Punjab PSEB Senior Secondary NSQF Agriculture flashcards

31 cards. Read the term and the definition here. The deck at the top of this page is optional.

Crown root initiation stage

The wheat growth stage at about 20–25 days after sowing when crown roots first appear; it is the most critical irrigation stage, and water stress here sharply reduces tillering and final yield.

Economic threshold level

The pest population density at which control measures are justified to prevent the pest from reaching economic injury level; spraying below ETL wastes money and harms natural enemies.

Dead heart symptom

A central shoot of rice or maize that dries and can be pulled out easily, caused by stem borer larvae feeding inside the stem; it indicates borer infestation in the vegetative stage.

Urea nutrient content

Urea fertiliser contains 46% nitrogen, the highest among common solid nitrogen fertilisers; about 2.2 kg urea supplies 1 kg of nitrogen to the crop.

DAP fertiliser grade

Di-ammonium phosphate has the grade 18-46-0, meaning 18% nitrogen and 46% phosphorus as P2O5; it is applied at sowing as a basal phosphorus source.

Real value of seed

Calculated as (physical purity % × germination %) ÷ 100; it shows the proportion of a seed lot that will actually produce seedlings and is used to raise the sowing rate.

Pre-emergence herbicide

A herbicide applied to the soil surface after sowing but before weeds emerge, such as pendimethalin; it forms a chemical layer that kills germinating weed seedlings.

Selective versus non-selective herbicide

Selective herbicides kill certain weed groups without harming the crop, for example 2,4-D in wheat; non-selective herbicides such as glyphosate and paraquat kill most green plants.

Trichogramma use in biocontrol

Trichogramma are tiny egg-parasitoid wasps released in fields to destroy the eggs of stem borers and bollworms, reducing larval damage without chemical sprays.

NPV biopesticide

Nuclear Polyhedrosis Virus is a host-specific biopesticide sprayed against bollworm and other caterpillars; larvae that ingest it stop feeding and die within a few days.

Soil pH range for crops

Most field crops grow best at pH 6.0–7.5; potato and tea tolerate pH 5.0–5.5, while alkaline soils above pH 8 suit barley and cotton but lock up phosphorus and zinc.

Crop rotation principle

Growing different crops in sequence on the same field, ideally alternating cereals with legumes, to break pest and disease cycles and restore soil nitrogen through legume root nodules.

Plant population formula

Plants per hectare = 10,000 ÷ (row spacing in metres × plant spacing in metres); a spacing of 0.60 m × 0.20 m gives about 83,000 plants per hectare.

Knee-high stage of maize

The stage roughly 30–35 days after sowing when the maize plant is about knee height; it is a critical irrigation and top-dressing stage for nitrogen.

Bollworm damage symptom

Circular bore holes in cotton bolls with damaged lint and frass inside, caused by bollworm larvae entering the boll; attacked bolls rot or shed early.

Aphid infestation sign

Curled, puckered and sticky shoots with clusters of tiny green or black insects, often on mustard and wheat; honeydew on leaves leads to black sooty mould.

Sprayer calibration formula

Output in L/ha = (nozzle flow in L/min × 600) ÷ (speed in km/h × swath width in m); this sets the spray volume and the pesticide dose per hectare.

Seed treatment order

Treat seed first with a dry fungicide, then an insecticide, and finally a biofertiliser slurry; shade-dry the seed before sowing and never mix biofertiliser with chemical fungicide.

Nursery bed dimensions

Raised nursery beds are made 1 m wide, 10–15 cm high and of convenient length, with 30 cm channels between beds; seeds are sown in lines 5 cm apart.

Three-point linkage levelling

Adjust the top link and lift arms until the implement frame is level and parallel to the ground; correct levelling gives uniform ploughing depth across the field.

Drip emitter discharge

Common drip emitters deliver 2–4 litres per hour at an operating pressure of about 1.0–1.5 kg/cm²; lateral spacing depends on crop row spacing, usually 0.6–1.2 m.

Compost pit layering

Alternate 15 cm crop residues, 5 cm cattle dung slurry and a thin soil layer, keep moisture near 60%, and turn every 15–20 days; compost matures in 60–90 days.

Representative sample collection

Collect material from at least five random points in a plot, mix thoroughly, quarter down to about 500 g, and label with date, plot and variety for testing.

Pre-harvest interval

The minimum number of days, usually 7–15, that must pass between the last pesticide spray and harvest so residues on produce stay within safe limits.

Ploughing depth setting

Set the depth wheel or linkage so the plough works 15–20 cm deep and drive at 4–6 km/h; this gives uniform furrow slices and good seedbed tilth.

Biofertiliser application

Rhizobium for legumes and Azotobacter for cereals are applied as a seed slurry or soil drench; they fix atmospheric nitrogen and must not be mixed with chemical fungicides.

Field germination test

Sow 100 seeds in a tray or plot, count seedlings after the normal germination period, and calculate germination percentage; it verifies whether the seed lot is worth sowing.

Pesticide handling safety

Wear gloves, mask and goggles, never mix concentrates in an open container, avoid spraying against the wind, and wash hands and equipment after the operation.

Lateral flushing in drip

Open the ends of drip laterals and let water run for a few minutes at the start of each season to remove silt, algae and salt deposits that block emitters.

Seedbed clod breaking

After primary ploughing, use a harrow or cultivator to break clods and level the surface so that seed is placed at uniform depth and germinates evenly.

Grain moisture at storage

Cereal grain should be dried to about 12–14% moisture before storage; higher moisture causes heating, mould growth and insect attack in the godown.