Date palm trees are among the most plentiful fruit trees in the Arabian Gulf States. Bioregulators have been used for the improvement of quality and productivity of date plam tree fruits. Application of gibberellic acid (GA3), naphthalene acetic acid (NAA), and ethephon, separately or in a mixture, has significant effects on fruit set, fruit dry matter percentage, fruit soluble percentage, fruit ripening, and yield of date palm trees. A study was conducted to assess relative effectiveness of GA3, NAA, ethephon, and a mixture of growth regulators on some fruit characteristics, and productivity of `Barhee' date plam trees. Five uniform female `Barhee' date palm trees were pollinated on 5–15 Mar. 1994, 1995, and 1996 by placing eight fresh male strands on female spadix centers (flower cluster). Ten flower clusters were used on each tree, and every two flower clusters were subjected to one of the following treatments: control (water), 150 mg·L–1 GA3, 100 mg·L–1 NAA, 1000 mg·L–1 ethephon, and a mixture of growth regulators. The fruit set (%), dry matter (%), total soluble solids (°Brix), fruit ripening (%), and fruit weight (kg per bunch and per tree) were measured. The data showed that the application of GA3 or ethephon on flower clusters of `Barhee' date palm trees had no constant effect on fruit characteristics and productivity of trees. NAA or a mixture of growth regulators reduced fruit dry matter percentage, fruit ripening percentage, and increased fruit weight per bunch and per tree. Spraying `Barhee' date palm flower clusters with NAA or a mixture of growth regulators 20 days after pollination decreased dry matter percentage, fruit ripening, and increased fruit flesh percentage and tree yield.
Hameed J. Aljuburi, Hasan. Al-Masry and Saeed A. Al-Muhanna
Yousef I. Dlaigan, A.E. Said and M.A. El-Hamady
The objective of this investigation was to study the effects of some antioxidants on the growth and elongation of in vitro-cultured date palm roots. Several trials were conducted to determine the antioxidant and the concentration of antioxidants used in date palm tissue culture. Three types of antioxidants were tested—activated charcoal, polyvinylpyrrolidone (PVP), and sodium metabisulfite (NA2S2O5)—in various concentrations, singly, or in combinations. The medium used for root culture consisted of MS salts mixture, 1/2 modified White's organics, 60% sucrose, 0.004% inositol, 240 mg adenine sulfate/liter, 1.0 mg 2,4-D/liter, and 2.0 mg kinetin/liter. pH was adjusted at 5.7 ± 0.1. Concentrations of activated charcoal tested (in g–liter–1) were: 0.0, 1, 2, 3, 4, 6, 8, 10, and those of PVP (in g–liter–1) were: 0.0, 5, 10, 20, 40 (with or without 4 g activated charcoal/liter). NA2S2O5 concentrations (in mM) tested were: 0.0, 0.2, 0.4, 0.8, 1.6 (with 4 g activated charcoal/liter). The addition of activated charcoal to the culture medium of date palm roots is of vital importance. Four grams per liter gave the best growth and elongation, and there was no significant difference between it and 10 g–liter–1. No growth or elongation occurred in the control. PVP, however, significantly inhibited growth and elongation of cultured roots at all concentrations tested. NA2S2O5, however, stimulated growth and elongation at 0.2 mM. Higher concentrations inhibited growth and elongation.
A. Talaie and B. Panahi
The type of pollen of date palm trees could affect the chemical characteristics of the fruit, and determine the quality and quantitative aspects. Careful selection of proper pollen for pollination of date palm is very important. This research was conducted for the selection of the best pollinizers and to study the effects of five varieties of male trees from the Shahdad area on the chemical characteristics of `Jiroft Mazafati' date. A completely random block was used for analysis of the 2 years of data (1991–1993). The study sight was in the Jiroft area of Kerman Province, Iran. Samples of fruit were collected after the pollination process and the required information recorded. Total dry matter, fruit moisture, total sugar content, fruit ash, and fruit pH were measured. Statistical calculations analysis and compound variations and evaluations of the treatments by Duncan's test indicate that, statistically, the different treatments have no effect on the fruit pH, and the difference are not significant. There are statistically significant effects on the other chemical characteristics of the fruit.
Essam A. Mawlood, H.H Hamood and E.S. Salah
This experiment was conducted to study the effects of bagging on fruit set, fruit characteristics and yield of Khastawi Date Palm CV. Two different types of bags were used: cloth and paper. The spadices were covered immediately at two different times during the first season; one month and the second continued until harvest time. Since positive results were obtained during the season, two extra bagging treatments were added in the second season (2 and 3 months). Unbagged spadices were used as control for both seasons. The results indicated that there were no significant differences between the two types of bags. Moreover, bagging for either two or three months produced positive results in fruit set improvement and yield.
A. Talaie and B. Panahi
The type of pollens of the date palm trees could affect on the outward and physical characteristics of date fruits, so far to determine its qualitative and quantitative aspects (15). Therefore careful selection of proper pollen for pollination of the date palms is considered of high importance. This research work was conducted to select the best pollinizers and to study the effects of pollens of five varieties of male trees, from Shahdad area, on the outward and physical characteristics of `Jiroft Mazafati'. For analyzing the results of this experiment, a completely randomized block statistical project was implemented for a period of 2 years from 1991 to 1993. The site of this experiment was in Jiroft area in Kerman Province. In this experiment, after pollination samples of fruit were collected during unripe (Kharak), ripe, and dry fruit stages and required information were recorded. Fruit length and diameter, seed length and diameter, weight of fruit, weight of seed, pulp weight, ration of fruit pulp to seed, ratio of fruit length to diameter, volume of fruit, weight of one full cluster of fruits, and finally the time of ripening were measured. Statistical calculations, analysis of compound variations and evaluation of treatments by Duncan's test indicate that different treatments of pollens will have no effect from statistical point of view on the ratio of fruit pulp to seed and the ratio of fruit length to diameter, and there are no significant differences. But there are significant effects on the other outward and physical characteristics of the fruit, and the differences from statistical point of view are considerable. The type of pollens are effective on the ripening time of the fruit and this difference ranges from 15 to 25 days for different treatments, which is important from early ripening point of view of the product.
Mohammed Aziz Elhoumaizi, Panchanoor S. Devanand, Jinggui Fang and Chih Cheng T. Chao
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.
Yousef I. Dlaigen, A. E. Said and M.A. El-Hamady
Several experiments were conducted in this investigation with the objective of determining the chemical components and the physical state of an optimal medium for the growth and elongation of excised date palm, cv Sukkari, roots. The chemical tests carried out included: Comparison of (MS)-salts with “White's”-salts mixture and different concentrations of (MS)-salts and its chelated iron; sugars; Modified White's Organics; inositol; adenine sulfate; growth regulators; and some antioxidants. The physical tests, on the other hand, included comparison of the growth and elongation of cultured roots in a liquid or on solidified nutrient media. The effects of various pH values were also tested. Roots were cultured in basal nutrient media composed of: (MS)-salts mixture, and (in mg·liter–1): NaH2PO4·H2O, 170; sucrose, 30,000; inositol, 200; Modified White's Organics; adenine sulfate, 120; activated charcoal, 1500; (2,4-D), 1; kinetin, 2. pH was adjusted at 5.7 ± 01. (MS)-salts mixture was found to be superior to “White's”-salts. No significant difference was observed between (1/2MS) and full-strength (MS)-salts. However, twice the concentration was found to be inhibitory. The normal concentration of (MS)-Fe was found to be optimum for root growth and elongation. The optimal concentration most suitable for the growth and elongation of excised date palm roots has been determined for each of: sugars; Modified White's Organics; inositol; and adenine sulfate. The only growth regulator that needs to be added to the nutrient medium is 2,4-D at 0.1–1.0 mg·liter–1. The study showed the importance of the inclusion of activated charcoal to the nutrient medium. The growth and elongation of roots were both stimulated at all concentrations tested. (PVP), on the other hand, was inhibitory at all concentrations tested. Shaken liquid media was recommended for better root growth and elongation at pH 7.0–8.0. Incidentally, the medium developed was found to support the growth and elongation of roots excised from two other cultivars, namely `Khudri' and `Khaias'.
Yousef I. Dlaigan, A.E. Said and M.A. El-Hamady
The effects of the physical state of nutrient media on the growth and elongation of excised date palm roots were investigated. Roots were cultured in a nutrient medium containing MS salts mixture, 1/2 modified White's organics, and (in mg–liter–1): NaH2PO4 –H2O, 170; sucrose, 60,000; inositol, 40; adenine sulfate, 240; activated charcoal, 4000; 2,4-D, 1; kinetin, 2. pH was adjusted at 5.7 ± 0.1. Both agar and Gelrite were singly used as solidifying agents. Liquid media were either stationary or rotated on gyratory shakers at 70 to 80 rpm. The effects of incubation of cultured roots under light or dark conditions were also studied. Media pH and its effects on growth and elongation of cultured roots were tested at various ranges (3, 4, 5, 6, 7, 8, 9, 10). Trials were also made to determine the passage length for transfer and subculture of cultured roots to a newly prepared medium. Liquid media highly supported better growth and elongation of cultured roots compared to solidified media. There was no significant difference in growth or elongation between agar or Gelrite media. Shaking liquid medium resulted in significantly better growth and elongation compared to stationary medium. No difference was observed between dark- and light-incubated cultured roots. Cultured roots grew and elongated better at pH 7.0–8.0. No growth or elongation occurred at pH 9.0. Roots continued to grow and elongate even after 12 weeks in culture. Therefore, 10 to 12 weeks after culture was determined to be the optimum passage length for date palm root culture.
Cesar Asuaje, Palm Beach County and Joe Garofalo
Hispanic agricultural workers are difficult to reach and educate. Many can't benefit from Extension programs because of the language barrier, education level and social factors. Safety (WPS) and Pesticide Applicator certification are required for workers to find employment and advance. In Florida, the total non-fatal agricultural occupational injuries among Hispanic workers rose 33% between 1999 and 2001, and total fatal injuries rose 18% between 1999 and 2002. Florida laws require that pesticide applicator exams be in English. Many Hispanics have experience and knowledge in pesticide use, but lack of sufficient language skills prevents their becoming certified. The University of Florida is addressing this issue with an extension agent whose main responsibility is to design and deliver programs in Spanish. First, we assessed the needs and started networking within the Hispanic community. Concurrently, training programs were developed in WPS and 7 certification categories in greatest demand. These have been offered in 11 south Florida counties to 4000+ workers. After each class, presentations were modified to incorporate effective content and methods, based on surveys and test scores. Among participants who took an exam, the passing rate has risen from below 50% to above 60%. The following have given good results: use two native speakers (Spanish and English); conduct the class in Spanish, but emphasize written and spoken English words; both trainers must interact with the audience; use props or good illustrations; teach at all levels, but recommend the exam only to those who can read an English label.