Effect of vernalization period and bulb size on bolting of onion cultivar “Texas Early Grano” grown under Gezira conditions, Sudan

     Texas Early Grano onion cultivar is very popular in Sudan and is used mainly as a salad vegetable. Unfortunately, this cultivar does not flower and produce seeds under Sudan conditions and seeds should be imported from abroad. Attempts to produce seeds of this cultivar under Gezira conditions have failed. Therefore, the objective of this research was to study the effects of bulb size and vernalization on the induction of flowering of Texas Early Grano onion cultivar. Experiments were conducted at the research farm of the Faculty of Agricultural Sciences, University of Gezira, Wad Medani, Sudan, during the  winter seasons of 2008/09 and 2009/10.   Treatments consisted of vernalization periods ranging from 45 to 180 days, storage temperatures of 4 to 50C, and bulb size which was small and medium. Treatments were arranged in a  randomized complete block design with three replicates. Results indicated that vernalization duration significantly affected emergence percentage. As vernalization duration increased, emergence percentage increased in both seasons. Bulb size had no significant effects on emergence percentage. Vernalization temperatures of 4 to 50C for 90 days or more was the key factor for the induction of bolting of Texas Early Grano cultivar. To obtain the highest bolting percentage and seed yield, a combination of venrnalization at 4 to 50C for 180 days and medium-sized bulbs should be recommended.       يعتبر صنف البصل "تكساس إيرلى جرانو" من الأصناف المعروفة في السودان التي تستخدم كأحد الخضر الرئيسية في طبق السلطة. محاولة إنتاج بذور هذا الصنف محلياً لم تعط نتائج إيجابية نسبة لعدم توفر درجات الحرارة المنخفضة اللازمة لتحفيز الإزهار تحت ظروف ولاية الجزيرة. لذا هدفت هذه الدراسة إلى تحفيز الإزهار لإنتاج البذور من هذا الصنف باستخدام ظاهرة الإرتباع (التخزين المبرد) لأحجام مختلفة من الأبصال. أجريت هذه الدراسة بمزرعة كلية العلوم الزراعية، جامعة الجزيرة، واد مدني، السودان خلال موسمي 2008/09 و 2009/10م. شملت التجارب فترات تخزين مبرد تراوحت ما بين 45- 180 يوما في درجات حرارة تراوحت ما بين 4 إلي 50 م ونوعين من حجم الأبصال (صغير ومتوسط).  استخدم تصميم القطاعات العشوائية الكاملة بثلاث مكررات. أشارت النتائج إلى أن التخزين المبرد في درجات الحرارة 4 - 5°م هو العامل الرئيسي المحفز للإزهار في صنف البصل "تكساس إيرلي جرانو". التخزين المبرد أظهر تاثيراً معنوياً في نسبة الانبات، فكلما زادت فترة التخزين المبرد زادت نسبة الانبات في كلا الموسمين، بينما لم يؤثر حجم الأبصال في نسبة الانبات. تم الحصول على أعلى نسبة للإزهار وإنتاجية البذور بزراعة الأبصال متوسطة الحجم والمخزنة في درجة حرارة 4 - 5°م لفترة 180 يوما. لذلك يوصى بتخزين الأبصال متوسطة الحجم في درجات حرارة تتراوح بين 4 - 5°م لفترة 180 يوما أو اكثر للحصول على بذور صنف البصل "تكساس إيرلي جرانو" تحت ظروف ولاية الجزيرة

Response of Banana "Williams Hybrid" to Nitrogen, Phosphorus and Potassium Fertilization

Field experiments were conducted at the National Institute for Promotion of Horticultural Exports (NIPHE) research farm during the period of 2001 to 2002 to determine the effects of nitrogen, phosphorus and potassium levels on growth parameters, earliness, nutrient uptake, yield and yield components of "William's hybrid" banana cultivar. Treatments included 5 N levels (0, 69, 138, 207 and 276g N/mat/year), 2 P levels (0 and 20 g P/mat/year) and 2 K levels (0 and 41 g K/mat/year) . The treatments were arranged in a randomized complete block design with 3 replications. Banana growth, yield and yield components were significantly increased by N and K application. The highest vegetative growth parameters, yield and yield components were obtained with the application of 207 g N/mat/year in combination with 41 g K/mat/year. Application of N in combination with K also resulted in a significant reduction in the period from plant-ing to shooting and from shooting to fruit maturation. The shortest number of days to shooting were obtained with the application of 276 g N/mat/year. Application of N, P and K also resulted in increased leaf N, P and K contents. Application of P alone or in combinations with N and K had no significant effects on growth or yield parameters

Effect of cultivar, packaging treatments and temperature on post-harvest quality of okra

ABSTRACT    Okra is one of the most popular vegetable crops in Sudan. The introduced cultivars such as Pusa Swani and Clemson Spineless have smooth pods and more adapted to the winter conditions of central Sudan. However, the local cultivar, Khartoumia, has hairy pods and not acceptable in international markets. Okra pods are highly perishable and subject to shriveling especially under the hot arid conditions of central Sudan. Therefore, the objective of this study was to determine the effect of packaging and temperature on the shelf life of okra pods of three introduced cultivars. Treatments consisted of three okra cultivars, namely, Clemson Spineless, Pusa Swani and Mahyco (hybrid); packaging treatments consisted of packing okra pods in cartons lined with intact polyethylene film, perforated polyethylene film or in cartons only and storage temperatures were 140C and 320C. Results showed that pods of the  cultivar Mahyco had the lowest weight loss, retained good colour and had the least decay and rot. Packaging of okra pods in intact or perforated polyethylene film and storing at 140C reduced weight loss and resulted in the best pod colour compared to the control. Packaging in perforated polyethylene film and storing at 140C resulted in the lowest incidence of decay and rot and best overall quality of pods. It is recommended to package okra pods in perforated polyethylene film and ship them to markets at 140C

Current status of sweet orange (Citrus sinensis L.) orchards in the River Nile State, Sudan

ABSTRAC     Production of sweet oranges in the Sudan does not cover domestic needs and sweet oranges are currently imported from Egypt, Iran and South Africa to satisfy the increasing demand. Hence, there is a need to investigate factors involved in the decline of sweet orange trees in one of the most important States for orange production in the Sudan. This research aims to study and evaluate different agronomic practices contributing to the prevailing sweet orange performance in the River Nile State, Sudan. A questionnaire and interviews with 120 sweet orange growers from Ketiab, Zeidab and Gandato citrus projects indicated that 75.8% of the farmers have orchards less than 2.9 ha. Low yielding cultivars such as “Sinnari”, the local selection (Baladi), Hamlin and Nori 16 dominate in the areas, 96.7% of the trees were budded on sour orange rootstocks, 85.8% of the seedlings were budded in private nurseries using bud wood collected from non-certified mother trees from private orchards. All sweet oranges were grown with other fruit species in 100% of the orchards, 80.8% used flat surface irrigation. There is no fixed fertilizer program. The type and quantity of chemical and organic fertilizers varied with different growers. No foliar fertilizers were used and nutrient deficiencies of Zn, Fe and Mn were observed in most orchards. Extension services for citrus production are highly needed for improvement of yield and quality of sweet oranges in the River Nile Stat

Propagation of Grapefruit (Citrus Paradisi Macf) by Shoot Tip Micrografting

This study was conducted to develop an in vitro technique for micrografting of grapefruit on sour orange rootstock during August, 2001 to May, 2002. The best in vitro germination of rootstock seed was obtained when both seed coats (hard and soft) were removed before in vitro culturing on a nutrient medium. The success of micrografting was affected by the age of rootstock seedling, light incubation conditions, source and method of placement of meristem tips and concentration of sucrose in the nutrient medium. High frequency of successful micrografts was obtained when the rootstock seedlings were germinated under darkness till the age of two weeks and then incubated in the same condition for two to three weeks after grafting. Plants grown in the greenhouse were the best source for meristem tips. Placement of scion on an inverted T incision at the point of decapitation was found to be the most suitable method of micrografting. The frequency of successful micro. grafts improved significantly when Murashige and Skoog medium was supplemented with 7.5% sucrose compared with normal sucrose concentration (3%).. INTRODUCTIO

Effects of nitrogen source, rate and foliar application on some leaf mineral nutrient contents and yield of “Sinnari” sweet oranges (Citrus sinensis L.) in the River Nile State, Sudan

      Sweet orange production in the Sudan is characterized by low yield and poor fruit quality. This research was aimed at determining the effects of nitrogen source, rate and foliar application on some leaf mineral nutrient content and yield of “Sinnari” sweet oranges in  the River Nile State during 2010/11 and 2011/12. Nitrogen sources were urea (100%), sheep manure (SM) (100%), or a combination of them (50% each), beside Wuxal foliar fertilizer. Nitrogen rates were 0, 43 and 86 kg N/ha. Treatments were arranged in a randomized complete block design with three replicates and 2 trees/plot. Results showed that nitrogen sources and rates were effective in increasing leaf nitrogen content and the highest values were obtained by the application of 86 kg N/ha using urea (100%) or a combination of urea and sheep manure. Application of Wuxal foliar fertilizer resulted in a significant increase of Zn and Fe leaf contents and total yield. Nitrogen source had significant effects on yield components and total yield. The highest values were obtained by a combination of urea and sheep manure or 100% urea, and the lowest values were recorded for 100% sheep manure. Nitrogen rate of 86 kg N/ha resulted in the highest yield components and total yield. It is recommended to fertilize sweet orange trees in the River Nile State with a combination of urea and sheep manure at the rate of 86 kg N/ha (12.4 kg SM/tree and 0.5 kg urea/tree) in addition to Wuxal foliar fertilizer

Effects of Ethrel Application and Packaging on Mango Fruit Quality

    Experiments were conducted at the National Institute for the Promotion  of Horticultural Exports, University of Gezira, Wad  Medani, Sudan, during May 1997 and 1998 to investigate the effects of Ethrel and polyethylene packaging on mango fruit quality. Mango fruit quality, Mango fruits were  harvested at the mature-green stage and treated with Ethrel or  left as control. Fruits were packed in either intact or perforated polyetlhylene packages or left unpacked. The experiments were set up in a completely randomized design with three replications. Ethrel treatment accelerated  the rate of fruit ripening as shown by an increase in total soluble solids, yellowing and a decrease in fruit firmness and starch content Fruits packed in intact polyethylene packages resulted in the  lowest weight loss, followed by those packed in perforated films, whereas unpacked fruits showed the highest weight loss and lowest quality manifested in shriveling and deterioratio

Effects of nitrogen source and effective micro-organisms on vegetative growth of shrubs of selected grapefruit (Citrus paradisi Macf) cultivars

   Grapefruit (Citrus Paradisi Macf.) is one of the most important citrus fruits in the Sudan. It can be successfully grown throughout the country where there are suitable soils and sufficient water to sustain tree growth. The objectives of this study were to find out the effects of different nitrogen sources, effective microorganisms (EM) and their combinations on the vegetative growth of shrubs of selected grapefruit cultivars. A field experiment was carried out at Umbarona, Wad Medani, Gezira State, Sudan, latitude 14.38 N, longitude 33.48 E and altitude 409 masl, in June 2012. Treatments consisted of three grapefruit cultivars: Marsh Seedless, Red Blush and Shamber. Fertilizer treatments were urea (100%), chicken manure (100%), urea with chicken manure (50% each), urea with EM, chicken manure with EM, urea (50%)+ chicken manure (50%)+ EM and unfertilized control. All fertilizer treatments were applied at the rate of 43 kg N/ha. Treatments were arranged in a split- plot design with two replicates. Grapefruit cultivars were allotted to the main plots and fertilizer treatments to the sub-plots. Data were collected on plant height (cm), stem diameter (cm), number of new branches, length of new branches (cm) and diameter of new branches (cm). Results showed that Marsh Seedless cultivar had the most vigorous vegetative growth compared to the other two cultivars. The results showed that the combination of urea, chicken manure and EM significantly gave the highest vegetative growth values, followed by chicken manure with EM, urea with chicken manure, urea with EM, urea alone, chicken manure alone and the least values of growth parameters were recorded for the unfertilized control. It is recommended to grow Marsh Seedless grapefruit cultivar and fertilize it with a combination of urea, chicken manure and EM.         يعتبر القريب فروت من أهم ثمار الحمضيات في السودان ويمكن زراعته بنجاح في جميع أنحاء البلاد حيثما توفرت التربة المناسبة والمياه الكافية لنمو الأشجار. أجريت تجربة حقلية في ام بارونة، واد مدنى ولاية الجزيرة، السودان. تهدف هذه التجربة لمعرفة تأثير مصادر النتروجين المختلفة والكائنات الحية الدقيقة الفعالة ومزجها مع بعضها البعض على النمو الخضري لشجيرات أصناف منتخبة من القريب فروت. تضمنت المعاملات ثلاثة أصناف من القريب فروت وهي مارش  ورد بلش وشامبر وسبعة معاملات أسمدة وهي  اليوريا، وزرق الدواجن، يوريا مع زرق الدواجن، يوريا مع الكائنات الحية الدقيقة الفعالة، زرق الدواجن مع الكائنات الحية الدقيقة الفعالة، يوريا مع زرق الدواجن مع الكائنات الحية الدقيقة الفعالة والشاهد. تمت إضافة الأسمدة لكل المعاملات بمعدل 43 كجم نتروجين للهكتار. صممت التجارب بطريقة القطع المنشقة بحيث كانت أصناف القريب فروت هي القطع الرئيسة ومعاملات النتروجين هي القطع الثانوية. جمعت بيانات عن طول النبات (سم) وقطر الساق (سم) وعدد الأفرع الجديدة وطول الفرع (سم) وقطر الفرع (سم). أوضحت النتائج أن الصنف مارش أعطى أعلى نمو خضري مقارنة بالصنفين رد بلش وشامبر. الخليط بين سماد اليوريا وزرق الدواجن و الكائنات الحية الدقيقة الفعالة  أعطت أعلى معدل للنمو الخضري ويليه زرق الدواجن والكائنات الحية الدقيقة الفعالة ثم اليوريا والكائنات الحية الدقيقة الفعالة ثم اليوريا وزرق الدواجن ثم زرق الدواجن لوحده ثم اليوريا لوحده وأدنى معدلات  النمو كانت في الشاهد .  يوصى بزراعة الصنف قريب فروت مارش وتسميده بخليط من اليوريا وزرق الدواجن والكائنات الحية الدقيقة الفعالة

Effect of plant spacing and pruning on vegetative growth, yield and fruit quality of introduced mango cultivars

   Kitchener is the most extensively cultivated mango cultivar in the Sudan. However, this cultivar is not popular in export markets due to its high fiber content. Hence, internationally popular mango cultivars have been recently introduced to the Sudan from South Africa. They  include Tommy Atkins, Kent, Keitt, Haden and Sensation. An experiment was conducted in Kamleen nursery, Gezira State, Sudan, during June 2008 to May 2011, to investigate the effects of plant spacing and pruning on vegetative growth, yield and fruit quality of these introduced mango cultivars compared to the local cultivar, Abusamaka . The trees were planted at a spacing of 5x5m and 10x10 m and subjected to three types of pruning, namely, pruning to two branches, three branches, tip pruning and control. Treatments were arranged in a split-plot design with three replicates. Plant spacing was assigned to the main plots and pruning treatments to the sub-plots. Results showed that the wider spacing resulted in significantly larger canopy diameter and larger number of fruits per tree than the closer spacing in all cultivars and seasons. However, the closer spacing resulted in significantly larger number of fruits/ha and  higher total yield/ha than the wider spacing due to the larger number of trees/ha. Pruning of mango trees to three main branches resulted in significantly the highest yield components and total yield, followed by two branches, tipping and the lowest yield components were produced by the un-pruned control. The introduced mango cultivars had significantly more vigorous vegetative growth, earlier in flowering, higher yield components and total yield and better fruit quality than the local cultivar Abusamaka. It could be concluded that the introduced cultivars Tommy Atkins, Kent and Keitt are promising cultivars to be grown in the Sudan using the high density planting system and pruned annually for high production of good quality fruit.        يعتبر الصنف كتشنر أكثر أصناف المانجو انتشاراً في السودان ولكنه غير مرغوب في أسواق الصادر نسبة لاحتوائه على نسبة عالية من الألياف. لذلك فقد تم استجلاب بعض الأصناف المرغوبة عالمياً من جنوب أفريقيا ، وقد شملت هذه الأصناف تومي أتكنز ، كنت ، كييت ، هادن وسنسيشن. أجريت التجربة بمشتل الكاملين ، ولاية الجزيرة ، خلال الفترة من يونيو 2008 حتى مايو 2011م لمعرفة تأثير أبعاد الزراعة والتقليم على النمو الخضري ومكونات الانتاج والانتاجية  ونوعية الثمار لهده الأصناف المستوردة مقارنة بالصنف المحلى أبوسمكة. زرعت الأشجار على مسافات 5x5 م و10x 10 م وتم تقليمها بثلاثة طرق للتقليم على النحو التالي : تقليم على فرعين وتقليم على ثلاثة أفرع وتقليم القمم النامية للأفرع وغير مقلمة للمقارنة. استخدم تصميم القطع المنشقة بثلاث مكررات، حيث اسندت القطع الرئيسية لأبعاد الزراعة والقطع الفرعية لطرق التقليم. اظهرت النتائج أن مسافات الزراعة 10x10م اعطت معنوياً أفضل نمو خضري وأكبر عدد الثمار للشجرة الواحدة بالمقارنة مع 5x5م فى كل  المواسم. أبعاد الزراعة  5x5 م اعطت معنوياً أعلى عدد للثمار وأعلى انتاجية للهكتار نسبة للعدد الكبير من الاشجار فى الهكتار. تقليم أشجار المانجو لثلاثة أفرع أعطى معنوياً أعلى انتاج يليه التقليم لفرعين ثم تقليم القمة وأدنى انتاجية كانت فى الاشجار غير المقلمة. الأصناف المستوردة اعطت معنوياً أفضل نمو خضري وأعلى انتاجية وأفضل نوعية للثمار بالمقارنة مع الصنف المحلي أبوسمكة. خلصت الدراسة إلى أنّ الاصناف المستوردة تومي اتكنز وكنت وكيت هى أصناف واعدة يمكن زراعتها فى السودان بطريقة الزراعة المكثفة وتقليمها سنوياً للحصول على أعلى انتاج من الثمار عالية الجودة

Effect of Antioxidants and Dehanding Methods under Different Temperature Levels on the Control of Banana Crown Browning

Two experiments were conducted at the National Institute for the Promotion of Horticultural Exports, University of Gezira, Sudan, during the period from 2000 to 2001 to investigate the effects of dehanding methods and antioxidants under two temperature levels on the control of banana crown browning. Dehanding methods included separation of hands under water or in air and cutting the hands using a knife under water or in air. The antioxidants were thiourea (1%), aluminum potassium sulfate (1%), ascorbic acid (150 ppm) and wax dissolved in petroleum ether. Dehanding by separation significantly reduced crown browning as compared to the other methods. The best antioxidants in reducing crown browning were thiourea and potassium aluminum sulfate which are sulfur-containing compounds and had an antioxidant activity. Banana hands stored at 14C˚ had significantly less crown browning as compared to those kept at 35C0 because the lower temperature reduced the activity of polyphenoloxidase enzyme which is responsible for banana crown browning. The interaction effects between antioxidants and temperature showed that the antioxidants followed the same trend mentioned previously within each temperature level, but were more effective in reducing banana crown browning at 140C