V. SUMMARY AND CONCLUSIONField work of this investigation was carried out during the two successive seasons of 2001 and 2002 on six-year-old commercial shrubs of the Egyptian prickly pear type(El- Shamy) grown in sandy soil at 3x4 meters apart, in Entelak district, Moudereyat Al- Tahrir Behera Governorate, EgyptThis study was planned to evaluate the effect of different nitrogen and potassium fertilization rates on vegetative growth, yield and physical and chemical fruit characteristics in an attempt to determine the fertilization regime of prickly pear plants grown in sandy soils.The experimental shrubs of each treatment were of uniform size and vigour. In winter of 2001 season all plants were supplied with 10 kg of organic manure and 300g superphosphate per plant. The plants were sprinkler irrigated for one hour at fortnightly intervals throughout the flowering and fruit development periods (March-early July). The chosen shrubs were subjected to three separate experiments as follows:The first experiment was conducted to evaluate different annual rates of nitrogen and potassium fertilization on the growth, yield and fruit characteristics. The experimental shrubs were subjected to the following N and K fertilization treatment.1. Adding N fertilizer at 0, 24, 48, 72, 96, 120 g N per plant.2. Adding K fertilizer at 0, 13, 26, 39 g K2O per plant.3. Different combinations between N and K fertilizer.All amounts of nitrogen and potassium fertilizer were added in two equal doses as a soil application, using ammonium sulphate (20.6% N) as a source of nitrogen and potassium sulphate (48 – 50 K2O) as a source of K. The first dose was applied just before the first irrigation (16 and early march) and the second at the end of the April (27 and 26 April) of each season, respectively.The obtained reuslts could be summarized as follows: -1. The number of buds/cladode was markedly increased with increasing nitrogen rate under all potassium rates recording the highest number at 96g N/plant. The highest K rate(39 g K/plant) recorded the highest number of buds/cladode in both seasons. The number of buds / cladode ranged between (4.40 - 9.27) and (3.67 - 7.00) in the first and second seasons, respectively.2. Number of flowering buds/cladode was significantly increased with increasing N application rate till 96g N/plant to decrease thereafter with increasing N rate to 120g/plant.Meaning that excess N fertilization reduce flowering buds. The highest K rate (39g K2o /plant) produced the highest number of flowering buds/cladode in both seasons. Control (unfertilized) plants recorded the least number of flowering buds /cladode.3. The percentage of flowering buds/ cladode responsed negatively to N fertilization in the two seasons, whereas it responsed positively for K fertilization in the second season only. The percentage of flowering buds /cladode ranged between 87.2 – 96.1% and 82.3 – 93.8 % in both seasons, respectively.4. The number of vegetative buds/cladode was significantly affected by N levels and insignificantly by K rates in both seasons .Since increasing N rate significantly increased number of vegetative buds /cladode.5. Nitrogen fertilization significantly increased the number of flowering buds /plant. This trend was markedly increased with increasing N supply, while potassium fertilization insignificantly affected it in both seasons. The number of flowering buds /plant ranged between 63.17-89.33 and49.13-87.33 in the two seasons, respectively. The highest number of flowering buds /plant was recorded when N was applied at 72 and 120g N and K at 26 g K2o / plant in the two seasons. Applying K AT 39 g K2O /plant without N gained the lowest number of flowering buds /plant in the two seasons.6. Total yield /plant as well as fruit and pulp weights were significantly increased with increasing N application rate. The yield was increased by 65.32 and 117.53 % in both seasons, respectively. The highest values of yield /plant and fruit and plup weights were gained when the plants were supplied with 120 g N / plant under all K rates in both seasons without significant differences between them in most cases. This trend indicate that N fertilization is the main factor for increasing yield and fruit weight of prickly pear plants. The highest total yield / plant (7.90 and 8.75 kg /plant) was recorded for plants fertilized with 96 g N and 39 g K / plant in the first season and 120 g N and 26 g K / plant in the second one, respectively. The highest fruit (98.45 and 100.03 g /fruit) and pulp (62.32 and 62.48 g) weights were produced by the plants fertilized with the highest rate of nitrogen under 39 and 26 g K /plant ,whereas those received no N and K fertilizers and those supplied with 26 g K /plant without N gained the lowest fruit (63.21 and 66.72 g /fruit) and pulp (37.12 and 40.24 g) weights in both seasons, respectively.7. Weight of Fruit peel was increased with increasing N rat, while K affect did not follow constant trend in both seasons. Peel weight ranged between 26.05- 39.18g and 27.09- 38.4 g in both seasons, respectively.8. Pulp percentage of prickly pear fruits ranged between56.33– 66.29% and (58.16%-63.17%) in the first and second seasons, respectively. The fifth N rate (96 g N /plant) and third rate of K (26 g K2O /plant) gained the highest pulp percentage in the first season, while in the second one the highest percentage was recorded for the highest ratesof N and K.9. The highest fruit length and diameter were recorded when the plants were fertilized with the highest N rate (120g N /plant) under all K rates without significant differences between K rates in most cases. Indicating that N fertilization is the important factor for increasing fruit length and diameter. No significant differences were detected between 120 and 96 N rates under all K rates in both seasons. Fruit length ranged between 7.2 – 8.7 cm and 7.0 – 9.3 cm, whereas fruit diameter was ranged between 3.9 - 4.9 cm and 3.8 - 4.8 cm in the first and second seasons, respectively. This means that length of prickly pear fruit is about fold its diameter.10. Seeds weight /fruit was significantly increased with increasing N and K rates, whereas seed number was insignificantly affected in both seasons. This indicate that N and K fertilization are important for seed developing and growing. Seeds weight /fruit ranged between 3.53 – 6.67 g, while seeds number was ranged between 130.67 – 142.33 seed /fruit in the first and second seasons, respectively.11. Moisture percentage in the whole fruit and both fruit pulp and peel were significantly increased with increasing N fertilization rate, while K fertilization reduced it. So the highest moisture percentage was recorded in fruits produced on plants fertilized with the highest N rate (120 g N /plant) without K fertilization in both seasons. Whereas, those supplied with the highest K rate (39 g K /plant) and the lowest N rate recorded the lowest moisture percentage in the considered orgams. The moisture percentage ranged from 78.7 to 89.4 % in the whole fruit , 76.2 –88.5 % in the pulp and 80.2 – 88.7 % in the peel during the two seasons.12. Total soluble solids percentage responsed positively for nitrogen and potassium fertilization, since the highest percentage were gained by the highest N and K rates in both seasons. The percentage of TSS ranged between 11.4 - 13.9 % and 11.5 - 14.00 % in the first and second seasons, respectively.13. The lowest total acidity percentage and the highest TSS /acid ratio and ascorbic acid content were gained by the highest potassium rate (39 g K / plant) under all nitrogen rates in the two seasons. This indicate that K fertilization is the main factor for decreasing the total acidity percentage and hence increasing TSS /acid ratio in the prickly pear fruit juice. Total acidity percentage in juice of prickly pear fruits ranged between 0.188 – 0.218% and 0.176 – 0.220 % in both seasons, respectively, whereas TSS /acid ratio was ranged between 55.89 - 73.48 and 52.38 - 74.92 and ascorbic acid content was ranged between 35.1 - 39.6 mg/100g and35.2 - 39.8 mg/100g in both seasons, respectively.14. Total, reducing and non-reducing sugars percentages were significantly increased with increasing potassium rate so, the highest percentages were gained by the highest K rate(39 g K / plant) under all nitrogen rates. Indicating that potassium fertilization is the main factor for increasing sugar percentages in prickly pear fruits. The highest percentages of total, reducing and non-reducing sugar were recorded when the plant were fertilized with 96 and 120 g N /plant under 39 g K /plant, while unfertilized control plants gave the lowest percentages in both seasons. Total sugar percentage in fruit pulp ranged between 10.3 – 13.0 %, reducing sugar between 9.6 – 11.6 % , while those of non-reducing sugar ranged between 0.7 – 1.5 % during both seasons. Non-reducing sugars percentage was increased by 62 – 85 % and62 – 114 % in both seasons, respectively compared with those of control.15. Both nitrogen and potassium fertilization increased total and reducing sugars percentages in the fruit peel of prickly pear fruits. The highest total (12.9 – 13.2 %) and reducing(11.5 – 11.8 %) sugars percentages in the fruit peel were gained by the highest N and K rates (120 g N and 39g k /plant), whereas control plants recorded the lowest percentages (9.8 – 10.30 % and 9.2 – 9.5 %) in both seasons, respectively.16. Non-reducing sugars percentage in the fruit peel responsed positively for increasing K fertilization and fluctuated under N rates indicating that K fertilization is an important factor for accumulating non-reducing sugars percentage in fruit peel. Anyhow, non-reducing sugars percentage ranged between 0.6 – 1.4 % and 0.7 – 1.5 % in both seasons, respectively.17. Total pectin in the fruit pulp and peel responsed positively to N and negatively to K fertilization. Since it was increased with increasing N rate and decreased with increasing K rate. Total pectin percentage in the fruit pulp and peel ranged between 0.47 – 1.24 % and 1.16 – 1.97% in the two seasons, respectively.18. Protein percentage was increased with increasing N fertilization to attain the highest percentage with the highest N rate under all potassium rates in both fruit pulp and peel in both seasons. The protein percentage ranged between5.35 –10.15% in the fruit pulp in both seasons. Protein percentage in the fruit peel was slightly higher than that of fruit pulp.19. Total nitrogen percentage in fruit pulp , peel and cladode was markedly increased with increasing N supply under all potassium rates. The highest N percentage was recorded for (120 g N / plant) rate while, potassium rates affected it insignificantly in the two seasons. Total nitrogen percentage in the fruit pulp ranged between 0.48 – 1.62 %), between 0.92 – 1.72 % in the fruit peel and between 1.42 – 2.48 % in the cladode during both seasons. It is worthy to said that total N percentage in the cladode was higher than that of peel which was higher than that of pulp.20. Potassium percentage in the fruit pulp, peel and cladode of prickly pear plants responsed positively and significantly to increasing both nitrogen and potassium fertilization rates in the two seasons. Potassium percentage in fruit peel is higher than that of fruit pulp, in spite fruit pulp responsed to fertilization treatment higher (87.62 and 74.28 %) than fruit peel (48.48 and 39.43 %) in both seasons, respectively. Potassium percentage in the fruit pulp ranged between(0.97 – 1.83 %) ,while in the fruit peel it ranged between1.98 – 2.94 % in the two seasons. Potassium percentage in the cladode came between for both percentage (1.57 –2.45 %) and response (55.41 – 54.04 %) to fertilization treatment during the two seasons.21. Phosphorous percentages in the fruit pulp , peel and cladode were increased with increasing N and K fertilization. The highest P percentages in these organs were gained by the highest N rate (120 g N /plant) and the third K one(26 g K /plant) in the two seasons. However, phosphorous percentage in the fruit pulp (0.144 – 0.196 %) was higher than those of cladode (0.114 – 0.159 %), which was higher than those in the fruit peel (0.082 – 0.156 %) in both seasons.22. Calcium percentage within each of fruit pulp, peel and cladode significantly responsed to nitrogen and potassium fertilization, but this response was positive with nitrogen and negative with potassium fertilization due mainly to the antagonism between K and Ca in the soil. Therefor, the highest Ca percentages (0.84 & 0.86 % in fruit pulp, 2.14 & 2.22 % in fruit peel and 2.76 - 2.78 % in cladode) were gained by (120 g N and 0 g K / plant) treatment, while the lowest corresponding percentages (0.37 & 0.38 %, 1.11 & 1.12% and 1.63 & 1.69 %) were recorded for (0 g N and 39 g K / plant) treatment in both seasons, respectively.The second experiment was carried out to study the effect of spraying chelated (EDTA) micronuitriants; i. e. Fe , Mn , Zn and Cu at 0.5 g /L from each on the whole shrub at 27 and 26 April in the two seasons, respectively. Spraying chelated micronutrients was conducted only on the shrubs received the two highest N rates (96 and 120 g N /plant)and the highest K rate (39 g K /plant). The obtained results could be summarized as follows:1. Spraying micronutrients on prickly pear plants fertilized with 96 and 120 g N with 39 g K /plant (for each) insignificantly affected on the number of total and flowering buds /cladode in the two seasons. Whereas percentage of flowering buds was significantly affected, especially on plants supplied with 120 g N and 39 g K /plant in the first seasons only.2. The total number of buds /plant was significantly affected by micronutrients spraying in the second season only ,while total yield /plant was insignificantly affected in both seasons. Since, plants fertilized with the highest N and K rates and spraying with micronutrients exhibited higher number of total buds /plant than unsprayed ones.3. Total fruit weight , pulp weight and percentage responsed positively to spraying micronutrients and gained their highest values for the plants sprayed with micronutrients.4. Fruit length, diameter and fruit shape index were insignificantly affected by the studied micronutrients treatment in the two experimental seasons.5. plants supplied with the lower N rate (96 g N /plant) + micronutrients spraying gained higher seeds weight /fruit than unsprayed ones in the two seasons. While, seeds number /fruit was insignificantly affected in both seasons.6. Whole fruit, fruit pulp and fruit peel moisture percentages were insignificantly affected by the tested N and micronutrients treatments during both seasons.7. Total, reducing and non-reducing sugar percentages in fruit pulp and peel were insignificantly affected by the tested micronutrients spraying treatments in the two seasons ,expect those of total sugars in fruit pulp in the second one ,since it was slightly increase8. Fruit pulp and peel protein percentages were significantly increased with spraying micronutrients. The highest percentages (10.46 and 10.94 %) were recorded for the fourth and second treatments, whereas the first treatment gained the lowest percentage (9.73 and 9.89 %) in fruit pulp and peel, respectively.9. Spraying micronutrients significantly increased total pectin percentage in the fruit pulp and peel in both seasons. Fruit peel contained higher pectin percentage (1.41 – 1.66 %) than fruit pulp (0.79 – 1.05 %) in the two seasons.10. Spraying micronutrients affected and increased TSS and TA percentage in both seasons, except TSS percentage in the second seasons. The highest TSS (14.10 – 14.20 %),TA (0.198 – 0.187 %) and TSS/acid ratio (74.74 – 79.22) were recorded for the 4th treatment ,except TA in the first season and TSS/acid ratio in the second one ,which was gained by the first treatment. The lowest corresponding values(13.50 – 13.90 %, 0.188 – 0.176 % and 68.34 – 74.92) were gained by the first treatment ,except TSS and TSS/acid ratio in the second season and TA in the first one, which was gained by the third treatment in both seasons, respectively.11. Total nitrogen percentage was positively affected by micronutrients spraying. Total nitrogen percentage in the cladode (2.12 – 2.33 %) was about two folds that on fruit pulp (1.46 – 1.67 %) which was slightly lower than that of fruit peel (1.52 – 1.76 %) during both seasons.12. Spraying micronutrients markedly increased K, P and Ca percentages either in fruit pulp and peel or cladode in the two seasons. Higher N rate (120 g N /plant) increased P and Ca percentages in the tested organs than the lower rate (96 g N /plant) in both seasons.13. The contents from Fe, Zn, Mn and Cu either in fruit pulp and fruit peel or cladode significantly responsed to micronutrients spraying in both seasons. Regardless, micronutrients spraying, the higher N rate slightly recorded higher Fe, Zn, Mn and Cu contents than the lower rate in the two seasons. However, fruit pulp contained 88.10 - 99.60 ppm Fe, 43.40 – 63.60 ppm Zn, 79.70 – 91.40 ppm Mn and 8.77 – 11.37 ppm Cu ,whereas fruit peel contained 121.60 – 138.00 ppm Fe, 39.80 – 55.00 ppm Zn, 124.60 – 148.90 ppm Mn and 13.07 – 15.30 ppm Cu. Cladode tissues contained 184.20 – 209.30 ppm, 66.00 – 89.40 ppm, 159.40 – 181.60 ppm and 15.43 – 19.17 ppm form Fe, Zn, Mn and Cu elements, respectively. In other words, cladode tissues contained the highest Fe, Zn, Mn and Cu contents ,followed by fruit peel, whereas fruit pulp recorded the lowest values in both seasons.The third experiment was carried out to evaluate the effect of different nitrogen at (120 g N /plant) and potassium at (39 g K /plant) doses on growth, yield and fruit characteristics. This amount of nitrgen and potassium fertilizers was divided into two, three and four equal doses and added as soil application. The first dose of N and K fertilizers was applied in all treatments with the first irrigation (at 16 and 1 March) in the first and second seasons, respectively. In addition, application was applied as:-1- In the first treatment, the second application was applied in 27 and 26 April in the two seasons, respectively.2- In the second treatment, the other application were applied in 27 & 26 April and 11 & 10 May in the first and second seasons, respectively.3- The last treatment, other application were applied in 13, 27 April and 11 May in the first season and in 12, 26 April and 10 May in the second season.The obtained reuslts could be summarized as follows:1. Applying N and K fertilizers at 4 doses gained the highest number of total, flowering and vegetative buds / cladode, followed by adding them at 3 doses, while 2 doses treatment recorded the lowest number in both seasons. This means that increasing number of N and K applications led to increase number of total, flowering and vegetative buds /cladode as well as percentage of flowering buds in the two seasons.2. Total buds and yield /plant were significantly increased with increasing number of N and K application in both seasons. Therefore, the highest total buds and yield /plant were recorded for plants received N and K fertilizers at 4 doses, while those of 2 doses gained the lowest values in the two seasons.3. Total and pulp fruit weights as well as pulp weight percentage were significantly increased with increasing number of fertilizers applications, while peel weight was not significantly affected in both seasons.4. Fruit length diameter and fruit shape index were insignificantly affected by the number of N and K applications in the first season, but in the second one, fruit diameter and fruit shape index were affected significantly.The highest fruit diameter (5.10 cm) and the lowest shape index value- (1.72) were recorded for plants received their N and K requirements at 4 doses, descendingly followed by those of 3 and 2 doses.5. Average weight of seeds /fruit was significantly increased with increasing number of fertilizers application ,while seeds number /fruit was insignificantly affected in both seasons6. Moisture percentages either in the whole fruit or fruit pulp and peel significantly increased with increasing adding number. So, the highest doses number (4doses) gained the highest percentages, whereas the lowest percentages were recorded for 2 doses treatment in the studied organs in both seasons.7. Increasing number of fertilizers application was of no significant effect on total, reducing and non-reducing sugar contents in fruit pulp and peel during both seasons. Total, reducing and non-reducing sugars contents in the fruit pulp were approximately similar to those of fruit peel in the two seasons. As such, Total sugars percentage ranged between 12.8 – 13 % and 12.9 – 13.2 % in fruit pulp and peel, respectively in the two seasons. Reducing sugars percentage ranged between 11.3 – 11.6 % and 11.5 – 11.8 %, whereas non-reducing sugars percentage ranged between(1.0 – 1.50 % and 1.3 – 1.5 %) in fruit pulp and peel in both seasons, respectively.8. Protein percentage in the fruit pulp and peel was increased with increasing adding number in the two seasons. The highest and the lowest percentages were gained by 4 and2 doses treatments, respectively. Protein percentage in the fruit peel was slightly higher than that of fruit pulp.9. Plants received N and K fertilizer at 3 doses revealed the highest pectin percentage either in fruit pulp or peel in the two seasons compared with those of 2 doses which gained the lowest percentages. Pectin percentage ranged between 0.97 – 1.14 % in fruit pulp and between 1.41 – 1.71 % in fruit peel in both seasons. Pectin percentage in fruit peel was much higher than those found in fruit pulp.10. Total soluble solids and total acidity percentages as well as TSS /acid ratio in the fruit juice were insignificantly affected by the tested N and K application number, while ascorbic acid content was significantly affected during the two seasons. So, the highest ascorbic acid content (41.0 and 41.22 mg /100g) was recorded for 4 doses treatment ,whereas 2 doses treatment gave the lowest content (39.6 and 39.3 mg /100g) in both seasons ,respectively.11. Fruit pulp contained 1.58 – 1.77 % N, 1.79 – 1.83 % K,0.182 – 0.194 % P and 0.48 – 0.68 %Ca , whereas fruit peel contained 1.61 – 1.81 %, 2.93 – 3.01 %, 0.148 – 0.155 % and 1.89 – 2.09 % for N, K, P and Ca, respectively. Prickly pear cladodes 2.26 – 2.31 % N, 2.44 – 2.66 % K, 0.148 – 0.158 % P and 2.11 – 2.36 % Ca. So, it could be said that the cladode tissues contained the highest percentage of nitrogen and calcium ,followed by fruit peel and pulp ,whereas fruit peel contained the highest potassium percentage ,followed by cladode and fruit pulp. As for phosphorous percentage, fruit pulp contained the highest percentage ,descendingly followed by cladode and fruit peel.Finally, it could be recommended to fertilize prickly pear plants grown in sandy soil with 120 g N + 39 g K /plant at4 doses throughout growth season, in addition to 10 kg organic manure +300 g super phosphate /plant at one dose in winter.VI. LITIRATURE CITEDAbdelal, A.F.1964. The effect of time of application and concentration of gibberellin on the development of prickly pear pathenocarpic fruits.The EgyptiaV. SUMMARY AND CONCLUSIONField work of this investigation was carried out during the two successive seasons of 2001 and 2002 on six-year-old commercial shrubs of the Egyptian prickly pear type(El- Shamy) grown in sandy soil at 3x4 meters apart, in Entelak district, Moudereyat Al- Tahrir Behera Governorate, EgyptThis study was planned to evaluate the effect of different nitrogen and potassium fertilization rates on vegetative growth, yield and physical and chemical fruit characteristics in an attempt to determine the fertilization regime of prickly pear plants grown in sandy soils.The experimental shrubs of each treatment were of uniform size and vigour. In winter of 2001 season all plants were supplied with 10 kg of organic manure and 300g superphosphate per plant. The plants were sprinkler irrigated for one hour at fortnightly intervals throughout the flowering and fruit development periods (March-early July). The chosen shrubs were subjected to three separate experiments as follows:The first experiment was conducted to evaluate different annual rates of nitrogen and potassium fertilization on the growth, yield and fruit characteristics. The experimental shrubs were subjected to the following N and K fertilization treatment.1. Adding N fertilizer at 0, 24, 48, 72, 96, 120 g N per plant.2. Adding K fertilizer at 0, 13, 26, 39 g K2O per plant.3. Different combinations between N and K fertilizer.All amounts of nitrogen and potassium fertilizer were added in two equal doses as a soil application, using ammonium sulphate (20.6% N) as a source of nitrogen and potassium sulphate (48 – 50 K2O) as a source of K. The first dose was applied just before the first irrigation (16 and early march) and the second at the end of the April (27 and 26 April) of each season, respectively.The obtained reuslts could be summarized as follows: -1. The number of buds/cladode was markedly increased with increasing nitrogen rate under all potassium rates recording the highest number at 96g N/plant. The highest K rate(39 g K/plant) recorded the highest number of buds/cladode in both seasons. The number of buds / cladode ranged between (4.40 - 9.27) and (3.67 - 7.00) in the first and second seasons, respectively.2. Number of flowering buds/cladode was significantly increased with increasing N application rate till 96g N/plant to decrease thereafter with increasing N rate to 120g/plant.Meaning that excess N fertilization reduce flowering buds. The highest K rate (39g K2o /plant) produced the highest number of flowering buds/cladode in both seasons. Control (unfertilized) plants recorded the least number of flowering buds /cladode.3. The percentage of flowering buds/ cladode responsed negatively to N fertilization in the two seasons, whereas it responsed positively for K fertilization in the second season only. The percentage of flowering buds /cladode ranged between 87.2 – 96.1% and 82.3 – 93.8 % in both seasons, respectively.4. The number of vegetative buds/cladode was significantly affected by N levels and insignificantly by K rates in both seasons .Since increasing N rate significantly increased number of vegetative buds /cladode.5. Nitrogen fertilization significantly increased the number of flowering buds /plant. This trend was markedly increased with increasing N supply, while potassium fertilization insignificantly affected it in both seasons. The number of flowering buds /plant ranged between 63.17-89.33 and49.13-87.33 in the two seasons, respectively. The highest number of flowering buds /plant was recorded when N was applied at 72 and 120g N and K at 26 g K2o / plant in the two seasons. Applying K AT 39 g K2O /plant without N gained the lowest number of flowering buds /plant in the two seasons.6. Total yield /plant as well as fruit and pulp weights were significantly increased with increasing N application rate. The yield was increased by 65.32 and 117.53 % in both seasons, respectively. The highest values of yield /plant and fruit and plup weights were gained when the plants were supplied with 120 g N / plant under all K rates in both seasons without significant differences between them in most cases. This trend indicate that N fertilization is the main factor for increasing yield and fruit weight of prickly pear plants. The highest total yield / plant (7.90 and 8.75 kg /plant) was recorded for plants fertilized with 96 g N and 39 g K / plant in the first season and 120 g N and 26 g K / plant in the second one, respectively. The highest fruit (98.45 and 100.03 g /fruit) and pulp (62.32 and 62.48 g) weights were produced by the plants fertilized with the highest rate of nitrogen under 39 and 26 g K /plant ,whereas those received no N and K fertilizers and those supplied with 26 g K /plant without N gained the lowest fruit (63.21 and 66.72 g /fruit) and pulp (37.12 and 40.24 g) weights in both seasons, respectively.7. Weight of Fruit peel was increased with increasing N rat, while K affect did not follow constant trend in both seasons. Peel weight ranged between 26.05- 39.18g and 27.09- 38.4 g in both seasons, respectively.8. Pulp percentage of prickly pear fruits ranged between56.33– 66.29% and (58.16%-63.17%) in the first and second seasons, respectively. The fifth N rate (96 g N /plant) and third rate of K (26 g K2O /plant) gained the highest pulp percentage in the first season, while in the second one the highest percentage was recorded for the highest ratesof N and K.9. The highest fruit length and diameter were recorded when the plants were fertilized with the highest N rate (120g N /plant) under all K rates without significant differences between K rates in most cases. Indicating that N fertilization is the important factor for increasing fruit length and diameter. No significant differences were detected between 120 and 96 N rates under all K rates in both seasons. Fruit length ranged between 7.2 – 8.7 cm and 7.0 – 9.3 cm, whereas fruit diameter was ranged between 3.9 - 4.9 cm and 3.8 - 4.8 cm in the first and second seasons, respectively. This means that length of prickly pear fruit is about fold its diameter.10. Seeds weight /fruit was significantly increased with increasing N and K rates, whereas seed number was insignificantly affected in both seasons. This indicate that N and K fertilization are important for seed developing and growing. Seeds weight /fruit ranged between 3.53 – 6.67 g, while seeds number was ranged between 130.67 – 142.33 seed /fruit in the first and second seasons, respectively.11. Moisture percentage in the whole fruit and both fruit pulp and peel were significantly increased with increasing N fertilization rate, while K fertilization reduced it. So the highest moisture percentage was recorded in fruits produced on plants fertilized with the highest N rate (120 g N /plant) without K fertilization in both seasons. Whereas, those supplied with the highest K rate (39 g K /plant) and the lowest N rate recorded the lowest moisture percentage in the considered orgams. The moisture percentage ranged from 78.7 to 89.4 % in the whole fruit , 76.2 –88.5 % in the pulp and 80.2 – 88.7 % in the peel during the two seasons.12. Total soluble solids percentage responsed positively for nitrogen and potassium fertilization, since the highest percentage were gained by the highest N and K rates in both seasons. The percentage of TSS ranged between 11.4 - 13.9 % and 11.5 - 14.00 % in the first and second seasons, respectively.13. The lowest total acidity percentage and the highest TSS /acid ratio and ascorbic acid content were gained by the highest potassium rate (39 g K / plant) under all nitrogen rates in the two seasons. This indicate that K fertilization is the main factor for decreasing the total acidity percentage and hence increasing TSS /acid ratio in the prickly pear fruit juice. Total acidity percentage in juice of prickly pear fruits ranged between 0.188 – 0.218% and 0.176 – 0.220 % in both seasons, respectively, whereas TSS /acid ratio was ranged between 55.89 - 73.48 and 52.38 - 74.92 and ascorbic acid content was ranged between 35.1 - 39.6 mg/100g and35.2 - 39.8 mg/100g in both seasons, respectively.14. Total, reducing and non-reducing sugars percentages were significantly increased with increasing potassium rate so, the highest percentages were gained by the highest K rate(39 g K / plant) under all nitrogen rates. Indicating that potassium fertilization is the main factor for increasing sugar percentages in prickly pear fruits. The highest percentages of total, reducing and non-reducing sugar were recorded when the plant were fertilized with 96 and 120 g N /plant under 39 g K /plant, while unfertilized control plants gave the lowest percentages in both seasons. Total sugar percentage in fruit pulp ranged between 10.3 – 13.0 %, reducing sugar between 9.6 – 11.6 % , while those of non-reducing sugar ranged between 0.7 – 1.5 % during both seasons. Non-reducing sugars percentage was increased by 62 – 85 % and62 – 114 % in both seasons, respectively compared with those of control.15. Both nitrogen and potassium fertilization increased total and reducing sugars percentages in the fruit peel of prickly pear fruits. The highest total (12.9 – 13.2 %) and reducing(11.5 – 11.8 %) sugars percentages in the fruit peel were gained by the highest N and K rates (120 g N and 39g k /plant), whereas control plants recorded the lowest percentages (9.8 – 10.30 % and 9.2 – 9.5 %) in both seasons, respectively.16. Non-reducing sugars percentage in the fruit peel responsed positively for increasing K fertilization and fluctuated under N rates indicating that K fertilization is an important factor for accumulating non-reducing sugars percentage in fruit peel. Anyhow, non-reducing sugars percentage ranged between 0.6 – 1.4 % and 0.7 – 1.5 % in both seasons, respectively.17. Total pectin in the fruit pulp and peel responsed positively to N and negatively to K fertilization. Since it was increased with increasing N rate and decreased with increasing K rate. Total pectin percentage in the fruit pulp and peel ranged between 0.47 – 1.24 % and 1.16 – 1.97% in the two seasons, respectively.18. Protein percentage was increased with increasing N fertilization to attain the highest percentage with the highest N rate under all potassium rates in both fruit pulp and peel in both seasons. The protein percentage ranged between5.35 –10.15% in the fruit pulp in both seasons. Protein percentage in the fruit peel was slightly higher than that of fruit pulp.19. Total nitrogen percentage in fruit pulp , peel and cladode was markedly increased with increasing N supply under all potassium rates. The highest N percentage was recorded for (120 g N / plant) rate while, potassium rates affected it insignificantly in the two seasons. Total nitrogen percentage in the fruit pulp ranged between 0.48 – 1.62 %), between 0.92 – 1.72 % in the fruit peel and between 1.42 – 2.48 % in the cladode during both seasons. It is worthy to said that total N percentage in the cladode was higher than that of peel which was higher than that of pulp.20. Potassium percentage in the fruit pulp, peel and cladode of prickly pear plants responsed positively and significantly to increasing both nitrogen and potassium fertilization rates in the two seasons. Potassium percentage in fruit peel is higher than that of fruit pulp, in spite fruit pulp responsed to fertilization treatment higher (87.62 and 74.28 %) than fruit peel (48.48 and 39.43 %) in both seasons, respectively. Potassium percentage in the fruit pulp ranged between(0.97 – 1.83 %) ,while in the fruit peel it ranged between1.98 – 2.94 % in the two seasons. Potassium percentage in the cladode came between for both percentage (1.57 –2.45 %) and response (55.41 – 54.04 %) to fertilization treatment during the two seasons.21. Phosphorous percentages in the fruit pulp , peel and cladode were increased with increasing N and K fertilization. The highest P percentages in these organs were gained by the highest N rate (120 g N /plant) and the third K one(26 g K /plant) in the two seasons. However, phosphorous percentage in the fruit pulp (0.144 – 0.196 %) was higher than those of cladode (0.114 – 0.159 %), which was higher than those in the fruit peel (0.082 – 0.156 %) in both seasons.22. Calcium percentage within each of fruit pulp, peel and cladode significantly responsed to nitrogen and potassium fertilization, but this response was positive with nitrogen and negative with potassium fertilization due mainly to the antagonism between K and Ca in the soil. Therefor, the highest Ca percentages (0.84 & 0.86 % in fruit pulp, 2.14 & 2.22 % in fruit peel and 2.76 - 2.78 % in cladode) were gained by (120 g N and 0 g K / plant) treatment, while the lowest corresponding percentages (0.37 & 0.38 %, 1.11 & 1.12% and 1.63 & 1.69 %) were recorded for (0 g N and 39 g K / plant) treatment in both seasons, respectively.The second experiment was carried out to study the effect of spraying chelated (EDTA) micronuitriants; i. e. Fe , Mn , Zn and Cu at 0.5 g /L from each on the whole shrub at 27 and 26 April in the two seasons, respectively. Spraying chelated micronutrients was conducted only on the shrubs received the two highest N rates (96 and 120 g N /plant)and the highest K rate (39 g K /plant). The obtained results could be summarized as follows:1. Spraying micronutrients on prickly pear plants fertilized with 96 and 120 g N with 39 g K /plant (for each) insignificantly affected on the number of total and flowering buds /cladode in the two seasons. Whereas percentage of flowering buds was significantly affected, especially on plants supplied with 120 g N and 39 g K /plant in the first seasons only.2. The total number of buds /plant was significantly affected by micronutrients spraying in the second season only ,while total yield /plant was insignificantly affected in both seasons. Since, plants fertilized with the highest N and K rates and spraying with micronutrients exhibited higher number of total buds /plant than unsprayed ones.3. Total fruit weight , pulp weight and percentage responsed positively to spraying micronutrients and gained their highest values for the plants sprayed with micronutrients.4. Fruit length, diameter and fruit shape index were insignificantly affected by the studied micronutrients treatment in the two experimental seasons.5. plants supplied with the lower N rate (96 g N /plant) + micronutrients spraying gained higher seeds weight /fruit than unsprayed ones in the two seasons. While, seeds number /fruit was insignificantly affected in both seasons.6. Whole fruit, fruit pulp and fruit peel moisture percentages were insignificantly affected by the tested N and micronutrients treatments during both seasons.7. Total, reducing and non-reducing sugar percentages in fruit pulp and peel were insignificantly affected by the tested micronutrients spraying treatments in the two seasons ,expect those of total sugars in fruit pulp in the second one ,since it was slightly increase8. Fruit pulp and peel protein percentages were significantly increased with spraying micronutrients. The highest percentages (10.46 and 10.94 %) were recorded for the fourth and second treatments, whereas the first treatment gained the lowest percentage (9.73 and 9.89 %) in fruit pulp and peel, respectively.9. Spraying micronutrients significantly increased total pectin percentage in the fruit pulp and peel in both seasons. Fruit peel contained higher pectin percentage (1.41 – 1.66 %) than fruit pulp (0.79 – 1.05 %) in the two seasons.10. Spraying micronutrients affected and increased TSS and TA percentage in both seasons, except TSS percentage in the second seasons. The highest TSS (14.10 – 14.20 %),TA (0.198 – 0.187 %) and TSS/acid ratio (74.74 – 79.22) were recorded for the 4th treatment ,except TA in the first season and TSS/acid ratio in the second one ,which was gained by the first treatment. The lowest corresponding values(13.50 – 13.90 %, 0.188 – 0.176 % and 68.34 – 74.92) were gained by the first treatment ,except TSS and TSS/acid ratio in the second season and TA in the first one, which was gained by the third treatment in both seasons, respectively.11. Total nitrogen percentage was positively affected by micronutrients spraying. Total nitrogen percentage in the cladode (2.12 – 2.33 %) was about two folds that on fruit pulp (1.46 – 1.67 %) which was slightly lower than that of fruit peel (1.52 – 1.76 %) during both seasons.12. Spraying micronutrients markedly increased K, P and Ca percentages either in fruit pulp and peel or cladode in the two seasons. Higher N rate (120 g N /plant) increased P and Ca percentages in the tested organs than the lower rate (96 g N /plant) in both seasons.13. The contents from Fe, Zn, Mn and Cu either in fruit pulp and fruit peel or cladode significantly responsed to micronutrients spraying in both seasons. Regardless, micronutrients spraying, the higher N rate slightly recorded higher Fe, Zn, Mn and Cu contents than the lower rate in the two seasons. However, fruit pulp contained 88.10 - 99.60 ppm Fe, 43.40 – 63.60 ppm Zn, 79.70 – 91.40 ppm Mn and 8.77 – 11.37 ppm Cu ,whereas fruit peel contained 121.60 – 138.00 ppm Fe, 39.80 – 55.00 ppm Zn, 124.60 – 148.90 ppm Mn and 13.07 – 15.30 ppm Cu. Cladode tissues contained 184.20 – 209.30 ppm, 66.00 – 89.40 ppm, 159.40 – 181.60 ppm and 15.43 – 19.17 ppm form Fe, Zn, Mn and Cu elements, respectively. In other words, cladode tissues contained the highest Fe, Zn, Mn and Cu contents ,followed by fruit peel, whereas fruit pulp recorded the lowest values in both seasons.--2- Effect of plant extracts on food consumption ofSpodoptera littoralis.Three wild plant; F. crispa, M. nodiflorum and A. canariense extracted successively by four solvents; petroleum ether, chloroform, ethyl acetate and ethanol 70%. These plant yielded different extracts. Fourth, instar larvae of S. littoralis tested with these extracts to know the effect of these extracts on consumption food. Some parameters were studied as; amount of ingested and digested food by treated larvae, mean weight, weight of larval gained, consumption index (C.I), growth rate (G.R), approximate digestibility (A.D), efficiency of conversion of ingested and digested food (E.C.I and E.C.D).2.1 Effect of petroleum ether plant extracts on food consumption of S. littoralisLarval weight, weight gained, food consumed and digested food were affected by larval feeding on different petroleum ether plant extracts. F. recorded the highest values followed by A. canariense at 10%. A canariense crispa at 5% recorded the lowest values, while M. nodiflorum at 10% showed the lowest C.I value 1.09, while F. crispa recorded that highest one. G.R affected slightly and M. nodiflorum at 10% caused the lowest G.R values 0.24 M. nodiflorum at 5% showed the lowest. A.D value 75.25%, while F. crispa at 5% showed the highest value 88.76%, this means that the production of feces on M. nodiflorum at 10% was higher than that of F. crispa at 5%. In contrary M. nodiflorum at 10% showed the highest E.C.I and E.C.D values 49.75% and 66.10% respectively, while F. crispa at 5% recorded the lowest values 23.77% and 26.78% respectively.2.2. Effect of chloroform extracts on food consumption ofS. littoralis:Larval weight, weight gained, food ingested and digested food affected by feeding larvae of S. littoralis on treated castor bean leaves with chloroform plant extracts. A. canariense at 10% recorded the lowest ingested food 6.66 gm, while 5% showed the lowest digested food, mean weight of treated larvae and weight of gained 6.66, 0.45 and 0.71respectively. In contrary, M. nodiflorum at 10% recorded the highest amounts of ingested and digested food were 7.08 and 6.75 gm respectively. while, A. canariense at 10% showed the highest mean weight of larvae 0.52 gm and M. nodiflorum at 5% showed the highest weight of larval gained 0.86 gm. C.I was affected by these extracts and M. nodiflorum at 10% recorded the highest C.I values 3.15 and A canariense at 10% showed the lowest values 2.56 compared with the chloroform control 3.12. G.R values were nearly similar at all extracts and chloroform control. A.D values increased and M. nodiflorum at 10% showed the highest values 2.56, while A. canariense at 5% recorded the lowest values 91.74 compared with the chloroform control 87.17. E.C.I values ranges between a minimum of 10.86 for A. canariense at 5% to a maximum of 13.10 for 10% compared with the chloroform control 11.02. E.C.D values ranged between a minimum of 11.83 for A. canariense at 5% to a maximum of 13.94 for 10% compared with the chloroform control 12.64.2.3 Effect of ethyl acetate extracts on food consumption ofS. littoralis.