Blight
in Nurseries
R. J. Meier,
J. F. Goggans,
ond T. C. Davis'
INTRODUCTION
AizoIna c\ press (0Cqurn (It izolle o
Greene) lots heeln utilized for Chiristmas
tree proidllctiitii il the South wxith some
success . fRecen tls, this speie has oot
beeii i aailIable from most 5) itliten ion-
sei ics because oft disease atiit inisect piroh-
ferns that louder seedliong pi 0(ictiiii.
arn agc has S arned fi in sli gh t to sex c
the latter resultitig ill reduced niimbers of
sal abl Icse) liiigs. These stud ie ss cccoil -
duicted to ev aluate ii secticides for cii
tr-ol of the lesser corn stalk borer and
Rest arc It\ssoit, P(frofetssor, 
and A S-
si sti it I 'ociessir ii I spcctix cly, Aubu~rn t nij-
versitv Aricoiiturat Experiment Station,
Forct srs De)partmnt.
I Iiiltricidle, foi- control of saiolls funigi
that caiiis folior diseases.
MATERIALS AND METHODS
Simiilar (\plociivilts \\ ( d 1 ied ill
two 0 (oiisciitisc ( as 't. Split-plot tiesigils"
wxer e used sx ith in0sectic ides assigi it' to
miioii p)lots ailt fIiigicides to Siti) plots.
liisecticides tested the first Near wsere
fDieldici and BIIC at I pound and~ 2
poiis active iii gredieitt I al.) per acre,
I espectis els ' y. iel (Ireii \\as a ppi ed in
(TrMaitar' forml and ixied into the top 4
ini es of soil wxith a rotot ii ic prior to
plantingr. 13H( wa a pplied as a mixtulre
of I1I percent emutlsifiable coiiceni-ate
wi~th wsater (1 Igallon per 45 feet ofnir
serv bedl). A Co., pressurized iaucf
AGRICULTURAL EXPERIMENT STATION
R. Dennis Rouse, Director AUBURN UNIVERSITY Auburn, Alabamao
sprayer at 40 psi (pounds per square
inch) was used to apply BHC. BHC ap-
plications were made every other week
from the first week in June until mid-
July and weekly thereafter until sample
collection in the fall.
Fungicides tested during both years
were Difolatan 4-F and Benlate 50WP
at 2.5 and 0.4 pounds a.i. per acre, re-
spectively. Both were mixed with water
and applied at 1 gallon of water per 45
feet of nursery bed. Applications were
made every other week with the same
equipment as used for BHC from mid-
June until evaluation. 
Each treatment
combination and untreated control plot
was replicated four times the first year
and six times the second year. Insecticidal
treatments the second year were BHC at
1, 2, and 3 pounds a.i. per acre. Applica-
tion methods and spraying schedules
were approximately the same as in the
first year.
Samples were collected during early
September the first year and during mid-
October the second. A less severe blight
incidence during the second year was the
reason for delayed sampling. Four ran-
dom samples of 25 seedlings each were
collected from each sub-plot. Seedlings
were examined individually for damages
caused by lesser cornstalk borers and
fungi. Borer damage was classified as
root damage, top damage, or both. Dam-
age by fungi, expressed as percentage of
dead crown, was placed arbitrarily in one
of the following classifications: 0 to 338
percent, 34 to 67 percent, and 68 to 100
percent. In addition to the main classi-
fication, seedlings with less than 5 per-
cent dead crown were called "perfect"
and completely dead seedlings were
given another sub-category.
Separate statistical analyses were made
for each year because additional levels
of insecticides were used the second year.
Duncan's New Multiple Range Test was
used to detect real differences among
treatment means within years.
RESULTS AND DISCUSSION
Results of the first year's study have
been published previously, but they are
included here for ease of comparison.
1
Table 1 shows that seedling mortality
was not significantly reduced by the ap-
plication of insecticides. Dieldren was
not significantly different from the con-
trol in reduction of seedling damage by
the lesser corn stalk borer. BHC, how-
ever, significantly reduced root damage in
both years and top damage the second
year. There was no significant difference
in damage when the levels of BHC va-
ried from 1 to 3 pounds a.i. per acre. It
appears that the lower levels of BHC
were as effective in reducing borer dam-
age as were higher levels. No toxicity to
Davis, T. C., J. F. Goggans, and R. J.
Meier, 1974. Pest Control Problems En-
countered in Seedling Production of Arizona
Cypress in Alabama. USDA Foiest Service
Tree Planter's Notes 25(2):7-10.
TABLE 1. INSECTICIDAL TREATMENT MEANS OF BORER DAMAGE AND MORTALITY.
MEANS GIVEN IN PERCENT OF SEEDLINGS SAMPLED
Ist yr. 2nd yr.
I ectide a.i. Mortality Top damagedamage Both root and
net e lb./acre 1st yr. 2nd yr. 1st yr. 2nd yr. 1st yr. 2nd yr. 1s d nd yr.
BHC 1 14a 36a 12a 
3a
2 22a 12a 59a 34a 25a 10a 6a 2a
3 12a 33a 10a 2a
Dieldrin 1 19a 11a 60a 54b 37b 26b 14b 11b
2 14a 50b 26b 11b
Control- 24a la 59a 51b 35b 28b llb 12b
Mean 22 12 60 48 33 19 10 7
Values followed by the same letter do not differ significantly at the .05 level of testing.
[2]
I Ir~+~hnr +hn cnr~r\~7rl a In~e c~n~rn ,I_ L
seedlings was noted at any of the insec-
ticide levels used in these studies.
Application of either fungicide signifi-
cantly reduced mortality in both years,
Table 2. In the first year Benlate was
significantly better than Difolatan in re-
ducing the amount of dead crown and
Difolatan was significantly better than
the control in all crown classes except
perfect. In the second year both fungi-
cides were significantly better than the
control but there was no significant dif-
ference between the two fungicides. The
reason for the difference between years
was probably the less severe blight inci-
dence observed during the second year.
In the two-year study, mortality was
reduced greatly by application of fungi-
cides and visible insect damage was low-
ered by treatments with BHC.
TABLE 2. FUNGICIDAL TREATMENT MEANS OF FOLIAGE CONDITION AND
MORTALITY GIVEN IN PERCENT OF SEEDLINGS SAMPLED
B
C
Am
Mortality 
Perfect
Fungicide 1st yr. 2nd yr. 1st yr. 2nd yr. 0-33%
1st yr. 2nd yr.
3enlate 2a 6a 82a 65a 92a 83a
)ifolatan 13a 8a 10b 63a 42b 82a
,ontrol 50b 24b lb 22b 8C 43b
ount of dead foliage
34-67% 68-100%
1st yr. 2nd yr. 1st yr. 2nd yr.
5a lOa 3a 7a
34b 9a 24b 9a
20c 19b 72c 38b
Values followed by the same letter do not differ significantly at the .05 level of testing.
ON THE COVER. Typical lower branch feeding damage caused by the lesser 
corn stalk borer.
Auburn University is an equal opportunity employer.
First Printing 3M, August, 1975
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