EVALUATION OF MELON FOR RESISTANCE TO BEMISIA-ARGENTIFOLII (HOMOPTERA, ALEYRODIDAE)

An experiment was conducted during 2 yr to develop a rapid and reprodu cible method of screening melon, Cucumis melo L., germplasm for resist ance to Bemisia argentifolii Bellows & Perring. Multiple tests were co nducted on plant response and response by insect for 31 selected melon entries when exposed to B. argentifolii in an open-choice greenhouse test for 2 wk. Frequency distributions of susceptible and resistant en tries and their F-1, F-2, and backcross families indicated genetic var iation for resistance. Whitefly immature density, plant condition, and change in whole plant biomass were good indicators of plant resistanc e. Data for root, stem, and leaf biomass, stern length, and plant mois ture were inconsistent. Resistance plants had lower whitefly density, were in better condition, and sustained less reduction in size and bio mass as compared with susceptible plants. This method allows the testi ng of germplasm and segregating populations throughout the year rather than in one portion of the year as has been done in the field.