This article describes a new project designed to develop and test novel hybrids to be used as scions and which combine the HLB tolerance traits of Australian limes (Microcitrus) and the fruit ...characteristics of Citrus. Field trials that are in progress in Florida are described; comparable field trials are being conducted in California and Texas.
Valencia sweet orange has always been considered the gold standard of processing oranges for the best orange juice in the world. However, now there is a new kid on the block that is now challenging ...this standard. We have been working with the late-great Citrus Hall-Of-Fame grower/researcher Orie Lee (and now his family) for nearly 20 years to develop the OLL (Orie Lee Late) series of sweet oranges, that mature during the Valencia harvest period.
Orange Opportunities Jude Grosser; Fred Gmitter; Bill Castle
EDIS,
11/2019, Volume:
2019
Journal Article
Peer reviewed
Open access
Florida orange juice has always been the gold standard among the growing portfolio of fruit juices and blends available to consumers. However, the now endemic citrus greening disease or huanglongbing ...(HLB) threatens this status by causing reduced fruit production, lower juice quality and higher prices. The University of Florida’s Citrus Improvement Team at the Citrus Research and Education Center (CREC) in Lake Alfred has been working for decades to develop new processing sweet orange cultivars. These cultivars have potential to improve the Florida citrus industry’s portfolio of oranges used to make the best not from concentrate (NFC) juice possible. This research has resulted in the commercial release of several new promising cultivars, with early-, mid- and late-season maturity dates.
The UF-CREC Citrus Improvement Team has developed a broad citrus germplasm base, providing opportunities to generate diverse and interesting and possibly lucrative selections with niche-market and ...dooryard potential. Several such selections are showing reasonable levels of HLB (Huanglongbing or citrus greening disease) tolerance, which is a very important attribute for trees to be grown by home gardeners. Combining these selections with new rootstocks exhibiting greater HLB tolerance, and growing trees with emerging enhanced nutrition programs, provides small growers and dooryard citrus enthusiasts a real chance to get back into the enjoyable fresh citrus production.
The USDA/ARS citrus breeding program has a long history of releasing successful scion and rootstock cultivars. There had been a fifteen year lapse in creating new hybrids and the recently released ...cultivars largely reflect breeding efforts that preceded the onslaught of HLB and overwhelming consumer demand for seedless fresh fruit. The USDA program has released eight citrus scion cultivars in the last six years and more are in the pipeline including the first scion for use as a fresh fruit containing Poncirus in the pedigree (Gnarlyglo). The UF/IFAS/CREC are the new kids on the block, and have recently released 18 new scion cultivars, including 8 processing sweet oranges and 4 seedless mandarins. Both programs have extensive germplasm collections currently undergoing a natural screen for HLB and canker. As our understanding of HLB-tolerance advances, we are making “better” crosses each year, utilizing high fruit quality and disease resistant parents. We are excited to introduce the following new selections for commercialization.
Cold hardy citrus have long history in north Florida and nearby states. After being “Satsuma Capital of the World” in the 20’s, North Florida cold hardy citrus production declined and was mostly ...eliminated after World War II. The relatively mild winter temperatures during the last three decades and the development of microjet irrigation in early 90’s to reduce the effects of freeze have led to a resurgence of interest in cold hardy citrus in north Florida. Currently, satsumas account for great majority of the new commercial citrus in north Florida. There is an urgent need to diversify fresh market citrus in north Florida to include varieties that ripen from September thru December. In this article, we detail cold hardy citrus varieties available for North Florida, and the challenges and opportunities associated with each of them. We also reviewing the different insect pests present in North Florida citrus grove. Finally, we present data on the population dynamic of the Asian citrus psyllid in backyard citrus of North Florida.
Huanglongbing (HLB) threatens the survival of the Florida citrus industry. The UF CREC citrus improvement team has made several significant contributions for the development of HLB resistant ...germplasm. Both conventional as well as genetically engineered cultivars have been developed that can grow in the presence of HLB. Among the two citrus improvement techniques, engineering citrus remains the fastest method for improvement of an existing commercial citrus cultivar and has been a key component in our overall citrus improvement strategy.
This article explores the relationship between Schubert varieties and equivariant embeddings, using the framework of homogeneous fiber bundles over flag varieties. We show that the homogenous fiber ...bundles obtained from Bott–Samelson–Demazure–Hansen varieties are always toroidal. Furthermore, we identify the wonderful varieties among them. We give a short proof of a conjecture of Gao, Hodges, and Yong for deciding when a Schubert variety is spherical with respect to an action of a Levi subgroup. By using BP-decompositions, we obtain a characterization of the smooth spherical Schubert varieties. Among the other applications of our results are: (1) a characterization of the spherical Bott–Samelson–Demazure–Hansen varieties, (2) an alternative proof of the fact that, in type A, every singular Schubert variety of torus complexity 1 is a spherical Schubert variety, and (3) a proof of the fact that, for simply laced algebraic groups of adjoint type, every spherical
G
-Schubert variety is locally rigid, that is to say, the first cohomology of its tangent sheaf vanishes.
The purpose of this article is twofold. Firstly, we address and completely solve the following question: Let (
X
,
L
) be a smooth, hyperelliptic polarized variety and let
φ
:
X
⟶
Y
⊂
P
N
be the ...morphism induced by |
L
|; when does
φ
deform to a birational map? Secondly, we introduce the notion of “generalized hyperelliptic varieties” and carry out a study of their deformations. Regarding the first topic, we settle the non trivial, open cases of (
X
,
L
) being Fano-K3 and of (
X
,
L
) having dimension
m
≥
2
, sectional genus
g
and
L
m
=
2
g
. This was not addressed by Fujita in his study of hyperelliptic polarized varieties and requires the introduction of new methods and techniques to handle it. In the Fano-K3 case, all deformations of (
X
,
L
) are again hyperelliptic except if
Y
is a hyperquadric. By contrast, in the
L
m
=
2
g
case, with one exception, a general deformation of
φ
is a finite birational morphism. This is especially interesting and unexpected because, in the light of earlier results,
φ
rarely deforms to a birational morphism when
Y
is a rational variety, as is our case. The Fano-K3 case contrasts with canonical morphisms of hyperelliptic curves and with hyperelliptic K3 surfaces of genus
g
≥
3
. Regarding the second topic, we completely answer the question for generalized hyperelliptic polarized Fano and Calabi–Yau varieties. For generalized hyperelliptic varieties of general type we do this in even greater generality, since our result holds for
Y
toric. Standard methods in deformation theory do not work in the present setting. Thus, to settle these long standing open questions, we bring in new ideas and techniques building on those introduced by the authors concerning deformations of finite morphisms and the existence and smoothings of certain multiple structures. We also prove a new general result on unobstructedness of morphisms that factor through a double cover and apply it to the case of generalized hyperelliptic varieties.
