UPMSP Class 12 Vocational Crop Science flashcards

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

Kharif season

Monsoon season cropping period, sown June–July and harvested September–October; crops include rice, maize, cotton, groundnut and moong, which need warm humid weather.

C4 crops

Plants such as maize, sorghum and sugarcane that fix carbon into a four-carbon compound first; they have higher photosynthetic efficiency, low photorespiration and better drought tolerance than C3 crops.

Cropping intensity

Ratio of gross cropped area to net sown area expressed as a percentage; it shows how many times the same land is cropped in a year.

Bulk density

Mass of oven-dry soil divided by its total volume, expressed in grams per cubic centimetre; high bulk density indicates compaction and poor porosity for root growth.

Field capacity

Water content remaining in soil after excess water has drained by gravity, held at about one-third bar suction; it is the upper limit of plant-available water.

Cation exchange capacity

Total negative charge of a soil expressed in centimoles of positive charge per kilogram; it indicates the soil's ability to hold and supply nutrient cations.

Liebig's law of the minimum

Rule stating that crop yield is limited by the essential nutrient in shortest supply; adding other nutrients beyond that point does not raise yield.

Rhizobium inoculation

Treatment of legume seed with nitrogen-fixing bacteria that form root nodules; it increases biological nitrogen fixation and reduces the fertiliser nitrogen requirement of pulses.

Fertiliser grade

Expression of a fertiliser's nutrient content as percentage nitrogen, phosphorus as P2O5, and potassium as K2O, written in that fixed order.

Seed germination percentage

Number of normal seedlings produced divided by total seeds sown, multiplied by 100, measured under standard test conditions; it is a basic label value.

Seed vigour

Potential of a seed lot for rapid and uniform seedling emergence under field stress; tested by accelerated ageing or electrical conductivity and distinct from germination percentage.

Seed certification classes

Sequence of seed generations from breeder seed through foundation and registered to certified seed; certified seed is the class normally sold to farmers with a certification tag.

Genetic purity

Proportion of plants in a seed lot that belong to the true variety; maintained by isolation distance, roguing and careful seed handling during production.

Roguing

Removal of off-type, diseased and volunteer plants from a seed production field; done at vegetative, flowering and maturity stages to protect genetic purity.

Tetrazolium test

Rapid seed viability test in which living tissue reduces a colourless tetrazolium salt to a red compound; it estimates viability without waiting for full germination.

Crown root initiation

Wheat growth stage about 20–25 days after sowing when the first crown roots form; irrigation at this stage is most critical for wheat yield.

Plant population formula

Number of plants per hectare equals 10,000 divided by the product of row spacing and plant spacing in metres; it converts crop geometry into plant density.

Detasselling

Removal of tassels from female parent rows in hybrid maize seed production before pollen shed; it prevents self-pollination and ensures hybrid seed.

Sugarcane sett

Piece of sugarcane stem with two or three buds used as planting material; setts are planted in furrows and buds sprout to form new stalks.

Retting of jute

Soaking harvested jute stems in water so that micro-organisms break down pectin and free the fibre from the woody core; over-retting weakens the fibre.

Duty of water

Area of land in hectares irrigated by one cubic metre per second of canal discharge over the crop season; it links canal flow with irrigated area.

Drip irrigation

Method that delivers water slowly through emitters directly to the root zone; it saves water, reduces weed growth and allows fertigation in horticultural crops.

Dryland agriculture

Crop production entirely dependent on rainfall without irrigation; moisture conservation practices and drought-tolerant short-duration crops are used to stabilise yields.

Critical weed competition period

Early crop growth interval, generally the first 30–45 days after sowing, during which weed competition reduces yield most; weeding in this period is essential.

Economic threshold level

Pest population density at which control measures should be applied to prevent the pest from reaching economic injury level; it guides need-based insecticide use.

Disease triangle

Concept that disease develops only when a susceptible host, a virulent pathogen and a favourable environment occur together; removing any one factor prevents the disease.

Root-knot nematode

Meloidogyne species that invade roots and cause galls, stunting and yield loss; managed by rotation with non-hosts, organic amendments and nematicides.

Seed-cum-fertiliser drill

Implement that places seed and fertiliser simultaneously in rows at controlled depth and spacing; it saves an operation and improves fertiliser placement near the seed.

Safe grain moisture

Moisture level, about 10–12 percent for cereals, at which grain can be stored without heating, mould growth or rapid insect damage.

Benefit–cost ratio

Gross returns divided by total cost of an enterprise; a value above one indicates profit and allows comparison between alternative crops or technologies.

Minimum support price

Government-announced floor price at which produce is purchased to protect farmers from a market price crash; it is fixed for major crops before the season.

Project record

Written account of practical work containing title, objective, materials, procedure, tabulated observations, calculations, results and conclusion, supported by dated field diary entries.