Correct Answer: A. 10,000

Correct Answer: B. motting of leaves

Correct Answer: C. preserved forms of grasses and legumes

Correct Answer: B. symptoms

Explanation

6(a) Effects of maize weevil on maize grains are: (i) destroys the endosperm, thereby, reducing the food value grains. ( (ii) reduces viability of infested grains as the embryos are damaged. (iii) reduces market value of infested grains. (iv) predisposes infested grains to other pathogenic microorganisms attack. (v) reduces the quantity of the maize grains and produce.

(b) General control measures of insect pests of grains in storage are: (i) Early harvesting of grains such as maize, guinea corn and cowpea reduces the level of infestation and damage in the field. (ii) Proper cleaning and fumigation of sores before grains are stored helps to reduce the level of infestation and damage. (iii) Storage of maize -cobs with or without the husks and guinea corn heads over fire places where they are regularly smoked has been found to be effective in controlling the insect pests (iv) Storage and fumigation of she in silos or sealed polythene bags/ containers. (v) maize cob stored in cribs and unthreshed guinea corn heads in rhumbus should be treated with insecticides such as Actellic 25 dust or liquid, (vi) Grains should be dried to reduce their moisture content to the desired level to kill the eggs and larva of pests.

(c) Insect vectors of crop diseases are: (i) groundnut rosette - aphid (ii) maize streak - Piercing and sucking insects e.g capsid or scale insects. (iii) cassava mosaic - white fly.

Correct Answer: D. guinea grass

Explanation

(a)Farm mechanisation is the application of engineering principles and technology in agricultural production, storage rnd processing on the farm. It is applicable to land preparation, planting, fertilizer application, weeding and crop harvesting, rearing, care and feeding of animals as well as processing and storage of farm produce using appropriate farm machinery.

b)(i) The advantages of farm mechanization are:

(1) It increases production of large quantity of food;

(2) The yield is maximised by using more efficient farm operators;

(3) Farm labour output per man hour is increased;

(4) Timelines of operations is enhanced;

(5) Elimination or minimization of human drudgery in form of work;

(6) increases the revenue base of farmers;

(7) Large acreage/hectarage of farms can be cultivated;

(8) accomplishes lots of work with less human labour;

(9) Certain farm operations can only be accomplished by mechanized devices;

(10) There is reduction in the cost of agricultural operations per unit output;

(11) usually improves the quality of some farm produce e.g. rice processing;

(12) It releases labour to other sectors of the economy;

(13) It saves time and quickens operations;

(14 promotes specialization in farm operations.

(ii) Disadvantages of farm mechanization are:

(1) It causes damage crops if care is not taken;

(2) It can also cause injury of fruits during harvest and the injury can serve as a source infection;

(3) The machines are costly to purchase

(4)inadequate technical know -how on the use and handling of the machines and equipment;

(5) inadequate spare or replacement parts;

(6) high cost of maintenance of machines

(7) It aids the spread of pests and diseases through contaminated machines;

(8) It does not need human labour to control it

(9) This can lead to unemployment;

(10) reliance on fuel whose supply is not always stable;

(11) It can lead to environmental pollution;

(12) leads to soil compaction and destruction of soil structure.

Correct Answer: C. deforestation

Correct Answer: B. phytoplankton and zooplankton

Correct Answer: B. rice