Squash (Calabasa) Production

Squash, also known as calabasa, is an important vegetable crop grown for its edible fruit, leaves, and flowers. It is widely cultivated in tropical and subtropical regions of the world, including the Philippines. Squash is a good source of vitamins, minerals, and dietary fiber. It is also low in calories, making it a healthy addition to any diet.

In this production guide, we will cover the essential information and practices needed to successfully grow squash. From site selection and preparation to planting and harvesting, we will provide you with a step-by-step guide to maximize your yield and profit. We will also discuss common pests and diseases and their management, as well as post-harvest handling and storage.

Whether you are a seasoned farmer or just starting out, this guide will provide you with valuable insights and tips on squash production. So let's get started! So let's get started!

Recommended Varieties

Nueva Vizcaya Strain, San Leonardo, and Suprema are the three varieties of squash recommended for commercial production . Other characteristics of these varieties are presented in Table 1.

Table 1. Characteristics of recommended varieties of squash.

Variety	Days to maturity	Yield range (t/ha)	Fruit			Other characteristics
			Shape	Texture	Flesh color
San Leonardo	90	25-35	Moderately flat	Fine grain / glutinous	Orange	Tolerant to insect pests and squash mosaic virus
Nueva Vizcaya	90	25-35	Moderately flat	Fine grain/ glutinous	Orange	Dry and wet season
Suprema	90	25-35	Flat	Fine grain /glutinous	Orange	Dry and wet season

 

Site Selection

Choose a 1000 m2 well-drained area previously planted to rice and accessible to water source. Squash grows in all types of well-drained soil, but the best soil type for the crop is sandy loam or clay loam with pH of 6.0 to 6.7.

Growing Season

For optimum yield and profit, plant in rice-based lowland areas from October to December, and May to July for hilly areas. Planting squash on these months will avoid the peak population of insect pests and the high incidence of plant diseases.

Land Preparation

There are two methods of land preparation being used, and these are:

1. Zero Tillage – after rice harvest, holes are made using grub hoe or peak mattock at a spacing of 2m between holes.
2. Complete Land Preparation – For lowland rice-based areas, soil must be pulverized and leveled. The land should be plowed and harrowed twice alternately. Plowing and harrowing should be done at the optimum soil moisture content when the soil is not too wet nor too dry. Make shallow furrows at a distance of 2m between furrows. Prepare hills at 1 m apart. Incorporate organic fertilizer and complete fertilizer thoroughly with the soil at planting.

Crop Establishment

1. Direct Seeding:


1. Plant 2-3 seeds 0.5 m between hills on mounds during wet season and in furrows during dry season.
2. Plant another 2-3 seeds 5-7 m between 2 rows of plants.
3. 3-4 weeks after planting, remove the weak and diseased plants leaving behind one healthy plant per hill.


2. Transplanting:


1. In planting hybrid squash because of the high price of seeds or when the seeds are few, let the seeds turn into seedlings first.
2. Sow one seed per hole of the nursery tray with a mixture of 2 parts garden soil, 1 part burned rice hull and 1 part compost.
3. Transplant 2 weeks after seedling emergence.
4. Irrigate immediately and mulch with rice straw.
5. Arrange the growing vines.
   

Nutrient Management

For lowland rice-based areas, incorporate organic fertilizer and complete fertilizer at harrowing before planting. For hilly areas apply 100 g organic fertilizer mixed with 1 tbsp of complete fertilizer in each hole. Table 2 presents the recommended fertilizer application. Follow the rate and time of application to produce healthy and vigorous vines and bigger fruits.

Table 2: Fertilizer Application

Type of Fertilizer	Rate of Application/ha.	Time of Application	Method of Application
14-14-14 46-0-0 + 0-0-60 (1:1) 46-0-0 + 0-0-60 (1:1) 46-0-0 + 0-0-60 (1:1) 46-0-0 + 0-0-60 (1:1)	2-3 bags 3 bags + 3 bags 3 bags + 3 bags 3 bags + 3 bags 3 bags + 3 bags	During planting 14 days after planting 28 days after planting 42 days after planting 56 days after planting	Basal Side dress Side dress Side dress Side dress

Irrigation

 Irrigate once week with one liter/hill every other day. The critical periods when irrigation water is needed are planting time, early vegetative, flowering and fruit development stage.  Irrigate also every after fertilizer application. Do not irrigate when the fruits have reached the matured green stage because this will result in lower quality.

Pest Management

Aphids and leaf hoppers are the most prevalent insect pests of squash throughout the year. For diseases, mosaic virus is the most damaging. The suggested management presented in Table 3 can be used as a guide in small scale production. However an alternative chemical control in Table 4 can be used also as a guide in cases of pests and diseases outbreaks.

Insect Pests

1. Squash beetle - Yellowish beetles damage the squash by scrapping the surface of the leaves producing a skeletonized appearance.  Infestation at cotyledon stage may result in death of seedlings.


2. Aphids (Aphids gossypii)  -- The insect is as big as a coarse sand and lives in colonies at the under surface of the squash leaves. They produce offspring even without male, so they multiply rapidly in a short period. They produce sticky substances that favor the growth of sooty molds on the leaves of squash. The soot-like growth of the mold interferes with the photosynthetic activity of the plant. Aphids also secrets substance that is toxic to the plant causing leaf curling and dwarfing of shoots.


3. Leaf hoppers  (Impoasca sp.)  suck the leaves of squash and other crops causing hopper burn.  In squash, they cause drying of leaves during severe infestation.  The plants can tolerate the damage if irrigated twice a week during the whole growing period but with reduced yield.


4. White fly Bemicia tabaci   -- These are small white and dainty flies that live in the under surface of the leaves.  It transmits viral diseases to squash and other crops causing abnormal growth of leaves and shoots.

Diseases

1. Mosaic virus - Cause mosaic or yellow green pattern of the leaves with slight curling.  This is transferred by insect vector or through the seed.


2. Leaf curl virus - Like mosaic virus, this disease is seed-borne. It is also characterized by curling of the leaves and shoots with shortened internodes exhibiting a dwarfed appearance.  The plant can survive and produce numerous leaflets but not capable of producing normal shoots and fruits.

Table 3. Biological and remedial control of pests and diseases of squash.

Insect pests/diseases	Suggested management
a. Insect pests: Squash beetle	Catch the beetle by sweeping it with insect net.
Aphids	Crush the colonies then spray infected and healthy plants with basil leaf extract at 200ml/16 L water.
Whitefly	Overhead irrigation twice a week can reduce the population of these pests. Use yellow sticky trap. Flooding once a week will replenish the plant sap sucked by the pest.
Leafhopper	Overhead irrigation twice a week can reduce the population of these pests. Flooding once a week will replenish the plant sap sucked by the pest.
b.Disease: Mosaic virus/ leaf curl virus	If symptoms appear on the plant at early stage, uproot the plants, then burn. If plants are infected at fruiting stage, irrigate the plant at weekly interval up to harvesting as it can tolerate the virus. If matured fruits are harvested, do not use the seeds as planting materials. Uproot and burn infected plants after harvesting.
Sources: Colting, L. M., et al, 2003; Farmers’/Gardeners’ Practices

 

Table 4.  Insect pests and diseases of squash and their chemical control

Insect Pests and Diseases	Suggested Pesticides		Rate Application (tbsp/16 li water)	When and How to Apply
	Common Name	Product Name
Insect Pests				Alternate spraying of the insecticides when insects appear and repeat weekly depending on level of infestation. Stop spraying 2 weeks before harvest.
Squash beetle	Carbaryl	Provin 85 WP	4.0-6.0
Aphids	Cypermethrin	Cymbush	1.0-1.5
Whitefly	Methomyl	Lannate 40 SP	2.0-3.5
Leafhopper	Profenofos	Selecron 500 EC	3.0-5.0
	Deltametrin	Decis R	2.0-2.5
Diseases	Rogue or remove infected plants and burn in isolated places. Mosaic virus can be prevented by controlling aphids vectors with the use of any of the above insecticides.
Mosaic virus,Squash Leaf Curl Virus
Source: Gajete, T.D. et. al 2004

 
Weed Control 

When the weeds start to appear, light weeding with the use of hoe should be done to eliminate germinating weeds. This should be done until the crop has attained sufficient size to cover the soil surface, which in turn will suppress the growth of weeds.

1. Remove the weeds while the plants are still small.
2. Off-bar and hill-up the plants taking extra care no to damage the roots.
3. Do manual spot weeding when the field is fully covered with vines.

Training of Vines

 Train the vines on the plot  for the ease of irrigation, .

Train or re-orient the vines  to crawl along the rows 25 days after planting and be evenly distributed over the area to facilitate watering, weeding, spraying of insecticide and hand pollination in the field. This should be done weekly. Prominent vines should not be touched anymore because this will affect the yield.

Hand Pollination 

• Bees and white flies are the primary pollinators of squash, when pollinators are few, hand pollinate the female flower between 6:00 and 8:00 in the morning to increase fruit setting.
• To increase seed yield, rub pollen into the pistil of female flowers every morning at early flowering to peak flowering.
• Squash is highly cross-pollinated and crossing between cultivars of same species is common. Crossing can also take place between species.
• Maintain an isolation distance of 500m for certified seeds and 1,200m for basic seeds.

Harvesting 

Harvest just before fruits are fully ripe or when the peduncle starts to dry up. It is best to harvest the fruits with a portion of the peduncle attached to prolong storage life.

Harvest immature fruits at 30-40 days from anthesis or pollination. The appearance of powdery, whitish substance on the surface of the fruit, and the hardening of the rind are indices of maturity if intended for seeds.

At such stage, the seeds of a squash are already matured and fully developed. Harvest the matured fruit when the fruits appear brownish orange.  Harvest fruits of plants that have no symptoms of viral infection, (mosaic, yellowing of leaves) if intended for seeds. This must be done to avoid virus-infected seeds for the next crop.

 

Source:
NUEVA ECIJA FRUITS & VEGETABLES SEED CENTER
CLSU Compound, Science City of Muñoz, 3119 Nueva Ecija

Philrice Training Guide for Palayamanan Vegetable Production

Bureau of Plant Industry- Los banos National Crop Research and Development Center