India is a land of diverse agro climatic zones, and each of these zones offers a great potential for cultivation of a wide range of crops across all seasons. Vegetables form major and important part of our dietary requirements, which are widely grown in the rural and peri-urban areas. Hi-tech Horticulture including protected cultivation of high value and exotic vegetables has been on the increase, targeting high end domestic and export market. Of late, due to the population pressure, fragmentation of land holdings and urbanization have led to declining in the cultivable area, more so in urban and peri-urban areas.
Production of vegetables under protected cultivation system results in effective use of the land resources, besides being able to increase the production of quality vegetables both for the export and domestic markets by offsetting biotic and abiotic stresses to a great extent that otherwise is prevalent in open cultivation. Under protected cultivation, capsicums are widely grown due to higher productivity and economic feasibility.
Capsicum, also known as sweet pepper, bell pepper or Shimla Mirch is one of the popular vegetables grown throughout India. It is rich in Vitamin A (8493 IU), Vitamin C (283 mg) and minerals like Calcium (13.4 mg), Magnesium (14.9 mg) Phosphorus (28.3 mg) Potassium, (263.7 mg) per 100 g fresh weight. Capsicum is a cool season crop, but it can be grown round the year using protected structures where temperature and relative humidity (RH) can be manipulated.
This crop requires day temperature of 25-300C and night temperature of 18-200C with a relative humidity of 50- 60%. If the temperature exceeds 350C or falls below 120C, fruit setting affected.
Coloured capsicums are in great demand in urban markets. The demand is mostly driven by hotel and catering industry. The traditionally grown green capsicum, depending upon variety and season, usually yields 20-40 tons per hectare in about 4-5 months. In the greenhouse, the crop duration of green and colored capsicums is about 7 -10 months and yields about 80-100 t per hectare. The advantages of protected cultivation are:
- Higher productivity resulting in increased yield,
- Provides better growing environment to plants,
- Protects from rain, wind, high temperatures and minimizes the damage of insect pests and diseases thereby improving the quality and yield,
- Facilitates year round production coupled with yield enhancement by 2-3 times compared to open cultivation.
Research and development of greenhouse/protected cultivation of vegetables were initiated at IIHR, Bengaluru in the year 2000 and the complete package for protected cultivation of capsicum was developed by 2005. Since then many farmers and entrepreneurs have adopted the
protected cultivation of vegetables, especially colored capsicum, on a commercial scale and are being benefited. Some of the points that have to be considered for successful cultivation of the crop have been enumerated in the following pages.
2. Selection of Site
Selection of site for taking up of protected cultivation is a critical step, and this has to be done with utmost care.
Places having high rainfall and humidity are not suitable for its cultivation since this encourages many foliar diseases. Also, the areas with high wind velocity are not suitable since they are likely to damage the structure and the polyethylene sheet frequently, thereby enhancing the maintenance cost of the structure. Avoid the location or area where heavy rains accompanied with gusty winds are prevalent to avoid damage to the protected structure. Well, drained sandy loam soils having good percolation is most suitable to grow capsicum. The soil pH of 6 to 7 and EC < 1 mm hos/cm is ideal for growing capsicums.
3.Capsicum cultivation in Green house
The green house is designed depending on the prevailing local climatic conditions. A good number of different types of structures are built for protected cultivation. However, cost effective poly house and net house structures are most commonly used to grow capsicum in our country.
a) Net house (Shade net house):
Growing of vegetables in the net house is the cost effective method in many parts of southern states particularly in and around Bangalore. It is mainly due to easy availability of the granite pillars, which can give good strength to the structure and highly durable. Net houses are constructed using granite stone pillars of 12 feet height, 8 inch X 4-inch thickness. These pillars are placed at 2 feet depth inside the soil with concrete cement grouting.
Uneven and sharp edge of stone pillars on the top has to be covered with smooth materials like rubber tubes to avoid tearing of net. A G.I wire grid is provided on the top of granite pillar to support the shade net.
Over the GI wire grid, 50% HDPE white shade net is fixed to support another layer of shade net (green or black with 35% shade), which is movable or retractable. This additional shade net is used during hot summer mid days (Feb-June), sparingly during the winter season and whenever the sunlight is more between 11.00 am to 3.00 pm. UV stabilized 40 mesh nylon net is provided on all sides of the net house. Construction of net house costs about Rs.180-200 per sq meter.
b)Capsicum cultivation in Poly house:
Poly house gives better protection compared to the net house due to total avoidance of rain water entry into polyhouse; hence leaf diseases can be easily controlled. Yield is normally 15-20 per cent more in polyhouse compared to a net house. GI pipes are used to construct a poly house, and in some cases, farmers use wooden or stone pillars which require less initial investment.
Transparent UV stabilized polyethylene film; the 200-micron thickness is used for covering the poly house roof. It is provided with retractable or movable shade nets, at about 11 feet height just below the structures from ground level. The sides of the polyhouse are covered with 200-micron thick polyethylene film to a height of 3 feet from the ground level, to have better protection from rain splash. Remaining height of side wall is covered with 40-micron white colored insect proof net from all the four sides. Construction of poly house costs about Rs.500 per sq. meter.
Net house and polyhouse are provided with an ante chamber with two doors constructed at opposite directions where entry or exit to the poly/ net-house is made through the first door and then after closing the first door, the second door is opened to make an entry into the polyhouse. Care should be taken not to open both the doors simultaneously to avoid the entry of pests into the protected structures. A small concrete trough of 2-meter length, 1-meter breadth, and 2-inch depth should be prepared between the two doors of antechamber for facilitating washing legs in the disinfectant solution (Potassium permanganate) to prevent any contamination inside the polyhouse/ net-house.
4. Cultural and Nursery practices
Selection of cultivars Growing of capsicum hybrids in the green house is used to obtain continuous and regular flower and fruit setting relatively for a long period of 8 to 10 months. Most of the capsicum hybrids produce green fruits that mature to red, orange or yellow depending on the hybrid. The fruits should have characters such as uniform size and shape preferably four lobes, fruit weight of >150g, uniform coloring after attaining complete maturity, with a better shelf life of more than five days under ambient conditions. Selected hybrid should be high yielding, with a potential yield of >40t/acre.
Hybrids should have shorter intermodal lengths (7 to 10 cm), attaining a maximum height of 10 feet in a cropping period of 10 months. Popularly grown commercial hybrids in India include Indra, Yamuna (Green); Bombay, Triple star, Natasha, Inspiration, Pasarella (Red); Sunnyez, Swarna, Orobelle, Bachata (Yellow). Capsicum hybrids with high yield potential (>100 t/ha) and having uniform size and shape needs to be selected. Hybrids preferably should have a long growing period of 8- 10 months. Fruits should have characters such as four lobes, uniform color and ripening with better shelf life.
- Good quality seeds are required for producing better seedlings. The seedlings are raised in pro-trays of 98 cells or cavities. About 16,000 to 20,000 seedlings are required to plant one acre for which 160-200 gm of seeds is required.
- The pro-trays are filled with sterilized coco peat, and seeds are sown, one seed per cell to a depth of ½ cm and covered with the same media
- The filled trays are stacked one above the other and covered with plastic sheets till germination of seeds.
- Seeds germinate in about a week’s time after sowing. The trays are shifted to net house/ polyhouse and lightly watered. After 15 days of sowing, Mono ammonium phosphate (12:61:0) (3g/L) and 22 days after sowing 19:19:19 (3g/L) solution has to be drenched. The seedlings in portrays are drenched with COC 3g/L before transplanting. The seedlings will be ready for transplanting in 30-35 days.
- Spray imidacloprid @ 0.2 ml/L and chlorothelonil @ 1gm/L before transplanting of seedlings. Always add about 0.3 ml/L of wetting agent per litre of water with each spray of pesticide.
5. Land preparation
The land should be thoroughly ploughed, and soil should be brought to a fine tilth. Well decomposed organic manure at the rate of 20-25 kg per sq meter is mixed with soil. One application is sufficient to grow three capsicum crops successively. Raised beds are formed after bringing soil to a fine tilth. The bed size should be 90-100 cms wide and 15-22 cms height. Between the beds walking space of 45 cms to 50 cm need to be provided.
The crop beds are drenched using 4 per cent formaldehyde (@4 L/ m2 of bed) and covered with black polyethylene mulch sheet. While treating with formalin, care should be taken to wear mask, gloves, and apron. Four days after formalin treatment, the polyethylene cover is removed; the beds are repeatedly raked every day to remove the trapped formalin fumes completely, before transplanting. Formalin treatment can be repeated after three crop cycles or whenever necessary. Fumigation with formaldehyde helps to minimize the soil borne diseases. Basamid can also be used for soil sterilization.
7. Fertilizer application
A basal fertilizer dose of 20:25:20 NPK is required per acre and is applied to the beds uniformly before transplanting in the form of 80 kg calcium ammonium nitrate, 125 kg super phosphate and 32 kg mutate of potash or 40 kg sulphate of potash.
8. Application of neem cake and Microbial Bio-control Agents
Fifteen days before transplanting, neem cake has to be enriched with bio agents like Trichoderma harzianam and Pseudomonas lilacinous. Neem cake of about 200 Kg is powdered and slightly moistened. Trichoderma harzianam, Pseudomonas lilacinous, and Paecilomyces chilmdosporia each of two kg are mixed thoroughly to the neem cake. The mixture is covered with wet gunny bags or dry grass and left for 8-10 days. Avoid direct exposure to sunlight and rainfall. After ten days, this enriched mixture of neem cake and bio-agent along with 600 kg of neem cake has to be applied uniformly to the beds for an area of one acre. This is highly useful to reduce the problem of soil borne pathogens and nematodes. Azospirillum or Azoctobacter or VAM which is a nitrogen fixing bacteria can also be applied to the growing bed.
After ten days, this enriched mixture of neem cake and bio-agent along with 600 kg of neem cake has to be applied uniformly to the beds for an area of one acre. This is highly useful to reduce the problem of soil borne pathogens and nematodes. Azospirillum or Azoctobacter or VAM which is a nitrogen fixing bacteria can also be applied to the growing bed.
9. Laying of drip line
Place one 16mm inline drip lateral at the center of the bed having emitting points at
every 30 cm interval with a discharge rate of 2 ltr/hr or 4 ltr/hr. Run the drip system to check each emitting point for uniform discharge before covering the beds with polyethylene mulch.
10. Mulching and Spacing
Black polyethylene non-recycled mulch film of 30-100 micron thick, 1.2 m wide, is used to cover the planting beds. Holes of 5 cm diameter are made on the polyethylene film as per the recommended spacing (45cm x 30cm). The planting beds are covered with the film by securing the edges of the sheet firmly in the soil. Mulching practice conserves water, controls weeds, reduces infestation of pests and diseases and results in higher yield, and good quality produces.
The planting beds are watered to field capacity before transplanting. Seedlings of 30-35 days old are used for transplanting.Care should be taken to see that no damage occurs to roots while taking out the seedlings from individual cells of portraying. Seedlings are transplanted into holes made in polyethylene mulch film at a depth of 5 cm. After transplanting, seedlings are drenched with 3 g/L copper oxy chloride or 3 g/L captan or 2 g/L copper hydroxide solution to the base of seedlings at the rate of 25-30 ml per plant. Watering the mulched beds daily during the afternoon by using hose pipe for a week continuously is essential to avoid mortality due to heat trapped by mulch sheet.
Capsicum plants are pruned to retain four stems. The tip of the plant splits into two at 5th or 6th node and are left to grow. These two branches again split into two giving rise to four branches. At every node, the tip splits into two giving rise to one strong branch and one week branch. The pruning is done after 30 days of transplanting at an interval of 8 to 10 days, resulting in bigger fruits with better quality and high productivity. The capsicum plants can also be pruned to two stems, and the same level of yield can be maintained.
The main stem of the plant is tied with four plastic twine to train along and tied to GI wire grid provided on the top of the plants. This is practiced after four weeks of transplanting. The new branches and plants are trained along the plastic twines.
14. Drip irrigation and Fertigation
Drip irrigation is given to provide 2-4 litres of water per square meter per day depending on the season.Water soluble fertilizers are given through fertigation for entire crop growth period, starting from the third week after transplanting.
Capsicum crop is sprayed with water soluble fertilizers like potassium nitrate and calcium nitrate at every 3-week interval after two months of transplanting @ 3g/ l as a foliar application. Apart from these sprays, vegetable special (micro nutrients formulation developed by IIHR, Bengaluru for foliar spray) @ 5g/L are also to be sprayed. 15.
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- Indian Institute of Horticulture Research