Six date varieties from Egypt, one `Deglet Noor' and four `Medjool' date accessions from California, and 66 accessions of `Medjool' date from Morocco, the country of origin of `Medjool' date, were examined using four sets of fluorescent labeled amplified fragment length polymorphism (AFLP) markers. A total of 402 AFLP bands were generated and 160 were polymorphic (39.8%). The 66 `Medjool' accessions from Morocco shared minimum 79% of genetic similarity. These results support the hypothesis that `Medjool' date is a landrace variety and not a genetically uniform variety. `Medjool' is the first confirmed landrace variety of date palm worldwide. This raises the possibility that other landrace varieties of date palm may exist in different date-growing areas and in centers of diversity. The confirmation of a landrace variety of date palm also has significant impact on future date palm germplasm collection and preservation. The mechanism(s) creating the genetic variation within `Medjool' accessions remains unknown. One possible mechanism is that spontaneous genetic changes could occur frequently within vegetative tissues of date palm like offshoots under high temperature and drought stresses.
Mohammed Aziz Elhoumaizi, Panchanoor S. Devanand, Jinggui Fang, and Chih Cheng T. Chao
Hussam S.M. Khierallah, Saleh M. Bader, Michael Baum, and Alladin Hamwieh
131 Akkak, A. Scariot, V. Dorello, T. Boccacci, P. Beltramo, C. Botta, R. 2009 Development and evaluation of microsatellite markers in ( Phoenix dactylifera L.) and their transferability to other Phoenix species Biol. Plant. 53 164 166 Al-Jibouri, A
Glenn C. Wright
Phoenix dactylifera G3 (Bethesda) 5 7 1429 1438 Mitchell, G.E. 1921 Americanizing the Arabian date Travel 37 2 17 20 46 Morton, J.F. 1987 Fruits of warm climates. J.F.M. Press, Miami, FL Negm, M.W. De Moraes, G.J. Perring, T.M. 2015 Mite pests of date
Yuval Cohen, Stanley Freeman, Aida Zveibil, Rachel Ben Zvi, Yaakov Nakache, Shimon Biton, and Victoria Soroker
The inflorescences of date palm ( Phoenix dactylifera ) develop within the crown of the tree, at the base of the leaves, from meristems located as deep as 1 m within the upper part of the trunk ( Tomlinson, 1990 ; Zaid and De Wet, 1999 ). Each
Dennis R. Pittenger, A. James Downer, Donald R. Hodel, and Maren Mochizuki
, Riverside Robertson, E. 1979 Drip irrigation of mature date palms Date Grower's Inst. 54 12 Salam, M.A. Mazrooei, S.A. 2007 Crop water and irrigation water requirements of date palm ( Phoenix dactylifera ) in the loamy sands of Kuwait Acta Hort. 736 309 315
Gerald G. Dull, Richard G. Leffler, Gerald S. Birth, Arthur Zaltzman, and Ze'ev Schmilovitch
Whole dates (Phoenix dactylifera L.) were analyzed for moisture content using near infrared spectrophotometry in a direct transmittance geometry. In the calibration experiment using 72 samples, the correlation coefficient was 0.977 and the standard error of calibration (SEC) was 0.89%. When the calibration equation was used to predict the moisture in another set of 72 date samples, the standard error of performance (SEP) was 1.5%. When the method was used to sort these 72 dates into four industry-standard grades, 74% were correctly graded and 15% missed the grade by <1 SEC.
Sam Aslan, Sam Cobb, Jose L. Aguiar, and Aref A. Abdul-Baki
Approximately 90% of total date production in the U.S. is localized in the Coachella Valley, southwest California. The remainder is in the bordering Imperial Valley, Calif., and Yuma, Ariz. The date trees (Phoenix dactylifera L.) occupy 2282 ha, have an annual yield of 24,000 tons, and a product value of $62 million. Major varieties include `Deglet Noor', `Khadrawl', `Zahide', and `Majhool'. Although climatic requirements for date production prevail in the Valley, major problems related to soil and water have adverse effects on yield and fruit quality. These include water and soil salinity, high water table, high soil compaction and stratification, and low fertility. Slip plowing has been a recommended practice for decompacting the soil. However, soils get recompacted by machinery used in cultural operations. We recently introduced planting cover crops in a no-till system to improve soil fertility, reduce compaction, and improve drainage.
Aref A. Abdul-Baki, S. Aslan, S. Cobb, E. Beardsley, and T. Burke
A 3-year experiment was conducted to identify problems in Coachella Valley date palm (Phoenix dactylifera) orchards that limit vegetative growth, yield, and fruit quality. Major problems that were identified included soil compaction and stratification that restrict water permeation into the root zone, and low fertility as reflected by the low organic -matter content of the sandy soils. To eliminate the impact of these stresses on plant growth, yield, and fruit quality, a no-tillage alternative management system was introduced to replace the conventional practice of tillage that compacts the soil. No-till was coupled with the use of cover crops to enrich the soil with organic matter, fix N, recycle nutrients, and improve water holding capacity of the sandy soil. In already established orchards, an additional treatment—slip plowing—was also implemented to loosen the soil at lower depths to facilitate water permeation. The positive effects of the alternative system on the soil, tree growth, yield, and fruit quality will be presented.
Boyang R. Cao and Chih-Cheng T. Chao
Polymorphisms of 21 date cultivars (Phoenix dactylifera L.) in California were determined by amplified fragment length polymorphism (AFLP) analysis with near infrared fluorescence labeled primers. Four primer sets were used to detect polymorphisms. Based on the UPGMA-cluster analysis of 328 polymorphic bands, the majority of the cultivars was separated into two major groups. Cultivars Abada, Amir Hajj, Ashrasi, Bentamoda, Boyer No. 11, Deglet Beida, Horra, Javis No. 1, Khadrawy, and Thoory belonged to group I. Cultivars Badrayah, Dayri, Halawy, Haziz, Khir, Medjool, Sayer, and Zahidi belonged to group II. Cultivars Barhee and Deglet Noor were further separated from groups I and II. `Hayany' was distinct from all other date cultivars tested. These results demonstrated that AFLP markers could efficiently identify individual date cultivars. The information will be useful for future date germplasm collection and facilitated selection of diverse parents for cross hybridization in a breeding program.
Mature 'Barhi' dates (Phoenix dactylifera L.) were stored in air or under controlled atmosphere (CA) storage conditions with 5%, 10%, or 20% carbon dioxide concentrations (balance air) during storage at 0 °C. CA conditions extended date storability by maintaining fruit quality. Fruit quality was maintained for 26 weeks when stored in 20% CO2, 17 weeks in both 5% and 10% CO2, and 7 weeks in air. Treatment with 20% CO2 maintained fruit color, firmness, SSC%, total sugar content, and total tannins. CO2 treatment also reduced degradation of caffeoylshikimic acid (CSA), which is one of the major phenolic compound of date fruit. This study indicates that 'Barhi' dates could be stored under CA conditions in cold storage with good eating quality for 17 to 26 weeks.