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تحميل الدليل التدريبي

أسئلة شائعة

Published Papers

Ali, Y.S., H.K. Tayama, T.L. Prince, and S.A. Carver. 1990. Identification of Developmental Phases in Poinsettia. J. Amer. Soc. Hort. Sci.115(5):728-731.

 Abstract.  Experiments were conducted with poinsettia [Euphorbia pulcherrima (Willd. ex. Klotzsch)] to determine the 1) existence of developmental phases from seedling establishment to flower induction and 2) characteristics that may be used to delineate the phases. The characteristics evaluated were flowering and rooting ability, heterophylly and other leaf characteristics, phyllotaxy, and internode characteristics. Tow developmental phases, juvenility and maturity, were identified . The transition between these phases occurred in poinsettias that were 6 to 8 weeks old, following establishment. Mean values for flowering ability, rooting ability, phyllotaxy, and heterophylly differed for the tow developmental phases, rendering them the most useful of the characteristics evaluated for identifying developmental phases in poinsettia.

Ali, Y.S., H.K. Tayama, T.L. Prince, and S.A. Carver. 1990. The Relationship between Maturity Level and Splitting in Poinsettia. HortScience, Vol. 25(12):1616-1618.

Abstract.  The relationship between poinsettia (Euphorbia pulcherrima Willd. ex Kl.) maturity and premature flower bud initiation (splitting) was evaluated. Changes in root growth, phyllotaxy, and heterophylly of 'Annette Hegg Dark Red' poinsettia stock plants and cuttings in response to repeated severe pruning (hedging) and the chemical growth regulators gibberellic acid (GA4+7), PBA, or ethephon were evaluated. Cuttings taken from hedged stock plants exhibited a phyllotaxy of 1/3 to 2/5, extensive root growth (characteristics of juvenility in poinsettia), and a low level of splitting (34%). Cuttings taken from nonhedged stock plants exhibited a phyllotaxy of 3/8, reduced root growth (characteristics of maturity in poinsettia), and a high level of splitting (77%). There was a moderate negative correlation    (-0.75) between root growth and splitting a strong positive correlation (0.94) between splitting and phyllotaxy. Cuttings treated with gibberellic acid or PBA exhibited elliptic to ovate leaves (a juvenile characteristic) and levels of splitting ranging from 20% to 90%, depending on concentration and application timing. Untreated cuttings and those treated with ethephon exhibited lobed leaves (an adult characteristic) and levels of splitting ranging from 82% to 100%. Names of the chemical growth regulators were: (1a,2b,4aa,4bb,10b,)-2,4a,7-trihydroxy-1-methyl-8-methylenegibb-3-ene-1,10-dicarboxylic acid 1,4a-lactone (GA4+7); N-(phenylmethyl)-9-)tetrahydro-2H-pyran-2-yl)-9H-purin-6-amine (PBA); (2-chloroethyl) phosphonic acid (ethephon).

Ali, Y.S. 1994. Effect of Nitrogen Source on Vase Life of Snapdragon. Egypt J. Appl. Sci. 9(9):412-418. Egypt.

Abstract.  Seeds of 'Rocket' hybrid snapdragon were sown, then, grown in 25 cm pots containing a mix of sphagnum peatmoss and washed sand (1:3 v/v) to which 5 gms trisuperphosphate were added and supplied with 150 ppm potassium with irrigation water which also contained 150 ppm NH4-N [(NH4)2SO4] or 150 ppm NO3-N [Ca(NO3)2], or 75 ppm NH4-N + 75 ppm NO3-N. Growth, flower quality, and vase life were best when the plants were given NH4 and were least when the plants received 50% NH4-N + 50% NO3-N, while they were intermediate when the plants supplied with NO3-N.

Ali, Y.S. and T. Alkiey. 1995. Effect of Chlormequat and GA3 on Growth and Flowering of Calla (Zantedeschia rehmannii). J. King Saud Univ., Vol. 7, Agric. Sci. (2), pp. 271-282.

Abstract.  Growth and flowering of calax (Zantedeschia rehmannii) were studied. Gibberellic acid (GA3) was applied at 0, 250 or 500 ppm either as a preplanting treatment for rhizomes (15- min soak) or as a foliar spray and chlormequat (CCC) was applied at 0, 1000 or 3000 ppm either as a preplanting treatment for rhizomes (10- min soak) or as a soil drench when shoots were 2 to 3 cm long. GA3 rhizome soaking significantly increased the number of flower produced. Chlormequat rhizome soaking or applied as a soil drench significantly limited plant height if not treated with GA3. GA3 and CCC sequentially treated interacted significantly reduced height and increased flowering. Treatment with GA3 overcame the dwarfing effect of CCC, while CCC alone treatment limited flower production. Production of malformed flowers was noticed on rhizomes treated with GA3 with no malformed flowers on control plants. The preplant soaking of rhizomes in either GA3 or CCC was more effective than the foliar spray or soil drench. Commercial producers of Z. rehmannii may wish to consider the use of GA3 in combination with chlormequat to produce plants with an aesthetically pleasing shape and adequate flower production. 

Ali, Y.S. 1995. Effect of Chlormequat on Growth of Dodonaea viscosa and Clerodandron inerme. Egypt J. Appl. Sci. 10(1):532-539. Egypt.

Abstract.  Dodonaea viscosa and Clerodendron inerme were treated with 0, 1000, 2000 and 3000 mg/liter chlormequat as spray. Clerodendron was also treated with 0 and 3000 mg/liter as spray, and 3000 and 4000 mg/liter/pot as a drench. Chlormequt reduced the growth of the plants which affected the distribution and the size of the plants. Concentration of the spray did not effect the growth three weeks after the second application. The drench method was better than the spray method and 4000 mg/liter/pot drench was better than 3000 mg/liter/pot.

Ali, Y.S. 1997. Influence of Orgaic and Inorganic Fertilization on the Growth of some Annual Flowers. King Saud Univ. Agri. Res. Bult. No. 70.

Abstract.  A greenhouse experiment was conducted to study the effect of organic fertilizer from slaughterhouse waste compared to mineral fertilizer on tne growth of petunia, snapdragon, celosia, and marigold. Organic fertilizer from the waste of slaughterhouse of sheeps, goats, cows and camels (contain 5.2-2.1-1.1% NPK respectively) at the rate of 18,22 and 27 kg/m2 and mineral fertilizer (200 ppm N and K with each irrigation and 5 gm P in the soil) were used on petunia, snapdragon, celosia and marigold for tow seasons. Generally, the growth of all four flower plants were the least with the control (no fertilizer), then, the organic fertilizer, and the best with mineral fertilizer for both seasons. Further research with different organic fertilizers is needed.

Nasroun, T.H., Y.S. Ali, and S.S. Al-Subaiee. 1998. The Effectiveness of Treating Seeds of some Local Trees by Boiling in Water or Soaking in Concentrated Sulphuric Acid for Breaking their Dormancy. J. King Saud Univ., Vol., 10, Agric. Sci. (1), pp. 113-124.

Abstract.  The seeds of many leguminous trees pass through a dormancy phase, which is due, in most cases, to the hard seed coat that is impermeable to water or gases. This causes delayed germination if seeds are not treated in a way or another to break this dormancy. This investigation was carried out with the aim of comparing the effects of four seed treatments on germination percent and germination rate of seeds of three tree species namely: Acacia tortilis, A. seyal and Parkinsonia aculeata. Seeds of each species were treated with each of the following treatments: soaking in concentrated sulphuric acid for one hour - boiling seeds in water for 5,15 and 30 minutes. Treated seeds were sown on germination trays lined with germination paper in the laboratory. Germination of seeds was monitored and recorded for 40 days. The experiment was repeated twice: in December, 1993 and in February, 1994. Results revealed significant differences in germination percentages and germination rates between species and within different treatments. A. Seyal showed the highest germination percent in both sowing dates. A. tortilis was the second and Parkinsonia came the last in the first sowing date. In the second sowing date, however, Parkinsonia moved to second place and A. tortilis came last. Results also revealed that the best and most effective seed treatment for breaking dormancy of seeds of these species was boiling seeds in water for 5 minutes, in both sowing dates. Soaking in sulphuric acid was second in first sowing date; but it moved to the third place in the second sowing date after boiling in water for 15 minutes. These results will be of great benefit as boiling seeds in water is a simple and cheap method, with no danger on workers as expected from acid treatment; and no special equipment is needed as in the case of mechanical scarification.

Nasroun, T.H., Y.S. Ali, and S,S, Al-Subaiee. 1999. Effect of Sowing Media on Germination of Seeds of some Trees Grown in Riyadh Area. J. King Saud Univ., Vol. 11, Agric. Sci. (2), pp. 93-104.

Abstract.  There are great variations bettween germination percentages and rates as well as between rates of seedlings growth between species, with different seed treatments and sowing media. This investigation focusses on the effect of sowing media on seed germination under laboratory and nursery conditions and selecting the best and the cheapest  sowing media for production of seedlings, as a step towards improving nursery technology. To fulfil these objectives the seeds of three species were treated by boiling in water for five minutes. Treated seeds were then sown in six media. Seed germination was monitored for forty days. The results revealed clear variations in germination percentages and rates between species and with different sowing media. As for species, seyal (or talh) - Acacia seyal gave the highest germination percentages followed by Parkinsonia and lastly samor -  A. tortilis, in both sowing dates. With regards to sowing media the highest germination percentages and rates in the first sowing date were obtained in the second medium followed by the first. These were followed in turn by the fourth and the third media; and the lowest germination was in the fifth medium. In the second sowing date, however, the third medium jumped  to first place followed by the fourth whereas the fifth medium remained at the bottom of the list.       

 Ali, Y.S. and M.S. Al-Safar. 2006. Effect of GA3 Treatment and Nitrogen on Growth and Development of Gladiolus Corms. PJBS 9(13): 2516-2519.

Abstract.  A field experiment evaluated the effect of nitrogen and gibberellin pretreatment on growth and development of two cultivars (Topaz and Sancerre) of gladiolus corms during 2003 and 2004 in Al-Hassa, Saudi Arabia. The experment soil was loamy sand and received four levels of nitrogen (0, 25, 50, and 75 kg N/ha) applied as urea. Gladioli corms were presoaked for 24 h in the gibberellic acid (GA3) solution at a concentration of 0 and 100 mg/L. Mean stem height, number of leaves per plant, leaf area, shoot dry weight, number of corms per plant, corms dry weight, and flower diameter increased significantly with nitrogen and GA3 treatment. A significant difference was observed between the performance of two cultivars and the Topaz proved superior to Sancerre in all growth parameters. This study also confirmed the higher potential of Topaz gladiolus esablished as a benchmark for nitrogen application rate of 75 kg/ha for gladioli in Saudi Arabia and suggested that high corm and flower yield of gladioli may be obtained when corms are soaked in GA3 solution of 100 mg/L before plantation.

Other Publications:

Ali, Y.S. et al. 1993.  Afforestation and ornamental plants and gardens landscaping. Agriculture extension center, college of agriculture, King Saud univ., Riyadh. (extention book 1413 H).

Ali, Y.S. et al. 1993. Irrigation and fertilization of trees and ornamental plants. Agriculture extention center, college of agriculture, King Saud univ., Riyadh. (extention book 1413H). 

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