Maharashtra HSC Crop Science (Bifocal B4) flashcards
Maharashtra HSC Crop Science (Bifocal B4) · Build recall with a focused review session.
33 cards. Read the term and the definition here. The deck at the top of this page is optional.
- Kharif crop
- A crop sown at the onset of the monsoon (June–July) and harvested in autumn, requiring warm, humid conditions; examples include rice, cotton, maize, and sorghum.
- C3 vs C4 plants
- C3 plants fix carbon into a three-carbon compound and lose carbon through photorespiration; C4 plants use Kranz anatomy and are more water- and heat-efficient.
- Cropping intensity
- The ratio of total cropped area to net sown area, expressed as a percentage; values above 100 indicate more than one crop grown on the same land in a year.
- Cation exchange capacity
- The total quantity of exchangeable cations a soil can hold, expressed in cmol(+)/kg; soils high in clay and organic matter generally have higher CEC.
- Soil pH correction
- Acidic soils below pH 6.5 are corrected with lime, while alkaline or sodic soils above pH 7.5 are corrected with gypsum to improve nutrient availability.
- Base saturation
- The percentage of the cation exchange capacity occupied by exchangeable bases such as calcium, magnesium, potassium, and sodium; high values indicate fertile soil.
- Essential macronutrients
- Six elements required in large amounts: nitrogen, phosphorus, potassium, calcium, magnesium, and sulphur; they support structural and metabolic plant functions.
- Liebig's law of the minimum
- Plant growth is limited by the essential nutrient present in shortest supply relative to need, even when all other nutrients are abundant.
- Nitrogen deficiency symptom
- Generalised chlorosis (yellowing) that appears first on older, lower leaves because nitrogen is mobile and is relocated to growing points.
- Fertilizer grade
- The percentage content of nitrogen, phosphorus expressed as P2O5, and potassium expressed as K2O in a fertilizer, written as three numbers such as 18-46-0.
- Green manure
- A leguminous crop such as sunnhemp or dhaincha grown and ploughed into the soil before flowering to add organic matter and nitrogen.
- Biofertilizer
- A microbial inoculant such as Rhizobium, Azotobacter, or phosphate-solubilising bacteria that enhances nutrient availability to crops without adding chemical nutrients directly.
- Seed rate
- The quantity of seed sown per unit area, calculated from seed weight, germination percentage, and the desired plant population for the crop.
- Intercropping
- Growing two or more crops simultaneously in the same field in a definite row arrangement; success is measured by a land equivalent ratio greater than one.
- Land equivalent ratio
- The ratio of land area needed in sole cropping to that needed in intercropping to produce the same yield; values above 1 indicate an intercropping advantage.
- Water use efficiency
- The crop yield produced per unit of water applied or consumed, expressed in kg per cubic metre; drip irrigation and deficit irrigation improve it.
- IW/CPE ratio
- The ratio of irrigation water depth applied to cumulative pan evaporation, used to schedule irrigation; a common value for many crops is 0.8 to 1.0.
- Drip irrigation
- A method delivering water slowly and directly to the root zone through emitters; it achieves high efficiency and reduces evaporation and weed growth.
- Economic threshold level
- The pest population density at which control measures are economically justified to prevent the pest from causing loss exceeding the cost of control.
- Integrated pest management
- A strategy combining cultural, mechanical, biological, and chemical control methods, using pesticides only when pest populations exceed the economic threshold level.
- Herbicide selectivity
- The property of a herbicide that kills target weeds without injuring the crop, achieved through differential uptake, metabolism, or placement and timing of application.
- Seed drill
- An implement that sows seed in rows at a controlled depth and rate; seed-cum-fertilizer drills also place fertilizer with the seed.
- Combine harvester
- A machine that performs reaping, threshing, and cleaning of grain in a single operation, reducing labour and harvest time in field crops.
- Tractor power conversion
- Tractor power is rated in horsepower or kilowatts; one horsepower equals approximately 0.746 kilowatts.
- Safe storage moisture
- The grain moisture content below which cereals can be stored without spoilage, generally about 12 to 14 percent; oilseeds require even lower moisture.
- Cold storage
- A facility that extends the shelf life of perishable produce by maintaining low temperature and controlled humidity, slowing respiration and microbial growth.
- Value addition
- Processing, grading, milling, or packaging of agricultural produce to increase its market price and reduce post-harvest losses.
- Benefit-cost ratio
- Gross returns divided by total cost of production; a ratio greater than one indicates that the enterprise is profitable.
- Gross margin
- Gross income from a farm enterprise minus variable costs such as seed, fertilizer, and labour; it measures returns before fixed costs are deducted.
- Break-even point
- The level of output or price at which total revenue equals total cost, so the enterprise makes neither profit nor loss.
- Soil sampling procedure
- Collect soil from several points across a field, mix thoroughly, quarter to obtain a representative sample, and send it to the laboratory for analysis.
- Germination percentage
- The number of normal seedlings produced from a seed lot, expressed as a percentage of the total seeds tested under standard conditions.
- Fertilizer dose calculation
- Divide the nutrient required in kg per hectare by the nutrient percentage in the fertilizer and multiply by 100 to obtain the fertilizer quantity needed.