Kales

Tillage operations of Kales

Initial cultivation should be deep to allow better and faster root development. Aggressive perennial weeds should be removed before planting. Early land preparation is recommended to expose pests to sunlight and birds. Land should be dry to avoid soil crumbling and creation of a hard pan. Incorporating of crop residue can significantly increase the soil organic content. Well decomposed and powdered organic matter at the rate of 10-30 t/ha is incorporated in the soil at the time of final ploughing.

• Nursery establishment
• Sow seeds into well-drained, light soil with a 6.5 ph
• Use 45-50gr of seeds per are or 4.5-5 kgs/ha;
• Sow the seeds in 1.2 cm deep in the soil;
• After sowing, cover the bed with dry materials and water;
• When the seeds sprout, remove the mulch and continue to water.

How to Plant kales

Planting

• Sow seeds into well-drained, light soil with a 6.5 ph
• Use 45-50gr of seeds per are or 4.5-5 kgs/ha;
• Sow the seeds in 1.2 cm deep in the soil;
• After sowing, cover the bed with dry materials and water;When the seeds sprout, remove the mulch and continue to water
• Transplant when there are 3–4 leaves.
• Spacing at 45–60 cm between plants and 0.6 to 1.2 m between rows.
• Sow seeds 12 mm in deep.

Crop husbandry of kales

Crop Managment

1. Manure and fertilizers

During the production of Kale, correct fertilization is the single most important factor that determines the success of a crop. Use well decomposed manure (10-30T/Ha), at the second ploughing and 130kgs of top dressing Urea to be applied 30 days after the manure application.

 2. Weeding and mulching

Weeding should be done regularly to keep the field free of weeds in order to avoid their competition for nutrients, sunlight and water with the main crop. Mulching is recommended to help prevent erosion, regulate soil temperature and conserve soil moisture. Earthing of plants may also be done after 2 -3 weeks after transplanting. Earthing operation will also help to remove weeds.

3. Irrigation

The supply of adequate water to the roots of a pepper plant is critical. Under- or over irrigation can have a devastating effect on the outcome of the crop. It is therefore very important to apply water at optimal times. More frequent light irrigations are needed on sandy soils. Higher applications with longer intervals will be needed on clay soils.

When scheduling irrigation, the size of the root system at the time of irrigation needs to be taken into account. In general, the root system can be compared

to the aerial growth of the plant. The roots spread into the soil at a similar rate to which the aerial growth develops.

Pests and diseases management of kales

1. Damping-Off

Damping-off is another leafy vegetable disease caused by Rhizoctonia solani. It is also caused by Fusarium spp or Pythium spp. The fungus causes decay and wilt in seeds and seedlings respectively. The infected seedlings have light brown stems.

The pathogen survives is cold and wet soils, so you need to keep the soil temperature and moisture at optimum levels to prevent the occurrence of this disease in your garden. You need also to use certified seeds.

ymptoms of Damping off on Kale seedling

Management

Uproot infected plants. Avoid leaving debris of Kale plants or residues of brassicas in the field. Rotate crops every 4 years. The soil should always be water drained and airy.

2. Black rot (Xanthomonas campestris pv. Campestris)

Black rot is one of the most serious cabbage diseases during high rainfall and heavy dew conditions. The black rot bacterium can over-season on infected cabbage seeds, in weeds from the family Cruciferae or in infected plant material in the soil. Disease is common during wet conditions with high temperatures.

Symptoms:

• Yellow, brown or black v-shaped patches at the edge of the leaves.
• In later stages, head turns black with an offensive foul smell. Bacterial ooze also will be visible on the surface of diseased tissue.

Photo. Symptoms of black rot on cabbage

Management:

• Disease-free transplants should be used.
• Remove all infected plants and debris from the field and destroy by burning
• Spray the remaining healthy plants using a copper-based protective fungicide (eg. Copper-oxychloride: 250g/250ml water/has) to suppress further damage.

3. Downy mildew(peronospora parasitica)

The characteristic symptoms are appearance of purplish brown spots on under-surface of leaves. Upper surface of leaves has lesions in tan (yellowish brown) to yellow color. Infection exposes heads to soft rot.

Photo: Symptoms of downy mildew on cabbage

Management:

• Destruction of diseased debris after harvest of the crop
• Spray the plants using Mancozeb or a copper-based protective fungicide at 15 days interval soon after appearance of the disease.

4. Cabbage alphids

Several species of aphids attack brassicas in East Africa: the cabbage aphid (Brevicoryne brassicae), the false cabbage aphid (Lipaphis erysimi), the green peach aphid (Myzus persicae).  In particular, the cabbage aphid is a major pest in the region. Cool, dry weather is most favourable for aphid development. Large numbers of aphids may kill small plants. Their feeding can distort leaves of older plants and causes leaf curl.

Photo: Aphids on cabbage

Management:

• Intercrop with onion, garlic, spider plant, coriander to attract natural enemies.
• Avoid too much N.
• Plant in a well prepared fertile seedbed to promote crop vigour.
• Keep the fields free of weeds and alternative hosts.
• Manage the field to favour natural enemies such as lady bird beetles and hover flies.

• Mulch with wheat/rice straw or clear/transparent polyethylene sheet as reflectors of UV light discourage aphids from landing on the crop
• Use overhead irrigation to knock aphids off the leaves
• For chemical control, spray insecticides like Cypermethrine, Roket,etc.

5, Diamond back moth (DBM)(Plutella xylostella)

DBM is a serious pest of Brassicas and attacks all Brassica species. A full grown diamondback caterpillar is about 1cm long.Young larvae feed on leaves, leaving intact parchment like epidermis. Growth of younger seedlings is inhibited and also produces holes in leaves.

Photos: DBM damages on cabbage

Management:

• To control DBM in small size farms, cover seedlings with row covers (fine nylon mesh) to prevent moths from laying eggs on the leaves and or next to the plant.
• Intercropping Brassicas with repellent plants such as tomato, reportedly reduces DBM infestation in cabbage. When intercropping with tomato, the cabbage crop is planted 30 days after tomato.

Biological control of DBM using parasitoid wasp Diadegma semiclausum has proven very effective

• in the highlands of Kenya, Tanzania and Uganda.
• Botanicals such as neem-based pesticides are very effective for control of DBM.
• Physical protection method: dense planting of maize or sorghum around the field like a fence may be effective because the insect cannot fly over the maize and sorghum.
• Chemical control: Cypermethrine based chemicals like DUDU-CYPER and ROKET (at 1ml/1L of water) may be effective. But insecticide application is less effective for egg, mature larvae and pupae.

6. whitefly (Aleyrodes proleltella)

Whiteflies (Bemisia tabaci, Trialeurodes vaporariorum and Aleyrodes proletella) feed on Brassicas. Adult whiteflies are about 1 mm long.

Photo: Whiteflies on cabbage

Management:

• In East Africa, whitefly populations on Brassicas usually do not build up to such an extent that control measures are required.
• Natural enemies such as ladybird beetles, predatory mites and lacewings can play an important role in reducing whiteflies
• Proper fertilizer application because application of high doses of nitrogen fertiliser favours development of the pest
• Use mineral oils, neem products or spray with soapy water solutions.

How to harvest Kales

• Kale is ready for harvest when the leaves are about the size of your hand.
• Pick about one fistful of leaves per harvest. Avoid picking the terminal bud (found at the top center of the plant) because this will help to keep the plant productive.
• Select tender leaves;
• The yield ranges between 120-140 kgs/Are or 12-14 Tons per Hectare;
• Harvest Kale early in the morning while the weather is still cool. When the temperature goes up, it is recommended to store Kale leaves in the refrigerator and the cost is high. High temperature causes high rate of transpiration and loss of Kale leaves quality. When harvested Kale leaves are exposed to the sun, they wilt, shrivel and lose water;
• Before you transport kale leaves to the packing area, it is recommended to put them in a shade or under the trees. They should be transported while covered within 4 hours after harvest.

Post harvest handling of kales

Kale is harvested in plastic bags and stored in refrigerated containers for about one week.

Packaging

Suitable packaging can facilitate handling, protect the produce, extend storage/shelf life and help to maintain good quality. Kale should be tightly packed with a plastic liner to maintain moisture content in storage, reducing water loss and shrivelling helping to maintain quality.