سالم, رضا2025-09-022025-09-022009https://dspace.omu.edu.ly/handle/123456789/479Two separate experiments were carried out during two successive seasons (2007/2008,2008/2009) at the Experimental Farm of Horticulture Department, Faculty of Agriculture, Omar El-Mokhtar University, El-Beida City, El-Jabal El-Akhdar region. The objectives of these experiments were to : 1- Study the effect of different planting conditions (plastic house and open field) and nitrogen sources (ammonium sulphate (20.5%N) and urea (46%N) at the rate of 50g N/m2) on the growth, flowering, corm productivity and chemical constituents of Gladiolus grandiflorus cv. Rose Supreme. 2- The effect of different planting conditions (plastic house and open field) and plant spacing (15x25 and 25x25) on growth , flowering, corm productivity and chemical constituents of two cultivars (Rose Supreme and White Prosperity) of gladiolus. In the two experiments cormes of 15-16 and 14-15cm in circumference (for first and second experiments, respectively) were planted on 5th December for the two seasons. The results and conclusions of this study could be summarized in the following: 8.1- Effects of planting conditions The data obtained on all studied parameters in the first experiment as affected by the different planting conditions were in parallel with the data recorded on the effects of the same factor in the second one. Planting the corms under plastic house condition significantly hastened sprouting, spike emergence and flowering (at the time of first floret opening), and increased plant height and length of floweing stalk and rachis. On the other hand, it significantly decreased diameter of floweing stalk compared to open field condition. Planting corms in the open field significantly increased the diameter of first floret opening in the first experiment, while the opposite was the right in the second experiment. Planting the corms under plastic house significantly increased number of florets per spike compared to open field in the first experiment, while in the second one a non significant difference was observed due to the different planting locations. Plastic house conditions significantly increased corm diameter and it,s fresh and dry weights in both seasons. Planting the corms under plastic house conditions significantly increased number and fresh and dry weights of large sized cormels [including grade sizes A(> 1.2cm in diameter) and B(dia. > 0.9 to ≤ 1.2cm)]. Whereas, the open field conditions increased small sized cormels [including grade sized C(dia. >0.7 to ≤ 0.9) , D(dia. >0.5 to ≤ 0.7cm) and E(dia.< 0.5cm)], and total number and weight of cormels per plant . Plastic house conditions significantly increased chlorophyll a , b as well as a+b contents of the leaves. Planting the corms under plastic house conditions recorded the highest values of nitrogen , phosphorus and potassium contents ( % ) in the leaves and corms compared to open field conditions. 8.2. Effect of nitrogen sources fertilization Application of the two nitrogen sources (ammonium sulphate and urea) significantly increased the plant height at time of spike emergence and flowering compared to control. Meanwhile, ammonium sulphate was the most effective treatment. Application of the two nitrogen sources significantly increased number of leaves at time of spike emergence compared to control , with non-significant differences between both nitrogen sources. Using urea delayed spike emergence and flowering while ammonium sulphate significantly hastened emergence and flowering, only in first season, but was statistically similar with control in the second one. The nitrogen fertilization from both sources increased length of floweing stalk compared to control in the two seasons . Meanwhile, ammonium sulphate was the most effective in the second season. The nitrogen fertilization from both sources increased length of rachis in the second season. Meanwhile, ammonium sulphate gave the longest rachis. Using ammonium sulphate was the most effective treatment for increasing the diameter of spike in both seasons. The nitrogen fertilization from the two sources increased diameter of the first floret opening and number of florets per spike compared to control in both seasons. Meanwhile, anon significant difference was observed between both nitrogen sources. Application of nitrogen of the two sources significantly increased diameter , fresh and dry weight of new corm, over control (no nitrogen) in both seasons. The new corms with higher number and heavier fresh and dry weights of cormels (including grade sizes of A, B, C, D, E and total number and weight of cormels per plant ) were obtained when plant were fertilized with ammonium sulphate. Application of nitrogen from the two sources increased chlorophyll a , b as well as a+b contents of the leaves and N,P and K percentages in both aerial parts and corms, especially with the ammonium sulphate more than the other treatments. 8.3. Interaction effect of planting conditions and nitrogen sources The longest plants at time of spike emergence and first floret opening , were produced from corms planted under plastic house conditions and fertilized with ammonium sulphate in the second season. Planting the corms under plastic house and fertilizing with ammonium sulphate resulted in the highest increment in number of leaves at time of spike emergence in the first season. Planting the corms under plastic house and fertilizing with ammonium sulphate gave the longest and heaviest fresh and dry weights of spike in the second season. The corms planted in the open field and fertilized with ammonium sulaphe showed significant increase of diameter of spike in both seasons. Planting the corms under plastic house and fertilizing with both nitrogen sources significantly increased diameter of new corm in the first season, and dry weight of corm in both seasons. Planting the corms under plastic house conditions coupled with ammonium sulphate significantly increased number of large sized cormels of grade A and fresh weight of large sized cormels of grade B in the second season. Whereas, the highest number and heaviest fresh and dry weights of small sized cormels (including grade sizes D, E and total number and weight of cormels / plant) were produced from corms planted under open field conditions coupled with ammonium sulphate fertilization . 8.4. Planting density Increasing plant spacing to 25x25 (low density) was accompanied with significant increases in most studied parameters (plant height at time of spike emergence, spike and rachis length and diameter of spike, as well as fresh and dry weights of spike ) in both seasons. The corms planted at low density (16 corms/m2) markedly increased the corm diameter , fresh and dry weight of corm , number of cormels, as well as fresh and dry weights of cormels (including all grade sizes and total number and weight of cormels / plant). Increasing plant spacing (low density), markedly increased the chlorophyll (a,b and a+b ), N,P and K% of the leaves , as well as N,P and K% of the corm. The different planting densities , showed a non remarkable effect on sprouting, , plant height at time of first floret opening , number of leaves , days to spike emergence and to flowering, and diameter of the first floret opening. 8.5. Performance of gladiolus cultivars under study conditions A significant difference was observed between the performance of the two cultivars of as Rose Supreme superior to White Prosperity in all vegetative, floral, corm and cormel parameters and chemical constituents. 8.6. Interaction effect of planting conditions, plant spacing and cultivars Planting corms of cultivar Rose Supreme under plastic house conditions was promising for all vegetative, floral, corm and cormel parameters, except for the diameter of spike and first floret opening and total number and weight of cormels per plant, which were greatly benefited from planting the same cultivar under open field conditions. The most studied parameters significantly responded to the combined application of planting the corms of cultivar Rose Supreme at low density under plastic house conditions as compared to other treatment combinations.Thesis