WAEC Agriculture 2019
Questions & Answers

A student might mistakenly select ploughing, which actually inverts the soil layers rather than just loosening the surface. Harrowing involves using a harrow to break up clods and loosen the soil surface after ploughing without turning it over, preparing a fine seedbed while preserving soil structure and minimizing erosion. Common mistake: Confusing the soil-inverting action of ploughing with the surface-loosening action of harrowing.

A reader might choose seed sowing or cutting, overlooking the specific horticultural challenges of growing true-to-type fruit trees. Mangoes are commonly propagated by grafting techniques such as cleft or veneer grafting to ensure true-to-type plants with desirable traits like disease resistance and fruit quality, since seed propagation leads to high variability. Common mistake: Assuming fruit trees grow true to type reliably from standard seed sowing.

1) Distractor check: A student might incorrectly choose options like 10-12 cm or 15-20 cm, assuming deeper burial provides better anchoring or moisture. 2) Reasoning to the answer: Because these seeds are naturally small-sized, placing them at a shallow level of 2-4 cm allows for rapid sprouting and breaking through the surface. Burying them deeper fails because limited seedling vigor prevents successful establishment. Common mistake: Confusing deep planting requirements of large seeds with small seeds.

1) Distractor check: A student might select Nitrogen, thinking of overall lush vegetative growth, or Potassium, which is also a major macronutrient. 2) Reasoning to the answer: Phosphorus is fundamentally involved in energy transfer pathways utilizing ATP and supports root development. These biological processes are vital for reproductive development, which directly drives flower bud formation and successful pollination. Common mistake: Forgetting that flower and fruit stages demand high phosphorus rather than just vegetative nitrogen.

1) Distractor check: A student might mistakenly pick Hydroponics, confusing the idea of a controlled indoor setup with growing plants in nutrient solutions without soil. 2) Reasoning to the answer: Greenhouse farming utilizes enclosed structures to gain precise environmental regulation over variables like temperature, relative humidity, and artificial lighting supplementation, thereby achieving year-round production success and maximizing crop yields. Common mistake: Confusing soilless culture with enclosed structure farming.

1) Distractor check: A student might select Mosaic, thinking it is a common plant affliction, or Leaf blight. 2) Reasoning to the answer: Maize smut originates from the pathogenic fungus Ustilago maydis, which specifically attacks corn ears and tassels to create tumor-like galls filled with spores. Producers typically manage this fungal infection through crop rotation and resistant varieties. Common mistake: Mixing up viral symptoms like mosaic with fungal galls like smut.

1) Distractor check: A student might choose Organic matter, thinking all natural nutrients come straight from composted plant or animal waste. 2) Reasoning to the answer: Rock phosphate serves as the foundational geological parent material that undergoes slow weathering to release phosphorus ions. This creates the inorganic pool from which plants acquire this crucial nutrient. Common mistake: Assuming organic matter is the primary geological reservoir for phosphorus.

1) Distractor check: A student might pick Chicken or Goat, overlooking the primary commercial scale of heavy meat production. 2) Reasoning to the answer: Cattle are primarily bred for beef production within extensive systems. They efficiently convert bulky forage into high-value protein meat, which sustains global supply chains. Common mistake: Equating all livestock production systems solely with poultry or small ruminants.

1) Distractor check: A student might choose Irrigation, mixing up the introduction of water with its removal. 2) Reasoning to the answer: Surplus water is cleared out using drainage systems such as open ditches or tile drains. Eliminating this excess prevents waterlogging, which otherwise causes root suffocation, severe nutrient loss, and decreased crop yields. Common mistake: Confusing drainage with irrigation.

1) Distractor check: A student might pick Drying or Freezing, since both are popular methods of food preservation. 2) Reasoning to the answer: Canning relies on applying heat to fruits inside sealed jars to eradicate enzymes and microorganisms. This procedure forms a secure vacuum seal that preserves shelf life for months without needing refrigeration. Common mistake: Assuming freezing is the only heat-free preservation method.

1) Distractor check: A student might mistakenly choose Inbreeding or Line breeding, confusing mating strategies. 2) Reasoning to the answer: Crossbreeding merges distinct genetic backgrounds from separate breeds to yield hybrids exhibiting hybrid vigor, also known as heterosis. This strategy enhances traits like disease resistance, growth rate, and overall environmental adaptability. Common mistake: Confusing the introduction of new genetic traits via crossbreeding with preserving traits via inbreeding.

1) Distractor check: A student might select Magnesium or Sulphur, which are macronutrients or secondary nutrients required in larger quantities. 2) Reasoning to the answer: Boron functions as a vital micronutrient responsible for cell wall construction, sugar transport, and pollen tube growth. Although required in tiny amounts, its absence leads to brittle tissues and poor seed set. Common mistake: Mistaking trace micronutrient requirements for macronutrient needs.

1) Distractor check: A student might choose Apiculture or Sericulture, mixing up animal rearing terms. 2) Reasoning to the answer: Cuniculture is the specific term for breeding and managing rabbits, scientifically known as Oryctolagus cuniculus, inside hutches or colonies. They are kept for their pelts used in the fur industry and their lean meat, which is low in cholesterol. Common mistake: Confusing cuniculture (rabbits) with sericulture (silkworms) or apiculture (bees).

1) Distractor check: A student might pick Wilting leaves or Stunted growth, which are general symptoms common to many nutrient deficiencies. 2) Reasoning to the answer: Although chlorine deficiency is rare in most soils, it causes distinct bronzing or yellowing along leaf margins, particularly on younger leaves. This occurs because chlorine plays an integral role in osmosis and stomatal regulation. Common mistake: Attributing leaf bronzing solely to disease rather than specific micronutrient shortages.

1) Distractor check: A student might choose Plowing or Burning, thinking physical manipulation fixes waterlogged land. 2) Reasoning to the answer: Swampy lands are reclaimed most effectively by draining them using channels or pumps. This action lowers the water table, aerates the soil, and permits the cultivation of crops like rice or vegetables, often followed by liming to adjust acidity. Common mistake: Trying to fix swampy soils with tillage instead of lowering the water table.

1) Distractor check: A student might select Pueraria or Centrosema, which are common pasture components. 2) Reasoning to the answer: Andropogon, such as guinea grass, is a tropical C4 grass utilized in pastures for its remarkable drought tolerance and high biomass yield. Unlike the other listed options, it does not fix nitrogen. Common mistake: Confusing leguminous cover crops with non-leguminous pasture grasses.

1) Distractor check: A student might select Rickets or Scurvy, which are linked to vitamin D and vitamin C deficiencies, respectively. 2) Reasoning to the answer: A lack of vitamin E causes oxidative damage within muscle tissues, resulting in white muscle disease, also called nutritional muscular dystrophy. This condition frequently affects young ruminants like calves and lambs. Common mistake: Confusing mineral-related bone disorders like rickets with vitamin E muscle degeneration.

1) Distractor check: A student might pick Reduces labor or Improves soil fertility, incorrectly assuming large-scale single-crop farming benefits the ecosystem. 2) Reasoning to the answer: Monoculture creates an environment that fosters pest and disease proliferation by continuously supplying the same host. This reliance requires heavy pesticide applications and increases resistance risks, unlike diversified crop systems. Common mistake: Assuming uniform crop fields simplify long-term pest management.

1) Distractor check: A student might select Intensive system or Zero grazing, mixing up free-range practices with confined management. 2) Reasoning to the answer: Extensive systems depend on utilizing natural pastures across vast geographical spaces with minimal human inputs. While suitable for low-density farming regions, they risk severe overgrazing if rotational management is ignored. Common mistake: Confusing extensive range grazing with intensive or zero-grazing confinement.

1) Distractor check: A student might pick Aphid or Mealybug, which are also common sap-sucking orchard pests. 2) Reasoning to the answer: Citrus fruit flies, such as Bactrocera species, deposit their eggs directly inside developing fruits. The resulting larval feeding triggers premature fruit drop and rot, which growers manage using sanitation and traps. Common mistake: Confusing foliage-feeding sap pests with internal fruit-boring flies.