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Page 55 · DO #455 · 204_Popenoe_Bx33FF25r
- Collection
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Wilson Popenoe (1892–1975) family papers
- Item/Folder
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The Citrus Fruits - Spanish & English manuscripts - chapter in outline for proposed book with Herbert Wolfe, n.d.
- Digital Object
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DO #455,
page 55
- Collection-level dates
- 1882–1975
Page transcription
16.
Trifoliate-orange (Poncirus trifoliata) seedlings are highly resistant to gumming, tristeza, and xyloporosis, but very susceptible to exocortis virus, which causes severe dwarfing. On heavy soils, if the scions used do not carry exocortis, it has advantages. Fruit quality is good on this stock; however, it is not suited to strictly tropical climates.
Citranges are hybrids between trifoliate-orange and sweet orange. They have trifoliate leaves like the Poncirus parent. Several have been tested as stocks in California and Florida, and one of them--Troyer or Carrizo--is being used to a certain extent; it is outstanding in resistance to footrot and cold, and in production of vigorous, high-yielding trees if the scions are free from exocortis virus. It merits testing widely in tropical America, although its cold-hardiness is of value only in the subtropics.
Propagation
- In commercial nurseries, citrus trees are almost always propagated by budding (bud-grafting), the common shield-bud generally being used. Grafting (scion-grafting) is successful but much slower and more troublesome to perform. It is used only in topworking old trees. Even in such cases, it is usually best to cut back large limbs and bud the sprouts, rather than to graft directly into the cut limbs.
Budsticks should be of well-rounded, well-matured wood, of the next to the last flush of growth. It is highly important that the budwood be free of virus infection.