Introduction

         Asparagus (Asparagus officinalis L.) is a perennial crop that can remain commercially productive for 10-15 years. The plant is composed of ferns, a crown, and the root system. Growing conditions that favor healthy fern develop and the accumulation of carbohydrates (food reserves) in the crown and root system enhance size and vigor of buds and subsequent spears.
Asparagus has separate male and female plants. Female plants produce seed and larger-diameter spears, but have lower yields. Male plants have higher yields, longer productive life, and produce spears earlier. Male plants, however, do not produce seeds.

Uses and Nutritional Value

          Young, tender shoots or spears are eaten half-cooked alone or mixed with other vegetables. The spears are also processed by quick freezing or by canning in brine.
Green asparagus spears contain the following nutrients per 100 g fresh weight:

 Nutrient                                                                     Amount
 Water                                                                          92.0 g
 Protein                                                                          2.8 g
 Fat 0.2 g
 Carbohydrates                                                               2.2 g
 Vitamin A                                                                    980.0 IU
 Vitamin B1                                                                   0.23 mg
 Vitamin B2                                                                   0.15 mg
 Niacin                                                                           2.2mg
 C                                                                                48.0 mg
 Ca                                                                              24.0 mg
 Fe                                                                                1.5 mg
 P                                                                                52.0 mg
 Energy Value                                                              113.0 kJ

Production Management

Varieties

         Mary Washington (OP), UC 157 (F1 Hybrid), Jersey Giant (F1 Hybrid), Jersey King (F1 Hybrid)

Climatic and Soil Requirements

         Asparagus is grown well with high light intensity, warm days, cool nights, low relative, and adequate soil moisture. It grows best in sandy loam soil good drainage and aeration, water table below 4 ft and a pH of 6.8-7.5.

Seedling Production

         Asparagus is grown from seeds and crowns. A 1-ha production area requires 1.3 kg seeds or 18,000-20,000 seedlings; A 200-300 m2 nursery area produces enough transplants for one hectare. Line sow pre-soaked seeds in 1 m wide seedbeds prepared from a mixture of equal parts animal manure, rice hull charcoal and garden soil. The lines should be 7-10 cm apart. Water before and after sowing. Mulch with rice straw or rice hull and provide partial shade. Water regularly. Apply foliar fertilizer for vigorous growth. Prick in 4" x 6" plastic bags.

Land Preparation

         Prepare land by plowing and harrowing twice. Make furrows 1.5 m apart. Dig holes along the furrows at 30-40cm between holes. Apply 500 g animal manure and 20 g complete fertilizer (14-14-14) per hole. Cover lightly with soil.

Transplanting

        Irrigate the area before transplanting. Transplant one seedling per hole. Trim the leaves, spread the roots evenly and cover with soil. Add soil gradually to the hills as spears develop into mature ferns. For single row technique, plant in the center of the furrow. For double row technique, plant on both sides of the furrow.

Maintenance

         Use herbicides to control specific weeds. Staking or trellising is advisable to prevent lodging of mother ferns. Irrigation schedules depend upon local weather conditions, soil texture and current stage of growth. Maintain only 3-5 vigorous mother ferns and cut all other small ferns.

Pests and Disease Management

 Insect Pests/                                                   Recommendations
 Diseases
 Mealybug                                        Prune and burn affected  leaves
 Cutworms                                        Spread wood ash
 Asparagus spotted beetle                 Spread wood ash
 Aphids                                            Spray hot pepper extract or insecticidal soap; remove old ferns
 Asparagus rust                                Spray pesticides; prune old ferns
 Fusarium root rot                             Use resistant variety
 Cercospora needle blight                  Use resistant variety

The following are other alternative methods of control:

  • Grow aromatic plants like basil, marigolds, and Alliums to repel insect pests.
  • Plant corn, sunflower, Aloe vera and amaranth as trap crop for some insect pests.
  • Spray with compost tea to minimize fungal and bacterial diseases (Compost tea is prepared by fermenting rice compost for 10-14 days. The effluent is sprayed to control foliar diseases).
  • Spray hot pepper extract at the rate of 100 g/16 L water for soft-bodied insects.

Harvesting

         Harvest at 6-12 months after transplanting. Cut all ferns and leave only three vigorous spears to serve as mother ferns. Cut all spears at the base. Harvest daily from 1-2 months. Allow a rest period of 2-3 months. Spears can either be snapped or cut with a special long-handle knife. Avoid damaging the crowns with harvesting knives. Harvest early in the day and refrigerate soon after cutting.

Grading

  • Grade 1 asparagus must be a minimum of ½" in diameter, with 2/3 of the spears being green, fresh, well trimmed; with closed, compact tip, fairly straight, and free from decay or damage.
  • Grade 2 asparagus is a minimum 5/16" in diameter, with half of the spears being green, well-trimmed, with closed tip, and generally free from serious damage.

Cost and Return Analysis Per Hectare

            ITEMS                                                           AMOUNT (P)
  Year 1
 I. VARIABLE COSTS                                                    P 109,430
   A. Labor                (P150/MD) 
       Plowing                                                 1,500
       Harrowing                                              1,000
       Bedding                                                1,500
       Manure Application                                1,500
       Seedling production (15 MD)                   2,250
       Mulching w/ rice straw (10MD)                1,500
       Fertilization; basal (12MD) 
      & side dress (10 MD)                              1,800
      Irrigation (30 MD)                                    4,500
      Weeding (20 MD)                                    3,000
      Spraying (30 MD)                                    4,500
      Pruning (24 MD)                                      3,600
      Miscellaneous (20 MD)                            3,000
                   Sub-total                                 31,150

  B. Materials
      Seeds (1.3 kg/ha)                                    19,500
      Animal manure (20 t)                                20,000
      Fertilizers
       46-0-0 (20 bags)                                       5,580 
       14-14-14 (9 bags)                                     3,150 
       0-0-60 (4 bags)                                        2,400
       0-18-1 (3 bags)                                        1,650
     Pesticides & herbicides (optional)              11,000
     Fuel & Oil                                                  5,000
     Miscellaneous                                           11,000
                   Sub-total                                   78,280

 II. FIXED COSTS                                                                23,189 
 Land rental                                                  10,000
 Depreciation
            10 pcs. Knife (2 yrs)                              126
              5 pcs. Scythe (2 yrs)                            63
              5 pcs. Hoe ( 3 yrs)                              125
              3 pcs. Shovel (3 yrs)                             75
              2 knapsack sprayers (5 yrs)                800
 Interest on Loans at 20% int. p.a.                  12,000
 TOTAL COSTS                                                                  132,619
 Year 2

 I. VARIABLE COSTS                                                          234,060 
 A. Labor (P150/MD) 
     5 regular laborers (264 MD)                     198,000
    Watering
    Weeding
    Fertilization
    Spraying
    Pruning
    Harvesting
    Post harvest handling
                   Sub-total                                                         198,000

 B. Materials
               Animal manure (20t)                                                20,000
               Fertilizers
                  14-14-14 (12 bags)                                                 4,200
                   6-0-0 (4 bags)                                                       1,860
               Packaging Materials
                  (styropor box, tape, etc.)                                       10,000
                  Sub-total                                                            36,060

 II. FIXED COSTS                                                                  23,139
    Land rental                                                10,000
    Depreciation
              10 pcs. Knife                                       126
                5 pcs. Scythe                                     63
                5 pcs. Hoe                                        125
                3 pcs. Shovel                                      25
                2 knapsack sprayers                          800 
 Interest on Loans at 20% int. p.a.                  12,000
 TOTAL COSTS                                                                   257,199
 GROSS INCOME b, c                                                240,000-320,000
 NET INCOME                                                            17,199 - 62,801

 a Cost of seeds; hybrid = P15,000/kg; OP = P1,8000/kg
 b Harvesting of marketable spears starts on the second year of production
 c With marketable yield of 6-8 t/ha at P40/kg