The article defines the terms graft compatibility and incompatibility between scion and rootstock. It describes incompatibilities that have recently emerged when combining some of the newer citrus ...scion and rootstock cultivars and illustrates what to look out for when propagating new combinations.
In this article we present the latest update on two field trials conducted with grower collaborators in Hendry County and Polk County. These trials compare the performance of Valencia trees grafted ...on rootstocks that have been propagated from seed and rootstocks that have been propagated by cuttings and tissue culture. Information from the first three years of field growth is presented.
In the last decade, huanglongbing (HLB) has reduced production of Florida grapefruit by 75%, mandarin by 78% and sweet orange by 52%. This decrease is significant for the Indian River District, which ...produces approximately 80% of the total grapefruit crop grown in Florida (National Agricultural Statistics Service, 2021). Several strategies have been considered to keep citrus groves productive in HLB times. Rootstock field trials are cost-effective since vigorous, healthy rootstocks enhance disease tolerance of the scion and boost yields that increase growers’ profits.
The UF/CREC and USDA/ARS citrus rootstock breeding programs have identified several rootstocks that can currently be planted with confidence when combined with appropriate scions, including mid- and ...late-season oranges, and grown with emerging enhanced nutrition programs. New websites with valuable information and data from historic and ongoing field trials are now available: UF/CREC: https://citrusresearch.ifas.ufl.edu/rootstock-field-data/ : and USDA/ARS: https://citrusrootstocks.org . We are also working hard to develop the next generation of rootstocks, that will allow for sustainable and profitable citriculture with any commercial scions, including more HLB-susceptible early oranges, grapefruits, and even ‘Honey’ Murcotts. The key to success is screening a tremendous amount of genetic diversity and identifying patterns in rootstock hybrids that can transmit their tolerance/resistance through the graft union to mitigate or prevent the disease in any grafted scion. This would be the ultimate solution to the HLB problem worldwide. Peer reviewed through UF/IFAS Citrus Research and Education Center; published in Citrus Industry Magazine.
This article presents information on large-scale commercial rootstock trials with Hamlin and Valencia scion. The trials were planted in 2015 and include more than 30 replicated rootstocks from ...Florida, California, and Spain, some of which are already commercially available. Yield data from the 2018/19 and the 2019/20 season are presented and rootstock effects on tree size and yield-efficiency are discussed
First published in 1989 as Rootstocks for Florida Citrus, the work of Dr. William Castle and his colleagues remains relevant 30 years later. The purpose of the Florida Citrus Rootstock Selection ...Guide (FLCRSG) is to provide timely and useful citrus rootstock information to help Florida citrus growers make well-grounded, practical decisions. New problems with abiotic factors, pests, and diseases make the FLCRSG a standard document for the Florida citrus industry. Initially published as a book, it was integrated into an informative wheel and is now a web-based expert system with an interactive table with 21 characteristics of 48 rootstocks. Much has changed within the Florida citrus industry since the discovery and spread of the vector-transmitted disease huanglongbing (HLB). Rootstocks were not initially part of the discussion related to managing HLB, but that has changed, particularly given the accumulating evidence that trees on various rootstocks may differ in the incidence or tolerance of the disease. The authors have prepared this timely and necessary update of the former editions and have expanded the list of rootstocks. We revised the information on the UFR series and added three new U.S. rootstocks (US SuperSours) that have not yet undergone the usual extensive field evaluation in Florida. These new rootstocks offer improvements regarding HLB tolerance and several other meaningful traits, such as tree size, high yield, and juice quality that appear essential to the future of our citrus industry.
The combination of HLB and Hurricane Ian have made this a disastrous year for Florida citrus, drastically reducing the quantity and quality of processing oranges. Brix values and yields are the ...lowest in history. Early season Hamlin juice of lesser quality is generally blended with late-season Valencia to achieve the target 12 Brix and 15 ratio for quality NFC juice. This is not possible when the Valencia crop is coming in around 9-10 brix, even from fully mature trees. The only blending option available to processors this season is to use higher quality imported juice. This article will discuss new options being developed by the UF-CREC Citrus Breeding Team to permanently solve this growing problem for Florida growers.
In this article, we provide estimates on the performance of different rootstocks grafted with Valencia sweet orange scions in commercial field conditions. These are the first estimates obtained from ...side-by-side trials that compare the performance of rootstocks developed by two breeding programs in Florida, namely that of the University of Florida and the USDA. Those estimates can be particularly useful to help growers decide which rootstocks to plant. Importantly, this analysis combines yield and economic performance.
Breeding and screening of HLB tolerant scion and rootstock cultivars have been recognized as one of the effective ways to control the disease and increase the supply of quality citrus fruit under ...these adverse circumstances. In order to make sure fruits from the new cultivars meet the conusmer demand, we characterized the flavor and consumer preference of HLB-tolerant scion/rootstock combinations. Orie Lee late (OLL) sweet oranges grafted on different rootstocks were used in this study. As a result, rootstocks could affect sweetness, consumer liking and overall flavor. Freshness and overall orange flavor were significantly influenced by the scion varieties. For maximum juice quality from HLB-impacted trees, such relationships should be considered when we choose the scion/rootstock combinations in the future.
The research was carried out at Ciano Research Station of Lattakia Research Center - General Commission for Scientific Agricultural Research in Damascus in 2019. The fruit maturity evolution of ...Clementine Mandarin variety (Strain 88) budded on seven citrus rootstocks (Sour Orange, Citrumelo 4475, Citrumelo 1452, Troyer Citrange, Carrizo Citrange, Macrophylla and Cleopatra Mandarin) and planted in 1989 was studied for a period of 84 days, starting from 16th September 2019 to the start of reaping the fruits on 9th December 2019. There were insignificant differences in the average weight increase of the fruit among the studied treatments. Fruit peel thickness significantly increased by (50.15%) in the trees grafted on Macrophylla compared to those grafted on Cleopatra Mandarin, Troyer Citrange and Citrumelo 1452 whose fruit peel thickness increased by (19.21, 9.58 and 2.61%, respectively). The highest increase in total soluble solids (%) was in the trees grafted on Troyer Citrange by (38.10%), while total acids (%) significantly decreased by (18.33%) in the trees grafted on Citrumelo 1452.
