PLATE 2 
Inoculation experiments with Fusarium cepae. 
A. —White Portugal onion sets were inoculated with spores through needle 
punctures at the base of the bulbs, and planted in sterilized soil in the green¬ 
house at about 22° C. Checks were wounded but not inoculated. Both lots 
produced top growth promptly, but the inoculated plants grew less rapidly. 
The disease appeared as loss of turgor and yellowing at the tips of the leaves on 
the tenth day. Progressive yellowing and wilting continued, while the checks 
grew as usual. Photographed 20 days after inoculation. 
B. —Large bulbs, Red Globe variety, inoculated with spores through needle 
punctures at base, placed in moist chambers for 48 hours, and then removed to 
laboratory temperature and humidity. Typical decay and shrinkage of tissue 
resulted with conspicuous production of mycelium on the exterior of outer 
rotted scales. Photographed 23 days after inoculation. 
96037—24f-7 
