PCC Nov/Dec 2019

Plant health starng from 1 week aer M. phaseolina inoculaon
5.0
4.5
4.0
3.5
1 wk 2 wk 3 wk 4 wk 5 wk 6 wk 7 wk
P = 0.117 0.002 0.182 0.030 0.130 0.038 0.018
a
a a a a
a
a
ab a
bc
bc
a
a ab
ab
ab
ab
abc
bc
bc
a
abc
c
b
bc
Plant health rang
3.0
2.5
2.0
c
bc
bc
c
c
bc
bc
1.5
1.0
0.5
0.0
Untreated control M. phaseolina Bb 1wk before Mp Ma 1wk before Mp Bb with Mp Ma with Mp Bb 1wk aer Mp Ma 1wk aer Mp
Continued from Page 21
health was monitored for about five
months prior to the commencement of
the study. Conidial suspensions of the
California isolates of B. bassiana and
M. anisopliae s.l. were applied one week
before, one week after, or at the time of
applying microsclerotia of M. phaseolina
to the potting mix. The following
treatments were evaluated in the study:
1. Untreated control
2. Soil inoculated with M. phaseolina
3. Soil inoculated with B. bassiana one
week prior to M. phaseolina inoculation
4. Soil inoculated with M.
anisopliae s.l. one week prior to
M. phaseolina inoculation
5. Soil inoculated with B. bassiana at
the time of M. phaseolina inoculation
6. Soil inoculated with M. anisopliae s.l.
at the time of M. phaseolina inoculation
7. Soil inoculated with B. bassiana one
week after M. phaseolina inoculation
8. Soil inoculated with M.
anisopliae s.l. one week after
M. phaseolina inoculation
EPF were applied as 1X10 10 viable
conidia in 100 ml of 0.01 percent Dyne-
Amic (surfactant) solution distributed
around the base of the plant. To apply
M. phaseolina, 5 grams of infested
cornmeal-sand inoculum containing
2,500 CFU/gram was added to 4-5
cm deep holes around the base of the
plant. Each treatment had six pots
each planted with a single strawberry
plant representing a replication.
Treatments were randomly arranged
within each replication. The study
was repeated a few days after the
initiation of the first experiment.
Plant health was monitored starting
from the first week after the M.
phaseolina inoculation and continued
for seven weeks. Plant health
was rated on a scale of 0 to 5 where
0=dead and 5=very healthy and the rest
of the ratings in between depending
on the extent of wilting. Data from
both experiments were combined and
analyzed by ANOVA using Statistix
software and significant means were
separated using LSD test. The influence
of EPF treatments applied at different
times as well as the combined effect
of different applications within each
fungus were compared for seven
weeks. Ratings for some plants that
were scorched from hot summer
temperatures and died abruptly
were removed from the analyses.
Results
Untreated control plants maintained
good health throughout the observation
period varying between the rating
of 4.3 and 4.9. In general, plant health
declined considerably from the 5th
week after M. phaseolina inoculation.
Plant health appeared to be slightly
better in plants treated with EPF, but
there was no statistically significant
difference in any except one instance.
Plants treated with M. anisopliae
s.l. one week prior to the application
of M. phaseolina had a rating of 3.0
compared to 1.6 rating of plants
inoculated with M. phaseolina alone.
When data from different treatments
Continued on Page 24
22 Progressive Crop Consultant November / December 2019