2015 JAMB AGRICULTURAL SCIENCE PAST QUESTIONS AND ANSWERS

Grafting is a technique where the stem or bud of one plant (the scion) is joined to the rootstock of another plant. This process allows for the combination of desirable traits such as disease resistance and higher yield. The other options are incorrect as they refer to different agricultural practices.

To calculate the number of seedlings, we first convert the area to square meters (2 hectares = 20,000 m²). Then divide the area by the space required for each seedling (2.5m x 4.0m = 10m² per seedling). This gives us 2,000 seedlings.

Quarantine is a regulatory measure that prevents the spread of pests and diseases by isolating affected plants. Roughing, crop rotation, and soil tillage help with pest control but are not direct regulatory controls.

Soil microbes thrive in soils with good texture and structure, which allow for better aeration and water retention. The other statements are true; soil pH and organic matter influence the population of soil organisms, and soil temperature affects microbial activity.

Feed conversion efficiency is determined by dividing weight gain by feed consumption. Animal P has the highest efficiency (20kg/50kg = 0.4).

Newborn piglets are prone to hypothermia and need warmth for proper suckling and survival. This prevents chilling and ensures they can nurse the mother’s colostrum.

Most biological activities such as microbial decomposition and root activity occur in the A-horizon, which is the topsoil.

Agricultural development increases food production, productivity, and often the labour force but does not necessarily increase processing unless specific infrastructure is established.

Under communal land tenure, land ownership is not individualized, making it difficult to use land as collateral for loans.

Pineapple is mainly propagated through vegetative methods, particularly using suckers or slips from the parent plant.

The proper sequence is ploughing first, followed by harrowing to break up soil clumps, and then ridging to form planting beds.

Feed utilization follows this sequence: ingestion, digestion, absorption, and assimilation. Assimilation is the final process where nutrients are used for growth and energy.

Human power has a low output compared to other sources of farm power, limiting its efficiency on large farms.

Deforestation is primarily caused by the expansion of farmland and urban growth, with population growth exacerbating the issue. Conservation efforts, however, are aimed at protecting forests.

The texture and structure of the soil are key in determining its water-holding capacity. Soils with fine particles (clay) hold more water, while coarse soils (sand) drain faster.

Yolk sac infections, coccidiosis, and pullorum are common diseases during brooding. These affect young chicks, especially in poorly managed conditions.

Bush burning destroys soil organic matter, reducing fertility. While it may kill weeds, it also damages the soil and contributes to erosion.

Government may provide subsidies, set up development programs, and establish farm settlements, but training farmer’s children is not directly related to agricultural development.

The sexual maturity of animals is influenced by breed, sex, and nutrition, but not by wearing age.

While pastures, diseases, and rainfall are major factors, light does not significantly influence the distribution of cattle.

Adequate sunshine ensures that cotton bolls mature properly, developing into large, bright, and unblemished bolls.

While agriculture helps reduce poverty, provide raw materials, and generate foreign exchange, it does not directly contribute to armament supply.

A newborn rabbit is called a bunny. Kids refer to newborn goats, while lambs refer to newborn sheep.

Crops like sugarcane, which have a fibrous root system, have numerous fine roots spread throughout the soil.

The mealybug is the primary vector of the swollen shoot disease in cocoa.

Capillary water is the water held in soil pores, which is available for absorption by plant roots.

The feed conversion ratio is calculated as the total feed consumed divided by the weight gained (60kg / 20kg = 3:1).

Micro-nutrients are essential for plant growth but are required in small quantities. They aid in processes like enzyme activation and chlorophyll production.

Nitrogen deficiency typically causes yellowing in older leaves first because it is a mobile nutrient.

Crops like Axonopus do not fix nitrogen, whereas leguminous crops like Calopogonium, pueraria, and centrosema enrich the soil with nitrates.

A magnetic compass is used to determine the direction of a baseline in surveying.

Ginger is propagated using rhizomes, which are underground stems that sprout new plants.

Staking tomatoes helps support the plant, keeps the fruit off the ground, and prevents rotting.

Crop rotation works by breaking the pest life cycle, making it difficult for pests to establish on the same crop year after year.

Sub-surface irrigation is efficient in reducing evaporation but may be limited to certain crops and specific soil conditions.

Basalt, pumice, and granite are formed from volcanic activity, with basalt and pumice being extrusive volcanic rocks.

Poaching is illegal because it threatens wildlife conservation efforts and the sustainability of species in protected areas.

The second filial generation (F2) of a monohybrid cross between heterozygous (Tt) and homozygous recessive (tt) parents results in a 1:2:1 genotypic ratio (TT:Tt:tt).

The Taungya system involves intercropping food crops with forest trees, commonly used to enhance land use efficiency.

Crossing a homozygous tall (TT) with a homozygous dwarf (tt) will result in all offspring being tall (Tt).