This genotype was acquired based upon interest expressed by several cooperators. Personal communications from Florida colleagues suggest that unpublished work by Prof Jim Graham, University of Florida, has shown that this genotype is either resistant to Phytophthora nicotianae or more resistant than other trifoliate selections but is susceptible to P. palmivora. At this time, it has not been possible to verify these statements with Prof Graham. According to the donor, Michael Kesinger (personal communication, 07/24/2009): "[P trifoliata] is not a commercially used rootstock in Florida except for Satsumas. I just looked at our database and we show no Poncirus trifoliata clones/budlines/selections registered in any nursery seed source blocks. Last year I showed 25 PT trees entered by nurseries as seed sources. In my report, I would usually lump all the trifolates together when reporting propagations for rootstocks used. Yes, I would recommend PON TRI DPI 50-7-6 as the PT to use for Florida growers. In fact it is the only PT selection other than flying dragon that we are including at Chiefland, so I guess it will become the standard." (RR Krueger, 07/24/2009)