Varieties
When selecting varieties for cultivation, prioritize those that are high-yielding, early-maturing, resistant to pests and diseases, and well-suited to local climate conditions. Additionally, consider the marketability of the variety. In Currimao, Ilocos Norte, the following varieties have been tested:
Variety |
Maturity |
Fruit Characteristics |
Other Characteristics |
Black Jack F1 |
46 DAT |
long, purple |
very productive |
Black Ninja F1 |
46 DAT |
long, purple |
very productive |
Casino F1 |
46 DAT |
long, dark purple |
very productive, long shelf life, glossy |
Mistisa |
46 DAT |
medium, light purple-striped |
very productive, soft & sweet flesh, not itchy, tolerant to EFSB |
Dumaguete Long Purple |
46 DAT |
long, purple |
long and slender fruits |
Llamado |
50 DAT |
long, purple |
dark purple and glossy fruits |
Oblong Green |
46 DAT |
medium, green |
tolerant to leaf hoppers, waxy and thick leaves w/ many trichomes (hairs) |
Ecological Requirements
Plow the field two to three times to help eliminate weeds, hibernating insect pests, and soil-borne diseases. The best time to plow the field is when a ball does not form when the soil is squeezed by hand and only a thin film of the soil sticks to the fingers and palm. Plow at a depth of 15-20 cm. Harrow twice to break the clods and level the field.
A well-pulverized soil promotes good soil aeration and enhances root formation.
Raising Seedlings
Eggplant seeds are very small and can be easily carried away by water and even ants. Hence, seedlings need to be raised in beds before they are transplanted.
Seedlings raised in seedbeds are exposed to adverse conditions. Raising seedlings in trays requires less seeds, promotes uniform growth of superior seedlings, minimizes transplanting shock, and lessens seedling mortality. It also saves on labor for thinning, weeding, watering, and pest management.
Here’s how to raise seedlings in plastic trays.
- Prepare the sowing medium by mixing thoroughly 2 parts rice straw compost, 4 parts carbonized rice hull (CRH), and 1 part processed chicken manure (PCM).
- Fill holes of the tray with the medium and slightly compact it using your palm.
Use a seedling tray with 100 or 104 holes. The volume of medium in each hole contains enough nutrients to sustain the seedling until transplanting time.
A 1000 m2 area (tenth of a hectare) requires 10 g of seeds. One gram (g) is approximately 250 seeds.
- Sow one seed per hole of the plastic tray at a depth of 0.5 cm.
- Cover the seeds with the medium.
- Water the seeds using a sprinkler with fine droplets.
- Cover the tray with old newspaper, plastic sack, or rice straw to maintain soil moisture and temperature. Remove the cover as soon as soon as 1 or 2 seeds have sprouted.
- Place the trays on the platforms of a simple nursery.
The nursery minimizes exposure of the seedlings to extreme weather and protects them from stray animals.
Roof the nursery with transparent plastic sheets during the rainy season; plastic nets or chicken wire during the dry season for the seedlings to take full advantage of the sunlight. Seedlings elongate abnormally when put under the shade. - Eggplant seeds germinate in 5-6 days under 25oC to 30oC temperature. During colder days, however, germination could take 8 days or more
- Water early in the morning and afternoon. Apply less water during rainy and cloudy days. The seedlings weaken and elongate with too much water.
- (a) When using plastic mulch, construct 1.0 m wide beds raised at 20 cm height. Space the beds 0.8 m apart (refer to Fig.1) to serve as path for manual watering and furrow irrigation.
- (b) For the conventional method, construct furrows (dry months) or ridges (rainy months) 1.0 m apart (refer to Fig. 2 and 3).
Collect soil samples for analysis at the nearest soils laboratory. Apply fertilizers based on the results of the analysis. Otherwise, use the following recommended rates:
a. With plastic mulch
Apply on both sides of the bed the following fertilizers every 10 linear meters of the planting row
- 0.5 kg PCM or any commercial organic fertilizer
- 0.4 kg ammonium phosphate (16-20-0)
- 0.4 kg ammonium sulfate (21-0-0)
- 0.1 kg muriate of potash (0-0-60)
Side dress
Drench 170 ml (1 small can of sardines) of fertilizer solution per hill. Follow this recommended schedule, and source and amount of fertilizer to apply.
Time of Application |
Drenching Solution |
3, 5, 9, 13 and 17 weeks after transplanting (WAT) |
3 tbsp urea (46-0-0) per 15 L water |
7, 11, 15 and 19 WAT (fruiting stage) |
3 tbsp muriate of potash (0-0-60) per 15 L water |
b. Conventional method (unmulched)
Apply 0.5 kg PCM or any commercial organic fertilizer and 0.4 kg ammonium phosphate (16-20-0) per 10 linear meters of the planting furrows or ridges. Cover the fertilizers with soil, or mix them thoroughly with the soil.
Side dress
Either dibble the fertilizer at the midpoint (25 cm) between plants along the rows; or distribute it evenly in a shallow furrow some 20 cm away from the base of the plant. Follow the recommended schedule, and source and amount of fertilizers:
Time of Application |
Amount of Fertilizer |
3 and 9 weeks after transplanting (WAT) |
6 g (0.4 tbsp) 46-0-0/hill; or 120 g (8 tbsp) 46-0-0/10 linear meters |
6 and 12 WAT |
3 g 0-0-60/hill; or 60 g (5.2 tbsp) 0-0-60/10 linear meters |
15 WAT |
8 g (1/3 tbsp)14-14-14/hill; or 160 g 14-14-14/10 linear meters |
Mulching
The use of plastic mulch is an improved technology for eggplant production. It controls weeds, preserves soil moisture, prevents soil erosion and leaching of fertilizers, and reflects sunlight to repel insect pests hiding under the leaves.
- Stretch the plastic mulch over the planting bed, with the silver color on top.
- Fasten the edges of the plastic mulch to the soil with bamboo slats spaced 1.0 m apart.
If bamboo slats are not available, cover its edges with soil using a shovel or rake, or by passing a moldboard plow near the edges.
(b) Making the planting holes:
- Measure 0.5 m planting distance 10 cm from the edge on both sides of the plastic mulch and mark the spots.
- Make the holes following any of these three ways:
- Using a serrated-lipped tin can:
Cut the lip of a 7-10 cm diameter tin can with metal scissors to form 1-cm long saw-like edges. Push the can on the marked planting spots of the plastic sheet, serrated side down. - Using a hot tin can:
Punch small holes using a nail at the sides and bottom of a 7-10 cm diameter tin can. Attach a wooden or bamboo handle. Fill the can with burning charcoal. The small holes ventilate the charcoal to keep it burning. - Using a cutter:
Cut intersecting lines 7-10 cm long to form “+” or “x” at the marked planting spots. During transplanting, fold up the 4 flaps to form square planting holes.
- For beds with plastic mulch, flood the beds two days before transplanting to cool down the soil under the plastic mulch and dissolve the fertilizers applied.
For the conventional method, irrigate the furrows to dissolve the fertilizers applied and minimize direct contact of the seedling roots with the fertilizers. - Transplant 30 to 35-day-old seedlings, which should now have 3-4 true leaves.
- Transplant only one seedling per hole preferably in the afternoon.
A 1000 m2 area (10th of a hectare) requires 2222 seedlings, when using plastic mulch.
A 1000 m2 area (10th of a hectare) requires 2000 seedlings, under the conventional method. - Water the transplants immediately with a sprinkler.
During the dry season, irrigate at 7, 21, and 30 DAT. Irrigate every 10 days thereafter. The mulched eggplant requires less irrigation water.
During the wet season, irrigate as the need arises. Irrigate after every fertilizer application.
Weeding
In unmulched fields, manage weeds by off-barring at 14 DAT and by hilling-up at 21 DAT.
Side shoot Removal
In both mulched and unmulched eggplant, remove all sideshoots before the first flower emerges to produce better quality fruits. Fruits must not touch the ground so they will grow straight and long. Also, sideshoot removal prevents overcrowding and controls vegetative growth, conditions favorable for insect pest and disease development.
Insect Pests and Diseases, and their Management
1. Eggplant fruit and shoot borer (EFSB), Leucinodes orbonalis Guenee, is the most damaging insect pest in eggplant. The larvae bore into tender shoots, flower buds, and fruits.
Larval feeding inside young shoots causes wilting, then they wither and drop off. This disrupts plant growth and eventually reduces fruit number and size.
Larval feeding inside the fruit destroys fruit tissue, making the fruit hard to sell.
Eggplant is the favorite food of EFSB. Other plants belonging to family Solanaceae, like tomato could host this pest also.
Adults are rarely seen because they hide under the lower leaf surfaces of the eggplant during the day, and become active only at night time.
Manage the pest through sanitation and proper disposal of infested plant parts to prevent pest build-up. Collect damaged shoots and crush the larvae inside. Harvest all damaged
fruits and dispose them by feeding to livestock, burying, or decomposing in sealed plastic bags.
2. Leaf-feeding 28-spotted lady beetle is a major eggplant pest at vegetative stage during the rainy season.
Manage the pest by picking and crushing it, especially the young larvae, which are concentrated under the lower leaves. Remove old leaves where insect pests like to hide. The use of plastic mulch minimizes pest infestation.
3. Sucking insect pests like aphids, thrips, mites, and green jassids (leafhoppers) are abundant during hot months.
To avoid or minimize their infestation, plant early in the season and maintain enough moisture in the soil. Spray chilli-soap solution two weeks after transplanting to make the leaves waxy. When spraying pesticide, aim the sprayer nozzle at the underside of leaves where the pests are located. Prune side shoots before the first flower appears to avoid overcrowded foliage, a very conducive breeding place for the pests.
Harvest and Post-harvest Handling
Harvesting starts 46-50 DAT, depending on variety and intended use of the fruits. Harvest fruits that are still tender. Harvest small and young fruits if the target market is for the Ilocano pinakbet
Harvest early in the morning and protect them from the sun, rain, and mechanical damage. Harvest all over-sized and damaged fruits to prolong the fruiting period of the crop. Harvesting is usually done 2 times a week.
Remove damaged fruits from the harvest and sort according to market standards.
Prick the bags with a pin for ventilation. Allot 2 pricks per kilogram of packed fruits. For some varieties, the fruits can be stored up to five days under this condition.
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