University of Khartoum Journal of Agricultural Sciences
University of Khartoum Journal of Agricultural Sciences (U. of K. J. Agric. Sci.) is a peer-reviewed periodical, issued every six months. Established on 1993
University of Khartoum, Faculty of Agriculture
In Vitro Expression of Sodium Chloride Tolerance of Some Solanum Species
Fifteen Solanum species (13 wild potato forms and two cultivars,Dèsiree and Hansa), representing different degrees of sodium chloride (NaCl) tolerance, were chosen to study the in vitro expression of NaCl. Two-node explants from in vitro propagated (on a medium of Murashige and Skoog (MS) –salts) plantlets were placed in honey jars containing 50 ml MS supplemented with 0.1mg/l indole acetic acid (IAA), 0.2 mg/l benzylaminopurine (BAP) and either one of four NaCl concentrations (0,40,80 and 120 mM/l). They were placed in a culture room at a temperature of 20°C-23°C, 4000 lux light intensity and 16 hours light period, and arranged in a complete randomized design with four replicates. The results showed that shoot growth in all species was inhibited by increasing NaCl concentration. Analysis of explant shoots and roots showed that Na+ and Cl - concentrations increased with increasing NaCl concentration, whereas those of K+ and Ca2+ decreased. There was a tendency of lower Na+ and Cl - concentrations in the shoots and higher concentrations in the roots of the NaCl tolerant compared to sensitive species. K+ concentrations in the shoots and Ca2+ concentrations in the roots were higher in NaCl tolerant species than in sensitive ones. Na+ and Cl - concentrations in the shoots and explant main stem length were negatively correlated (r=- 0.91 for both). The correlation coefficients between the main stem length and K+ concentration in shoots and Ca2+ concentrations in the roots were positive and highly significant (r= 0.74 and r = 0.90, respectively). However, Na+ and Cl - concentrations in the root were not correlated with shoot length. Shoot length could be a good trait for a quick screening of potato genotypes for NaCl tolerance
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A Note on Supplementation of Feterita Sorghum Flour with White Bean Flour and its Effect on Sorghum Protein Quality
Changes in Feterita sorghum amino acids profile, protein score and net protein value as well as the ratios of leucine to isoleucine, leucine to lysine and arginine to lysine due to white bean supplementation were studied. The results confirmed that the protein quality of Feterita sorghum is very low as reflected by its low protein score (35%), low net protein value (5.7%) and imbalanced ratios of its amino acids. Supplementation of Feterita sorghum flour with white bean flour had beneficial effects on the quality and quantity of Feterita sorghum protein. Addition of 30% decorticated white bean flour to Feterita sorghum flour (70% extraction rate) overcame lysine deficiency in Feterita sorghum protein, whereas the other essential amino acids were more abundant than is needed for the physiological needs of children as envisaged by the FAO/WHO/UNU. Also, the protein score and the net protein value were increased from 35% and 5.7% in Feterita sorghum flour to 99% and 19 %, respectively. Moreover, the ratios of leucine to isoleucine, leucine to lysine and arginine to lysine were favourably changed to the safety limits predicted by the FAO for preventing the pellagragenic effect of sorghum proteins.
Effect of Extended Irrigation Intervals at Different Growth Stages on Growth and Yield of Cotton in the Sudan Gezira
A field experiment was conducted for two consecutive seasons (1998/1999 and 1999/2000) at the Gezira Research Station, Gezira, Sudan, to study the effect of extended irrigation intervals at different growth stages on growth and yield of cotton (Gossypium barbadense L.) variety Barakat 90. The experiment was laid out in a complete block design with four replications. The treatments were irrigation every two weeks (standard) and extended irrigation intervals of one month during predetermined stages of cotton growth. These stages were early vegetative growth, late vegetative growth, early flowering, late flowering, early fruit opening and late fruit opening. The results indicated that growth and yield of cotton were adversely affected by extending the irrigation interval to one month throughout the growing season as well as when the irrigation interval was extended during the early flowering stage. The magnitude of this reduction was significant, and the levels of yield exhibited wide seasonal variation. The extended watering intervals had significant and substantial adverse effects on yield, associated with shorter plant height and reduced shoot dry weight and forced early 50% flowering and bolling compared with standard irrigation. The three components of cotton yield, i.e., lint index, seed index and ginning-out turn, were not affected significantly, because they are genetically controlled.
Yield Responses of Three Groundnut (Arachis hypogaea L.) Cultivars to Water Stress at Different Growth Stages *
This study was conducted to investigate the effect of water stress on the yield of three groundnut cultivars (Kiriz, MH383 and Sodari) for two successive seasons (in the summers of 1996/97 and 1997/98) in the Demonstration Farm of the Faculty of Agriculture, Shambat, Sudan. The experiment was executed in a split-plot design, where water stress (irrigation every 21 days) was applied at 50% flowering, at pegging and at pod filling stage. A non-stressed treatment (irrigated every ten days) was used as a control. The stress period was for three weeks for each of the three stages of growth. Yield components (number of pods/plant, weight of 100 seeds, number of seeds per pod and weight of 100 pods) were not affected by the stress treatments. Shelling percentage was greatly different among the cultivars
Monitoring and Forecasting of Pearl Millet (Pennisetum glaucum L.) Yield in Two Areas of Traditional Rain-fed Agriculture in Western Sudan
A study was conducted to test the validity of an FAO method for monitoring and forecasting pearl millet yield in two traditional rain- fed areas in western Sudan; namely, Al-Obeid and Al-Fashir. The periods of crop development were delineated from the graphs of mean normal (30 years) rainfall (Pn) and potential evapotranspiration (PET) versus 10-day interval (dekad) during the growing season. Annual water satisfaction indices (SI) were estimated for 10 years from annual water balance for the period 1987-1996. This index indicates the extent to which the water requirement of the crop was satisfied in a cumulative way. Highly significant cubic relationships between Pn or PET and seasonal dekads were obtained for both areas. For Al-Obeid, Pn for three dekads were equal to 0.5 PET and for the remaining dekads they were below 0.5 PET, while for Al-Fashir Pn was below 0.5 PET for all dekads. Thus, according to the FAO classification system, the two areas have no growing seasons. Since this conclusion contradicts with acctual practice, a modification of the system is proposed. According to the modified system, there is a growing season but it is still very dry in both areas. Trendline equations for the distribution of Pn and PET were developed for the two areas. An example for the calculation of SI for millet (dukhn) grown in 1987 in the two areas was presented and analyzed. The corelation between millet yield and seasonal rainfall was not significant in Al-Obeid area, but it was highly significant (r2 =0.947) and cubic in Al-Fashir area. The correlations between yield and SI were significant and cubic in Al-Obeid (r2 =0.447)
Groundnut Response to Irrigation Frequency Under Different Tillage Systems
Three irrigation frequencies and four tillage systems were studied for two consecutive summer seasons (2002/03 and 2003/04) to test their effect on growth and yield of groundnut (Arachis hypogaea L.). The study was carried out in the Demonstration Farm of the Faculty of Agriculture and Natural Resources, University of Kassala at New Halfa, Sudan. The irrigation frequencies were 10, 15 and 20 days, and the tillage systems used were discing, ridging, harrowing and no-tillage. There were significant differences in the studied parameters due to irrigation frequency. Except for days to 50% flowering and shelling percentage, the 10 days frequency recorded higher values than 15 and 20 days frequencies. On the other hand, tillage system had significant effects on all tested parameters except 100-seed weight and shelling percentage. Disc ploughing gave higher values than the other tillage systems. The interaction between irrigation frequencies and tillage systems had significant effects on the studied parameters except days to 50% flowering, seed weight and shelling percentage. Ten days irrigation frequency with disc ploughing gave the highest yield and field water use efficiency
Production of Fuel Ethanol from Molasses by Thermotolerant Yeast
A thermotolerant strain of the yeast Kluyveromyces marxianus, isolated from Kenana sugar factory in the Sudan, was used for the production of ethanol from molasses. Fermentations were carried out in a bioreactor with 10-litre working volume at three temperatures and three sugar concentrations in batch and at one temperature and three feeding rates in fed-batch processes. In the batch fermentations, the best results were obtained at 40°C and 20% sugar, where a maximum of 9.2% (w/v) ethanol concentration was produced in 30 hours with a yield of 90% of the theoretical and a maximum ethanol specific productivity of 0.65 g per gramme yeast and hour. In the fed-batch process at 40°C, the best results were obtained at 0.5 l/h feeding rate of a substrate with 400 g/l sugar. Under such conditions, the yeast produced up to 9.34% (w/v) ethanol with 91.6% of the theoretical yield in 14 hours of fermentation and a maximum specific ethanol productivity of 0.9 g per gramme yeast and hour.
Air Compressor Assembly, Installation and Evaluation on Agricultural Tractor
This study was carried out to develop an air compressor and container to be installed at the rear side of a tractor and operated from the power take-off shaft. Three iron frames and flexible hoses were used to link the air compressor and air container. The compressor was tested with three sizes of tires (254,406 and 965 mm) during three times per day (10.00 am, 12.00 and 3.00 pm). Tire air filling with the assembled compressor was compared with manual and electrical workshop compressing mechanisms. The results showed that the difference in average fuel consumption between tractor engine operated alone and the assembled compressor was only 117 ml/hr. There was no significant difference in fuel consumption when the compressor was operated at any time during the day. The time taken for air filling of the three sizes of tires (254, 406 and 965 mm) was 0.73, 2.0 and 5.3 hours for manual, 4.0, 4.01 and 4.1 hours for electrical workshop and 0.01, 0.05 and 0.12 hours for the assembled compressor, respectively. The difference in average total time taken for tire air filling between the three air compressing mechanisms was highly significant (P= 0.01). The average cost of tire repairing and air filling by the assembled compressor was 76% lower than the cost at the nearest electrical workshop.
Studies on Identification and Prevalence of Viruses Affecting Faba Bean (Vicia faba L.) in the River Nile State, Sudan*
Extensive surveys were conducted in the main production areas of faba bean (Vicia faba L.) in the River Nile State to identify the viruses prevalent at different stages of growth and to determine their distribution and relative importance. Thousands of samples from infected plants were collected and tested serologically in the Virology Laboratory at the International Center for Agricultural Research in the Dry Areas (ICARDA), Syria, for identification of the causal viruses. Bean yellow mosaic virus (BYMV) proved to be the most dominant virus (68%) responsible for yield reduction. Tissue blot immunoassay proved to be an efficient tool for surveying vast areas and for testing in distant production areas. Being simple, fast, inexpensive and very sensitive, it is best suited as a tool for virus diagnosis in developing countries like the Sudan.
Isolation and Pathogenicity of the Causal Fungus of Black Scorch Disease in Sudanese Date Palm*
This study reports the natural occurrence of black scorch disease in date palm (Phoenix dactylifera L.) in Khartoum and River Nile States. It also aims at establishing the identity and pathogenicity of the causal organism. The symptoms consisted of black scorch on fronds, inflorescence blight, trunk rot and terminal bud rot leading to a characteristic bend at the region of infection (Medjnoon phenomenon). Based on the typical visual symptoms, the disease incidence was estimated at 2% - 4% in Khartoum State and 6% - 10% in the River Nile State. The fungus, isolated from typical disease lesions, was identified as Thielaviopsis paradoxa (de Seynes) Von Hohn. depending on its cultural and morphological characteristics, showing two types of vegetative spores (microconidia and macroconidia). This was further confirmed by the pathogenicity test of the isolated fungus which produced the commonly known pineapple disease symptoms in sugarcane setts. This is the first confirmation of the occurrence of black scorch disease on date palm in Sudan, based on the identity and pathogenicity of the causal agent. Previous reports on the occurrence of this disease in Sudan, however, relied only on visual symptoms.
Variability in the Contribution of Male and Female to Cross- Fertilization in Faba Bean (Vicia faba L.)
The objective of this study was to determine the dispersal of own pollen and acceptance of foreign pollen in some faba bean (Vicia faba L.) lines using random amplified polymorphic DNA markers. It was carried out on four lines at Goettingen, Germany, in 2001 season. The lines' introgressive cross-fertilization (acceptance of foreign pollen) ranged from 18.9% to 46.9% with a mean of 31.2%. The mean dispersive cross-fertilization (i.e., contribution to introgressive cross-fertilization of the others) varied from 7.4% to 13.0%; indicating that there may be genetic differences as to these features. The importance of studying both pollen dispersal and pollen input in faba bean breeding programmes is discussed.
A Comparative Study on the Life Cycles of the Leaf Miners Liriomyza trifolii (Burgesss) and Liriomyza sativae (Blanchard) (Agromyzidae: Diptera)*
The life cycles of the leaf miners, Liriomyza trifolii (Burgess) and Liriomyza sativae (Blanchard), were studied in a growth chamber (Temp, 25  1C; R.H. 75  5%; L/D 12 hL/12 hD and 3000 – 4000 LUX) at CIRAD, Montpellier, France. The host plant used was haricot bean (Phaseolus vulgaris). The egg incubation period of both species lasted for two days. Highly significant differences (P<0.01) were recorded between the number of feeding punctures caused by L. trifolii and L. sativae. Differences between the larval periods and number of emerging adults were not significant. Upon hatching, during 1996, the number of larvae of L. trifolii was significantly higher than that of L. sativae, but the total life span of L. sativae was significantly longer than that of L. trifolii.
Yield Losses Due to the Natural Infestation of Faba Bean (Vicia faba L.) by the Leaf Miners, Liriomyza spp., in Central Sudan*
This study was carried out at the Experimental Farm of the Faculty of Agricultural Sciences, University of Gezira, during the seasons 1996/97 and 1997/98, on two faba bean varieties: Shambat and SML. Two experiments were conducted: one for each variety where two treatments were laid out in a randomized complete block design with six replicates. One treatment was the natural infestation of leaf miners (untreated plots), and the other was protected by the insect growth regulator Trigard 75% wettable powder (treated). In both seasons, the untreated plots were heavily infested by the leaf miners, while the protected plots were lightly infested. Infestation resulted in yield losses of 22.86% and 42.25% for Shambat and 29.16% and 27.64% for SML during the two seasons, respectively. Also, there were highly significant differences (P<0.01) in plant height and number of pods between the treated and the untreated plots. Negative correlations between the percentage of leaf infestation and plant height in the treated plots were detected.
Effect of Synchronization Protocols on Timing and Duration of Estrus in Nubian Goats
Three protocols were conducted to evaluate estrus onset, duration and synchronization in 18 Nubian goats. The goats were divided into three groups according to the body weight, 6 animals in each group. The animals in group one were treated with vaginal sponges (VSP) impregnated with 45 mg flurogestone acetate (FGA) for 18 days. Following the removal of the VSP, a single dose of 400 i.u. of pregnant mare serum gonadotrophin (PMSG) was applied intramuscularly for each doe. The second group was injected with 7.5 mg/ml prostaglandin (PGF2α) on day 1 and day12. For the third group, a vasectomized buck was introduced for 15 days to initiate behavioural estrus after a complete isolation for four weeks. These experiments were repeated using the same animals. The results indicated that all protocols (buck effect, PGF2α and VSP+PMSG) synchronized estrus in Nubian goats with 100% response. However, the hormonal methods produced more compact synchronization of estrus than the buck effect. Therefore, the hormonal methods are more desirable for estrus synchronization, especially in fixed-time artificial insemination programmes. The mean duration of estrus in the buck effect
Impact of Using Treated Wastewater for Irrigation on Soil Chemical Properties, Plant Growth and Forage Yield
The objective of this study was to evaluate the impact of using treated wastewater for irrigation under Khartoum State conditions. The experimental treatments were treated wastewater, treated wastewater alternating with River Nile water and River Nile water in combination with three different tillage operations: harrowing, disc ploughing and chisel ploughing. Replicated soil samples were taken from three depths: 0-20, 20-40 and 40-60 cm. 'Abu Sabein', a variety of forage sorghum (Sorghum bicolor), was used as indicator plant. Chemical analysis showed that the level of different constituents of treated wastewater conform to FAO standards for irrigation water. Treated wastewater significantly (P< 0.01) increased Ec, pH, OC, N, Na, Ca, Mg, K, Cl, Cu, Zn, Fe, Mn, Pb, Co and P in the soil, followed by irrigation with treated wastewater alternating with River Nile water and irrigation with River Nile water. Similarly, highly significant (P< 0.01) effects were also recorded for plant growth parameters and forage yield. Tillage operations and depths showed significant (P< 0.01) effects on the distribution and concentration of trace elements and nutrients in the soil. High transfer factor was registered for Ca and Co, followed by P, K, Cu, Zn, Pb, Fe, Mn and Na.
Evaluation of Some Tillage Systems for Cotton Production in New Halfa Agricultural Scheme– Sudan
Selection of optimum tillage systems can reduce the cost of land preparation and maintain or increase crop yields. The present study was carried out on a heavy clay soil in the New Halfa agricultural scheme to compare and evaluate the costs of some land preparation tillage treatments for cotton production. Five tillage treatments (disc ploughing, chisel ploughing, ridging, disc harrowing and no-tillage) were used in a randomized complete block design. Data on soil, crop, machinery and land preparation costs were collected. Significant differences (P = 0.01) between the effect of tillage implements on the measured machinery parameters were obtained. Although the conventional tillage treatments (disc ploughing and chisel ploughing) resulted in significantly higher yields than the conservational tillage treatments (ridging, disc harrowing and no-till), they were more expensive and time and fuel consuming.
Assessment of Three Artificial Inoculation Methods for Sugarcane Smut Disease Incited by the Fungus Ustilago scitaminea (Syd.)
A field experiment was conducted during 2000/01, 2001/02 and 2002/03 seasons, at the Sugarcane Research Centre, Geneid, Sudan. The objectives of the study were (a) to assess the efficiency and ease of use of three artificial smut inoculation methods; namely, Taiwanese pin- prick (TPPM), dip (DM) and natural spreader-row infection (NSIM) and (b) to evaluate the field response of the tested genotypes to smut. Nine sugarcane genotypes were tested against three checks, in a randomized complete block design with three replications. The mean percentage of smut infection was 2.81, 1.96 and 2.26 for TPPM, DM and NSIM in plant cane (PC); 5.51, 4.39 and 7.4 for the first ratoon (R1) and 6.54, 6.06, 8.66 for the second ratoon crop (R2), respectively. TPPM and NSIM gave slightly high mean percentage of infection values in PC and R1. However, these values were almost similar in R2 for all three artificial inoculation methods tested, indicating the general effectiveness of the three methods in inciting the disease. Therefore, they can all be used; the choice of any one of them should be according to local circumstances and objectives of the study. However, considering the time saved and ease of use, DM is preferred. Four sugarcane genotypes BJ 82105, B 70531, COC 671 and TUC 75-3 had reaction types similar to the resistant checks CO 997 and CO 6806. Three sugarcane genotypes BT 74209, DB 75159 and B 79136 rated either resistant or highly resistant; thus, they are equally suitable for inclusion in the production system. Two sugarcane genotypes, BJ 7938 and BJ 7451, however, had a moderately susceptible reaction type similar to the susceptible check CO 527 and are, therefore, not suitable for commercial production.
Effect of Plant Age on Fresh Rhizome Yield and Volatile Oil Composition of Acorus calamus Linn.
The effect of plant age on growth, yield and oil content and composition of sweet flag (Acorus calamus) was studied in four populations at four different ages, raised at CIMAP Experimental Research Farm, India. The plant age had significant effect on total fresh yield and leaves and rhizomes fresh weights. These parameters showed increasing trend with advancement of harvesting age up to 6 years, and age increase to more than 15 years resulted in their decrease. Significantly highest number of shoots per square metre was recorded in more than 15- year old crop, and the lowest number was recorded in the 6-year old crop. The highest oil yield of rhizomes was obtained from the six-year old plants. Shoot length, rhizome: leaf ratio (R/L) and oil yield of leaves did not show significant differences with the age of the plant. However, 6- year old plants recorded the highest average shoot length, and the three- year old plants gave the highest oil yield of leaves. The total fresh yield showed a highly significant positive correlation with rhizomes fresh weight (r=0.999), leaves fresh weight (r= 0.994) and with rhizome: leaf ratio (r= 0.998). Highly significant positive correlations (r=0.999) were also obtained between rhizomes oil content and rhizomes oil yield and between leaves oil content and leaves oil yield. β-asarone was the most dominant constituent in the oils of both leaves and rhizomes, constituting an average of 84.2% in the leaves and 88.9% in the rhizomes oil. The study indicated that the oil content of fresh rhizomes and leaves is the main contributor to their oil yields, and selection for high oil content will be effective. The constituents of the volatile oil remained the same irrespective of the plant age.
Appraisal of Ground Water Quality and its Impact on Irrigated Soils in Khartoum State, Sudan
A study was undertaken to appraise the quality and impact of well waters on irrigated soils of fifty farms widely spread in Khartoum State, Sudan. Water quality indicators and pertinent soil properties were measured by standard procedures. The determinations were electrical conductivity of water (ECw) and soil saturation extracts (ECe) and soluble Na+ , K+ , Ca++ + Mg++ , Cl - , HCO3- and SO4-- . Sodium adsorption ratio (SAR), residual sodium carbonate (RSC), theoretical pH (pHc) and Langeleir's saturation index (LSI) were computed. A questionnaire including pertinent well and farm data and information was filled. ECw ranged between 0.4 to 4.8 dS/m. According to the United States Salinity Laboratory (USSL) classification system, 30% of the water samples lied within the medium salinity class, 62% lied within the high salinity class and 8% within the very high salinity class. In agreement with USSL, highly significant linear correlations between ECw and total salt concentration of water expressed in mmole+ /l or mg/l with 99% accountability were found. Ninety-eight percent of the water samples were non-sodic. Only one water sample gave a SAR value equal to 19.1 and the remaining waters had SAR ranging between 1.1 and 9.4. RSC was negative for all water samples with the exception of two samples (4%) that gave RSC values ≤ 0.6 and thus within the safe level. In general, LSI data agreed with RSC data. The well waters were predominantly Ca- Na/SO4 =Cl waters. The results showed that 70% of the top layer of the
Effect of Plant Density on the Performance of Two Sesame (Sesamum indicum L.) Cultivars under Irrigation *
A field experiment was conducted for two consecutive seasons (2000/01 and 2001/02) at Kenana Sugarcane Research Farm to investigate the effect of planting density on the performance of two cultivars of sesame (Sesamum indicum L.); namely, Khidir and Promo. The plants were sown at four planting densities: 5, 10, 15 and 20 plants/m 2 (0.5x10 5 ,1.0x10 5 ,1.5x10 5 and 2.0x105 plants/ha, respectively). The treatments were arranged in a randomized complete block design with four replications. The results indicated that the leaf area index and dry matter production increased with increasing plant density. Increasing plant density significantly decreased the number of capsules per plant, number of seeds per capsule and seed yield per plant, and increased seed yield per unit area. There were no significant differences in oil and protein content between plant densities. The differences between the two cultivars were significant in all the studied characters, and Promo cultivar outyielded Khidir by 11% in the first season and by 22 % in the second season. The higher yield of Promo was associated with higher number of capsules per plant and greater number of seeds per capsule. It is recommended that irrigated sesame should be sown at a stand density of approximately 15-20 plants/m 2 (1.5x10 5 –2.0x10 5 plants ha-1 ).
Genotype x Environment Interaction for Yield and Yield Components in Some Sunflower (Helianthus annuus L.) Hybrids *
A field experiment was carried out at two locations, New Halfa and Rahad, in the summer of 2003/04 and winter of 2004/05 to estimate the genotype x environment interaction for yield and its components among 19 locally developed sunflower (Helianthus annuus L.) hybrids and one introduced hybrid (Hysun 33). A randomized complete block design with four replications was used at each location. Data on yield and its components; namely, number of seeds/head, percentage of empty seeds, 1000-seed weight and seed yield/plant, were collected. The combined analysis of variance for all characters showed highly significant differences at the genotype level. The genotype x season interaction was only significant for 1000-seed weight and seed yield/ha. The genotype x location interaction was significant for 1000-seed weight, seed yield/plant and seed yield/ha, whereas genotype x season x location interaction was only significant for 1000-seed weight. The number of seeds/head and the percentage of empty seeds showed non-significant differences at the first and second order interactions. The highest yield per hectare and per plant averaged over the four environments was recorded for Hysun 33, whereas the lowest ones were scored by Ka99x11. The analysis of genotype x environment interaction for 1000-seed weight, seed yield/plant and seed yield/ha showed that the major part of the variance was due to non-linearcomponents. The significant differences among the evaluated hybrids at the different interaction levels suggest that seed yield of sunflower is highly dependent upon the environmental conditions. Therefore, multi- location testing for several years is needed to identify high yielding stable hybrids.
The Hydrothermal Soil Regime under Gum Arabic Trees [Acacia senegal (L.) Willd.] in Al-Rawashda Forest, Al-Gedarif State, Sudan*
The study was undertaken to generate broad-base data on the hydrothermal regimes in a Vertisol under Acacia senegal in Al Rawashda forest, 35 km northeast Al-Gedarif town. The indicators measured for describing the moisture regime were rainfall, infiltration and evaporation rates from U.S. Class A pan, soil moisture storage and actual evapotranspiration. In 1997, the total rainfall was 403 mm, 48% was received in August and 82% was received in July, August and September. The soil was fully recharged with moisture during June-September, depleted and desiccated during October-March and started to rewet in April-May. The daily evaporation ranged from 2.9 to 5.6 mm in autumn, 7.5 to 13.6 mm in winter and 12.8 to 16.0 mm in summer. The soil moisture storage was lowest in 14th May and highest in 5 th September, 1997. Although rainfall reduced the vapour pressure gradient, it increased the availability of water to the evaporating site and consequently increased evaporation. Thus, mean monthly evaporation (Em, mm) increased significantly (P = 0.05) with increase of mean monthly rainfall (Rm, mm) as shown by the following power relationship: Em = 1738 Rm 0.5402 (r2 = 0.790). The pooled infiltration rate (IR) as a function of time for the two sites in three successive months’ best fitted the following
Effect of Harvesting Method on Quality and Storability of Grapefruits
The effect of harvesting method on fruit quality and storability of the pink-fleshed 'Foster' grapefruits, at 18±1°C and 85%-90% r.h., was evaluated. The traditional method, using a hooked pole, was compared with an improved technique, where the picking pole was equipped with a long cloth sleeve held open by a ring for collecting the harvested fruits. The fruits were stored for three months at 18±1°C and 85%-90% r.h. Fruit samples were taken at specific times for determination of fruit quality in terms of respiration rate, total soluble solids (TSS), water loss and titratable acidity. At the termination of the experiment, the fruits were evaluated for general quality. The results showed that the improved method significantly decreased respiration rate and water loss, delayed TSS accumulation and reduced titratable acidity, resulting in improved fruit quality, reduced post-harvest losses and extended shelf-life of fruits.
Anthracnose Disease in Common Bean (Phaseolus vulgaris L.) in Shambat, Sudan II. Disease Incidence, Severity and Effect on Yield
A field experiment was conducted for two seasons (1999/2000 and 2000/2001), at Shambat Research Station, to investigate the effect of anthracnose disease incited by Colletotrichum lindemuthianum (Sacc. and Magn.) Bri. and Cavi. in three common bean (Phaseolus vulgaris L.) cultivars. Mean disease incidence of 15.70% was recorded in 1999/2000 season and 13.79% in 2000/2001. Mean disease severity of 0.39 and 0.47 were recorded in seasons 1999/2000 and 2000/2001, respectively. Mean pod infection in season 1999/2000 was 19.59% and mean seed infection in the same season was 15.77%. The corresponding results for season 2000/2001 were 49.62% and 20.98%, respectively. Mean seed weigh reduction was 24.72% in season 1999/2000 and 26.33% in season 2000/2001. The introduced cultivar Cranberry out-yielded the two local cultivars in both seasons. The increase in mean yield was 21.13% in season 1999/2000 and 54.04% in season 2000/2001
A Note on the Pathogenicity of Metarhizium anisopliae (Metschnikoff) Sorokin on Larvae of Schizonycha sp. (Coleoptera: Scarabaeidae)
An experiment was conducted in the laboratories of the Research Department of Kenana Sugar Company during 2004/2005 season to study the efficacy of Metarhizium anisopliae as a pathogen against the white grub Schizonycha sp. The fungus was isolated from a dead larva of white grub found in the root zone of a sugarcane plant. It was cultured in the laboratory and used to inoculate healthy larvae of Schizonycha sp. The typical symptoms of mycosis disease were observed two days after inoculation. Death started on the third day and 94.3% of the population were killed within two weeks at 27ºC and 92% RH. Percentage of mortality and days after inoculation were highly associated with a positive linear relationship
Assessment of Sorghum Genetic Resources for Genetic Diversity and Drought Tolerance Using Molecular Markers and Agro-morphological Traits
Forty sorghum genotypes were investigated for genetic diversity and drought tolerance. Diversity parameters were estimated using 16 Simple Sequence Repeats markers. For assessment of drought tolerance, the genotypes were field evaluated under normal and drought stress conditions for two seasons in three environments, in Sudan. In total, 98 SSRs alleles were detected with an average of 6.1 alleles per locus. The estimated polymorphic information contents ranged from 0.33 to 0.86. The genetic similarity ranged from 0.00 to 0.88 with a low mean of 0.32. The dendrogram, generated from the UPGMA cluster analysis, showed two main clusters differentiated into nine sub-clusters with close relationship to morphological characters and pedigree information. Mantel statistics revealed a good fit of the cophenetic values to the original data set (r = 0.88). The overall mean genetic diversity was 0.67. Significant differences were detected among genotypes under both normal and drought stressed conditions for all measured traits. Based on the relative yield, the most drought-tolerant genotypes were Arfa Gadamak, Wad Ahmed, El-Najada, Korcola, ICSR 92003 and Sham Sham. Drought
The Role of Trichoderma, VA Mycorrhiza and Dry Yeast in the Control of Rhizoctonia Disease of Potato (Solanum tuberosum L.)
Laboratory and pot experiments were conducted to evaluate the efficacy of Trichoderma viride, VA mycorrhiza and dry yeast, separately and in combination, as an integrated strategy of Rhizoctonia disease management in potato crop. The challenge inoculation with T. viride caused a significant reduction in vitro in the linear growth of Rhizoctonia solani, particularly when it was performed closer to the time of pathogen inoculation. With the exception of the number of stems, yield and growth attributes of potato plants infected with R. solani were significantly affected. T. viride application significantly increased the growth components (i.e., plant height, shoot fresh and dry weights, root fresh and dry weights) and tuber yield (i.e., number and weight of tubers) compared to potato plants inoculated with R. solani alone. Moreover, the disease incidence and severity, as stem canker or black scurf on progeny tubers, were also significantly alleviated by T. viride inoculation. Similarly, VA mycorrhiza enhanced both the growth and yield measurements of Rhizoctonia-inoculated potato plants and significantly reduced the harmful effects of the disease. The dry yeast appeared to be the least efficacious biocontrol agent to Rhizoctonia compared to the other two organisms; yet it also significantly improved the disease situation of the infected plants. The combined effect of T. viride and VA mycorrhiza with or without yeast excelled other treatments in alleviation of almost all tested facets of the disease development.
The Role of Gender in the Adoption of Innovations in Jebel Marra Area, West Darfur State
The main objective of this study was to determine the role of gender in the adoption of innovations in Jebel Marra area, West Darfur State, Sudan. The study was based on primary data collected through a field survey that covered three localities in Jebel Marra area; namely, Zalingei, Garssela and Mornei. The stratified sample technique was used for collecting information by using a questionnaire (120 respondents). The multiple regression analysis revealed that although the respondents were highly aware of agricultural technology, their rates of adoption were still below optimum, and male respondents exceeded female respondents in their rate of adoption. Therefore, the study concluded that West Darfur State government could realize more agricultural output through educating and training the female farmers in Jebel Marra area.
Effect of Sowing Date on the Performance of Two Sesame (Sesamum indicum L.) Cultivars under Irrigation at Kennana, Sudan
The effect of five sowing dates (15/6, 1/7, 15/7, 1/8 and 15/8) on phonology and yield of two sesame cultivars grown under irrigation was studied at Kennana Sugarcane Research Farm during 2001and 2002 seasons. The results showed that plants sown earlier (June sowing) significantly took more days to 50% flowering and physiological maturity than the late-sown plants (August sowing) in both seasons. In contrast, no significant difference between the cultivars was recorded in number of days to 50% flowering. Seed yield and yield components were significantly affected by sowing date. Early-sown plants (mid June) gave 100% and 75% higher seed yield than the late-sown plants (mid August) in the first and the second season, respectively. The higher seed yield of the early-sown plants was associated with high number of capsules, number of seeds per capsule and seed weight. The cultivar Promo significantly exceeded Khidir in seed yield, capsule setting and in number of seeds per capsule particularly in the first season. It can be concluded that the optimum sowing date for sesame under irrigation at Kennana is mid June, and that the cultivar Promo is more promising than the cultivar Khidir
Effect of Polyethylene Film Lining and Gibberellic Acid on Quality and Shelf-Life of Banana Fruits
The effect of polyethylene film lining, sealed or perforated, and gibberellic acid (100 ppm), by dipping the tip of the fruit only or the whole fruit, on quality and shelf-life of banana fruits at 18ºC ±2ºC and 90% - 95% relative humidity was investigated. Polyethylene film liners, sealed or perforated, significantly delayed fruit ripening, maintained quality and extended shelf-life of bananas. Treatment with gibberellic acid (GA3 ) by dipping the tip of the fruit only or the whole fruit, resulted in more delay of fruit ripening and extension of shelf-life of banana fruits. The sealed film liners was more effective than the perforated ones and dipping the whole fruit in GA3 was more effective than dipping the fruit tip only, in delaying fruit ripening and extending shelf-life of bananas. That was reflected in more delay in the climacteric peak of respiration, peel colour development, total soluble solids accumulation, fruit softening and reduced weight loss during storage of bananas.