Allelochemicals Biologica... - Name

NATURAL PRODUCT BASED FUNGICIDES 11
No systemic or translaminar activity was detected when azoxystrobin, CAY-1, or
sampangine was applied 24 hrs after inoculation with C. fragariae (Pre, Table 1).
Field studies indicated that significant differences occurred in marketable yield
of strawberries as a result of fungicide treatments. The highest marketable yield (17,071
kg/H) was recorded from plots receiving Pristine fungicide at the rate of 0.62 kg ai/H.
The next highest yield (16,960 kg/H) was harvested from plants treated with Switch
fungicide at the rate of 0.8 kg/H. Plants from the untreated control plots yielded more
fruit than plants from four of the fungicide-treated plots. Plants treated with CAY-1
produced the lowest yield of cull fruit weighing 1,390 kg/H. compared with the highest
yield of cull fruit weighing 5,816 kg/H produced on the plots treated with Pristine.
CAY-1 produced high yields of diseased fruit weighing over 9,400 kg/H. Five fungicide
treatments resulted in the production of marketable fruit at 60%: Switch® (69.8%),
Pristine (68.51%), Cabrio® (65.5%), and the two CaptEvate® treatments (5.8 kg.
and 3.9 kg, 65.8% and 62.7% marketable fruit, respectively). Most treatments that
were combinations of two fungicides produced the highest marketable yields and
lowest disease percentage.
The total number of berries with fruit rot symptoms and the number of berries
with symptoms of anthracnose or stem end rot from the April 24 harvest time were
significantly lower from plots treated with the fungicides Switch, Cabrio®,
CaptEvate®, and Pristine® than from those receiving no fungicide treatment (Table
2). The most prevalent diseases in the Louisiana field study were anthracnose caused
Table 2. Fruit rot and field data from April 24, 2003 harvest of fungicide treated
strawberry plots, Hammond, Louisiana.
Fungicide Total Rots1 Anthracnose2 Stem end rot2 Plants Dead (%) 3 Foliar disease4 Switch 1.5 f 5 0.8 e 0.0 d 16.3 a 2.8 a
Cabrio 5.8 f 3.8 e 0.5 d 8.8 cde 2.6 ab
CaptEvate (High) 6.0 f 5.0 e 0.5 d 5.0 e 1.1 e
Pristine 7.0 ef 5.0 e 0.3 d 5.0 e 2.5 abc
CAY-1 (Half) 22.0 def 18.0 de 2.0 cd 15.6 ab 2.8 a
Captan 27.8 cdef 21.3 cde 3.0 cd 7.5 cde 2.0 bcd
Quadris 28.3 cdef 20.3 cde 2.8 cd 8.1 cde 1.9 cd
CaptEvate (Low) 29.0 cdef 23.3 bcde 2.5 cd 7.5 cde 1.8 de
Captan+Elevate 43.0 cdef 28.8 bcde 7.0 bcd 12.5 abc 2.0 bcd
CAY-1 (Full* 50.5 bcde 37.8 bcd 7.5 bcd 10.6 abcde 3.1 a
Scala 59.0 bcd 47.8 bcd 7.0 bcd 9.4 bcde 1.9 cd
Control 63.5 bcd 45.3 bcd 9.8 abc 5.6 de 2.8 a
Emerald 70.5 abc 50.3 Bc 7.8 abcd 5.6 de 2.9 a
Nova 87.8 ab 54.5 Ab 16.0 a 7.5 cde 2.0 bcd
Elevate 109.5a 84.5 A 14.3 ab 11.9 abcd 2.6 ab
LSD (0.05) 44.1 31.6 8.4 6.8 0.7
1Total number of fruit/20 plant plot with any disease symptom.
2Number of fruit with anthracnose fruit rot symptomn (Colletotrichum acutatum) or Stem-End Rot
(Gnomonia comari).
3Percentage of plants/20 plant plot dead from anthracnose crown rot.
4Foliar disease scored on scale of 0 – 5, where 0 = no disease and 5 = plant defoliated due to foliar disease.
5Average values followed by the same letter were not significantly different at the 0.05 level using a Least
Significant Difference.