MAIZE IN UGANDA

                                 MAIZE IN UGANDA.

Maize is a cereal grown crop rich in starch commonly known as corn. Maize is one of the major staple foods in Uganda providing 40% of  Uganda's daily calorie intake. There is an increase in maize production in Uganda due to the change in consumption patterns, today we see a progression from being an entire subsistence crop to becoming commercial.

           CLASSIFICATION OF MAIZE.  

Maize is scientifically known as Zea Mays however, there are many forms of maize used as food in relation to the amount of starch each has. These are referred to as subspecies   

Taxonomy of maize.

Kingdon  Plantae – Plants

Subkingdom  Tracheobionta – Vascular plants

Superdivision  Spermatophyta – Seed plants

Division  Magnoliophyta – Flowering plants

Class  Liliopsida – Monocotyledons

Subclass  Commelinidae

Order  Cyperales

Family  Poaceae – Grass family

Genus  Zea L. – corn P

Species  Zea mays L. – corn P

MAIZE ANATOMY AND MORPHOLOGY.

Maize is a monocot plant. Its seeds have one cotyledon with a large endosperm that stores food for the plant. Maize has long leaves with parallel venation. The longness of the leaves plays a role in increasing the surface area for light absorption.

The stem of the maize plant has vascular bundles (Phloem and Xylem). The xylem plays a role in the transporting of water and water-soluble substances in the plant and the phloem transport proteins, sugars and other organic compounds (Phloem).

The vascular bundles are spread throughout the stem's ground tissue.            
The roots of the maize plant are shallow and widespread growing from the stem, these absorb water and nutrients from the soil and also provide anchorage to the whole plant in the soil.
Maize is monoecious plants meaning both the female and male flowers are found on the same plant. The corn grains we eat are formed by the female flowers.

 The maize plant forms clusters of the male flowers and these are called tassels. 


Picture showing a male maize flower with tassels.

The dangling grain like parts on the tassel arms are the pollen grains.
The female flower of the maize plant is made up silks threads. The male and female flowers do not mature at the same time, therefore self-pollination does not take place. The commonest form of pollination in the maize plant is air pollination. The pollen grains from another plant are blown by air and fall on the female flower (Silk threads) and that is where fertilization takes place. The ovules of the female plant develop into the corn seeds that we consume.

 MAIZE PLANT PHYSIOLOGY.

In a maize plant like all other plants, the main processes that sustain life include; Photosynthesis, Respiration, transpiration, and translocation.

Food of the maize is manufactured in the leaves, the plant uses some of the food in plant development and other processes all the remaining food of the maize is stored in its seeds.

 The maize plant consists of organic compounds carbohydrates (starches, sugars, and fructans). Lipids (Fats and Oils) and protein, however the maize plant like other grains has an abundance of starch stored as food. This explains why it is a commonly consumed food in Uganda especially in schools.

Photosynthesis.

 This is one of the most important reactions for both the plants and humans because it excretes oxygen as a by-product. In this process, simple sugars are manufactured by the plant by capturing light energy.

6C0₂ + 6H₂O+ Light energy = C₆H₁₂O₆ + 6O₂

This process takes place in cell organelles called chloroplasts. These organelles contain chlorophyll a color pigment that absorbs light. This process mainly occurs in the leaves because there is a high abundance of these organelles in comparison to other plant organs.

Photosynthesis can be divided into the light dependent reaction and the light-independent(Dark/ Calvin cycle) reactions. 

The light-dependent reactions take place in the thylakoids, The thylakoids have the pigmentation chlorophyll that absorbs mostly the blue and the red wavelengths of light. This reaction converts light energy into chemical energy.

The dark reaction occurs during the day but it does not require light for the reaction to take place. This reaction results in carbon fixation hence the production of simple sugars.

Maize is a C4 plant, this means it can thrive through the hot climate of Uganda. Uganda has an annual average temperature of 26 degrees rising up to 29 degrees.
Maize plants like other C4 plants have efficiency in trapping carbon dioxide. Carbon dioxide is temporarily stored as 4-Carbon organic acids.
The main reason for the plants storing carbon dioxide in the hot environments is to avoid over opening up of the stomata in order to reduce water loss.
 During respiration, the stomata excrete oxygen and release water, this process is commonly known as transpiration. Excessive loss of water can lead to wilting of the plant if there is lack of water in the soil and the plant has damaged roots, this causes the plant to lose its rigidity. Continual loss of water will lead to permanent wilting of the plant.

MAIZE IMPROVEMENT.
In Uganda, there are many different maize species grown, both local and improved species are grown. The local varieties can yield about 300-600kg per hectare depending on the area in which they are grown, they are grown by most farmers without the use of fertilizers and pesticides.
However, due to the increase in variability of the rain patterns and droughts, better maize species have been developed with different traits.
The following maize species were introduced in Uganda by Global Climate change Alliance Project;

• MM3: Open-pollinated, drought tolerant, fast maturity, Maturity, 90 days
• Longe 4. Open pollinated, drought tolerant, Maturity 100 days.
• Longe 5: Drought tolerant; Quality protein maize, maturity 115 days.
• Longe 7-H: Hybrid drought tolerant, Resistant to maize streak virus, gray leaf spot, Northern Corn Leaf blight, and Turcicum. Maturity 120 days.
• Longe 10 H: Hybrid drought tolerant, Resistant to maize streak Virus, Grey leaf spot, Northern Corn Lead blight and Turcicum. Maturity 120 days.There are five major steps in the development of a commercial corn hybrid

Plant breeding is done with an aim of crop improvement, It involves selection, growth, and cross-pollination of particular plants. Plant breeders select plants that have the desired traits they are looking for for example bigger fruit, higher yield, taste, resistance to pests and diseases and adaptability to the harsh environment. 

Traditional farmers in Uganda do this by simply saving seed from those plants that have good characteristics. 

In the process of maize plant breeding, pollen grains of one plant with the desired characteristics are manually transferred to the stigma of another plant with equally desired characteristics, Seeds resulting from this process must turn out to have the desired traits like for the parent plants that were used. The probability of achieving the desired traits is not always 100% if we are to consider Mendel's formulated law of segregation, therefore, the process can be continued until the plant breeder feels the desired traits have been achieved.

                               DEVELOPMENT OF MAIZE HYBRIDS.

The ultimate goal of breeding maize in Uganda is to improve the adaptation of maize to the hot climate of Uganda. Improved adaptation means higher yield and better quality. The development of a new maize hybrid is a slow and costly process. New Hybrids must possess improved yield, standability, pest resistance and tolerance to various stresses.

The steps taken to develop a commercial maize hybrid are;

1. Selection and development of appropriate source germplasm
2. Development of superior inbreds
3. Testing of inbreds in experimental hybrid combinations.
4. Identification of a superior hybrid combination.
5. Multi-location testing of the precommercial hybrid.
6. Extensive seed production and marketing of all new hybrids is required

To understand how a new hybrid is developed, basic knowledge of maize pollination and breeding should be well understood. Like mentioned before, a maize plant has separate male and female flowers, the tassel is the male flower and produced the ear is the female flower.

Because maize has separate male and female flowers that develop at different times, they carry out cross-pollination. In this type of pollination, the ovules are pollinated by pollen from a neighboring plant. Extra care should be ensured in a breeding program to be certain that pollen from the appropriate tassel fertilizes ovules on the appropriate ear and this can easily be done by hand-pollinating and after a shoot-bag is placed over the shoots. This allows the ear to continue growing without any pollen falling on the silks.

Picture showing shoots covered by shooter-bags after and pollination.

SELF-POLLINATION AND CROSS-POLLINATION.

Higher-yielding maize varieties can be developed by open-pollination. In this form of pollination, plants are allowed to shed pollen without covering silks, resulting in a mix of cross and self-pollinated kernels on each ear.

The best plants would be selected usually the large ones and their ears would be kept to use as a seed for the next growing season.

The resulting maize crops will have improved agronomic traits with variations in many features for example plant height, ear height, maturity rate and many others. This is due to the random cross-pollination. 

If self-pollination of maize is carried out for more or six generations, plants become smaller and less vigorous due to inbreeding depression and their traits get more uniform as more generations are produced. At every generation, selection can be made for specific desired traits such as pest resistance, or plant size. Repeated breeding produces an "inbred' line of maize

Picture showing inbreeding depression.
  

 Cross-pollinating two inbred plants from two different backgrounds causes hybrid vigor.  This means the offspring of this form of pollination will have larger yielding ear and a lot much healthy and strong and also uniform in most traits. This phenomenon is, however, still not fully understood because if an ear of a hybrid corn is self-pollinated the resulting offspring will vary in yield and other traits. That alone explains why Uganda farmers should buy their hybrid seed each year and should not plant a seed from the hybrid.

 It is very important to note that there are many theories that explain the hybrid vigor (heterosis) concept.

ENVIRONMENT AND AGROSYSTEMS IN UGANDA.

Uganda was referred as the pearl of Africa by Sir Winston in 1908 by because of its greenness and high in bio-diversity among other reasons. Uganda is located along the Equator. This means the country has equal days and night, therefore, Agriculture in Uganda is not affected by the day length.

Uganda's climate differs in different regions/parts of the country. TheNorth of Uganda being extremely hot with an average daytime temperature of about 40 degrees and the south being warm with an average temperature of  24-33 degrees.
Because of the difference in the temperatures most maize is grown in the southern part of the country.

Uganda has two rainy seasons, the first season rains are Mid February or March to June and the second rains from Mid August to December. Before the drastic climate change, these periods where the best period to grow rain. Rainy seasons have changed a lot over the last years, and it is not easy anymore to tell when rain is expected. However, farmers plant at the onset of rains, and dry planting is done, when rains are expected.
In order to attain high maize yields, it is very important to have a dynamic balance in the ecosystem. This includes the soil condition, water availability, Nutrient availability and so many others.

SOIL.
Soil health is a very important factor that determines maize yields. Maize can be grown on most Ugandan soils but does best on soils that are well-drained. It, however, does not do well in swampy areas that are waterlogged and in sandy soils that are to say very fine/ smooth seedbed, a rough seedbed allows better water infiltration and control of erosion.

Soil management in maize growing begins right from land preparation. Land preparation should begin at the end of the last rains so that crop residues will be broken down during the dry season, Maize needs soil that has good levels of organic matter and residues.
 Early land preparations ensure that you will have the best yields through timely planting.            Land preparation in Uganda is commonly carried out using hoes and tractors, this helps reduce the risk of soil compaction.

Soil nutrient management is very essential to soil health during maize production. Soil nutrients are restored back into the soil using both organic and inorganic methods. Organic methods are the most common methods used in Uganda since a lot of production is on small scale. This involves manuring and applying mulches on the field. The mulches not only decompose and provide nutrients to the soil together with hummus. They also help keep the soil moisture by protecting the soil from direct heat from the sun.
Inorganic methods used include using artificial fertilizers. Fertilizer application is highly recommended to greatly improve maize yields. It is, however, important to use these fertilizers in weed-free maize fields.

There are two types of fertilizers recommended for maize and these are DAP (Diammonium Phosphate) providing Nitrogen and Phosphate and Urea providing Nitrogen to the soil.
At planting, DAP is applied to the soil. A farmer needs 50kg of DAP per hectare.                                                                                             
During the application of DAP fertilizer, holes are dug to at least 2-3 cm for wet or moist soil and 10 cm for dry planting. Only one teaspoon of DAP is applied per hole. Care has to be taken that the fertilizer is completely covered with the soil and it can not come into contact with the seeds.

                                             Picture showing DAP application.

Urea is applied by top dressing when the maize is about 3-4 weeks after planting. It is important to note that Urea can burn the plant if it touches the plant, so it is applied at least 5-6 cm around the plant. If you place it too far, it will not be of benefit to the plant.

                                     Picture showing Urea application in a maize farm.

The application of these fertilizers together with other factors can affect the PH the soil, for example, these DAP and Urea are weak bases they, therefore, increase the alkalinity of the soil. Acidity can be restored by using acidic fertilizers and in case the soil has low pH (acidic), liming can be carried out to restore a neutral soil PH since soil thrives best at a PH of 6-7.2

 WEEDS IN MAIZE GROWING.
 Weeds are among the top most hinderances to maize production in Uganda. They have a potential of causing 16-80% maize yield loss. They compete with crops for water, soil nutrients and space thereby reducing crop yields. To avoid competition from weeds, weeding should be conducted within the first 30 days after germination. However, many times, weed control at this stage is costly. Farmers often weed shoddily in order to minimize expenses. The availability and adoption of appropriate cost-effective maize weed management technologies by farmers is one strategy to overcome the limitations of higher on-farm productivity. Successful weed management in maize is dependent upon knowing the characteristics of the weed infestations in individual fields, how the weeds interact with the crop and understanding the strengths and weaknesses of the control techniques being used. Weed control is labor intensive when done with the widely used and traditional hand-hoe.

 Every maize growing area is characterized by the presence of certain weed species, the specific weed encroachment being influenced by soil conditions and technologies used before and at the time of the maize crop. Thus, each area needs specifically integrated weed management strategies.

 Maize requires at least 3 times to be weeded at about 5 cm, 45 cm and 90 cm in height in order to acquire good yields. The first and second weddings are a bit intense in comparison to the third weeding. The third weeding is usually lighter due to less grass and weeds later in the season.

The weeds are categorized into annual and Perennial Weeds.

 Annual weeds complete their life cycle within one season for example blackjack. They usually will germinate from their seed faster than the rate at which maize will be germinating. They will definitely interfere with the growth of the crop during the critical period of the first three weeks

 One of the most disturbing annual weeds in maize production is  Striga spp.They mainly attack cereals like maize and other crops like sorghum, millet and upland rice. In Uganda, there are two species of Striga, Striga hermonthica and Striga asiatica. Yield losses attributed to Striga in maize can go up to 100% at the farm level.

Picture showing a farm attacked by Striga weeds

They produce numerous tiny seeds (50,000 - 500,000 seeds per plant). Once shed, the seeds can stay viable in the soil for up to 20 years. The seeds normally germinate only in response to chemical stimulants exuded by the host roots. Once germinated, the weed establishes parasitic attachments (haustoria) with the root of the host and starts deriving all nutrients from the host.

Perennial Weeds are always in a maize garden all time every year. They multiply through roots and stems e.g. couch grass. Mechanical weeding only cuts off the tops but the bottom continues consuming the nutrients and water meant for the maize plants. These should be controlled early before the beginning of the growing season as a later attempt to control them will damage the maize crop.

Weeds can be controlled by using Biological, Physical or Chemical methods.

The chemical method used to control weeds is the use of herbicides, They control weed growth, however, It is no guarantee for the farmer that one herbicide could help control many weeds since some weeds may be resistant to that particular herbicide.

The most commonly used herbicide for maize is Lasso plus Atrazine applied at the rate of 5 liters per ha (2 liters per acre) at the time of planting, this will control grasses and broad-leafed weeds. The herbicide 2,4- D at 1 liter/Ha can also be used for control of broadleaf weeds before maize is 45 days old, perennial weeds are controlled by application of 3 liters of Glyphosate per hectare.

Cultural methods include; crop rotation, timely planting, proper spacing, hoeing and hand pulling and using good seeds that are resistant to weeds.

                       MAIZE CROPPING SYSTEMS , TILLAGE                                                                                                 AND CROP ESTABLISHMENT.
During field preparation, tillage of the land is carried out. In Uganda, a lot of land preparation is carried out using conventional methods.  Some of this methods include using;
                                     
                                                         Tillage.

• Hand Hoe. This is the mainly used method used to till the land. This method is sought to be slow, labor intensive but the most reliable.

• Animal traction involves the use of oxen to plow the land. With this method, the farmer is able to open more land and plant more maize as compared to hand hoe. It is however not appropriate where soils are heavy and the terrain is steep. It, however, requires proper management of the oxen.

• Walking tractors. The use of walking tractors is commonly used for small and medium scale farms. Its fuel efficient and cost effective though it does not work so well on heavy soils.

• Conventional Tractors. These are used by large and medium scale farmers.They are, however expensive and the maintenance fee is expensive for example buying fuel. Getting spare in Uganda is also very hard to find.

Conservation tillage is also another method used in Uganda. Under this method, the land is not disturbed. there is no tilling of the land.

                                         Crop establishment.
When establishing maize there are four major considerations to be taken into account;

• Seed type
• When to plant
• Depth of planting
• Plant population.

                                                            Seed type.    

Choosing the correct seed type to be planted is very essential for this will determine the potential yield. it is very important to plant seeds that are resistant to diseases, drought, and pests, they have a high growth rate and produce big ears. 

  

                                                           When to plant.

The best season to plant maize in Uganda is usually at the onset of a rainy season. The first rainy seasons starting in mid-February or March and end in June while the second rainy season starts around mid-August to December.

Dry planting can also be carried out since maize is a robust crop, however, this should only be carried out when rain is to expected. Dry planting is beneficial because it spreads out the planting duration hence enabling the farmers to open more land.

Delayed planting in relation to the onset of rains will lead to reduced yield. This explains why breeders categorize the maize seed varieties as early maturity, early-medium, and late maturity. This information should be taken into consideration by the farmer when choosing the variety. However, time to plant is not such a critical factor when one is to irrigate.

  

                                                   The depth of planting.

 Planting depth depends on the moisture level of the soil. A suitable plating depth for moist soils is 2-3 cm is and 5-10 cm is recommended for dry planting. Deep seed placement under dry planting is recommended so that seeds germinate only after adequate rains have fallen. However, the depth of planting should be uniform to allow uniform plant growth. 

                                                 Plant population.

The recommended spacing for maize is 75 cm between rows and 30 cm between hills when planting one seed per hill. When hand planting, it is easier to plant at a spacing of 75 cm between rows and 60 cm between hills in a row allowing 2 seeds per hill. With this spacing, the amount of seed required will be 25 kg per hectare or about 10 kg per acre. Plant populations that are higher than the optimum will lead to competition among the maize plant resulting into slender plants that will give a low yield. Lower plant population will result into low yields (though with bigger cobs) due to the reduced number of ears per unit area, it might be appropriate under intercropping but it will lead to increased weed intensity when maize is under monocropping system. It should be planted in rows. Without planting in rows, a farmer will never achieve an optimum plant population. In addition, rows ease field operations like weeding and will facilitate harvesting.

                                                    Cropping systems.

Some of the commonly carried out cropping systems in maize production are crop rotation and polycultures.

Crop rotation is usually carried out with legumes because they help fix Nitrogen in the soil hence enhancing the soil fertility. Crop rotation also has a benefit of breaking the life cycle of pests that may attack the maize plant.

Polycultures involve the growing of two or more crops on the same piece of land. This is a common practice in Uganda since most farmers produce maize for home consumption. They find themselves growing maize together with other crops. This not only improves their diet but also increase their capital since they not only sell maize but also other crops.

Polycultures include; intercropping and multiple cropping. During these cropping systems, cover crops are usually used. Cover crops are succulent and they provide green manure to the soil.

                                     Picture showing maize intercropping with beans.

                               MAIZE PESTS AND DISEASES IN UGANDA.

Pests and diseases are some of the limiting factors that prevent maximum maize production. There are many pests and diseases that attack maize production in Uganda and these include;   
          
                                   Armyworm (Spodoptera exempta)
                                                              

 Effects.
They usually feed heavily leaving only stem and midrib of leaves. They make sudden outbreaks when a large number of moths break into the country. 

Control

Chemical control at a young stage with insecticides like dimethoate or organophosphorus insecticide. Control is also possible with Ambush.

      Apply a band spray along the edge of the field to prevent the worms from 'marching' into the field

                    Cutworms (Agrotls spp)

                 

Effect.
They eat the maize plant right after germination at ground level inhibiting its growth.

Control.

Leave the land weed free for 6 weeks prior to planting.

      Apply pyrethroid sprays in bands over the rows.

                           Leafhoppers (Clcatfuiina spp)

Effects.

They suck sap from the maize plant and spread Maize streak virus to maize

Control.

Farmers should have clear field barriers of 10-20 m using plant resistant varieties.

                                              Termites   

 Effects.  

Termites attack maize and damage is particularly noticeable during drought seasons or in areas with erratic rainfall. They destroy the roots and the base of the stem leading to lodging

 Damage after physiological maturity will lead to grains of poor quality because, after lodging, cobs are exposed to contamination.

Control.

   Spray with insecticide Dusban(Chloryrifos): Dusban kills by contact. Apply 20-40 ml using 10-20 liters of water per termite mound/ anti-hill. Other chemicals include; terminator, Dusban, Pyrines, proban, Imidacloprid and Malataf.

·   Regent 3-G (Fipronil) can also be used where there are no mounds in the garden. Mix 50 gm with two liters of water and apply to locations of feeding termites. Apply to several locations in the field. The Fipronil kills the worker due to excitement, leading to overworking and exhaustion, then eventually death. The queen stops feeding and dies of starvation.


     Diseases affecting maize in Uganda can be divided into fungal, viral and bacterial diseases. The common diseases of maize include;

Maize Smut

Maize smut is a disease caused by the pathogenic plant fungus Ustilago maydis. Smut can cause significant economic damage in dry, hot maize growing areas, as well as in mid hill zones and under temperate conditions. The infection is systemic: the fungus penetrates the seedlings and grows inside the plant without showing symptoms, until the tasseling and silking stages. The most conspicuous symptoms are abnormal development of the tassels, which become malformed and overgrown, black masses of spores that develop inside individual male florets; and masses of black spores in place of the normal ear, leaving the vascular bundles exposed and shredded. The smutted ear develops no grains.

                                    Picture showing maize cob affected by maize smut.

Management of Maize Smut Host resistance

Maize varieties that are resistant to common smut are widely available and offer the most cost-effective and practical means of disease management.

Fungicide

Efforts to control common smut through the application foliar fungicides and seed treatments have not been highly successful.

Cultural control

·  Avoiding mechanical damage to plants will reduce plant injury, which is the primary means of infection by the fungi.

·   Controlling insect damage (e.g. controlling maize borers) will also limit plant injury.

·   Removing galls before they rupture will limit the spread of teliospores but is not practical in large-scale maize cultivation.

·  A well-balanced fertilizer regime will reduce disease severity. High levels of nitrogen fertilization increase disease severity, although application of phosphorous reduces disease incidence.

Maize Streak Virus

The disease was reported first from East Africa and has now extended to many other African countries. The virus is transmitted by Cicadulina spp. Leafhoppers. Cicadulina mbila (Naude) is the most prevalent vector and will transmit the virus for most of its life after feeding on an infected plant. Early disease symptoms begin within a week after infection and consist of very small, round, scattered spots in the youngest leaves. The number of spots increases with plant growth; they enlarge parallel to the leaf veins. Soon spot become more profuse at leaf bases and are particularly conspicuous in_;.the youngest leaves. Fully elongated leaves develop chlorosis with broken yellow streak along the veins, contrasting with the dark green color of normal foliage. Severe infection causes stunting, and plants can die prematurely will not develop cobs. Many cereal crops and wild grasses serve as reservoirs of the virus and vectors.

                                     Picture showing maize leaf of a maize streak virus affected plant.

Management of maize streak virus

· Grow resistant maize lines

Gray Leaf Spot                             

The disease is caused by Cercospora zeae-maydis, C. sorghi varmaydis. This disease, also known as Cercospora leaf spot, may occur in subtropical and temperate, humid areas. Lesions begin as small, regular, elongated brown-gray necrotic spots growing parallel to the veins. Occasionally, lesions may reach 3.0 x 0.3 cm. Minimum tillage practices have been associated with an increased incidence of GLS. Development is favored by extended periods of leaf wetness and cloudy conditions and can result in severe leaf senescence following flowering and in poor grain fill.
                               
                                        Picture showing maize leaf affected byGray leaf Spot.

Management of Gray Leaf Spot

·          Use of resistant cultivars

·        Because moisture on leaf surfaces is important throughout the disease cycle, efforts should be made to avoid practices that extend dew periods. Therefore, irrigation should not be scheduled during late afternoon or early evening, especially after outbreaks have already occurred. Other cultural practices appear to have little effect on gray leaf spot development. Fungicides are important for gray leaf spot control.

Turcicum Leaf Blight (TLB)

The disease is caused by Exserohilum turcicum, an early symptom is the easily recognized, slightly oval, water-soaked, small spots produced on the leaves. These grow into elongated, spindle-shaped necrotic lesions. They may appear first on lower leaves and increase in number as the plant develops and can lead to complete burning of the foliage. Turcicum leaf blight (or northern leaf blight) occurs worldwide and particularly in areas where high humidity and moderate temperature prevail during the growing season. When infection occurs prior to and at silking and conditions are optimum, it may cause significant economic damage. Development of the disease later in the season might not cause heavy yield losses.

Picture showing maize plant affected by theTurcicum Leaf Blight.

Control

•  Plant resistance maize varieties. Currently, no varieties are immune, hybrids like SC627, Longe 2H, Longe 6H, Longe 7H and Longe 8H have higher levels of resistance.

•   Rotate diseased fields to non-cereal crops (like sunflower, soybean) for at least one year. Never plant maize after a diseased maize crop. Bury infected debris soon after harvest to enhance breakdown of the residue so that the fungus dies in a short period of time.

Management of Turcicum Leaf Blight

Host resistance

Host resistance is the most efficient and cost-effective means of disease resistance.

• Four genes offering major resistance to Turcicum leaf blight have been identified and are incorporated in many commercial hybrids. However, the success of disease management using qualitative resistance will depend on the race of the pathogen present.

• Quantitative levels of host resistance are also available that restrict lesion development and sporulation.

Cultural control

• Rotating maize with non-host crops can reduce disease pressure.

•Management of overwintering infected crop residue will reduce the amount of available inoculum at the onset of the subsequent growing season.

Fungicides

•  Fungicide application can effectively control Turcicum leaf blight when applied at .., the right time. Fungicide should be applied when lesions first become visible on the lower leaves.

•In seasons not favorable to Turcicum leaf blight (cool and dry seasons), the fungicide application may not be cost effective particularly for grain production.

Ear Rot

Ear rots are commonly found in hot, humid maize-growing areas. Maize ears show characteristic development of irregular bleached areas on husks. These areas enlarge until the husks become completely dried, although the plant is still green. If husks are removed, ears appear chaffy and bleached, with a white, cottony growth between the kernels. Late in the season, many small, black pycnidia form on kernels and cob tissues. These pycnidia serve as sources of inoculum for the following season's crop. Microscopic observation of the spores is the only way to identify which pathogen is present. Severely infected ears are very light. Infection more frequently occurs through the shank and moves from the cob to the kernels. Stem borer injury in the ear often increases of this disease. Stenocarpella maydis produces the mycotoxin diplodiatoxin and S.macrospora produces diplodiol, both harmful to birds.
                                         
                 Picture showing maize cob affected by the ear rot disease.

MAIZE HARVESTING AND STORAGE.

                                      Time to harvest

 Maize can be stored for a considerable period in unprocessed form without undergoing deterioration. Its shelf life greatly depends on the prevailing ambient temperature and relative humidity, and other factors like the inherent moisture pests and diseases. Therefore, recommended post-harvest handling and managing operations involve the manipulation of the above factors in order to obtain high-quality maize grains. Quality control starts with harvesting. Harvesting is the single deliberate action to separate the cob from its grown medium. The optimum time of harvesting maize is when the stalks have dried and moisture of grain as about 20-17%.

                          

                                            Pre harvesting and Harvesting.

Currently, most of the maize grown in Uganda is harvested by hand. Considering the need for a farmer to keep the cobs clean, dry and to avoid infestation of the harvested cobs, a farmer ensures the drying place or equipment is clean and disinfected, ready to receive the cobs, all old grain and dirt from anything that will come in contact with the good or new grain is removed, all harvesting tools, carts, wheelbarrows, bags, and baskets are thoroughly cleaned. Fumigating them or at least treating them with boiling water to kill insects or their eggs is very effective. This is done in order to avoid infection of new grain by insects and their eggs. 

Since maize is harvested by hand, labor is very intensive, Organizing enough labour to reap and carry the cobs to the drying place should be dome prior to harvesting.

After harvesting, the maize cobs are transported to the maize crib without putting them on the soil to avoid contamination.

                                      Post-harvesting activities.

Drying.

Wet grains attract insects and mold it is therefore very important the grains are dried as soon as possible after harvesting. Drying is the systematic reduction of crop moisture down to safe levels for storage, usually 12%-15.5% moisture content. It is one of the key post-harvest operations since all down-stream operations depend on it. This is particularly so in some regions of Uganda where humidity and rainfall remain high at harvesting delaying the harvest and constraining actual drying. Sometimes the next season starts early when the crops are still in the field as much as possible the choice of varieties should be such that they mature at the beginning of dry season. In Uganda maize are mainly sun-dried. 

    Picture showing maize being sun-dried.

Drying permits the escape of moisture from grain to an acceptable level which can sustain very low metabolism. The enzyme activities and grain tissue respiration is reduced to a very low level thus inhibiting germination.

During drying, the dry air rapidly takes moisture away from the grain, especially if the air is moving and has got low humidity. Grains can be dried in a crib before shelling and on tarpaulins after it has been shelled. 

Shelling.

Shelling is commonly done by beating maize cobs with a stick in a sack or a confined floor space where farmers can afford it. Beating maize will result in physical damage which makes it more vulnerable to pests and molds and damage to the germ. Using a maize shelter is preferred although it will not be afforded by most farmers. 

Shelling machines are also used to shell maize though they can not be afforded by many farmers.

                                Picture showing men shelling maize by beating it with sticks.

Storage.

The main objective in any maize grain storage system is to maintain the stored grains in good condition so as to avoid deterioration both in quantity and quality. During storage, the grain must remain dry and clean. Grain storage can be extended for up to 2 years without any significant reduction in quantity and quality. However, the majority of farmers sells off their maize grains cheaply soon after harvesting due to anticipated losses in storage and later buy food at exorbitant prices. There are improved storage structures that can prolong the storage duration until market prices for grains are favorable for example storage silos. However, In Uganda, most of the maize produced by local farmers is stored in local maize crips.

                                                  Picture showing a local maize crib.

 Storage room.

 Bag storage of shelled grains in well-designed storerooms is the most suitable in a tropical country like Uganda. Although the bulk system of storage also exists and has its advantages, bag storage is more appropriate for Ugandan farmers because at the moment all buyers in Uganda require bagging before dispatch, the transport system available is more suited to transporting bagged than bulk grains and Bagged grain is easily quantified when receiving, dispatching or checking stock.

ORGANIC AGRICULTURE.                                                                                                               There are four main principles of organic agriculture established by the International Federation of Organic Agriculture Movements (IFOAM) and these are;

1. The Principle of Health - Organic agriculture should sustain and enhance the health of soil, plant, animal, and human as one and indivisible.
2. The Principle of Ecology - Organic agriculture should be based on living ecological systems and cycles, work with them, emulate them and help sustain them with the help of it.
3. The Principle of Fairness - Organic agriculture should build on relationships that ensure fairness with regard to the common environment and life opportunities.
4. The Principle of Care - Organic agriculture should be managed in a precautionary and responsible manner to protect the health and well-being of current and future generations and the environment.

Organic Agriculture uses agro-ecological systems that promote diversity, biological cycles and soil biological activity.
USDA, Classification,2017, accessed on, 7/7/2017, available at  https://plants.usda.gov/java/ClassificationServlet?source=display&classid=ZEMA
Geo Chem-Bio, 4/10/2018, Zea Mays, Maize, Corn, Mealie,  accessed on 15/09/2017. available at, http://www.geochembio.com/biology/organisms/maize/  
BBC Bitesize Biology, Transportation in Plants, 2017, accessed on 15/09/2017, available at http://www.bbc.co.uk/education/guides/zps82hv/revision/3
Backyard nature, 2017,  corn, (Maize) flowers, accessed on 15/09/2017, available at http://www.backyardnature.net/fl_corn.htm
RSC org, 2017, Chemistry for Biologists, Photosynthesis, accessed on 21/09/2017, available at; http://www.rsc.org/Education/Teachers/Resources/cfb/Photosynthesis.htm
Weather and climate information, 2016, Climate and average weather in Uganda, accessed on 21/09/2017, available at;                                                                                                             
ThoughtCo. 15/02/2017, Mendel's Law of segregation, accessed on 29/09/2017, available at; https://www.thoughtco.com/mendels-law-of-segregation-373472

The Ugandan government has taken several important steps in transforming conventional agricultural production into an organic farming system which prohibits the use of synthetic inputs, such as drugs, fertilizers, and pesticides this was to promote sustainable agricultural growth. Most of the farming in Uganda may be mistaken as organic since no chemicals are used however, there is a thin line between Organic and natural agriculture.

In 2004, Uganda adopted the Uganda Organic Standard., In 2007 the regional standard, the East African Organic Products Standards developed by a UNEP-UNCTAD initiative and in July 2009, the government released a Draft of Uganda Organic Agriculture Policy. 

  Sustainable agriculture is seen as a means of improving people's livelihoods as it could provide significant benefits for its economy, society and the environment. 

Farmers making a transition to organic farming secures a market for their produce since organic products have a stable market. Organic farmers in Uganda can be certified within a year. However, if a farmer has been using chemicals, he has to undergo a conversion period of three years. This is counted from the time he/she last used the chemicals. During this period, his/her produce can be certified as "Organic in conversion". The market for their produce is small so they can not get premium prices until they are fully certified.

The Organic certifying body in Uganda is the Uganda Organic Certification Ltd, UgoCert,  this company was founded by the National Organic Agriculture Movement of Uganda (NOGAMU).

                                          REFERENCES

Crop Life International, 2017, Maize in Uganda, accessed on 7/7/2017, available at; https://croplife.org/news-views/sharing-the-story/maize-from-uganda/



http://www.backyardnature.net/fl_corn.htm



https://weather-and-climate.com/average-monthly-Rainfall-Temperature-Sunshine-in-Uganda


FAO, 2014, Intellectual Property rights in Plant varieties, accessed on 29/09/2017, available at http://www.fao.org/docrep/007/y5714e/y5714e00.htm

FAO, TECA, 2017, Drought tolerant maize varieties in Uganda, accessed on 29/09/2017, available at; http://teca.fao.org/read/8920

  Farm West, 2004, How corn hybrids are developed, accessed on 6/10/2017, available at http://www.farmwest.com/node/31

Sasasawa Global (2000), Maize production in Uganda, accessed on 18/11/2017, available at: http://teca.fao.org/sites/default/files/resources/Maize%20Production%20in%20Uganda_SASAKAWA_%20GLOBAL%202000.pdf

Safari bookings, Weather and Climate Uganda, accessed on 18/17/2017, available at https://www.safaribookings.com/uganda/climate


Yara company, Soil and liming for maize accessed on 18/11/2017, available at; http://www.yara.co.uk/crop-nutrition/crops/maize/key-facts/soil-and-liming/

Elizabeth K, Bukirwa, (7/1992) Market Research  and Production In Uganda, accessed on 18/11/2017, available at; http://pdf.usaid.gov/pdf_docs/Pnabt623.pdf

Ministry of Agriculture, Fisheries, and Animal Husbandry, National Agricultural Research Organization, (n.d) accessed on 1/12/107, available at,  http://teca.fao.org/sites/default/files/resources/Maize%20Production_Ministy_NARO.pdf

http://teca.fao.org/read/7019
http://www.monitor.co.ug/Magazines/Farming/Organic-agriculture-Ugandan-farmers/689860-2862680-d27gkhz/index.html
http://www.psfuganda.org/new/index.php?option=com_community&view=profile&userid=146