Research
Melcast results for 2002
ISU
Horticulture Farm (Gilbert, IA)
Using the Melcast disease-warning system resulted in two or three fungicide sprays when on-site or SkyBit weather data, respectively, were used as inputs, whereas pre-scheduled spray timing regimes required four to seven fungicide sprays. Anthracnose lesions were first observed 2 weeks after inoculation. When harvest began, percent symptomatic foliage was significantly (P<0.05) greater in the two Melcast treatments than in the 7- or 14-day spray treatments, but none of these treatments differed significantly from the unsprayed control. The marketable weight and number of melons harvested from the unsprayed control were significantly lower than in the other treatments. Therefore, the Melcast treatments resulted in yields equivalent to those in the conventional, pre-scheduled spray treatments but required one to five fewer fungicide sprays.
| Treatment | Rate per A |
Spray frequency |
Number of Sprays |
% Disease | # of marketable melons (/ plot)z |
Marketable Yield (lb/plot)z |
|
Non-treated control
|
---
|
---
|
0
|
12.4
ab
|
6.2 b
|
32.9
b
|
|
Bravo Ultrex 82.5WG
|
1.8
lb
|
Melcast
y
|
2
|
20.1 a
|
12.2
a
|
66.2
a
|
|
Bravo Ultrex 82.5WG
|
1.8
lb
|
Melcast
x
|
2
|
19.7 a
|
12.0
a
|
61.6
a
|
|
Bravo Ultrex 82.5WG
|
1.8
lb
|
7-day
|
7
|
6.2
b
|
13.2
a
|
71.0
a
|
|
Bravo Ultrex 82.5WG
|
1.8
lb
|
14-day
|
4
|
7.7
b
|
12.2
a
|
65.3
a
|
|
LSD (0.05)w
|
|
|
|
8.6
|
4.0
|
20.0
|
z
Values
calculated from four 25-ft. plots
y
Using on-site weather
data
x
Using SkyBit weather estimates
w
Means followed by identical letter are not statistically different according to
Fisher's protected least significant difference when P=0.05.