"About 1500 acres of Washington navels are grown in Japan...Strains of the Washington navel are recognized...The Fukumoto strain, discovered in Wakayama prefecture, has a deeper orange-colored peel than other selections. The flesh color and texture are good. However, it is rather a light yielder in Japan and the ripening period is somewhat midseason." (Bitters, 1963) Original import was infected with tristeza (Thermo 1546-15,16). This import was chosen by Dr Bitters as the best appearing navel in a Japanese produce display. (EM Nauer, ca 1987)
Dr Bitters says he brought in Fukumoto navel for large size fruit and better color. NOW he tells us. Bah! and Humbug! (EM Nauer, 08/1989)
Trees of Fukumoto/Flying Dragon in SH are small and weak growing; fruit is small on average but best color of all. In 12B trees are of average vigor; fruir medium sized at best, good color. Fruit still a bit tart -- probably mid-season in maturity. (EM Nauer, 12/14/1989)
View information about 'Fukumoto' from Saunt (2000).
Although 'Fukumoto' has good early-season fruit characteristics, production problems have become apparent in California. The foaming bark rot syndrom referenced above becomes apparent within two years of planting. This is preceded by lanky growth, abnormally large leaves, and the oozing of gum at the base of the shoots and at the crotch. A crease 2 - 3 cm wide, filled with gum and bark appears at the bud union and numerous suckers develop below the union. These symptoms are especially apparent on trees budded on 'Carrizo'. Trees budded on 'C35' may have less apparent symptoms but may decline more rapidly. Similar symptoms have been observed on 'Swingle' but not on sour orange or C volckameriana (Marais and O'Connell, 2002). Research involving irrigation levels and soil pH did not result in a strong association with the decline. Declining 'Fukumotos' appeared at random throughout the various treatments. There appeared to be an association between the tree trunk gumming and ants, suggesting that ant control might be beneficial. Additional suckering might also prove beneficial. Finally, prompt replacement of declining trees is suggested in managing 'Fukumoto' plantings (Kallsen and O'Connell, 2010).
Due to these problems, 'Fukumoto' was reimported from IVIA, Valencia, Spain (where these problems have not been observed), in order to assess whether or not some contamination or change had occurred to 'Fukumoto' in California. Investigations in this area are ongoing, but it will be some time before the results are known. The new introduction is RRUT 475. (RR Krueger, 08/29/2010)
Information on 'Fukumoto' from the UC Riverside Citrus Variety Collection.
Information on 'Fukumoto' from the Citrus Clonal Protection Program.