Maharashtra SSC Green House Grade flashcards

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

Gutter height

Vertical distance from floor to the lowest roof channel. For tomato and cucumber, 3.0 to 4.0 metres is recommended; lower heights trap heat and hinder labour.

Vapour pressure deficit

Difference between saturation and actual vapour pressure of air. Ideal greenhouse VPD is 0.5 to 1.2 kPa; above 2 kPa stomata close and blossom-end rot risk rises.

Leaching fraction

Proportion of applied nutrient solution that drains away to control salt build-up. Use 20 to 30 percent in soilless culture and 10 to 15 percent in soil.

Coir buffering

Treating coir pith with calcium nitrate solution to displace sodium and potassium before planting. Untreated coir has high salts and can damage young roots.

Blossom-end rot

Dark sunken lesion at the fruit's blossom end caused by calcium deficiency, often triggered by irregular moisture or high VPD. Maintain stable irrigation and calcium above 150 ppm.

Encarsia formosa

Parasitic wasp used for biological control of whitefly in greenhouses. Release at first sign of infestation; avoid broad-spectrum insecticides that kill the parasitoid.

Parthenocarpic cucumber

Cucumber hybrid that sets fruit without pollination, suited to polyhouse culture. Plant at 1.5 to 2 plants per square metre with vertical training.

Venturi injector

Low-cost fertigation device that draws stock solution using pressure difference. Simple but EC varies with flow; dosing pumps give more precise control.

Forced-air pre-cooling

Rapid removal of field heat by pulling cold air through stacked produce. For tomato, cool to 10 to 12 degrees Celsius within 2 to 4 hours of harvest.

Re-entry interval

Waiting period after pesticide spray before workers may enter the treated area. Typically 24 hours; follow the product label and wear protective equipment.

Agriculture Infrastructure Fund

Government credit scheme offering 3 percent interest subvention and credit guarantee for post-harvest and community farming assets, including grading and cold storage units.

Basic wind speed

Design wind speed from IS 875 Part 3 used to size greenhouse structures. Coastal Maharashtra is about 39 to 44 metres per second; inland areas lower.

Anti-drip film additive

Additive that makes condensation flow down the film instead of forming droplets. Prevents leaf wetness, disease spread and fruit spotting under the cover.

Spring wire lock

Aluminium profile and spring wire system that fixes plastic film into a channel. Provides a tight, replaceable hold along the greenhouse frame.

Fan-and-pad cooling

Evaporative cooling system where air passes through wet pads. Pad efficiency 70 to 85 percent; gives 6 to 10 degrees Celsius drop in dry summer heat.

Crop coefficient Kc

Factor multiplying reference evapotranspiration to estimate crop water use. Tomato Kc is about 0.6 at establishment, 1.15 at mid-season and 0.8 at late season.

Nutrient film technique

Hydroponic system with a shallow recirculating nutrient film in sloped channels. Use 1 to 2 percent slope and keep solution below 25 degrees Celsius to protect roots.

Fe-EDTA chelate

Stable iron fertiliser used at 2 to 5 ppm in nutrient solutions. Deficiency appears as interveinal chlorosis on young leaves; excess can antagonise manganese.

Yellow sticky trap

Coloured adhesive card used to monitor whitefly and other flying pests. Place 10 to 15 traps per 1,000 square metres and inspect weekly to guide sprays.

Bumblebee pollination

Use of bumblebee hives to pollinate tomato in greenhouses. One hive per 1,000 square metres; do not spray insecticides while bees are foraging.

Climate controller

Computer that reads sensors and operates vents, fans, screens and fertigation by setpoint. Logs data every 5 to 15 minutes for crop decisions.

Chilling injury

Physiological damage from storage below the safe temperature. Capsicum should be held at 7 to 10 degrees Celsius; colder storage causes pitting and decay.

RCCB protection

Residual current circuit breaker that trips on earth leakage. Essential in greenhouses where water, pumps and electrical fittings are close together.

MIDH polyhouse subsidy

Mission for Integrated Development of Horticulture support for protected cultivation, generally up to 50 percent of cost within notified norms. Apply through the district horticulture office.

Soil bearing capacity

Load the soil can carry without excessive settlement, in kilonewtons per square metre. Polyhouse footings need at least 100; avoid expansive black cotton soils.

Insect-proof mesh 40

Screen with 40 openings per inch that excludes whitefly and thrips. It reduces ventilation by 30 to 40 percent, so the structure needs larger vent area.

Thermal screen

Aluminised fabric drawn at sunset to cut night heat loss by 30 to 40 percent. Retract at sunrise to avoid shading the crop during the day.

Closed soilless system

Recirculating system where drainage is collected, disinfected and reused. Saves water and nutrients but needs UV or slow sand treatment against root pathogens.

Ammonium to nitrate ratio

Share of nitrogen supplied as ammonium versus nitrate. Keep ammonium at 10 to 20 percent; higher levels damage roots and raise blossom-end rot risk.

Soil solarisation

Covering moist soil with transparent film for 4 to 6 weeks in summer. Solar heat reduces soil-borne pathogens and nematodes before planting.

Grafting on resistant rootstock

Joining a susceptible tomato scion onto rootstock resistant to Fusarium or bacterial wilt. Extends cropping life in infested greenhouse soils.

Fertigation dosing pump

Metering pump that injects stock solution at a set ratio with EC and pH feedback. More precise than a venturi injector and better for soilless crops.