Agricultural and Biosystems Engineers Licensure Examination (ABELE) · Philippines · Professional Regulatory Board of Agricultural and Biosystems Engineering, PRC
Original practice questions written to the published syllabus · not past papersEnough agronomy to design for the crop: sowing geometry for planters, application rates for sprayers, moisture at harvest.
In the exams: Allied agricultural sciences in PRC ABE; core in the ICAR 6th Deans' Committee B.Tech
PRC Agricultural and Biosystems Engineers Licensure Examination (Philippines)
Allied agricultural sciences: crop classification, seasons and growth stages; seed rate, plant population and planter or drill calibration; fertiliser computations from N-P₂O₅-K₂O grades including complex fertilisers; sprayer calibration (L/ha from nozzle flow, speed and spacing) and pesticide dose; harvest index; wet- and dry-basis moisture and drying shrink. Expect short calculations with unit traps.
How our questions for Agricultural and Biosystems Engineers Licensure Examination spread across the units of Crop Production & Protection for Engineers. Difficulty: 35 easy, 63 medium, 24 hard.
| Crop classification and seasons | 20 | |
| Seed rate and sowing geometry | 18 | |
| Fertilisers and manures | 18 | |
| Pest and disease management and application rates | 18 | |
| Cropping systems | 14 | |
| Harvest index and harvest moisture | 13 | |
| Weed management | 12 | |
| Farming-based livelihood systems | 9 |
Choose an answer, then open the working. Each explanation says why the right answer is right and why the others are not.
Why do C4 crops such as maize generally out-yield C3 crops under hot, bright conditions?
D. They concentrate CO₂ around Rubisco in bundle-sheath cells, which suppresses photorespiration
The C4 pathway pumps CO₂ into the bundle sheath, so Rubisco works near CO₂ saturation and photorespiration is suppressed. Night stomatal opening describes CAM plants such as pineapple, not maize. Nodule nitrogen fixation is a legume trait. Rubisco's affinity for oxygen is what causes photorespiration; a higher oxygen affinity would lower, not raise, carbon fixation.
Further reading: Gardner et al., Physiology of Crop Plants
On the Zadoks decimal scale for cereals, the principal stage numbered in the 60s describes:
D. Anthesis
Zadoks principal stages: 2x tillering, 3x stem elongation, 4x booting, 5x ear emergence, 6x anthesis (flowering), 7x milk, 8x dough, 9x ripening.
Further reading: Zadoks, Chang and Konzak (1974)
Which sowing method raises seedlings in a nursery and then moves them to the main field?
B. Transplanting
Transplanting uses nursery-raised seedlings, as for most Asian rice and many vegetables. Dibbling places seeds in holes; drilling meters seed into rows; broadcasting scatters seed over the surface.
Further reading: Reddy, Principles of Agronomy
Why are maize and other row crops usually planted in rectangular geometry (wide rows, close in-row spacing) instead of square geometry with the same plant population?
D. Wide rows leave room for tractor wheels and inter-row cultivators and match the planter toolbar
Rectangular geometry is a compromise for machinery: tractor tracks, cultivators and row headers need wide inter-rows. Square geometry actually gives each plant the most equal area and light; any population can be laid out square; and intra-row competition does not raise harvest index.
Further reading: Reddy, Principles of Agronomy
Which biofertiliser is specific to legumes and fixes nitrogen in root nodules?
A. Rhizobium
Rhizobium forms nodules on legume roots and is host-specific, so the right strain must be matched to the crop. Azotobacter is free-living and Azospirillum associative, both used for cereals; phosphate-solubilising bacteria release P, they do not fix N.
Further reading: Reddy, Principles of Agronomy
A herbicide applied after sowing but before the crop and weeds emerge is described as:
C. Pre-emergence
Pre-emergence herbicides are applied to the soil surface after sowing and before emergence. Post-emergence products go on emerged weeds; pre-plant incorporated products are mixed into soil before sowing; a directed spray is a post-emergence spray aimed below the crop canopy.
Further reading: Zimdahl, Fundamentals of Weed Science
A knapsack sprayer operator walks at 3.6 km/h spraying a 1.0 m swath and the nozzle delivers 0.6 L/min. What volume is applied per hectare?
D. 100 L/ha
Rate = 600 × 0.6 ÷ (3.6 × 1.0) = 100 L/ha. 10 L/ha is a factor-of-ten slip; 216 multiplies flow by speed instead of dividing (0.6 × 3.6 × 100); 167 puts the 1.0 m swath in place of the 0.6 L/min flow (600 × 1.0 ÷ 3.6).
Further reading: Matthews, Pesticide Application Methods
Which crop is geocarpic, developing its pods below the soil surface, so that harvesting requires a digger rather than a combine header alone?
C. Groundnut
Groundnut pegs push the developing ovary into the soil where the pods form; diggers or digger-shakers lift the plants. Soybean, chickpea and black gram bear pods above ground.
Further reading: Reddy, Principles of Agronomy
A loam field is ploughed when its moisture is well above the plastic limit. What is the most likely result?
D. Smearing and compaction that leave hard clods and a sealed furrow sole
Wet soil deforms plastically: it smears, compacts and dries into hard clods, and the plough sole is sealed. Friable tilth forms near the lower plastic limit; draft may be low but structure is damaged; crusting follows rain on fine dry seedbeds rather than wet ploughing.
Further reading: Reddy, Principles of Agronomy
Which crop is a pulse (grain legume)?
C. Pigeonpea
Pigeonpea is a grain legume. Pearl millet is a cereal; sesame and safflower are oilseeds.
Further reading: Reddy, Principles of Agronomy
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