WHAT IS ALLELOPATHY: [VERNOINA AMYGDALINA (BITTER LEAF) AND TOMATO PLANT]
Allelopathy refers to the beneficial or harmful effects of one plant on another plant, both crop and weed species, from the release of biochemical, known as allelochamicals, from plant parts by leaching, root exudation, volatilization, residue decomposition, and other processes in both natural and agricultural systems. ALLELOCHEMICALS are subset of secondary metabolites not required for metabolism (growth and development ) of the allelopathic organism. Allelochemicals with negative allelopathic effects are an important part of plant defence against herbivory (i e. animals eating plants as their primary food) (Fraenkel 1959 ;stamp 2003).
The term allelopathy is from the greek elerived compounds allele and pathy (meaning “mutnalharm” or suffering ) and was first used in 1937 by Austrian scientist Hans molisch in the book Der Einfluss enies PFlanza auf die andere allelopathic (the effects of plants on each other) (willis 2010 ). First widely studies in forestry systems, allelopathy can affect many aspects of plants ecology, including occurrence, growth, and plant succession, the structure of plant communities, dominance, and diversity and plant productivity. Initially, many of the forestry species evaluated had negative allelopathic effects on food and fodder crops , but in the 19805 research has begun to identify species that had beneficial, neutral, or selective effects on companion crop plants.
NATURE OF ALLELOPATHY
Commonly cited effects of allelopathy include reduced seed germination and seeding growth. Like synthetic berbicides , there is no common mode faction or physiological target site for all allelocbermicals. However ,known site of action for some allelochemicals include cell division , potten germination, nutsient uptake, photosynthesis, and specific enzyine function. For example , one study what determined the effect of an allelochemical known in velvetbean ,3-(3,4—ditrydroxyphary )-1-alanine (1-DOPA), medicated that the inbition by this compound is due to adverse effects on amino acid metabolism and 180n concentration equilibrium.
CAPISCUM ANNUUM (PEPPER)
Capiscum annuum (Sweet and chili peppers) with cultivated varities including bell, sweet, chili and paprika peppers (is a pereunical herbaceous plants in the solanaceae (might shade family), which originated in central and South African and the Caribean and was domesticated over 5,000 years ago. Peppers from Capsium annuum have been developed into numerous varieties that are now cultivated around the world for sweet and hot varieties of green and red bell peppers and chili peppers, that are one of the world’s most widely used spices, with dried forms including paprika, chili powder and conjenne.
Capsicum annuum, which is perennial but often cultivated as an annual in temperate climates, is a many branched plant, growing up to 75cm (30in) in cultivated varieties, often subrubby in appearance. The leaves are simple and alternate, elliptical to lanccolate, with smooth margin (entire).
LYCOPERSICON ESCULENTUM (TOMATO)
Tomato (Lycopersicon escutentum) is an important commercial crop because of its nutritive value. It is rich in Vitamin A, B. C thiamine, ruacine, riboflarine and mineral like, iron and calcium. (Macdonald and Low, 1984) Fibres in Tomato fruit serve as roughage and promote digestion (Ephenbuijen, 1974). Tomato is among the vegetable products cultivated worldwide that has the greatest mitritional value (Thompson, 1998). Ripe tomato fruit has high vitamin C and potassium. More importantly, previous researchers indicated cholecterol related Cardiac Disease (Simon and Schuster, 1996). Tomato is essential in human diet; it can be prepared into stew, puree, salad etc. Despite the needs of tomatoes, its low yield as a result of disease infection has been a source of serious concern.
2.1 VERNONIA AMYGDALINA. (BITTER LEAF)
Vernonia amygdalina, a member of the Asteraceae family, is a small shrub that grows in the tropical Africa V. Amygdalina typically grows in a height of 2-5m. The leaves are elliptical and up to 20cm long. Its bark is rough V. amygdalina is commonly called bitter leaf in English because of its bitter taste. The cooked leaves are a staple vegetable in soups and stew of various cultures throughout equatorial Africa. Africa Common names include grawa (Ambaric) ewuro (Yoruba), etidot (Ibibio) omigbu (ngbo), Hyuna (TIV), oriwo (Edo), Chrisar – doki (Hausa), mululuza (luganda) Labwon (Acholi), Olusia (Luo) and ndoleh (Cameroon).
2.2 BOTANICAL CLASSIFICATION
The plant is scientifically classified as belong to the kingdom plantae. It is an angiosperm, of the order asterales, of the family Asteraceae, genus vernonia and species v. amygdalina. The binomial name is vernoina amygdalina Del.
2.3 COMPOUNDS ISOLATED FROM VERNOINA AMYGDALINA
Several investigators have isolated and characterized a number of chemical compounds with potential biological activities from the leaves of vernoina amygdalina. Some of the previously isolated continuents in vernoina amygdalina Del. Include: Sesquiterpene lactones, flavonoid like luteolin, luteolin 7 – 0 –glucosides and luteolin 7 – 0 – glucuronide, steroid glycosides, and Vernoniside A, B, A1, A2, A3, B2, B3 and A4. Edotides from the aqueous extract of the plant was characterized in. very recently, (Owoeye et al) isolated and characterized a sesquiterpene lactone, epivernodalol, another elemanolide from the dichloromethane fraction of vernonia amygdalina Kow et al isolated the compound epivernodaloh from another species of the plant called vernomia lasiopus.
2.4 TRADITIONAL USES VERNOINA AMYGDALINA
Leaves of this plant are used in Nigeria as a green vegetable or as specie in soup, especially in the popular bitter-leaf soup. Such preparation includes freshly harvested leaves which are macerated with either cold or hot water to reduce the bitterness of the leaves to a desirable level. The latter are then added with other condiments for the soup while the water extract may be taken as atomic to prevent certain illness. The leaves can be taken as an appetizer and the water extract as a digestive tonic. These are largely consumed by the female Hausas in their beliefs that it makes them more sexually attractive.
In Northern Nigeria, it has been added to horse feed to provide a strengthening or fattering tonic called ‘chusar Doki’ in Hausa. The leaves have also been used in Ethiopia as shops in preparing tela beer. The leaves are wisely used for fevers and known as a guinne – substitute in Nigeria and some other African countries. The young leaves are used in folk medicine as anthelmintic, antimalarial, laxactive/purgative, enema, expectorant, worm expeller and fertility inducer in subfertile, woman. Some wild chimpanzees in Tanzania had been observed to use this plant for treatment of parasite related diseases. Many herbalists and naturopathic doctors have recommended the aqueous extracts for their patients as treatment for emesis, nausea, diabetes, loss of appetite- induced ambrosial dysentery and other gastrointestinal tract problems.
2.5 BIOLOGICAL ACTIVITIES OF VERNOINA AMYGDALINA
(Iwalewa et al) reported the antioxidant and cytoprotective activities of boiled, cold and methanotic extracts of mine edible vegetable in South West Nigeria which were evaluated in the 1,1-diphenyl -2- picoylhydrazyl free radical assey and hemaglutination assay in bovine erythrocytes, respectively. While crassoccphalum rubbers showed the highest antixodiant activity (65.5%), solanum americanum and vernoina amygdalina exhibited significant antioxidant activity. Subsequently, (walokun et al.) reported the antioxidant effects of an aqueous extracts of vernoina amygdalina leaves against acetaminophen- induced hepatotoxicity and oxidative stress in mice. Pre-administration of vernoina amygdalina resulted in a dose-dependent reversal of acetaminophen – induced alternations of all the liver function parameters and suppressed acteaminiphen induced lipid peroxidation and oxidative stress. The study suggested that vernoina amygdalina protected against acetaminophen-induced hepatic damage in mice by antioxidant mechanisms. The antioxidant mechanism of vernoina amygdalina has been justified by the recent studies of Adesanoye and farombi. In this study, vernoina amygdalina protected against carbon tetrachloride –induced liver injury by inducing antioxidant and phase 2 enzymes.
The antioxidant activity of vernoina amygdalina has been attributed to the presence of flavonoids as reported by igile et al. Using spectroseopic techniques, the study had isolated and characterized the flavonoids occurring in vernoina amygdalina. Three flavons were identified with chemical and spectroscopic techniques namely: Luteolin, Luteolin 7 – 0 – ?-glueuronoside and inteolin 7 – 0 – ? – gluoside. Determination of the antioxidant activity of the threeflavones had shown that luteolin showed greater activity than the other two. Since flavonids are established as possessing antioxidant activity. It can be speculated that the antioxidant properties of vernoina amygdalina can be attributed to the presence of these flavonoids. The advantage of this antioxidant property has been revealed in neurotoxic studies since it has been established that flavonoids can traverse the blood brain, barrier. In this connection, Owoeye et al. reported the neuroprotection of the cerebellum by the methanolic extract of vernoina amygdalina leaves on the gamma-irradiated brain of wistar rats.
Grows under a range of ecological zones in Africa and produces large mass of forage and is drought tolerate (Hutchioson and Dalziel, 1963 cited by Boni et al., 1995a). There are about 200 species of vernoina.
2.6 MAJOR USES AND FUNCTIONS
The leaves are used for human consumption and washed before eating to get rid of the bitter taste. They are used as vegetable and stimulate the digestive system, as well as they reduce fever. Furthermore, are they used as local medicine against Leech, which are transmitting billar3100se. Free living chimpanzees eat the leaves, if they have attacked by parasites. vernoina amygdalina is also used, instead of hops to make beer in Nigeria (Anonymous, 2000). Furthermore, is vernoina amygdalina found in homes in village as fence post and pot-herb (Anonymous, 1999).
2.7 FEEDING VALUE
Vernoina amygdalina has been observed to be eaten by goats in central zone of Delta State, Nigeria. However, in general has there found, that vernoina amygdalina have an astringent taste, which effects its intake (Bons, et al., 1995a). The Bitter taste is due to anti-nutritional factors such as alkaloids, saponins, tannins and gloycosides (Buttler and Bailey, 1973, Oloyunde et al., 1992 cited by Bonsi et al. 1995a; Anonymous, 1999). It has been tried to mix vernonia with molasses to make it more palatable, but 6.6% of DM intake had to be added to improve the intake of vernonia. During the dry period Dairy farmers from Southern Ethiopia feed boiled vernoina, since the boiling decreases the content of secondary plant compounds and makes the feed more palatable.
Vernoina amygdalina has also been feed to broilers, whre it was able to replace 300gKg-2 of maize based diet without affecting feed intake, body weight gain and feed efficiency (Teguia et al., 1993) cited by Bonsi et al., 1995a).
2.8 THE CLIMATE AND NUTRITIVE REQUIREMENT
A study of wild growing bitter leaf (Vernoina amygdalina) plants at Ibadan in South Western Nigeria showed that the growth parameters of mature individual bitter leaf plants ranged as follows: Leaf number, 1300 to 10986, mean leaf area 20.3 to 86cm2, total leaf area 62959 to 62959 to 626416cm2, stem height 76 to 530cm and branch number 9 to 29. Plant mean leaf area was not strongly correlated to other growth parameters which were they positively correlated to one another. The values of coefficient of correlation (r) ranged from 0.76 to 0.89. Young single stemmed bitter leaf plants were coppiced and allowed to regenerate. Their mean growth rates per day for leaf number, stem height and leaf area were 1.5, 0.93cm and 49.7 cm2 respectively.
The leaves were harvested and when the plants regenerated the number of leaves produced within 20 – 80% harvesting intensity range, increased (R2 –0.92), while plants that had 100% harvesting intensity produced the least number of leaves in subsequent regeneration. The growth parameters were positively correlated to rainfall, relative humidity correlated to the growth parameters. Leaf shape fact Ca mathematical quantity which gives the true leaf area when it is multiplied by the product of the length and maximum width of the leaf) was 0.637 for this species. The total leaf area lost to insect attack ranged from 0.2 to 12%. On average the nutritive values of both young and mature leaves of bitter leaf did not differ significantly and they compared favourably to those of other commercially importantly leafy vegetable in Nigeria.
2.9 HEALTH BENEFIT OF VERNOINA AMYGDALINA (BITTER LEAF)
Bitter leaf (Vernoina amygdalina) is a vegetable use for preparing the popular bitter leaf soup. It is also known as Onugbu, Shiwaka and Ewuro by the Igbos, Hausas 7 Yorubas in Nigeria.
Although this plant has been around for hundreds of years, only a few people known of its medicinal and healing properties.
Bitter leaf (Vernoina amygdalina) as the name implies, is actually a bitter plant whose leaves, extracts, steams and barks are used for culinary, medicinal and curative purpose. Vitamin in Bitter leaf includes; Vitamin A, Vitamin C, Vitamin E, Vitamin B1 and Vitamin B2.
2.10 SOME OF THE HEALTH BENEFIT OF BITTER LEAF
- It speeds up metabolism and therefore is great for weight loss Bitter leaf juice relieves fever and feverish conditions. Take the squeezed juice, 3 times daily until the symptoms disappear.
- It also helps to reduce high sugar level in the blood and great for diabetic patients.
- Squeeze the fresh leaves on your palm and apply the juice on skin rashes, Eczema, ring worms and any superficial skin ailments, you’ll notice a change in few days. Don’t apply to open wounds
- Bitter leaf is said to soothe and also curepile
2.11 CHEMICAL CONTENT OF THE EXTRACT (VERNOINA AMYGDALINA)
Vernoina Amygdalina (Bitter leaf) is a popularly consumed in many homes in Nigeria as a vegetable in soup preparation, while the infusion is used in folk medicine in the treatment of malaria fever. In this study, fresh leaves of Vernoina amygdalina were subjected to Absasion (to remove the bitter teste) as is normally done in soup preparation, subsequently the nutrient, anti-nutrient and zinc bioavailability of the processed and unprocessed leaf were determined. The hemolytic effect of the leaf infusion on human ervthrocytes (Genotype – SS, AS, AA) was also determined.
The study revealed that vernoina amygdalina leaf has high protein (33.3%), fat (10.1%) crude fibre (29.2%), ash (11.7%), mineral (Na, K, Ca, Mg, Zn & fe), phytate (1015.4mg/100g) and tannin (0.6%) content, which it contain low cyanide (1.1mg/kg). Abrasion of the leaf cuased a significant decrease (P<0.05) in both the nutrient and antinutrient content of the leaf except in carbohydrate where there was a significant increase (P<0.05) and mg where there was no significant change (P>0.05). The result of the calculate [Ca] phytate]/[2n] molar ratio (the best index for the prediction of Zn bio-availability) indicated that the phytali content of both the processed and unprocessed vernoina amygdalina leaf will not reduce the Zn content to a critical level (0.05mol./Kg). Further studies on the leaf revealed that the infusion induced the heamolysis of human erythrocyte (in vitro). Human genotype – SS (1024) were highly susceptible to haemolysis of induced by vernoina amygdalina infusion, genotype – As moderately susceptible (512) while genotype – AA (256) is highly resistant to haemolysis induced by the same infusion.
Bitter leaf has high nutrient and anti-nutrient content, however, abrasion will bring about a significant decrease (P <0.05) in both. The infusion of the vernoina amygdalina leaf induces the haemolysis of mammalian erythrocyte invitro, with Human SS having the highest susceptibility.
Vernoina amygdalina extracts and isolated chemical constituents have been studied for their potential pharmacological effects, including.
- Induction of apoptosis as determined in cell culture and animal studies.
- Enhanced chemotherapy sensitivity vernoina amygdalina extracts may render cancerous cells to be more sensitive to chemotherapy.
- Inhibition of the growth or growth signals of cancerous cells.
- Suppression of metastasis of cancerous cells in the body by the inhibition of NF kB is an anti-apoptotic transcription factors as demonstrated in animal studies.
- Reduction of estrogen level in the body by the suppression of Aromatese activity. The involvement of blood estroger level in the etiology of estrogen receptor (ER) positive breast cancer has been widely reported. Additional source of estrogen production in human besides the ovary and adrenal gland is the conversion of testosterone to estrogen in a reaction catalyzed by aromatase. Many studies have shown positive correlations between blood estrogen levels and breast cancer risks. Therefore, compounds that inhibit aromatase activity are used for the treatment of breast cancer may strengthen the immune system through may cytokines (including NF kB, pro inflammatory molecule regulation.
- Studies conducted using streptozotocin-Induced diabetic laboratory animals showed that vernoina amygdalina administration decreased blood glucose by 50% compared to untreated diabetic animals.
- Extracts of vernoina amygdalina possess in vitro anthelominthic anti-paracific properties.
2.12 THE ARGRONOMY OF PEPPER (CAPSICUM ANNUUM) PLANT
Capsicum annuum is a species of the plant genus capsicum native to Southern North America and Northern South America. The species is the most common and extensively cultivated of the five domesticated capsicums. The species encompasses a wide variety of shapes and sizes of peppers, both mild and hot, ranging from hell peppers to chili peppers. Culivars are descended from the wild America bird pepper still found in warmer regions of the Americas. In the past some woody forms of this species have been called C. frutescens, but the features that were used to distinguish those forms appear in many populations of C.annuum and there is no consistently recognizable C. frutescens species.
Although the species name annuum means “animal” (from the latin annus “year”), the plant is not an animal and in the absence of winter firsts can survive several seasons and grow into a large perennial shrub. The single flowers are an off-white (Sometimes purplish) color while the stem is densely brached and up to 60 centimetres (24 in) tall. The focust may be green, yellow or red when ripe. While the species can tolerate most climates. C. annuum is especially productive in warm and dry climates.
Culinary: The species is a source of popular sweet peepers and hot chilis with numerous varities cultivated all around the world.
Common naming in English falls generally in line with flavor and size of the variant. Larger, sweeter variants are called red or green peppers, “bell peppers” or “Capiscum” and the smaller, hoter varieties “Chillis”, Chilies” or “chili pepper”.
Capsimid chemicals provide the distinctive tastes in capsicum annuum variants. In particular capsaicin creates a burning sensation (“hotness”), which in extreme cases can last for several hours after ingestion. A measurement called the scoville scale has been created to describe the hotness of peppers and other foods.
2.14 THE AGRONOMY OF TOMATO PLANT
Tomato (Lycoperisicurn esculentum) belongs to the family Solanaceae (night shade family). The wild type tomato specie is said to orginate from South America, especially in the coastal desert of Peru. The first historical reference in Europe to tomato was a yellow-fruited type in ltaly in the year 1544 and cultivated in Germany in 1533 (Chamber, 1979). The Italians were said to have acquired it from Turks. Tomato was first grown in Spain then taken to Italy where it was called ‘promd’ ‘oro’ or golden apple, because of its yellow colour.
The French called it “pma aman’s’ or apple of love. The African Indians used to name it “tomall” Tomoato was not very popular until in the 10th century. It was suggested that certain famines during this century forced people to try this plant (Stary, 1983). There is also evidence that tomato originated in Mexico (bianchini, Corbetta and Postoria, 1987). These tomatoes show great diversity in size and shape including all colour types such as pink, red, and yellow.
2.14.1 RAISING TOMATO SEEDINGS
Sprout tomato seeds indoors in small containers, sow tomato seeds about 1/8” inch deep, using seed starting soil. Seeds will sprout in 10 – 14 days, depending upon soil temperature. Sprouting seeds is quicker and more productive, when using a heated germination mat.
As soon as the seedlings emerge, they need full sunlight to grow sturdy. Lack of sunlight causes the plants to grow “leggy”.
Tip: To help your plants grow sturdy, keep them where they will get plenty of air or lightly brush the tops of the plants with your hands a couple times each day.
2.14 HOW TO GROW TOMATOES
On planting day, pour liberal amounts of water with a soluble liquid fertilizer on them. Plant them in the garden carefully. To minimize transplants shock, avoid disturbing the roots. Normal spacing is 24” part, in rows 30” to 36” apart (Hartz, 2013).
Fertilize plants on a regular basis. Early applications should be high in nitrogen. As blossoming occurs, switch to fertilizers which are higher in Phosphorus and Potassium. Too much Nitrogen fertilizer results in lots of lush green leaves, and little fruit. A fertilizer specifically formulated for tomatoes, will help to maximize your crop.
Tomato Cages and Staking: Maximize your crop, and minimize disease and insect damage, by staking or caging tomato plants. They will reward you with more tomatoes. The fruit will be cleaner, as they will not be sitting on the soil. Cold and hot spells will affect development and growth. Fruit set will not occur below 55 degrees or above 90 degrees Fahrenheit. (Hartz, 2013).
Growing Tomato Plants is Easy: Most varieties produce an abundance of fruit. The best tomato is one the ripens on the vine. With a wide range of varieties to choose from, there is a tomato plant that’s just right for every home gardener. (Allen, A. (August, 2008).
2.15 VARIETIES OF TOMATOES
There are hundreds of different varieties of tomatoes to choose from. The varieties of tomatoes can be found in the following group:
Cherry Tomato: A favorite of kids of and adults. These bite-sized tomatoes are easy to grow, ripen early, and are a perfect snack right I the garden. Leave a bowl of cherry tomatoes on used in a variety of ways, including salads, vegetable trays with dip, and shish-ka-bob. After the gardening seasons is over, Cherry Tomatoes all but disappear from the marketplace. Those that remain command a high price.
Grape Tomato: Small and bite-sized, like it’s cousin the Cherry Tomato, these tasty morsels have gone from unknown to “the rage” in just a few years.
Main Crop: These are the mainstay in home gardens. Main crop varieties mature from early to mid-season, are big, round, meaty, and prolific producers.
Plum or Roma: Often called paste tomatoes, they are small and plum or cylindrical in shape. They usually have a pointed bottom. This contains far less “juice” than other varieties, and is not as sweet. Plum tomatoes are used to make paste, sauces, canning, and even ketchup. (Food & Agric, Organization, 2012).
Beefsteak: Beefsteak tomatoes are the king of the tomato crop. They grow so big, that one slice covers an entire sandwich! They also have a big, flavorful taste. Beefsteaks have the longest maturity dates. They are well worth waiting for. (Jones, August 2012).
Long Keepers: This variety is small, usually yellowish organic in color. They can be stored in a cool, dark place for several months. (Cornes 2005)
Heirloom Varieties: Varieties can be found in most of the type above. (UC Davis, 2 April, 2009).
2.15 SUNLIGHT REQUIREMENT
Tomatoes are a warm-weather crop that requires full sun, which means six o more hours of sun per day. Tomatoes benefit from exposure to as much sun as they can possibly get. This means site selection for your tomato plants is key. Before planting your tomatoes, observed the garden throughout the course of the day. As the sun moves across the sky, some areas will be in shade while others are not. Gardens surrounded by free or structures may not get enough sun exposure to properly grow tomato plants.
Growing healthy tomato plants takes plenty of sunlight. Plants need a minimum of six hours of direct sunlight. The plant converts the sunlight to energy, which it then uses to produce strong plants and abundant fruit, if you don’t have a area in your yard that gets this much sunlight each day, there are a few things you can do to enhance the light that is available (Bennett, 2011).
Tomatoes prefer direct sunlight. Ideally, tomatoes need at least six hours of direct sunlight, but will thrive with eight hours of light each day. To get this amount of light, plant your tomatoes on the south side, the west side of your home or yard is a decent second choice.