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Field Notes
June 10, 2011
Johnny Saichuk
S
o photographs of brown
n spot on Jazzzman 2. It iis somewhat surprising ssince
Below arre a couple of
it is rated
d moderately
y resistant to brown spot, however thhis disease iss often assocciated with sttress
especially
y nutrient strress or deficciency. I do not know alll of the partiiculars in thiis case. Thee
main point is to comp
pare these sp
pots to thosee of blast shoown in an eaarlier edition of Field Nootes.
These spots are much
h more circu
ular than the elliptic spotts of leaf blaast.
i a photograaph of recenttly
At right is
ovipositeed rice stink bug eggs. We
W
know theey are rice sttink bug eggs
because of
o their size and the
characterristic two row
w arrangemeent.
We know
w they have been
b
recently laid
because of
o their color. As they mature
m
they will change colo
ors becoming
g pink
or red jusst before hattching. Last week
was the first
f
week wee started to pick
p up
stink bug
gs in significcant numberss. This
cluster was
w found in Madison parrish. In
the south
h they are ahead so keep an eye
out for th
hem.
This weeek we receiveed several caalls about th
he
same sym
mptom – whiite heads or more
correctly
y white spikeelets. The most
m common
n
variety on which it was
w noted waas CL111, bu
ut
s it on Cheniere. The common
we also saw
denominator is the sttage of grow
wth; in every
case it was beginning
g to head.
Up close the grains appear
a
to hav
ve been
o by someth
hing. In som
me cases therre
chewed on
may havee been somee insect feediing, but this
does not account for all of the blaank kernels.
We really
y do not kno
ow the causee. The floral
organs (p
pistil and stamens) are prresent. Therre
is no obv
vious sign off bacterial paanicle blight..
I suspect the injury occurred
o
wheen the plantss
were at panicle
p
differrentiation orr earlier. Thaat
might have been wheen we experiienced near
record lo
ow temperatu
ures in the middle
m
of
May. Th
he problem is too widesp
pread to be
accounted for by inseect damage and
a does nott
fit any diisease.
Another problem bro
ought in is sh
hown at righ
ht.
I looked through my photograph files and
found thee same symp
ptom among the
unidentiffied problem
ms. I recall visiting
v
with
Dr. Groth
h about this problem som
metime in the
past. At that time he attributed itt to some
mental cause. In this case it is on
environm
Jupiter an
nd the farmeer said this happens
h
on
Jupiter ev
very time hee grows it. Itt shows up
after greeen ring (interrnode elongaation). The
spots are most prevallent on loweer leaves.
Next weeek I hope to sample som
me leaves
taking a spotted
s
leaf and a clean leaf from thee
same plant with a tottal of about 50
5 plants to be
b
sampled. We will then have a nu
utrient
analysis performed
p
with
w hope thaat it will at
least givee us a hint off what mightt be going on
n.
The prob
blem may no
ot reduce yielld, but it surre
looks uglly.
Every yeear I am askeed about leav
ves that
show thiss “dimple” or
o narrowing
g of the
leaf marg
gins just belo
ow the leaf tip.
t
This is veery common
n and does no
ot
indicate anything
a
is wrong.
w
It occcurs
when thee affected leaaf is trying to
o
emerge from
f
the colllar of the leaaf
above it and
a for somee reason the collar
is very tight. I have never
n
paid enough
e
attention to notice if it is cold or hot
prior to seeing
s
them in the field. It is
quite norrmal.
When I started
s
in thiss business no
o one
even notiiced this. No
ow more gro
owers
are payin
ng more atten
ntion to theirr fields
and makiing observattions that piq
que
their curiiosity. That is a good thing;
I’m glad to see it.