Agriculture Reference
In-Depth Information
Figure 19.1. Growth response of onion bulb rotting fungi,
in vitro
.
Botrytis allii
,
Aspergillus
niger
,
A. fumigatus
(redrawn from Maude, 1990a).
Table 19.3. Occurrence of
Aspergillus niger
on onion seed collected from different
geographical localities ( from Hayden and Maude, 1992)
Percentage seeds with
A. niger
Climate
No. of samples
Mean
Range
Temperate, humid (rainy with
mild winters, warmest month
below 22°C)
24
1.9
0-26
Sub-tropical, humid (rainy with
dry winters, warmest month
above 23°C)
5
16.9
0.5-41
Tropical, humid (mostly rainy,
warmest month >18°C, e.g.
Savanna)
3
21.0
10.5-40.5
Tropical, dry (hot, semi-arid
climate, e.g. Steppes; ambient
temperatures generally >20-
30°C)
1
23.0
-
Tropical, desert (hot, dry, arid
climate; ambient temperatures
generally >30°C, 50°C common)
30
88.9
26-100
