Solanum tuberosum is a low- growing, branching perennial plant with weak stems. It is an herbaceous annual plant that grows up to 1metre produces a tuber which is commonly known as potato. Potatoes contains high carbohydrates and many different proteins, minerals especially calcium and potassium and vitamins particularly vitamin C. Potatoes are ranked fourth after maize, wheat and rice in terms of both area cultivated and total production. It is one of the world’s most important non cereals crops.
It is a dicot plant which belongs to the Solanaceace family and the genus Solanum with at least 2000 species, including tomatoes and tobacco. In Zimbabwe tradionally potatoes was grown by commercial farmers, but currently smallholder famers are growing the crop now. Communal areas of Nyanga, Mutasa, Domboshawa, Mhondoro and Goromonzi. Varieties which are mostly grown in Zimbabwe include BPI, Amethyst, Monte Claire, Opal, Jacaranda and Emerald. Some varieties such as Garnet and Amethyst can be grown 3 times as summer crop, first winter and second winter crop.
2.2 Early blight disease
2.2.1 Causal agents
Early blight is one of the most devastating diseases of potatoes; it is caused by fungus Alternalia solani. Alternalia species have dark coloured mycelium, and in older diseased tissues they produce short, simple erect conidiophores that bear single or branched chains of conidia. Conidia are large, dark, long or pear shaped and multi cellular, with both transverse and longitudinal cross walls (Agrios, 20005). Conidia are easily detached and are carried by air currents. Most of Alternalia spores are saprophytic, therefore they cannot attack infect living plant tissues but grow only on dead and decaying plant tissues and at most on old ti...
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...soaked circular lesions within a few weeks of infection (Wharton et al., 2007). The circular lesion may coalesce, forming large scabby areas. Scab is most severe when tubers develop under warm, dry soil condition with a soil ph above 5.2.
2.4.3 Disease cycle
It is a soil inhabitant pathogen and it spreads through soil water, by windblown soil, and an infected potato seed tubers. Streptomyces Scabies can live on decomposing material in the soil and does not require a potato or root crop to remain alive. It penetrates tissue through lenticels, wounds and stomata and in young tubers directly. Pathogen feeds on cells saprophytically and it also secretes compound that promotes rapid cell division in the living cells surrounding the lesion. Rapid cell division causes the tuber to produces several layers of cork cells that isolate the bacterium and surrounding tuber cells.
Student ID: 23137443 The Human Desire of Control Michael Pollan uses the potato to address the idea of control, in particular, whether we have control over nature or it has control over us. Potatoes were first found in South America growing in the Andes. The ancestors of the Incas lived in that area and were the first known humans to cultivate these potatoes for human consumption (Pollan 131). When settlers came to the New World, they marveled at these new crops that grew from spuds and shipped them back to Europe.
In the 1880's a harmful fungus known as blight, inhabited the United States from imported Japanese chestnut trees. Blight quickly spread, killing chestnuts and chinquapins, which is another species of chestnut that produces 1 nut per bur. In 1904, Chestnut blight appeared infecting trees in New York City and spread at a rate of 20-50 miles per year. By 1906, W.A. Murrill reported that this disease is known to occur in New Jersey, Maryland, District of Columbia, and Virginia. In 1912, the Planet Quarantine Act was passed to reduce the chances of plant deterioration or devastation prevention. Chestnut Blight or Chestnut Bark Disease was originally found in 1904 and within 50 years, it spread across the eastern United States, from Maine to Georgia and as far west as the edge of Michigan. By 1950, the American chestnut was essentially eliminated as a forest tree. In 1972, importation from Italy gave a biological control in which a virus helped prevent the blight f...
may last one to three weeks. In many cases new clusters of blisters appear as
Phythophthora infestans was the lethal fungus that infested Ireland's potato crop and eventually ruined all of the land it grew on. This time is called the Great Famine and has impacted Ireland due to its destructive extinction of the potato farms which caused disease, extreme poverty, and death.
The beginning of this chapter focuses on the J.R. Simplot Plant which is located in Arberdeen, Idaho and processes around a million pounds of potatoes per day (Schlosser 111). John Richard Simplot was born in 1909 and spent much of his childhood working on his family’s farm. Simplot went against his father and dropped out of high school at the early age of fifteen and began working at a potato warehouse in Declo, Idaho. When J.R. turned sixteen, he became a potato farmer (Schlosser 112). It only took about ten short years for J.R. Simplot to become the largest shipper of potatoes in the West. World War II brought a lot of wealth to Simplot. He sold dehydrated onions to the U.S. Army and he eventually became one of the main suppliers of food to the U.S. American military during World War II (Schlosser 113). By the time Simplot was 36 years old, he was able to grow, fertilize, proces...
Life History and Characteristics: Staphylococcus aureus is a gram positive bacterium that is usually found in the nasal passages and on the skin of 15 to 40% of healthy humans, but can also survive in a wide variety of locations in the body. This bacterium is spread from person to person or to fomite by direct contact. Colonies of S. aureus appear in pairs, chains, or clusters. S. aureus is not an organism that is contained to one region of the world and is a universal health concern, specifically in the food handling industries.
There were many arbitrary causes of the Irish potato famine, one of which was a fungus, Phytophthora infestans, which was accidentally transferred to Ireland from Mexico. Since the fungus was airborne it was virtually impossible to stop, and it wiped out almost all of Irelands potato crop in just a few years. Specifically, this fungus c...
Size of potato-will be the same as it will be cut using a cork and borer which cuts them all to the same diameter.
Schumann, Gail L., and Cleora J. D'Arcy. Hungry Planet: Stories of Plant Diseases. St. Paul: American Phytopathological Society, 2012. Print.
In conclusion, Potatoes were first grown in South America and in Mexico by the Inca people and the potato was introduced to Ireland from South America in 1565. The Irish Potato Famine of the 1800s was caused by Phytophthora infestans. Many Irish people depended greatly on the potatoes for a source of food in the winter and early spring months; potatoes were a staple in the diet of the Irish People. About 1.5 million people immigrated to the United States and another million died of disease or starvation.
The blight caused a catastrophic effect on the Irish peasantry. The blight is a combination of parasitic fungus and bird droppings imported as fertilizer (Kelley 136). Furthermore, the farmers did not know what a problem this fertilizer would cause, which ended up ruining all of the Irish crops. The parasitic fungus, also known as phytophthora, is a destructive spreading fungus causing a brownish rot in plants. In addition, the blight first infected Irish potato crops in September of 1845 (Kelley 136). The blight caused the potato to rot in the ground, making it inedible (Kinealy, The Great Irish Famine 34). In addition, spreading the fertilizer all over the land not only ruined the crop, but the crop field as well. Consequently, the crop fields were in no condition to produce new crops for many years because the land was ruined. There were “recurrent infestations of the blight, which led to the failure of the potato crop in three seasons out of four” (Kelley 136). The blight traveled to Ireland from North America and Cont...
Potatoes have become a staple to the diet of humans.They have become so popular since they come in a variety of shapes, sizes, and tastes. They are also cheap and easy to grow, and they taste delicious! Potatoes have changed the course of history in several ways. Who knew that potatoes, just a starchy vegetable, could have helped shape the world in so many ways. First, the Irish Potato Famine killed a million people and caused another million to move out of Ireland. Second, soldiers in the United States army were able to eat potatoes throughout the war. Third, they prevented a famine from occurring in England after there was not a sufficient amount of crops going to sustain the country's cries for food. Many people wonder if potatoes have
Domesticated potatoes were once all belong to one botanical species, Solanum tuberosum; it included thousands of varieties that had diversity in size, shape, color and other characteristics. The potato was first domesticated in the South America Andes, then the Puritans who took Mayflower arrived the land and the First Nations taught them about potatoes. Then the sailors went back to Europe and people started to plant potatoes in Spain, England, France, and many other countries in Europe. Later, potatoes were spread into Africa by the colonists. The crop was once believe to be poisonous by the local farmers who refused to plant them. However, the colonists persuaded the farmers and introduced potatoes as a low-price and high-production crop in substitute of wheat and rice.
The great famine of Ireland began around the year of 1845, when a deadly fungus reached the crops, leaving thousands of acres of land filled with black rot, and diseased crops (Szabo). This disease has become commonly known as the blight. The blight was a “mysterious disease” that “almost universally affected the potatoes on the island” (Kinealy 31). This suspicious “blight” had traveled to Europe from North America, affecting mostly Ireland (Bloy). The blight turned the potatoes black, making them deadly for people to eat. Problems with agriculture came to an all-time high during the famine (Foster 201), and the crop most affected by this blight was the potatoes. The cause of the potato disease was suspected to be due to many factors such as: frost, winds, moon, manure, or thunderstorms; however, the trouble was actually due to an unknown fungus (phytophthora infestans) which caused mould on the potatoes (Kee 78). The Irish had experienced blights before this, but did not cause famine; this was the first case of phytopthora infestans (Poirteir 9). The blight was a major cause of the great famine, however; many other factors attributed to the tragedy that would forever change the great country of Ireland. The geography and history of Ireland had left many of the people dependent for survival on cultivation, specifically reliant on one main crop (Kee 78). This was the potato. When the crop had been introduced to the country, the Irish loved it for numerous reasons. Their land was perfect for growing potatoes; the potatoes flourished in the rich, Irish soil. In addition, they were easy to prepare and cook, very nutritious, and extremely abundant. This caused the potato to be the “staple food” f...
Sweet potatoes are a vegetable in the Convolvulaceae family, signifying that it is a vine, funnel shaped flower, and bisexual plant. Its botanical name is Ipomoea batatas. Sweet potatoes are also assimilated with “yams” in the United States; this is because of its orange-flesh. (Encyclopedia Britannica, 2013)