Cultivation Techniques for Vinh Chau Purple Onion: Revealing Secrets to Achieve Superior Yields

Vinh Chau purple onion has long been famous for its distinctive delicious flavor, favored by the market. But how can we cultivate Vinh Chau purple onion to achieve high yields, uniform large bulbs, and superior quality? Let’s explore systematic and scientific cultivation techniques with Baconco!

A brief introduction to Vinh Chau purple onion specialty

Vinh Chau, the purple onion center of the Mekong Delta, boasts over 6,500 hectares of cultivation, with an annual output exceeding 100,000 tons. Of this, 5,000 hectares are dedicated to commercial onions, providing high-quality bulbs, and 1,500 hectares are specialized in producing seeds to meet widespread cultivation needs. This crop adapts well to a variety of soil conditions, particularly clay loam and sandy loam, opening up cultivation opportunities for many regions.

Plump purple onions will be harvested after 2.5 - 3 months of care. Photo: Van Duong

Committed to quality and safety, Vinh Chau purple onion is produced according to VietGAP standards, offering consumers organic products that are good for health. The harvest season typically begins before the Lunar New Year and lasts until March of the following year.

The journey of the purple onion bulb begins in the ninth lunar month when Vinh Chau farmers start planting seeds. After 2.5 to 3 months of care, depending on weather conditions, the plump purple onions will be harvested, bundled neatly in net bags, ready to reach traders, markets, supermarkets, and agents across the country.

Growing seasons and purple onion varieties

Vinh Chau purple onion has three growing seasons:

• Early onion season: Planted in September-October of the solar calendar, harvested in November-December (duration of 65-70 days).
• Main onion season: Planted in November-December, harvested in January-February (duration of 75-80 days).
• Seed onion season: From March to June.

Vinh Chau purpleerrorerror has two varieties: Tu Coong and Sai Coong, both of which have the same quality, but Sai Coong yields higher.

Seed bulb standards: The seed bulbs should be free from pests and diseases, have a deep purple color, a round bottom, and compact root ends without new roots.

Note: Farmers need to treat the seeds with Mancozeb fungicide to create a protective layer for the onion bulbs, preventing fungal attacks during the seedling stage.

Cultivation techniques for Vinh Chau purple onion

The ideal soil for growing purple onions is loose, nutritious, and well-drained soil. Image: Internet

Step 1: Prepare the soil

Before planting purple onions, thorough soil preparation and appropriate fertilization are crucial for plant growth and development. Ideal soil for purple onions should be loose, rich in organic matter, and well-drained. The ideal soil has a pH of 6-7.

To achieve this, farmers need to plow and harrow thoroughly, expose the soil to sunlight, remove weeds, and break up the soil. In addition to applying well-rotted organic fertilizers to provide nutrients for the plants, adding calcium is also essential.

The soil preparation process includes the following steps:

• Plowing: Plow to a depth of about 20-25cm to loosen the soil, allowing the onion roots to grow well. Harrow thoroughly 2-3 times to eliminate weeds and break up the soil.
• Sun exposure: Expose the soil for 7-10 days to eliminate pathogens and pests present in the soil. Sunlight also helps improve soil structure, making it looser.
• Creating beds: Create beds about 20-25cm high, 1-1.2m wide, with 30-40cm wide furrows to ensure good drainage, preventing flooding during the rainy season. Bed creation also helps warm the soil, facilitating the growth of the onion bulbs.
• Fertilizing: Fertilization is an important step that provides initial nutrients for the seedlings.

Step 2: Planting purple onions

After thoroughly preparing the soil, proceed to plant purple onionserrorerror the following steps:

• Choosing seeds: Select firm, healthy seed bulbs that are free from pests and diseases, with uniform sizes. It is advisable to treat the seed bulbs before planting by lightly sunning them for 1-2 days or soaking them in a fungicide solution.
• Planting distance: Purple onions are planted in rows, with a distance of 15 cm between rows and 10-15 cm between plants. The density is 4000-4500 clumps per 1000m2, planting 1-2 bulbs per hole; if the soil is clayey (loamy soil), insert the bulb 2/3 of the way down, and if the soil is sandy, plant the bulb just below the surface. After planting, cover with a thin layer of straw and water.
• Watering: After planting, water sufficiently to keep the soil moist so the seed bulbs can take root quickly. Avoid overwatering to prevent flooding and rotting of the bulbs.

Step 3: Pre-planting Fertilization 

Pre-planting fertilization provides essential nutrients for seedlings right from the early stages. In addition to well-rotted manure, the addition of calcium and specialized fertilizers is very important. 

Role of Calcium:  

• Detoxification for crops: Calcium helps neutralize some harmful salt ions in the soil, minimizing their toxic effects on plant roots.  
• Improving soil structure: Calcium helps improve soil structure, making it more crumbly, increasing its ability to retain water and nutrients, and allowing plants to absorb water and nutrients more easily.  
• Enhancing resistance: Calcium helps increase the sturdiness of cell walls, allowing plants to better withstand adverse environmental conditions such as salinity and acidity.  
• Supporting physiological processes: Calcium is involved in many important physiological processes of plants such as cell division and nutrient transport, helping plants grow and develop better. 

Fertilizing plants: Farmers can choose the product NPK CON CO 20-10-0.5CA+7S with Baconco's exclusive USP technology to provide a complex fertilizer with a composition of 20-10-0+10.5Ca+7S, which helps meet the timely demand for Nitrogen (20%) and Phosphorus (10%) right at the beginning of the season when the onions are just planted, while also supplementing a generous amount of Calcium to improve the soil.  

The planting stage is the foundation that determines the success of the entire purple onion crop in Vinh Chau. Thorough soil preparation, sufficient nutrient pre-planting fertilization, especially Calcium, combined with proper seed selection and planting techniques, will help seedlings grow strong, resist pests well, and lay the groundwork for high yield and quality bulbs.  

Hopefully, the shared insights on planting techniques for Vinh Chau purple onions above will be useful for farmers. Please apply the correct techniques and choose quality fertilizer products like Baconco to achieve the best results for your crop.