Polyhouse Cultivation of Bellpepper
Pepper or Capsicum annuum is commonly referred to as Capsicum from a flowering plant belonging to the family of Solanaceae which is native to America and it has many names depending upon the place and type such as Chilli pepper, green pepper, red pepper, paprika, bell pepper etc.
It is a herbaceous perennial plant that is cultivated all around the world and it is a high value vegetable crop that is cultivated in greenhouses and under shade net houses in milder climatic regions of India like Bangalore, Pune etc. In green houses or Polyhouses, the cultivation is done using an indeterminate variety of peppers that can be produced continuously and the plant keeps developing from numerous meristems.
The vegetable is rich in vitamin A & C and numerous minerals and it is very popular in peri-urban production systems because of the easy access to Urban markets in India like Bangalore, Hyderabad, Pune etc and it has also become famous in Goa state because of the ready market available throughout the year.
In an open field cultivation, the yield ranges between 20 to 40 tons per hectare whereas in a Polyhouse the yield ranges from 100 to 120 tonnes per ha. It is a cold season crop but is cultivated throughout the year using polyhouse and it is commonly used as a vegetable stew or salads.
The average height of Capsicum plants ranges from 30 to 90 cm. However, it is different for different varieties. The leaves are oval in shape and bright green in colour. Small peppers have smaller leaves and the roots are shallow and extended upto 20 to 30 cm deep in the soil.
The flowers are star shaped and white in colour. The fruit has different shapes like round, oblong or tapered with smooth and shiny skin and is available in many colours like red, yellow, purple and green. Generally it is green in colour under immature conditions but it turns red upon ripening. The vegetable contains many white seeds that give it a spicy taste.
Scope & Importance of Polyhouse Cultivation
In India, it is cultivated over 24,000 hectares of land producing about 3.1 lakh metric tonnes and it has an increasing demand because of the different varieties of Capsicum in the market and therefore it has scope for expanding the area under the production for these fruits.
India is the 4th leading producer of Capsicum with the states including Uttar Pradesh, Andhra Pradesh, Karnataka, Maharashtra, Tamil Nadu and Himachal Pradesh. The export market is also very high and there is a huge demand for peppers having good size, longer shelf life and attractive colour.
In open farms, there is an inadequate supply because of low productivity as it is greatly controlled by external environmental factors so polyhouse cultivation is the ultimate solution for increasing the productivity and also the quality with minimal loss.
It also has the chance of increasing employment among the rural population thereby effectively contributing to the economy of the country.
The protected gardening in a polyhouse is more advantageous as a normal traditional farming method because it has less or no dependence on external environmental conditions and it has higher yield compared to them with a good quality produce and a very good environmental protection.
It has less damage due to the insects or pests. The production can be available all throughout the year and the harvest is also possible nearly two to three times a year.
Varieties of Bell pepper for a Polyhouse
There are five major spaces of Bell pepper which includes 50000 varieties. Capsicum varieties are recognised by their matured colour i.e Green, Red, Yellow, Orange, Black, Cream, Brown and Lime coloured varieties. In India, the important varieties are classified as:
- Introduced varieties – California wonder, Yolo wonder, Chinese giant, World beater.
- Selected varieties – Arka Mohini, Arka Gaurav, Arka Basant.
- Public sector hybrid varieties – Pusa deepti, Green gold, Pusa meghdoot.
- Private sector hybrid varieties – Bharat, Solan hybrid 2, Early bounty, Lario, Hira.
Some of the common cultivated varieties are:
Polyhouse Cultivation Requirements
The optimum temperature for growing bell pepper is around 20 to 25 °C during the daytime and 18 to 20 °C at the night time. The minimum humidity should range about 65% and to control the temperature and humidity, misters are needed which should be started within the polyhouse everyday for 3 to 4 minutes in a half an hour interval.
Bell peppers require well drained soil which would be highly porous and the salinity should not be more than 1 ms/cm. The optimum pH of the soil should range from 6-7.
Depending on the climate and weather conditions of the region there are different types of polyhouses structures that can be used. For bell peppers, generally there are two types of structures that are commonly used. They are – Shade net house or a Greenhouse.
The Shade net houses are built using granite stone pillars with two feet depth in the soil and the pillars are constructed with 12 feet height and 8 by 4 inch thickness. The ends are sealed with rubber to avoid tearing the fabric. The Shade houses are also protected with a 40 mesh nylon net which is UV stabilised.
Selection of Planting material
Before planting, selection of proper planting materials is important to get a better quality of crop.
- The planting material should be healthy and resistant to pests and diseases.
- The Seedling should be 35 to 40 days old.
- The height of the seedling should be 16 to 20 cm.
- The plant should possess a good rooting system and it should have at least 4 to 6 leaves during plantation.
Some other characteristics like fruit shape, fruit colour, production, fruit quality and vigor are also to be considered while selecting the plant material for getting good quality of crop.
About 16 to 20 thousand seedlings are required for 1 acre of land which can be grown from 16 to 200 gram of seeds. These seeds can be directly sown in pro trays with 98 cavities which need to be filled with the sterilized Coco Peat and then the seeds are sown to a depth of half cm.
These trays are then covered with plastic sheets until the germination occurs and after one week the seeds are moved to the Polyhouse structure and irrigated lightly. Then they are transplanted to the main area after a month.
The soil is loosened to a fine tilth and beds are formed with dimensions of 75 by 45 cm and 45 cm space is left between two beds. Add well decomposed organic manure or vermicompost along with sand or sawdust @ 10 kg per m² before bed formation and then the beds are drenched with 4% formaldehyde and covered with a polythene sheet for three to five days.
Then the polythene is removed afterwards and the beds are raked repeatedly everyday so as to remove the trapped formaldehyde fumes completely before the planting process.
Transplanting, Pruning & Training
Before transplanting, the bed is watered adequately. The roots of the seedlings are transplanted into the holes of the polyethylene mulch with a depth of 5 cm. The raised beds can have two rows of seedlings with a space of 60 cm between the rows and 30 cm between the plants.
The seedling is sprayed with a pesticide during the initial stages to avoid pest infestation and the mulched growing beds are regularly irrigated to avoid the warmth generated by the mulch film and for also assisting the seedlings to establish well within the soil.
The plant is trained so as to retain its 2-4 stems only and for this the plants are regularly pruned after every 15 to 20 days with an interval of 7 Days. After 4 months, pruning is done once every 10 days.
Drip irrigation is recommended for irrigating purposes with a discharge rate of approximately 2 litre per hour. Before irrigation, the soil should be tested for moisture content.
Fresh water should be used for irrigation and through the summer season water is supplied at the sides of the growing beds so that it could catch up with the loss of water due to evaporation. The polyhouse should have the power of a water outlet so that it could get rid of excess water.
Fertigation & Manure
N:P2O5:K2O @ 150 kg each per hectare to be used with water soluble fertilisers for the entire crop growth period of 6 to 8 months.
The fertiliser should be used at the rate of 2.5 – 4 g per m² for every fertigation 2 times a week, after the 3rd week of plantation. The micronutrients are also supplied as and when the plants require and the fertigation system should be thoroughly cleaned at regular intervals.
Pest & Disease Control
The common pests of Bell pepper plants are:
- Fruit borer
- Mites etc
The common diseases found on these plants are:
- Damping off
- Powdery mildew
- Cercospora leaf spot
- Phytophthora and some other viral diseases.
For controlling these pests and diseases, good cultural practices should be adopted within the poly house and the debris should be cleaned properly after every harvest. Disease resistant varieties should be used for planting and for keeping the plants healthy and apart from all these, use proper chemical pesticides and insecticides for controlling them.
Sometimes the fruit also have some physiological disorders like:
- Blossom end rot
- Fruit cracks
- Fruit splitting
- Fruit spots
- Misshapen fruit
- Internal growth within the fruit
These can be controlled by optimising the growing environment inside the polyhouse and watering the plants sufficiently. Avoid water logging and adopt proper management inside the Polyhouse.
Fruit thinning is the removal of some fruits to promote better development of remaining fruits when there are too many fruits on the plant. It is done when the fruit is of pea size and is normally followed to increase the size of fruit thereby increasing the quality of production.
Harvesting & Yield
The harvesting starts after 60 days of planting in case of green colour bell peppers, and after 80 to 90 days in case of Yellow or Red fruit hybrids. The harvesting can continue up to 170 to 180 days at 10 days interval in green and 200 to 250 days in red and yellow hybrids.
The fruit is generally picked up in the early morning and the maturity of the fruit is known by the smooth and firm look of the fruit. They are to be removed from the plants with the stem attached to the fruit and are then collected in strong cloth bags and these bags should not be placed on the bottom rather hung on the shoulder of the picker.
The fruits should be carefully removed so that the plant doesn’t get harmed. After harvesting, they are kept in a cool place.
The harvesting is done at the green, breaker and coloured stage and it depends upon the purpose or distance of the ultimate market.
In India, it is generally harvested at the breaker stage for a longer distance and for the local market it is harvested at coloured stage. Breaker stage represents 10% of the fruit surface as coloured and Coloured stage represents 90% of the fruit surface as coloured.
From a single crop an average of 80-100 tons per ha or 8 to 10 kg per metre square is expected and an individual fruit varies from 150 to 200 grams.
Post Harvest Management
The harvested fruits are graded according to size and colour so as to ensure uniform attractive packaging. Shrink wrapping is adopted for each fruit and they are stored at 7-8°C upto 45 to 60 days. The fruit is packed in cartoons with a capacity of 10 to 12 kgs and most of the farmers use Apple boxes for packaging them for the local market.