How to produce Cucurbits in a Polyhouse
Cucurbits belong to the family of Cucurbitaceae in which there are about 800 species in 130 genera. They are vegetable plants that are very popular for human consumption worldwide and is eaten in various forms, for examples: Cucumber, Gherkins and Long melons in the form of salad; Ash gourd, and Pointed gourd in the form of sweets; Gherkins in the form of pickles; and Melons in the form of desserts. Some of them such as Bitter pumpkin have some unique medicinal properties.
Read more: How to do organic farming of Capsicum?
These Crops make up one of the largest plant families of crops and they are best suited for warm temperatures and they need full Sun and well drained soil to thrive.
We have already seen Organic production of Cucurbits in the previous article. Today we will see about Growing Cucurbits in a Polyhouse.
Introduction to Polyhouse Production of Cucurbits
Growing Cucurbits within a Polyhouse is a very profitable business and it is gaining interest among the masses as it can be grown in a controlled environment throughout the year. Apart from Organic vegetable farming, Polyhouse cultivation of vegetables is also increasing rapidly as people can obtain decent profits and protected environment conditions.
Some vegetables can also be grown hydroponically in the polyhouse and the Cucurbits can be grown in backyards, containers, pots, balconies and Home Gardens as well and if they are provided with proper standing support, we can expect them to creep fast and yield more.
Among all the Cucurbits, Cucumber is one of the widely grown plants in the Gourd family for its dark green vegetable. The size & yield of the vegetable depends on the variety and management practices.
Varieties of Cucurbits
The varieties of different Cucurbits are as follows:
- Cucumber – Japanese Long green, Straight Eight, Balam Khira, Khira Poona, etc
- Muskmelon – Pusa Sharbati, Lucknow Safeda, Hara Madhum Kutana, Durgapur, Madhu, Arka Jeet, Arka Rajhans, etc
- Watermelons – Sugar Baby, Asahi Yamato, Charleston Grey, Pusa Bedana (seedless), Tetra-2, etc
- Bottle Gourd – Pusa Summer Prolific Long, Pusa Summer Prolific Round, Pusa Meghdut and Pusa Manjari
- Bitter Gourd – Pusa Dumousmi, Kalianpur Baramasi, Coimbatore white long, etc
- Sponge Gourd – Pusa Chikni
- Ridge Gourd – Pusa Nasdar, Satputia
- Summer Squash – Early yellow prolific, Australian green, Butternut, etc.
- Winter Squash – Arka Suryamukhi
- Tinda – Arka Tinda
Growing Conditions of Cucurbit Crops in a Polyhouse
Cucurbits grow best in hot weather when days and nights are consistently warm and they need a fair amount of space to scroll and twine. It is also possible to train their traditional vines to vertical structures in order to save space.
They need full sun and well drained soil to thrive well and before planting, organic matter is added for best results. In case of heavy soils, peat or rotted manure can be added. However, it is always recommended to take a soil sample before fertilizing them.
Read More: How to start organic farming?
The following conditions are ideal for a growing Cucurbits in a polyhouse:
- The Polyhouse should be selected with abundant light and ventilation.
- The height of the polyhouse to the gutters should preferably be over 5 metres.
- The growing site of the plant should be facing North-South direction in Rows within the polyhouse.
- The optimal humidity inside the polyhouse should be maintained for better growth of the plant and for Cucurbits, the optimal relative humidity is 80%. High humidity can result in powdery mildew disease, so ventilation should be adjusted to maintain optimum temperatures and humidity.
- Do not over ventilate the planting area as it can reduce the relative humidity and can result in lower yields and the fruit can also have gummy ends.
- For cooling and ventilation, fans can be installed and make sure that the misters do not increase the relative humidity.
- A thermal blanket over the crop can be used to automatically provide the shade for the plants at a selected temperature.
Read More: How to produce organic cucurbits?
Cucurbits are widely grown throughout tropics and subtropics and arid regions. They grow under frost free conditions because it is frost sensitive but it can also grow in cold weather conditions. The Melons require about 25 to 30 degree celsius temperature for a longer time period.
For hot climatic regions, day temperatures can be decreased and if no thermal blanket is used in the warmer climatic months, it is recommended to maintain the temperatures at about 15 degree Celsius and in winters the optimum temperature should range between 23 to 34 degrees celsius.
Temperatures over 40 degree Celsius or less than 14 degree Celsius are not favourable for Cucurbit production in the polyhouse.
Cucurbits thrive well in well drained soils with a rich content of organic matter. Light soils are generally preferred to produce early crops. The farmers should implement practices that nurture the soil, stimulate soil life and conserve nutrients. In general, the preferred pH for all Cucurbits is from 6.0 to 7.0 .
Propagation in Polyhouse Production
Cucurbits are generally propagated by seeds.
Season and Seed Rate in Polyhouse Production
Inside the polyhouse, the Cucurbit crops can be cultivated throughout the year and the seed rate depends upon the variety and the planting method of the crop.
In general, the seed rate for Cucumber, Watermelon and Muskmelon are 2 to 3 kgs per hectare; while Bottle Gourd, Ridge Gourd and Sponge Gourd need 4 to 5 kgs per hectare; and Pumpkin and squash needs 7 to 8 kgs per hectare.
Read more: What is Nano Urea for the plant?
Seeding/Sowing/Transplanting in a Polyhouse
Before transplanting Cucurbit seeds in the polyhouse, the seedlings must be raised in seed trays. The Seeding should be done in sterilized plastic cell trays which are filled with a good potting mix and make sure that the seeds are covered with 8 to 10 mm of perlite.
The seeds can also be planted in Peat blocks or Rockwool blocks for 3-6 weeks before planting in the Polyhouse.
The seeds should be placed directly on top of the slabs. Lower temperatures can result in slow germination and uneven sprouting and it can also cause the plants to have poor vigor. The day and night temperature should be maintained for better germination of the seeds.
Spacing in Polyhouse Cucurbit Cultivation
The spacing for planting the seeds of Cucurbits is 2 to 3 metres in Rows and 60 to 90 cm in Plants. Make sure that the plants are not planted very close as it can result in poor yield and it can also build up diseases due to insufficient light.
Irrigation/Nutrient Supply inside the Polyhouse
Read More: Guide for the Drip Irrigation System.
For Organic Cucurbits, you must use Organic fertilizers, micronutrients and plant growth regulators for supplying the nutrients and these nutrients should be supplied through irrigation channels.
Irrigation is very important for the Cucurbit crops as both yield and product quality are affected by irrigation management and in order to maintain an adequate supply of oxygen to roots, sufficient water and aeration have to be maintained in the root zone.
However, there are many other factors that determine how much water is required by the plants each day such as temperature, light intensity, relative humidity and plant density. If light sandy soil is used, the frequency of water in the plants is increased as it loses moisture fast.
Mulching reduces evaporation so irrigation is significantly reduced when it is applied. The best form of irrigation system inside the polyhouse is Drip irrigation.
Manures & Fertilizer Requirement
The application of fertilizers is solely based on the type of soil and its nutrient content. However, it is recommended to conduct a soil test before using any type of fertilizers as the crops are very sensitive to the variation or excess of nutrients.
Any type of micronutrient deficiency in the soil as indicated by the soil test or plant analysis, should be supplemented by incorporating them into the soil before planting them. For growing Cucurbits in soil beds, carry out the required Potassium, Phosphorus and Nitrogen before planting.
Flowering in Polyhouse Production
Cucurbit crops under the Polyhouse produce fruits without pollination. However, pollination can take place from nearby fields and if the flowers are pollinated inside the polyhouse, the fruit becomes bitter and unmarketable.
Harvesting & Storage
The harvest and the storage requirement for Cucurbit crops vary according to the plant species and desired market. Summer Squash have the most variable harvest requirement as market preferences determine the maturity stage at which the fruits are picked.
For cucumbers, the first harvestable cucumbers are very important to be picked up so as to ensure continuous production throughout the season and cooling them just after the harvest helps in maintaining the quality of the crop and extending shelf life.
The Melons should be picked at full maturity with some variations in muskmelons according to the market locations. The pumpkins and winter squash might be picked at full maturity stage and they can be stored the longest of any other major Cucurbit crops.
It is always recommended to wear gloves during harvesting for some Cucurbits such as squash and cucumber to avoid scratching or damaging the fruit. During harvesting, the matured fruit should be carefully removed from the vines by cutting them through the stalks because the damage to the fruit can reduce the storage life and can even promote various diseases.
Yielding of Cucurbits inside Polyhouse
Yield of Cucurbit crops depends on variety, disease control, organic inputs, soil quality, irrigation and other polyhouse management practices. Different Cucurbit crops have different yields. On an average, Cucumbers have a yield of about 500 to 550 tonnes per hectare per year with about 85 to 90 fruits per square meter per year. Melons yield about 150 to 250 quintals per hectare.
Some Tips for Polyhouse Production
- The crop selected should be disease free, disease resistant and high yielding variety.
- Don’t consider marketing bent or marked or damaged crops.
- Remove old flower parts before grading and packing.
- Check the humidity inside the Polyhouse periodically as it impacts the growth of the crop and its yield.
- Make sure to sterilize all the plant growing containers between uses inside the polyhouse.
- Ensure that the growing medium is free of any type of plant disease organisms and care should be taken to store all the containers or pots and soil mix material at a place where contamination can be avoided.
- If you are using containers for growing the plants, then it should be filled to a uniform depth and the surface should be levelled. The containers should be filled to 1/2 or 3/4 inch from the upper edge to leave space for water during the irrigation supply.
- During watering or supplying the nutrient solution, ensure to thoroughly wet the full depth of soil in the container to prevent any build up of salt and maintain uniform moisture throughout the container.
- The containers should be covered with clear polyethylene film until the seeds start to germinate. It also helps in improving soil temperature and moisture conditions.