PERFORMANCE OF HAMLIN ORANGE ON 16 ROOTSTOCKS IN EAST-CENTRAL FLORIDA

'Hamlin' orange (Citrus sinensis L, Osbeck) was grown on 15 rootstocks : four citrumelos [C. paradisi Macf. je Poncirus trifoliata (L.) Raf.] , five mandarin x trifoliate orange hybrids (C. reticulata Blanco x P. trifoliata), two pummelo x trifoliate orange hybrids [C. grandis (L.) x P. trifoliata], Vangasay lemon (C. limon Burm. f,), Norton citrange (C. sinensis xP, trifoliata), and two Smooth Flat Seville (C, aurantiu m L, hybrid?) hybrids, These scion-rootstock combinations were compare d to trees oh Swingle citrumelo, the most widely used citrus rootstock in Florida, One Smooth Flat Seville hybrid was eliminated early becau se of poor growth and variability in size, and the Vangasay lemon root stock was eliminated because of severe freeze damage, At age 5, the tr ees on Norton citrange developed citrus blight and we're eliminated, R emaining in the experiment for 7 years, 'Hamlin' trees on six of the 1 3 rootstocks produced more fruit than trees on Swingle citrumelo, Of t hese six, HRS 852 (Changsha mandarin x English large-flowered trifolia te orange) was the best overall rootstock, with trees on it producing large quantities of high-quality fruit bn medium-sized canopies,