Brassica (Cabbages/Kales)

Cabbage, scientifically known as Brassica oleraceae var capitata, can be distinguished from other varieties by its short, petioled leaves and the later development of a compact head. Its stem and leaves are compressed, and the leaves grow from within but swell outward.

Kale, on the other hand, also belongs to the Brassica oleraceae species, specifically the var acephala variety. It is a type of cabbage that has green leaves, but unlike traditional cabbage, the central leaves do not form a head.

The ideal pH range for optimal growth is between 6.0 and 6.5.
It is advisable to use soils that are rich in organic matter, such as sandy loam or loam, and ensure they are well-drained.
For accurate fertilization, it is recommended to conduct a soil analysis.

Cabbage is a crop that thrives in cool seasons, with optimal growth temperatures ranging from 15 to 20°C. However, head formation tends to be reduced when temperatures exceed 25 degrees Celsius. Adequate and well-distributed rainfall is necessary for cabbage cultivation. Moisture levels play a crucial role, particularly during the early stages of crop growth. If moisture levels are low, irrigation should be implemented to supplement and alleviate any moisture stress.

Kale plants thrive in well-drained and fertile soil that is rich in organic matter, with a preferred pH range of 6.0 to 7.5. They can tolerate slightly alkaline soil conditions. Adequate moisture is essential for kale, and it prefers consistent and plentiful watering. While kale can tolerate drought conditions, the quality and flavor of the leaves may be negatively affected.

When choosing a kale variety to grow, farmers should consider several key factors. These include the maturity duration, yield potential, tolerance and resistance to pests and diseases, good field holding capacity, uniform maturity for a single harvest, and market preference, among other qualities.

The spacing of kale plants is an important consideration that depends on the specific variety and the farmer’s choice based on market demands.

The recommended spacing for kale plants varies depending on the variety. For large-headed varieties, a spacing of 60cm x 60cm is suitable. Medium-sized varieties thrive with a spacing of 60cm x 45cm, while small-headed varieties require a spacing of 30cm x 30cm.

In terms of nursery management, it is advisable to use raised beds to promote root development and ensure proper drainage. The recommended bed width is 1 meter, and the length should be convenient, preferably not exceeding 100 meters. The height of the raised bed should be around 15 centimeters.

When using Greenlife products, we recommend the PLO combination for optimal results:

  1. Pyramid: Apply 100g/20L of Pyramid to control soil-borne diseases such as Damping off.
  2. Loyalty: Use 10g/20L of Loyalty to control soil-borne pests.
  3. Optimizer: Add 20ml/20L of Optimizer to break seed dormancy and ensure uniform growth.

When it comes to transplanting the seedlings, follow these guidelines:

  1. Seedlings should be ready for transplanting after 4-6 weeks in the nursery, depending on the temperatures.
  2. Wet the seedlings an hour before transplanting.
  3. Plant the seedlings at the same depth as they were in the nursery, which is typically around 15cm.
  4. To alleviate transplanting shock, use 10ml/20L of Optimizer.

Cabbage is susceptible to various pests, including the diamondback moth (DBM), aphids, and cabbage sawfly. It is also prone to diseases such as black rot, fungal spots, and bacterial soft rot.

When it comes to pest management, let’s focus on the diamondback moth:

The diamondback moth larvae emerge from their mines during the first instar, molt beneath the leaf, and then feed on the lower surface of the leaf. They create small holes in the leaves of the host plants, often leaving the outermost layer of cells, known as the leaf epidermis, intact. This creates a distinctive “feeding window.” The caterpillars primarily cause damage by tunneling into the heads of plants such as cabbage.

To manage aphids, we recommend using the following combination:

  • Escort: Mix 10ml of Escort with 20L of water.
  • Integra: Mix 3ml of Integra with 20L of water.

Aphids feed by extracting sap from their host plants. Their continuous feeding can result in yellowing, wilting, and stunting of plants. Severe infestations can cause the plants to be covered in a sticky mass of small aphids, which is a result of their honeydew secretions. Over time, this can lead to leaf death and decay.

To manage leaf sawfly infestations, we recommend using the following combination:

  • King Code Elite: Mix 10ml of King Code Elite with 20L of water.
  • Integra: Mix 3ml of Integra with 20L of water.

Leaf sawflies are occasional but significant pests of brassicas. They are caterpillars with a black or green coloration and a black head. These pests often feed on cabbage leaves, consuming the leaf material while leaving behind the midrib.

To manage cutworms, we recommend using the following combination:

  • Escort: Mix 10ml of Escort with 20L of water.
  • Integra: Mix 3ml of Integra with 20L of water.

Cutworms can be identified by their smooth skin, greasy gray color, and their “C-shaped” posture when disturbed. The moths lay eggs on grasses, weeds, and other host plants during the night. Cutworms feed at night, causing significant damage to the stems and foliage of young plants. During the day, they retreat to their underground burrows.

To manage black rot disease, we recommend using Pentagon at a rate of 10ml per 20L of water.

Black rot disease is characterized by the presence of large yellow to yellow-orange “V”-shaped areas that extend inward from the margin of a leaf. Additionally, infected areas may exhibit black veins.

To manage downy mildew, we recommend using the following combination:

  • Green Cop: Mix 50g of Green Cop with 20L of water.
  • Integra: Mix 3ml of Integra with 20L of water.

Downy mildew is caused by Hyaloperonospora parasitica (previously known as Peronospora parasitica). The initial signs of downy mildew include a fluffy or powdery-white mass of spores on the undersurface of brassica leaves. This is followed by black speckling and puckering on the upper surface of the leaves. Infected leaves turn yellow prematurely and may fall off the plants.

In the field, symptoms on mature plants are usually observed on the leaves closest to the ground. The fungus produces spores on the undersurface of leaves and results in brown to black, sunken, angular lesions with a pepper-like appearance on the upper surface of the leaves.

To manage Alternaria leaf spot, we recommend using the following combination:

  • Pyramid: Mix 50g of Pyramid with 20L of water.
  • Integra: Mix 3ml of Integra with 20L of water.

Alternaria leaf spot is a common disease of cabbage caused by the fungal pathogen Alternaria brassicicola. The primary symptom of Alternaria diseases is the presence of yellow, dark brown to black circular leaf spots with concentric rings resembling a target pattern. In some cases, the centers of the lesions may fall out, giving the spots a shot-hole appearance. As the disease progresses, individual spots may merge, forming large necrotic areas, and leaf drop can occur.

To manage damping off, we recommend using the following combination:

  • Chariot 500SC: Mix 20ml of Chariot 500SC with 20L of water.
  • Integra: Mix 3ml of Integra with 20L of water.

Damping off is a seedling disease that can occur at different stages of germination and early growth. Seeds may become infected as soon as moisture penetrates the seed coat, or later when the radicle begins to extend. This can result in pre-emergence damping-off, where the seeds rot immediately below the soil surface. Alternatively, post-emergence damping-off can occur, where healthy-looking seedlings suddenly wilt, wither, or collapse.

Damping off is caused by pathogens such as Pythium, Rhizoctonia, and Fusarium, which result in lesions at or below the soil line. Infected seedlings may discolor, wilt suddenly, or simply die. Proper management and the use of Chariot 500SC and Integra can help control damping off and promote healthy seedling growth.

To manage head rot disease, we recommend using the following combination:

  • Pyramid: Mix 50g of Pyramid with 20L of water.
  • Integra: Mix 3ml of Integra with 20L of water.

Head rot disease is caused by the fungus Sclerotinia sclerotiorum. The symptoms of head rot typically begin as water-soaked spots on the lower or upper leaves of cabbage. These spots enlarge, causing the infected tissue to become soft and some outer leaves to wilt. As the disease progresses, a white cottony growth becomes visible on the leaves. Eventually, the entire cabbage head may be covered with this white cottony growth, and overwintering sclerotia start to form. The sclerotia initially appear white and round, but they later turn black, become hard, and assume an irregular shape. These black sclerotia can be seen on the outside of the cabbage head, but they also form inside the head.

To promote crop nutrition, we recommend using the following combination:

  • Green Cop: Mix 50g of Green Cop with 20L of water.
  • Integra: Mix 3ml of Integra with 20L of water.

The specific amount of fertilizer to be applied will depend on the soil analysis report and the soil type. During the early stages of growth, it is crucial to provide an adequate amount of phosphorus to support root establishment. This can be achieved through foliar feeding with Goldchance Super Start (14:28:18) at a rate of 50g per 20L of water or Lavender (24:24:18) at a rate of 20ml per 20L of water.

During the vegetative stage, a sufficient amount of nitrogen is required for plant growth. This can be provided through foliar feeding with Lavender at a rate of 20ml per 20L of water or Goldchance Super Growth at a rate of 50g per 20L of water.

When the heads of the cabbage start to form, potassium is essential for proper head formation. This can be achieved by foliar feeding with Lavender at a rate of 20ml per 20L of water.

To effectively manage weeds, it is crucial to implement successful weed control practices. Weeds compete directly with the cabbage plants for nutrients, water, and light, leading to reduced yields.

Effective weed control is crucial, especially early in the season, as weed competition can significantly reduce vigor, uniformity, and overall crop yield. Weeds present in and around the field can also act as hosts for insects and disease pathogens, which can invade or spread to the crop soon after planting.

At Greenlife, we recommend using Commander, a pre-emergence herbicide, at a rate of 50ml per 20L of water. Apply this herbicide 2-3 days before transplanting to effectively control weeds.

When it comes to harvesting cabbage, it can be done once the heads have formed. For the highest yield, it is best to cut the cabbage heads when they feel solid to hand pressure, but before they start to crack or split. Mature heads that experience a sudden heavy rain may be prone to cracking or splitting wide open, rendering the exposed internal tissue unusable.

The time frame for harvesting kale is a personal preference based on flavor preferences. If a lighter taste is desired, younger leaves can be harvested. However, for those who prefer the more pungent and bold flavor of kale, mature leaves from the fall season are preferable.

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