PCP 201 History of agriculture Is breaking down into four ages: 1)Paleolithic or stone age: Age:-It is the earliest and longest period of human history. Early man spent about one million years Farming:- does not exist Source of livelihoods:- hunting and gathering Tools used:- hard stones and rough implements 2)Mesolithic or middle stone age Age: Between 12,000 and 6,00 BC Farming : Exist but primitives farming. Gradual shifting from food gathering to food production Tool: Spear, bow and fishing net

3) Neolithic new stone age Age: about 6,000 BC Farming: By trial and error, early man identified those plants of greater value to him and saved for subsequent planting Tool: Polished stone 4) Bronze age Age: 3000 BC Farming: Development of crop production Tool: Appearance of plough, replacement of the man-drawn (i.e. hoes. even though our traditional farmers still use hoes). By ox-drawn

DEVELOPMENT OF MODERN AGRICULTURE Modern agriculture started in England in 18 th century. Precisely in 1701, Jethro Tull inverted grain drill horse- Hoeing Van Helmon investigated on the phenomenon of soil fertility and plant growth. He concluded water is the sole nutrient for plant 1699 – John Woodward experimented with several water with varying degree of impurities. He reported that the growth rate was directly related to increase quantity of Impurity. He concluded that that plant are not made up of water alone but some other terrestrial material.

1775- Joseph Priestly reported that the respiration of plant and animal has reverse effects on the atmospheric air. (i.e. animal breath out CO 2 while plant release O 2 during respiration). He concluded that plant keeps atmosphere wholesome and pure Jan Ingen - Housz ‘ contribution to knowledge is that plant purify in light or during day While pollution take place in night or darkness Theodure d’ Saussure gave an explicit explanation of plant respiration. Absorption of O 2 and releasing of CO 2 take place during the day or light whereas absorption of O 2 and releasing of CO 2 occur in the night or darkness. He also established the essentiality of nutrient elements

1840- Liebiy established the law of minimum. This law stated that if one crop nutrient is missing or deficient, plant growth will be poor, even if the other elements are abundant. This law is still valid today. Relationship between Agriculture and other Sciences Engineering greatly facilitated the development of farm tools, implements, farm powers etc. which reduces physical exertion and drudgery in agriculture and encourage large scale farming Chemistry- understanding of plant nutrient requirement and the production of fertilizer. Botany and physiology- knowledge of forms and functions in crop production Biochemistry and toxicology – chemical control of weeds thus modern day agriculture is an embodiment of all aspect of sciences and technology

Center of origin of cultivated crops Center of origin is the region of the world where a crop is believed to have originated. Center of diversity:- is the region of the world where the greatest variability in crop species is believed to have occurred. It can also be referred to as center of origin. Primary center:- where the crop is believed to have been first cultivated or domesticated. Secondary center:- These are area of diversity to which plant have migrated from a primary centers

Countries or regions of crops origin 1. Southwest Asia:- Barley, carrot, date palm, grapes, melon & wheat. 2. Mediterranean :- alfalafa, cabbage, clover, hops, lettuce & Olive. 3. Ethiopia :- barley, castor, coffee (arabica), finger millet, walnut, okra & sorghum. 4. Central Asia :- apples, foxtail millet & hem. 5. South East Asia :- bamboo, banana, chinese yam, citrus, Coconut & sugar cane.

6. Indo-Burmese :-cocoyam, cotton, garden egg, jute, mango, pigeon pea & rice. 7. Chinese :- onions orange, small bamboo & soybean. 8. West central Africa :- banboo, ground nut, coffee (robusta), kola., cowpea, sorghum, oil palm, red rice & yam. 9. Central America and Mexico :- Guava, kidney bean, maize, red pepper, sisal & cotton. 10. Ecuador and Peru :- Avocado pear, potato, paw-paw, cotton, sweet potato tobacco & tomato

11. Brazil and Paraguay :- cashew, cassava, cocoa, Ground nut, pine apple & rubber. Important of origin of crops Breeders used it to identify diverse forms of the species with useful traits or characters for crop improvement. Used by crop protectionist in designing biological control e.g. cassava meal bug