Category: hydroponic growing

The mineral nutrient can be introduced into a plant’s water supply which is then readily absorbed by the plant’sroot. Many vegetables are grown using hydroponics. The principle behind its operation is that, the land is a mere storage of nutrients needed by plants to grow. Thus, if the same nutrients are to be provided using treated water, the same result may be had.The hydroponic technology allows small farmers to grow food even in dry spells. The prolonged dry season, caused by El Nino phenomenon, will not affect the onion production. According to one expert, “If the time comes when there’ssevere water shortage, at least we have a system where we can plant and grow crops with little water” . However, critics of the method in developing countries considered the significant amount needed to implement the technology.

The startup costs to implement a hydroponic farm can vary widely but, they are usually much more significant than soil-based farming . The initial capital required, is seen as a factor that will slow the adoption of the technology. The vertical hydroponic grower is a 9-m, diamond-shaped structure consisting of 30 tiers of troughs made up of 7.6-cm-diameter, 2.5-m-long PVC pipes.The gutters are connected to a chain-sprocket system so that it will rotate around the A-frame for the checking and caring for the plants and harvesting the crops. Water is supplied at the upper-middle trough from an overhead tank, 9.2 m high and circulated through each pipe and then drains at the lower-middle channel. Drain water will be recalculated again by a pump. During checking and harvesting periods, the valve connecting to the main water supply will be shut down and will be opened again once the plants were checked for any waterborne disease or cutting of rotten leaves. The same method will also be used during harvesting.The pipe that connects each trough is a flexible hose so that it will conform to the A-shape of the frame as the troughs rotate. Each trough will contain 25onion bulbs spaced at 10cm apart.

The frame has afoot area of 2.5 m × 2 m . A 1500 m2 lot area could contain 200 racks and would produce 15,000 kg of onion almost equivalent to 1 hectare of traditional farming unaffected by any adverse weather and growing conditions. The study employed the experimental method of research. The dependent variable will be the onions that will be grown in the hydroponic vertical grower which is considered as the independent variable. The vertical hydroponic grower will control the growth of the onions. Other methods of gathering data were also used, such as library research, literature review, interview and personal observation.The use of interview was devoted to determining the acceptability of vertical farming to Onion farmers and growers. The literature review was used to determine the current agricultural practices and compare it with the hydroponic method. Meanwhile, interview with onion farmers to estimate the cost of onion production using traditional method was set. The experimental method was used to determine the suitability of vertical farming using the hydroponic system to onion production. The sampling method used was convenience sampling and purposive sampling observing the following criteria: 1) must be a farmer or grower of onion; 2) must be doing the planting for more than five years; 3) willing to be interviewed; 4) a resident of Bongabon Nueva Ecija.

The respondents were identified on actual farm environment. The researchers went to the farm and interviewed onion planters /farmers. Some did not cooperate because they are already satisfied with the yield produced by using traditional method or land based onion production. Focus Group Discussion was also held to reinforce the results and findings using other tools to gather data.The weather condition affects the plant growth. As shown in Figure 2, the hottest temperature in the month of August 2016 when the first phase of experiment was done is 37˚C – 38˚C. The weather conditions during the three-phase experiment are presented below. Figure 3 shows the highest actual dry temperature of 38 degrees celsius in the month of May 2017 when the experiment was undertaken. Figure 4 shows the weather temperature of around 34 degrees Celsius when the last phase of the experiment was held in July 2017. Based on the temperature graph shown, the hottest temperature was in the month of August2016 is 37˚C – 38˚C. Both the hydroponically and soil grown onions were exposed to sunlight from 7 am to 11 am and then kept under the shed from 11 amonwards. Since August is a rainy season in the study area, the volume of rains may contaminate the chemically treated water in the hydroponic technology.Thus, the researchers made it sure that the samples are kept in a shed otherwise rain water would mix up with the nutrients in the water and may affect the growth of the onion.The rainy season officially starts in the month of May. The experiment was performed mainly under the shed where it may be exposed to indirect sunlightin the morning.

In addition, it is said that when persimmons ripen and become sweet, the abovementioned water-soluble tannin is further oxidatively polymerized by the action of polyphenol oxidase and becomes insoluble polymers, which reduce the astringency of the fruit. There are more than 800 to 1000 cultivars of persimmon in Japan, but only 10 well known cultivars, such as the ‘Fuyu’ and ‘Hira Tanenashi’, which are widely cultivated throughout the country. Among these cultivars, Tone Wase and Fuyu were used in this study. At harvest time, Tone Wase, which is a partially astringent persimmon, contains 1% to 2% soluble tannins and is intensely astringent. Anaerobic treatment with carbon dioxide or ethanol increases the acetaldehyde content, allowing the removal of its astringency . Meanwhile, Fuyu was first reported by Dr. Onda in 1902, and since then has rapidly spread. The Fuyu’s tree is robust and produces large fruits; however, excessive fruiting causes the lateral branches to droop, which in turn results in poor fruit growth and an increase in the proportion of small fruit.

Consequently, it is necessary to regulate fruiting, mainly through disbudding. The ripening period varies by region, but in the Kinki region of Japan, it is from late October to mid-November. The process of growing persimmons is shown in Figure 1, and fruit thinning, which is the process of cutting off unripe fruit, is done in July and August. The unripe fruits that are cut off are called immature persimmons, or ‘Tekka-kaki’. The immature persimmons are left on the ground after being cut off and can be considered a discarded, unused resource. Therefore, the purpose of this study was to investigate “the effective use of immature persimmons”. An example of the use of immature fruit includes unripe Citrus unshiu. The extract of unripe Citrus unshiuhas shown anti-allergic effects in in vivo studies using type I allergy models and type IV allergy models . The relationships between fruit ripeness and the intensity of the anti-type I and anti-type IV allergic effects were investigated, and it was reported that these effects were stronger in unripe fruit and weakened as the fruit ripened. This effect has gained attention, resulting in the use of unripe Citrus unshiuas a dietary supplement .

One of the best examples of the use of persimmons in processed foods includes the use of dried persimmons; however, compared to other fruits, their application is limited. Furthermore, the processing ofimmature persimmons into dried products has the potential of minimizing the associated labor cost, as it does not directly generate income and the fruit that have already grown to a certain size are cut off before harvesting. If immature persimmons could be used for processed foods,it is expected that it would increase the motivation of persimmon growers because it would be possible to generate income from that work, and it would also increase the consumption of processed persimmons. The first step in the microencapsulation process is to emulsify a two-phase solution consisting of an oil phase and a water phase containing a gelling agent. At this stage, flavoring is added to the oil phase as a secondary function, and functional components are added to the water phase as a tertiary function. These are then used to make emulsions, which are then dried and microencapsulated. Regard for functional components is necessary, as they are intended for the elderly, prevention of aging, and age-related diseases such as skin aging, arteriosclerosis, osteoporosis, and diabetic complications.

Therefore, we searched for AGE formation inhibitors in immature persimmons. The term “AGEs” is a general term for a group of structures produced by glycation reactions and does not indicate a fixed structure. Various structures of AGEs have been elucidated to date, including those produced in vitro. AGEs are characterized by their yellowish-brown color, fluorescence, and the formation of cross-links between proteins. In recent years, AGEs have been suggested to be involved in diabetic complications, atherosclerosis, tumor growth, metastasis, inflflammatory reactions, osteoporosis, and skin aging . Therefore, we focused on anti-glycation and conducted tests to inhibit AGE formation to prevent the progression of disease and aging. Regarding flavoring and fragrances, citral, a citrus fragrance, was used to mask odors and add flavoring because when the food is ground into a gel, its flavor degrades. The flavoring and fragrance industry has been expanding annually, and the global market for food flavoring agents is estimated to be 1.5 trillion yen . Flavoring and fragrances generally contribute to the taste and flavor of foods. The citral used in this study is also widely used as a flavoring agent in citrus fruit juice beverages and foods . However, odor problems may occur during the process from food production to actual consumption. Off-flavors refer to the “odor” perceived by the addition of odorous components not originally present in the food, the increase or decrease of some odorous components present in the food, or the change in the overall balance of the odorous components . The elucidation of the conditions for the formation of off-flavors and the study of the methods to control them may lead to improvement in food processing technology and ultimately to improvement in food quality.

Circularity showed only small to medium significant correlation with seed width, minimum, and mean and median Gray Value . Integrated density had a negative correlation with the rest of the variables, statistically significant only to height and width. Partitioning of the variance and grouping of the accessions, regarding seed morphology, were estimated by hierarchical clustering under the Unweighted Pair Group Method with Arithmetic mean and Principal Component Analyses . The UPGMA analysis gave formation to a three cladded dendrogram , with most of the landraces grouped together in one clade, along with some of the cultivars that were separated in subclades. A particular landrace, GR2, presenting unique seed morphology formed a single clade alone. A third clade consisted exclusively of cultivars and breeding lines. A PCA performed to calculate the Eigenvalues and variability partitioning to thedifferent vectors, with the first two dimensions explaining 61.92% of the data variability.

In a bi-plot graph of the PCA, the genotypes that were found to be highly correlated, are in close proximity with one another, and the distribution of the accessions forms two groups, with GR2 being an outlier . Regarding the seed surface, landraces GR24, GR25, GR27, and GR28 have biconcave seeds of orange-white color, with dark flecks and a characteristic black line peripheral to the hilum, while the rest of the accessions have white-yellowish seeds with no spot pattern . Interestingly the partitioning of the 16 alkaloid compounds assessed in each sample varied between accessions, indicating that each alkaloid biosynthesis product may accumulate in different amounts in different genotypes . Furthermore, landraces GR24, GR25, GR27, and GR28 with spotted seeds had no higher alkaloid content compared to those with white-yellowish seeds. Further studies implementing more specific markers of alkaloid biosynthesis pathways are required to complement systematically the seed alkaloid profile and the genetic alleles configuration of the genotype. Moreover, the partitioning of the 16 alkaloids in the metabolic profile of landraces is quite diverse indicating that a more thorough assessment of critical alleles that impart accumulation of alkaloids is necessary for an integrated assessment of valuable germplasm that could be underscored in the sole absence of the pauper allele.

Genetic diversity of white lupin genetic resources in Greece was assessed using morphological and molecular markers. This is the first report for molecular characterization of local white lupin germplasm in a country that is considered as a center of genetic variation for this crop. Seed morphological characteristics were selected because heritability of seed morphological traits and ease of access to seeds may provide a reasonable alternative to estimate the distribution of genetic variation . Considerable variation was recorded for TSW, seed size, and coloration while less variation could be detected for circularity. Clustering of genotypes formed subclades consisted solely of landraces, although some landraces were partitioned with the cultivars. Other studies indicate high level of polymorphism for selected morphological traits in white lupin, while generally these characters are not very informative for landrace genetic diversity studies. Wide range of variation was recorded for proportion of pod walls and other pod components in 325 ecotypes originated from 17 countries of the Mediterranean region and north Africa. The variation was related with the country of origin of the accessions since Egyptian ecotypes had the lowest proportions of pod walls while the Greek and Italian ecotypes had the highest . Analysis of Ethiopian landraces indicated the existence of high level of polymorphism for different agronomic traits and nutrient contents of grain . In an extensive study of 35 Spanish white lupin accessions estimating variation for 50 quantitative and 51 qualitative characters, described in the literature as highly heritable, only a small number of three quantitative and one qualitative parameters were variable enough to provide good separation of the accessions .

It is conceivable that as valuable as they may be, agronomic traits and morphological characteristics as genetic markers are of limited resolution power for genetic diversity assessment, compared with molecular markers. In this study, molecular polymorphism was considerable. Relatively moderate to high PIC values, indicating a high level of genetic diversity in the germplasm assessed. The markers were suitable for discrimination of most landraces that clustered apart from the commercial cultivars indicating a unique diversity. Specifically, landraces were grouped into two clusters with those originated from Andros island forming a distinct group representing the wild graecus form of lupin, while all the others were grouped together regardless of geographic origin. Interestingly, all the commercial cultivars were grouped in one cluster. Molecular markers have been proved valuable tools for germplasm diversity studies in many plant species. Yet, limited number of studies on white lupin molecular diversity are cited in the literature. To the best of our knowledge, genetic diversity using molecular markers has been estimated for local germplasm from Ethiopia and Egypt .

All those results clearly indicate that the main BrCl-flav mechanism of action is related to membrane disruption followed by cell lysis. Hyphae and biofilm formation—two critical virulence factor of C. albicans—were investigated to better understand how BrCl-flav affects fungal cells. Both Candida virulence attributes are interlinked, contributing not only to the host tissue invasion but also to the evasion of host immunity . Our study revealed that BrCl-flav prevented both yeast to hyphal transition and biofilm formation. The effect was concentration dependent, increasing BrCl-flav concentrations resulting in an increased inhibitory activity. Moreover, the tested antifungal impaired plasma membrane organization, a cell structure which promotes also the virulence of the human fungal pathogen C. albicans highlighting BrCl-flav therapeutic potential. Biofilm formation also contributes to Candida antifungal resistance—a major problem faced by modern medicine. One solution could be the use of synergistic combinations of new molecules with traditional antifungals used in therapy to which Candida strains have already become resistant.

Flavonoids in combination with fluconazole have been shown to display remarkable synergistic antifungal effects and are considered as reliable compounds for antifungal drug research and development . In our study which involved a fluconazole resistant C. albicans clinical isolate, the MIC of fluconazole was 128-fold reduced in combination with BrCl-flav,suggesting an important synergistic antifungal activity. We have to emphasize also that a combination of BrCl-flav and fluconazole in lower concentrations compared with individual MIC values showed important fungicidal effect with total kill after 48 h of incubation.The structure and purity of the final compound have been established by NMR, MS, IR and elemental analysis. UV-Vis spectroscopy was employed to monitor the stability of BrCl-flav towards Sabouraud dextrose broth , RPMI 1640 and phosphate buffer saline . The tricyclic flavonoid proved to be stable over a time span equivalent to the performed tests.Developing countries are facing an increasing demand for protein and other nutrientrich foods. In this context, legumes can contribute as the most valuable source of nutrients and provide high-quality dietary proteins .

Legume plants have desirable characteristics such as an abundance of carbohydrates, the ability to lower serum cholesterol, high fiber, a high concentration of polyunsaturated fatty acids, and long shelf life. In addition to B complex vitamins such as folate, thiamin, and riboflavin, minerals, and fiber, legumes are also major sources of proteins and calories . Furthermore, it is evidenced that sprouts are the richest source of proteins and other compounds of nutritional value compared to un-sprouted plants . Moreover, sprouts have also been associated with a variety of biologically active constituents with potential health benefits. During germination, metabolic enzymes are activated, which can lead to the release of some amino acids and peptides, and the synthesis or use of them can form new proteins. As a consequence, the nutritional and medicinal value might be enhanced by sprouting in legumes. Research has to be geared to exploit the sprouting of legumes and enhance their nutrition values to meet the nutritional requirements of the increasing population. The genus of Canavalia is considered the third largest family among flowering plants . It comprises approximately 50 species of tropical vines widely distributed in tropical and subtropical regions all over the world . This genus was used traditionally as a food due to its nutritional significance.

Sridhar and Seena envisaged a comparative account of nutritional and functional properties of Canavalia species . Canavalia gladiata and Canavalia ensiformis are the common legume species having the potential to be a rich protein source, like edible legumes . Pharmacological effects of Canavalia gladiata are reported for cancer , allergies , antioxidants , and inflammation . Canavalia gladiata in complex with Arctium lappa extract is proposed to develop as a functional food for stimulating immunity . Similarly, the seeds of Canavalia ensiformis are a source of proteins with biotechnological importance including ureases and proteases . Processed seeds of Canavalia ensiformis are reported for enhanced antioxidant activity . Hence, Canavalia species are of high medical importance, and with proper seed priming with micronutrients and using other treatments nutritional and pharmacological values can be enhanced. Micronutrients are vital for plant growth because they act as a cofactor of the enzyme, take part in redox reactions, and have several other important functions . Furthermore, despite addition to the soil, micronutrient application using seeds improves the stand formation, advances phenological events, and increases yield and micronutrient grain contents . Like different micronutrients, molybdenum is very vital and essential for plants’ physiological functions. In plants with inadequate Mo, nitrates accrue in leaves, which then do not assimilate into proteins. In legumes, Mo serves an additional function: to help root nodule bacteria to fifix atmospheric nitrogen.

Moreover, the African continent is also affected by a number of vector-borne zoonotic infections caused either by viruses , Rift Valley Fever and Yellow Fever or by bacteria , which require parasitological and entomological expertise to be effectively addressed, due to their vectoral components . Indeed, recognising the parasitological/entomological constituents in the epidemiology of these infections is essential as it helps identifying potential arthropod or vertebrate reservoirs, thus ultimately preventing and controlling the diseases in humans and animals. In Uganda, for example, when it was first encountered, in 2013, CCHF was initially feared to be the more deadly Ebola , which has occasionally crossed the country’s border with the Democratic Republic of the Congo . Ever since, CCHF has occurred in the country in the form of outbreaks within or in the proximity of the “cattle corridor”, a region spanning northeastern, central and southwestern districts, known indeed for the density of its cattle herds . With most cases being associated with exposure to bites of ticks who have fed on viraemic cattle or ruminant hosts , the effective control of this infection could be achieved through the rollout of strategic targeted tick control programmes and the sensitisation of the general public and farming communities on the epidemiology of CCHF.

Considering that the same cattle corridor witnesses sporadic cases of mosquito-borne RVF , whose reservoir is also represented by ruminants , One Health efforts in this area should opt for the use of “arthropocidal” molecules, halting both ticks and mosquitoes, rather than merely “acaricidal” products or “insecticidal” ones .Moreover, the role of “companion” animals or non-livestock species, such as dogs and cats, is also critical for certain parasitic zoonoses in Africa. In addition to their involvement in a number of NTDs , these species are also implicated in the epidemiology of several zoonotic geohelminths such as Toxocara spp., Ancylostoma spp. and Strongyloides stercoralis, and cestodes , entailing direct or indirect transmission through an intermediate host . The frequent freeroaming behaviour of dogs and cats, typically in rural milieus across Africa , coupled with the usually poor hygiene and water sanitation of such settings, can particularly favour the spread of these parasitoses and enhance exposure risks in humans and other animal species. In addition, with the size of middle class rising in the continent , ownership of dogs and cats as “pets” may potentially increase in urban areas in the next decades, highlighting the importance of parasite control also in urban and peri-urban sites, where encounters between “owned” and “free-roaming” animals, and their excretions, may occur.

Furthermore, the contribution of wildlife needs also to be considered, either as definitive or intermediate hosts or even reservoirs of zoonotic parasites . Therefore, in order to be fully and durably effective, One Health initiatives tackling parasitic conditions should aim to tackle all final, intermediate, potentially vector and even paratenic or transport hosts involved in life cycles of target aetiological agents. Overlooking even a single host species, wildlife included, can indeed cause the reappearance or impede the elimination tout court of cases of infection or disease in certain other hosts, despite generous control efforts being addressed towards them.Should the One Health approach be envisaged only in the case of zoonotic parasitic or arthropod-borne infections that are shared between humans and animals? This concept paper advocates for a more comprehensive assessment of parasites and vectors in this paradigm. The health of livestock in Africa is indeed undermined by several parasites or arthropods that, although not zoonotic per se, cause major chronic deterioration and productivity losses, being responsible for low body condition scoring, poor protein conversion and, overall, scarce production .

In the case of cattle, for instance, gastrointestinal nematodes, ticks and tick-borne infections and animal African trypanosomiasis are the most important examples to be incriminated in these regards . The productivity losses that they entail are therefore inextricably connected with the continent’s food insecurity, especially considering that the largest bulk of Africa’s food production is used for local consumption . With food insecurity being recognised as a global health challenge , all its major causes in the animal sources should be thoroughly investigated and tackled under the One Health lens. This applies also to animals’ and livestock parasitic infections, given the burden they pose, ultimately, to human sustainment and nutrition. As the OIE puts it, “pathogens of animal origin that are not transmissible to humans, but which have a severe impact on the production of animal protein, should not be neglected either, particularly in developing countries. In fact, they can lead to production losses and a reduction in the available food supply, leading to serious public health problems caused by food shortages and protein deficiencies” .

The activity of DAHPS was measured at 549 nm. Regarding PAL, it was extracted in 1 mL of 200 mM sodium borate buffer and then evaluated by measuring the production of trans-cinnamic acid at 290 nm. For centuries, Cannabis sativa L. has been widely used around the world for various applications . These days, interest has been focused on medicinal and recreational facets, furthering commercial expansion. With Canada recently adopting the more globally appreciated view of cannabis, there exists an ever evolving, multi-billion-dollar industry focused on vegetative propagation . Despite the reliance on clonal propagation, there is a continual need to germinate seeds to select new elite genotypes, perform pheno-hunting, as well as supporting breeding programs. To select new elite genotypes, plants are started from seed .

During the vegetative phase of growth, a cutting is taken and maintained as a vegetative plant while the seedling is grown to maturity. Once the elite genotypes are selected, the cutting is then used as a source to propagate the clonal line. Maintaining the large population of cuttings during the phenotyping exercise represents a significant cost to producers and leaves the cutting derived mother plants exposed to insects and diseases. To address the issues of insect, disease, and viral infections in mother plants, many producers use plant tissue culture to ensure that they are starting with clean material. Forthis process, nodal segments are disinfected and established in culture, a time consuming and relatively expensive endeavor. Once the seedlings are established and multiplied, micropropagated clones can be transferred into the growth facility and cultivated to maturity to identify elite genotypes. After selecting the elite genotypes, the in vitro parent material would be available for clonal propagation. This approach would greatly reduce the amount of space required for selecting new cultivars and provide a ready source of clean planting material once elite genotypes are identified.

However, this approach requires an effective in vitro seed germination protocol with high germination speed and frequency. An efficient in vitro seed germination system would also support downstream biotechnologies in which seedling-derived tissues are preferred .We previously reported the effect of different types and strengths of media in addition to carbohydrate types and levels as primarily important factors contributing to in vitro cannabis seed germination indices and morphological seedling traits . Our results demonstrated that maximum germination percentage was achieved with 0.43 strength mMS medium and 2.3% sucrose . While the germination rate was over 80%, this was after 40 days of culture. Typically, the cannabis seed germinates within several days in the greenhouse/growth room, suggesting that something during the disinfection process was interfering with subsequent germination. To improve our previous protocol, we hypothesize that optimizing the disinfection protocol and seed scarification would increase the speed and frequency of seed germination. As with most aspects of a tissue culture system, in vitro disinfection is a complex and non-linear process that is affected by numerous factors such as disinfectant and contaminant types and levels, media pH, immersion time, temperature, and theirinteractions .

In the disinfection process, the concentration of disinfectants plays a conflicting dual role relating to contamination frequency and seed viability. Higher disinfectant concentrations generally lead to a greater control over contaminants; however, lower seedling viability is often the trade-off. Therefore, it is necessary to optimize the disinfection process. The disinfection process cannot be represented by a simple stepwise algorithm, especially when the datasets are highly imbalanced and noisy . Therefore, artificial intelligence models combined with optimization algorithms such as a genetic algorithm can be employed as an efficient and reliable computational method to inter-pret, forecast, and optimize this complex system . This strategy has been successfully used for modeling and optimizing different tissue culture systems, including in vitro decontamination, shoot proliferation, androgenesis, somatic embryogenesis, secondary metabolite production, and rhizogenesis . Ivashchuk et al. employed multilayer perceptron and radial basis function as two well-known artificial neural networks for modeling and predicting the effect of different disinfectants and immersion times for Bellevalia sarmatica, Echinacea purpurea, and Nigella damascene explant decontamination. They reported that both algorithms were able to accurately model and predict the disinfection process . In another study, Hesami et al. applied a hybrid MLP and non-dominated sorting genetic algorithm-II for the modeling and optimization of disinfectants and immersion times for chrysanthemum leaf segment decontamination. It was reported that MLP-NSGA-II had a high performance to predict and optimize the system .

In 1991, the Brazilian national and state research institutions in coordination with CIAT, had initiated a 5-year project for breeding cassava in drier tropics and subtropics with funds from the International Fund For Agriculture Development . Cassava germplasm from northeastern Brazil and the north coast of Colombia was initially screened at four semiarid sites in northeastern Brazil, characterized by extended drought for several months, hot weather, and sandy infertile soils with presence of pests and diseases . Some accessions were selected for their broad adap- tation across sites to contribute in a recombination and selection program . Yields of selected clones at 12 months and 18 months after planting demonstrate the high potential of cassava in these drier areas.

Also, some progenies, via hybridization, have been developed and sent to ITTA, Nigeria, for adaptation and selection under drier areas in sub-Saharan Africa . Farmers had participated in evaluating and selecting adapted materials that resulted in rapid acceptance and, consequently, in the release of several improved clones . The research reviewed here on cassava productivity, ecophysiology, breeding, and responses to environmental stresses was conducted in collaboration with a multidisciplinary team at CIAT. Under favorable environments in lowland and mid-altitude tropical zones with near-optimal climatic and edaphic conditions for the crop to realize its inherent potential, cassava is highly productive in terms of root yield and total biological biomass, conferring a competitive advantage over other tropical energy crops. Under stressful environments with extended drought of several months and low-fertility soils, where major cereal and legume crops might fail, cassava produces reasonably well.

This inherent capacity to tolerate complex stresses is supported by several morphological, physiological and biochemical mechanisms and traits, such as long leaf life, tight stomatal control over gas exchange, high photosynthetic potential and extensive fine root systems. Core germplasm was characterized and several clones tolerant to water stress and low-fertility soils were identified to breed for drier areas in Africa and Latin America. Selection for nutrient use efficient shortto-medium cassava was found to be advantageous for soil fertility conservation while retaining yield potential. Modeling predicts the suitability of cassava in globally warming climate versus other food crops, confirming its high level of tolerance . Cassava has high optimum temperature for photosynthesis and growth, and responds positively to elevated CO2 that point to its potential as food, feed and energy crop in tropical and subtropical zones adversely affected by climate changes. Because of its high costs using sophisticated methodology, currentclimate research is still confined within developed temperate zones .

Yet, there is an urgent need to conduct climate research in representative tropical ecosystems where GCMss cenarios predict the worst consequences for agricultural productivity and food security . The use of the Free Air CO2 Enrichment technology in combination with rain shelters which facilitates evaluating interactions of CO2 with soil water status , may further enhance developing improved cassava cultivars adapted to increasing atmospheric CO2. Moreover, temperature influences may be studied under field conditions using the “Temperature Free-Air Controlled Enhancement ” technique, as was recently described and used at U.S. Arid-Land Agricultural Research Center, USDA, Maricopa, Arizona . Developed countries, who are the main polluters of the atmosphere, via excessive carbon emissions, must shoulder the costs of climate research in tropical and subtropical regions. Oil-rich Arabian/Persian Gulf States should take the lead in supporting developing countries to cope with-and-adapt-to consequences of warming climate. Molecular biology technology is also needed with focus on applications into crop improvement.

For example, this technology is useful for genetically transferring simple qualitative traits controlled by one or two genes, as already had been demonstrated by the successful production and use of insect-resistant transgenic commercial crop cultivars containing the soil bacterium, Bacillus thuringiensis genes that produce the toxic Cry proteins. In contrast, quantitative multigenic traits such as tolerance/resistance to compound abiotic-stresses are unlikely to be easily amenable to genetic engineering via inserting few exotic genes. These traits when expressed at the whole organism level are mostly attributed to a range of morphological, anatomical, physiological and biochemical characteristics and mechanisms. So far, modest advances at the experimental levels were recently reported for the use of genetic molecular markers in cassava selection and breeding efforts for developing drought-tolerant cultivars .

A serious problem, however, yet lies in the early identification of dispersive soils . In spite of all the knowledge obtained over the years, there is still no fast, simple and dependable mean of conclusively recognizing dispersive soils. Many methods have been suggested including the pinhole, double hydrometer, crumb and chemical tests, individually or in group. These, but, have not always been totally credible and it looks like that the cause sets in the factual testing procedures. The standard testing procedures for the Soil Conservation Service double hydrometer test, the pinhole test, crumb test and chemical analyses have lately been studied and problems/abnormalities identified. Although no discussion concerning these anomalies has been discovered in the literature, the recent testing proposes that many of these deficiencies may have been looked out during past routine investigations. This paper summarizes a proportional study including the testing of three specimen utilizing one standard laboratory test, namely the SCS double hydrometer test and discusses some potential means of conquering the problems identified.

The other tests have been discussed separately. SCS double hydrometer or dispersion soil test has been identified as one of the most suitable tests for classifying dispersive soils. The test assesses the dispersibility of a soil by measuring the natural propensity of the clay fraction to go into annotate in water. The procedure involves the estimation of the percentage of particles in the soil that are finer than 0.005 mm utilizing the standard hydrometer test. A parallel test is also carried out, in which no chemical dispersant is added and the solution is not mechanically excited. The quantity of particles finer than 0.005 mm in the parallel test is explicit as a percentage of this fraction determined in the standard test, which is defined as the dispersion ratio or dispersivity of the soil . Dispersion ratios greater than 50% are observed extremely dispersive, between 30% and 50% are moderately dispersive, between 15% and 30% are a little dispersive and less than 15% are non-dispersive . Similar systems with various limits were used by, and the dispersion test was first described by Volk  as a means of determining the potential dispersive of soils.

The test has since been utilized extensively in this concern with minor modifications. Volk’s test contrasts the weight of soil grains, 0.005 mm or smaller that slaked free when air-dried lumps of soil were soaked in silent distilled water with that of the complete soil. This was shown as the percentage dispersion. The pipette method itself was announced by Middleton in 1930 as a means of determining the erosion potential of a soil. The difference in the methods was that the samples collected in the pipette depend on particles of a maximum diameter of 0.05 mm . Volk’s method was, however, chosen because studies in the southwest of the United States point out that the dispersion of the clay fraction was more significant in assessing the piping potential of soils . The SCS involvement in earth dam construction in the United States reproduces in the 1940’s and early 1950’s. It was during this time that the test procedure was appropriate to utilize a hydrometer to instate a pipette .This study was performed in Sulaimani Governorate to determine the effect of ten land use and clay content on dispersion ratio. The soil samples from 0 – 30 cm depth were collected from different locations. All soil samples were air dried, sieved through a 2 mm physical properties were measured such as particle size distribution by the pipette method, bulk density by Clod method. A single point using water under isothermal condition was measured the according to . Chemical properties were measured like soil organic matter which determined by the Walkley-Black method  and calcium carbonate by titration method. Correlation and regression were used to analyze the relationship between land use and some soil parameters of the samples .

Analysis of variance for complete randomized design was used to compare the influence of the land usage types on the measured soil properties. DUNCAN at P < 0.5 level was used to separate the mean where applicable.The soil texture of the study area was significantly affected by land use. Data obtained in Table 1 showed the variation in sand, silt and clay fraction of the soil. The result shows that the textural class across all the land use types of the study area is different soil texture, indicating the different of parent material. The result is in agreement with . However, over a very long period of time, paedogenesis processes such as erosion, deposition, eluviations, and weathering can change the soil texture.