Planning polyhouse farming in Gopalganj? Gopalganj is a town in Gopalganj district, Bihar, home to about 67,000 people (GeoNames)[1][2], about 590 km from Kolkata. Below we use the town's monthly temperatures, humidity and rainfall to work out which structure fits, which crops to grow and in which months, before you spend on construction.
Climate for polyhouse farming in Gopalganj
May is the hottest month in Gopalganj, with average daily highs of about 41°C. January has the coolest nights, averaging 8°C.[3] The area gets about 1,112 mm of rain a year, most of it in June to September, peaking in July at about 321 mm. Average humidity stays at 75% or more in July to September, which raises the risk of leaf disease and slows evaporative cooling. Gopalganj sits about 66 m above sea level.[2] On the Köppen–Geiger climate map, Gopalganj falls in the humid subtropical with dry winters zone (Cwa).[4]
Gopalganj climate by month
Month
Avg high (°C)
Avg low (°C)
Humidity (%)
Rain (mm)
Jan
22.6
7.8
52
11
Feb
27.5
11.5
44
16
Mar
34.2
17.0
32
13
Apr
39.8
23.3
27
20
May
41.0
27.1
35
64
Jun
39.3
28.8
51
176
Jul
33.8
26.8
77
321
Aug
32.4
26.0
83
251
Sep
31.3
24.5
84
189
Oct
30.5
20.1
73
47
Nov
27.1
14.2
63
1
Dec
23.1
9.3
57
3
Area averages (a grid cell of about 50 km) for 2001–2025, from NASA POWER, centred on Gopalganj. Rainfall and night temperatures at your plot can differ, especially near hills and the coast.[3]
Advantages of protected cultivation in Gopalganj
1
Year-round crops
A polyhouse stretches the season: in Gopalganj cucumber can be grown for about 9 months a year under cover, longer than in the open field.
2
Better yield and price
Plants grow without rain, hail and wind damage, so yields are higher and more even, and clean, graded produce sells at a better price, especially off-season.
3
Less water
Drip irrigation under cover uses less water than flood irrigation, and the roof keeps July's 321 mm of rain off the crop and the soil.
4
Less pesticides
Insect net on vents and doors keeps out most pests, and controlled ventilation helps with leaf disease in the humid months (July to September), so you spray less often.
5
Subsidy eligible
Polyhouse, shade net and nethouse projects in Bihar can apply for Mission for Integrated Development of Horticulture (MIDH) assistance through the state horticulture department.[5]
Which polyhouse suits Gopalganj?
For polyhouse farming in Gopalganj, the structure decides which months you can crop and what it costs to run. The heat in Gopalganj comes with dry air. In April to June, average highs reach 41°C while average humidity is only about 38%. In that dry air, wet pads can bring a 41°C May afternoon down to roughly 31°C inside a Fan & Pad polyhouse, which keeps herbs and vine crops going; lettuce will still struggle in the hottest weeks. For vine crops such as capsicum and cucumber, a naturally ventilated polyhouse with a shade screen works from February and October to November and costs less to run.
Plan for heavy rain in July (about 321 mm): raise the plinth, size the gutters for that month and keep drains away from the nutrient tank. Sunlight peaks in April at about 6.4 kWh per m² a day, so add a shade screen for leafy greens in the brightest months. A nethouse, the lowest-cost option, can grow hardy crops in February and October to November, when it is mild and fairly dry.
Crops for Gopalganj
Based on Gopalganj's climate, the crops with the longest growing windows are cucumber (9 months), chilli pepper (9 months) and brinjal (8 months). Cucumber fits March to November with Fan & Pad cooling. These are the crops we would plan first for polyhouse farming in Gopalganj.
Months each crop suits in Gopalganj
Crop
Naturally ventilated polyhouse
With Fan & Pad cooling
Capsicum
Feb and Oct–Nov
Feb–Apr and Aug–Nov
Tomato
Feb and Oct–Nov
Feb–Apr and Sep–Nov
Cucumber
Jul–Nov
Mar–Nov
Chilli pepper
Feb and Aug–Nov
Feb–May and Jul–Nov
Brinjal
Aug–Nov
Mar–May and Jul–Nov
Lettuce
Nov–Feb
Oct–Apr
Broccoli
Dec–Jan
Nov–Mar
Strawberry
Dec–Jan
Nov–Feb
Rose
Feb and Nov
Feb–Mar and Oct–Nov
Gerbera
Feb and Nov
Feb–Apr and Oct–Nov
Carnation
Dec–Jan
Nov–Mar
Chrysanthemum
Feb and Nov
Feb–Mar and Oct–Nov
Anthurium
Difficult
Mar–May and Jul–Oct
Orchids
Difficult
Mar–May and Jul–Oct
Lilium
Dec–Jan
Nov–Mar
Kryzen planning estimate from the monthly averages above and each crop's usual day and night temperature range. Variety, soil or substrate temperature and shading change the result, so confirm with a trial.
₹5,165Spending per person per month, urban Bihar, 2023–24[6]
590 kmto Kolkata, the nearest metro (straight line)
Urban households in Bihar spent an average of ₹5,165 per person per month in 2023–24, below the all-India urban average of ₹7,078.[6] Local demand in Gopalganj may be small for exotic greens, so plan where the rest of the harvest goes.
Polyhouse farming in Gopalganj with Kryzen
We have built 2 projects in Bihar so far (see our project map (opens in a new tab)). Gopalganj is about 1,180 km in a straight line from our Chhatrapati Sambhajinagar warehouse, our nearest site.
Towns near Gopalganj
We also plan and build farms in these towns near Gopalganj:
Map: LGD 2024 boundaries via bharatlas, CC BY 4.0. For illustration only.
Polyhouse farming in Gopalganj: FAQs
Can a polyhouse farm run all year in Gopalganj?
Yes, with the right structure. For Gopalganj we would plan a Fan & Pad polyhouse for leafy greens. Even then, lettuce is hard to grow in May to September, so plan another crop for those months.
Which polyhouse is best for Gopalganj?
With May highs of about 41°C and 35% average humidity in that month, we would start with a Fan & Pad polyhouse for leafy greens.
Which crops should I grow in a polyhouse in Gopalganj?
Going by the monthly climate, cucumber, chilli pepper and brinjal have the longest growing windows. Confirm prices and volumes with buyers before you plant.
Is polyhouse farming profitable in Gopalganj?
It can be, if the crop, the structure and the buyers match. In Gopalganj, cucumber and chilli pepper have the longest seasons under cover. Confirm prices and volumes with buyers first; our Detailed Project Report works out the cost, yield and returns for your plot.
Does Kryzen build polyhouses in Gopalganj?
Yes. Our nearest site is our Chhatrapati Sambhajinagar warehouse, about 1,180 km away, and we have built 2 projects in Bihar.
Is there a subsidy for polyhouse or hydroponic farms in Bihar?
Yes. Protected cultivation projects in Bihar can apply for Mission for Integrated Development of Horticulture (MIDH) assistance through the state horticulture department. Check the current rate and area limit when you apply.
Discuss your Gopalganj farm project
Share your plot location, water test and crop targets. We will suggest the right structure and growing system, and send an itemised quotation.
A computer engineer turned hydroponic farmer from a multigenerational farming family in Satara. Sudhir founded Kryzen in 2019, and the team has since built 350+ protected and hydroponic farms across India.
