Submitted to: Silverleaf Whitefly: 1997 Supplement to the Five Year National Research and
Publication Type: Abstract Only
Publication Acceptance Date: 2/27/1998
Publication Date: N/A
Technical Abstract: Melons are good hosts for Bemisia argentifolii (Homoptera: Aleyrodidae), a key pest in the western U.S. We have been conducting studies on western U.S. shipping-type melons for plant resistance against B. argentifolii over the past few years. Selected germplasm entries from our previous trials were used for further evaluation. Data from 1997 laboratory and greenhouse tests were collected using bioassays for plant tolerance, antibiosis, and antixenosis. 'Top Mark' was used as the commercial standard in the tests. Plant survivability, plant condition, and size and biomass of different plant parts were determined. Whitefly survival from egg to adult was variable and ranged from about 95% on 'Top Mark' to 50-70% on some entries. Using selected resistant germplasm, inbred and F1 families were made, and the seeds were field-planted for additional evaluations against natural whitefly infestations in the southwest. Not all F1 progenies had fewer whitefly eggs than 'Top Mark.' The inbred entries generally demonstrated higher whitefly resistance than the F1 families, based on whitefly density. The data indicate that the mechanisms of resistance in melon are not necessarily synchronized within a given entry. For example, an entry with good plant tolerance to whitefly feeding may or may not also result in a deleterious effect on the performance of B. argentifolii compared with the susceptible commercial standard.