliat li
arisen. Th? Clllsni tr?l* iltat It "i-i
most hair --inclliii-a- mmm |*
refSI-iliuB thr IVerj-rrrii rburcb ci-ntr-H-l
at Mayl.i'1,1 and IHI ol tbr mi-orwlil<<
waytli? tint,.it- un- trv.itini- Cuntructoi
ote taam. aho built Ha* ubiib.
It will Is- iiissslisiia* Uiat -.l.i-ii tlw
8^
m
<
Tear up your Carpet
and use rugs and painted, varnished,
stained or waxed floors. You'll have a
more stylish home, and your tloors will
be better, cleaner, and more healthful
in every way.
Sherwis-Wiuuks
Modem Method Floor Finishes
(jive the dressiest Iloor effect* at a cost
that is always towcsL
If you sre undecided
as to bow you sbslt
faOtsb your floors,
Ulk to us about it*
we c sn help yon, y
J. F. Parkinson Company
./ "we Want Your Business"
LUMBER - - HARDWARE - - - PLUMBING - - - MILLW0R1C
>
0
!
A
la.
ih?
Easy Way
LdSt
■m-i-biig lhat thr*** tin* wrk * int..
nl-.,!,'* ba-BSS. Tl-.dmr.-b Isanl knew
rigbt w?ll tliat th* Uut.lins o-uU not I-
mjuwanoi l.*r Uh- -..in naui.-l in ii.--.-tiV.
ilual Ind. but it tdloaad bint to taki- ih?
work iil-.iiil..-|—.tit.'..-ti.iiii,-.- rerl-al
el .-.-.tar' tliat tin' union, of --anla
rhtracmntj" wii-ild SSS thr i-.oili-arl.-r
.tif.lt tl,t..unit with lb? job.
Tb? hlda Of - i Hi? UUIOll Klll-
lna**St*a will, a «-.1 ..( i«nbina1-h- ton-
spiracv [tn lb? union- MIST Is-
thought uf that
ftlhsin I'-smtSv.—0««Ua
Hi ■■■■ I -:■■
til IJ.'la.-1-g.-al till Sill Flilll-
I'.*. !.> i-t-t*-.iial1v ti>u-
■lacti-1 t.-ari.t car .-Till prion* in
qurckct In... tm -t.!....1.t.-t
an.1 .t„ il.-t Mam Highway I .
Merri Nevada sceneri-, tb,-
Oml --.it labs ex-sashs* ami
tbr I; akira bydayliglit.
Agent A. P. Michelson
or writ?. Paul --hoop, ft, P. A
P. A.. San /o*?.
Southern
Pacific
l*anltTii*tl mr l'U'1'IIIIIIi-JTT
..-id.. nn.lti.Hli
*.-tindiiig taflv baiKlitt ..nt t>. lha rvadv-
lo-Is'Ii,.,.....yfrytbiug -ufT.-.tiig public-
ib,. K\ Klt-l'KI -I NT DEHlttE or
TIIK t*:.ti\S TO t'oNTIIHU TK. IN
A WAY THAT Unl l.l» P.K AI'I'IIK-
01ATED, To ThK I I'llttl.l'IN.. 0V
iTii'.iin licit.
That ....knl g—I t- .-viryoiK-. Bui
a*k OI-...1 and llw church l-ard b8*J il
look* Irtiui tin- *taud]*>iut oj tbc
Oh : mat Charily ; You ar? a k??n-
clgt-l tal in the bands -4 ih? union.
hot von an* -**-m dull.-1!
Winn 11 conn-* to ,i -.hon-down. tht-
and rvwanlinii tb? cliili-and-1>ill> naa
who ihi* b during boycotts In an effort
to I'l T THK FKAIl OF 000 INTO
THK IIKAI'TS "f thi*..' wlm p?mist >u
their .■florl* to cam n livitii-. Ofttiur-e
th.* wslklng delcgatr. il lie cannot graft
lor bis kerp, mnst b? giicn sontrlbtng
now and then, but 01? Olson and the
Kn'ij-ti'i'ii cliun-h Ismrd know to s
ct-rtainty that there Is nothing in the'
iiittuu treasury i-t i III l.CII III II.I'-
reo.
Thal i-.i-tii-ii!.ii fcatiir? s??tii* to have
bsan ovi.rl.*>kt-l trtlt-.it Ur- unions were
.-rgant-ed and tb? -evcral fund* *-.at-
BAad,
Tin' biiiiii' itiivaiimarv agitator was ofl
on a jag alien the Constitution was
aitopt-nU. that was hcftirc lb<< .l.-t.v-ttc
Inwi the San Jo** ■'!'*.lot-'
t'uioii'- was atluiilU-d lo the Ihiilding,
-iriiir-iT'tirinPlT, " '
It was a |«rt ot Ihe "l-enrvolencv"
|dan that union men in I'alo Alio, Martini,!, Mou ii Win View and i-l-rivbrti-up
nnd down lha line slnaitd turn .ml t-u
gm*n I "ark got a tlO.tSSI church for
tV'«*M. tell 'em to ask Ota Olson—he
know*. Tin- church board knos*. too.
Hut don't ask tbc 11. T. (". aiiylhlug
ni...ui il or you'll get a siusy reply, no
doubt.
It mac be m-attuned, i.y the way,
that th? sub-oiti tract or* couldn't do thu
job justice all th? way through; tin*
painter, for insiaticc, mussed tilings
over tu such an est***-* that the architect
—K. II. Walker—would not accept that
■caliiro of th? work slid ta* a enns-.-
i,l.ii
after
Iikling
ami i
rt
i >ir an.1 Uie *uli* bad to "p> tt alone."
and il must be -aid to the credit uf Mt.
UIm-ii that be did admirably; he la
t.-j-.'iti-l to lutve l.tst more llisn he
cookl aril aflord to 1 -*■*, but be man-
agt-t linallv to grt tbr t-burcli In *liaj^
to be ■ letlicated.
Their we* an .ill .lay service that
!-undav Sn*!, thank* to some kindly ilis-
l*t****l "o-*eti »lmp" ilivtriciaus Irom
Pslo Alto, a night service, but the
records of thr .-ccasiun do not show tliat
tli* I'., T. C. and thr union* ol t-anta
Clara county bad more than a vct-i
pocketful of eulogle* Hhowcrcd tt|.,ii
Ihcm.aiid thai'* letting 'em down ju-t
as easy as it is [wasible lor The C'tlii*-*
to da-mi-* tbe subject,
j It anybotly ever asks >-ou bow Ever- i
qucii.*?, tin,* tar, asphalt or whale
wa* tliat aa* first daul.ed on has been
trurnrd of. and a cuat ol somtrlliing
N'tit-r put on.
Tbe electrical couiiaclor was three or
-u-q****-*! I., put tbc litii.biug tia-Kbe* oa
a tl.'-u job that he "ami the union*.''
bad agreed lodo for Kw* than bull tbat
sum, ami I" liours before the tights
were actually needed for th? drttkab.ry
•s-rticr* some ".q-rtt shop" men Irum
1'ul.i Altttwci? pretaitcl ii|-ou lo put in
Ihr lii lure- and make llie ciiiuetiioii-i.
board wilt stand la-hind him. The
union* will do nothing but blaS and
bulldiiac.
When unions talk tn you at tout
CHAltlTY, gi-t au interrogation point
into your "nrdinic" smile and let ll go
at thai-
-SEAMANS:
Bell's Stables i>
Fin* RublHir-tireil Itlgs
ami .Sui-rey*. llonw*
hoarded. l>rivet-- lur-
ninhcl. '
BELL & DONALDSON
High and Harraltori
mj l-MVERSITY AVE. PALO ALTO. CAL
fr**VV ■ as *wra*}*%% a ■ *V'^g
Everybody reads The Citi-en
And ;
.-: tal
The
U-atd ha* been advised by the 11. T. C.
and the thrt*.. walking dclt-gaics wlio
nltendi-*t a -private bounl miftilig one
night thia week, NOT TO PAY THE
loll, i" Tin -i ai;-.
Th? real aaeistanw the unions gave
the board was when they sent llirec
waiking drlc-gnte* to the board inert ing
to advue ft* mrnil-m to rrliaw- to -ay
Mils, some ot which, il Is t-aid, acre
incurred hy Olson himself aa contractor
and for which be and the board wer**
rightfully obligated.
Ol?. like a man, li-.wetrr. -aj* every
bill will be paid. The cliaucea are the
r***as»a*s"-s»a»**s^
ON RUTHVEN AVENUE
Another Chance
Seven tine lota on Rutltvrn avenue
were oflered st »17.". and a"*.*) but
von did not come in tn -,-.- .ii.--.it
them. We arc uftrring lots tor f-v-o
now*—one week unit-—so ynn hint
better luveatigatr. if n-al quick v.m
can have one T-". x III' tor pv-i
II mtcii-atcd DONT WAIT.
PALO ALTO REALTY CO.
JOHN F. BYXBEE and B- F. HALL, Manajeers
iweswtwmwtee*sssssmsmsmfets^
