Fruits formed 135 days after hand (upper two)

and natural (bottom two) pollination.

As many as 80% of the pollinated flowers produce fruits that will stay until harvest, and which as compared to open pollinated fruits weigh about 90% more (450-500g) and possess very good uniform shape with no loss in edible fruit attributes. Since Arka Sahan flowers are big hand pollination is relatively easy and fast. One can pollinate 150-200 flowers/ hour. Eight years onwards a tree of Arka Sahan can produce 40-45 kg fruits, hence in each tree about 150 flowers should be hand pollinated to achieve an expected yield of25 tonnes/ha.

QUALITY VEGETABLE SEEDLING PRODUCTION

"Well begun is half done". Similarly production of good quality seedlings is very essential for getting higher yield and quality. In most of the advanced countries vegetable seedling production is taken up by specialized companies or as a specialized activity. In India, vegetable seedling production is gradually changing from open field nurseries to protected raised bed or seedling tray productions in some of the intensive vegetables growing areas. Seedling production as a specialized practice is also fast catching up.

Seedling production using seedling trays

In the past, the farmers themselves used to produce the seedlings required for transplanting at lower cost, as most of varieties were open pollinated types. Nowadays, many progressive farmers and entrepreneurs are taking up quality seedling production using seedling trays as a commercial activity mostly for F1 hybrids as the cost of seeds is quite high. Seedling production of tomato, capsicum, cauliflower, brinjal and cabbage F1 hybrids using seedling trays and protective structure such as insect proof net houses, shade houses and low cost naturally ventilated greenhouses are already a commercial venture.

Advantages

• Provides independent area for each seed to germinate and grow
• Improve germination and minimises wastage of expensive seeds
• Reduces seedling mortality or damping off because of sterilized growing media.
• Uniform, healthy growth and early maturity. .
• Ease in handling and cheaper transportation.
• Better root development and less damage while transplanting .
• Good main-field establishment and crop stand.

 The seedling trays are commonly kept under nylon net house or poly house. Net house is cost effective and feasible to grow vegetable seedlings. It is commonly built using granite stone pillars of size 10' x 6" x 4". These stone pillars are spaced at Sm x Sm and grouted to a depth of 2 feet. The stone pillars all along the periphery of the net house should be tied to a peg stone using guy wire. The height of the structure should be 8 feet. On top of each stone pillar used rubber tube is tied so that sharp edges of the pillars do not damage the nylon mesh and shade net. Wire grid is provided at the top of the structure as support for the nylon mesh. Normally farmers cover the sides with 40 mesh UV stabilized nylon insect proof net and in the top 50% UV stabilized HDPE shade net is used to cover the net house. It is recommended to cover the sides and top of the net house with 40 mesh UV stabilized nylon insect proof net. During summer and hot sunny days 25 % or 35% UV stabilized HDPE shade net is spread over the nylon mesh on the top of the net house to maintain ambient temperatures suitable for crop growth. Provision should be made to pull polythene sheet over the pro-trays in the event of rainfall by way of making low tunnel structure. For preparing low tunnel structure, 3/4" HDPE pipes or bamboo stick and 400-gauge polyethylene sheet can be used. The approximate cost for building stone pillar net house will be Rs. 80 to Rs. 100 per square meter depending on the locality.

Seedling trays

Seedling trays are also called as pro-trays (propagation tray) or flats, plug trays or jiffy trays. The most commonly used are 98 celled trays for tomato, capsicum, cabbage, cauliflower, chilli, yellow wax, brinjal and bitter gourd. The dimension is 54 cm in length and 27 cm in breadth with a cavity depth of 4 cm. Trays are made of polypropylene and reusable. Life of the tray depends on the handling. Seedling trays have been designed in such a way that each seedling gets appropriate quantity of growing media and the right amount of moisture. Trays have pre punched holes to each cavity for proper drainage of excess water and also have right spacing. These trays are readily available with nursery input suppliers in Bangalore.

Growing media for seedling trays

     Sterilized commercial growing media is better as the incidence of seedling diseases is less or nil and it contains right amount of moisture in it. The most common growing media used is coco peat, a by-product of coir industry and it has high water holding capacity. It should be well decomposed, sterilized and supplemented with major and minor nutrients before using as it is  low in nutrients and high in lignin content. Other growing media which have given good result are cocopeat:vermicompost and vermicompost:sand in equal proportions.

Method of seedling raising

• Fill the seedling tray with the appropriate growing medium.

• Make a small depression (0.5 cm) with fingertip, in the center of the cell sowing. Alternatively, depression can be created by stacking 10 trays one over other and pressing the trays together.

• Sow one seed per cell and cover with medium.

• No irrigation is required before or after sowing if coco peat having 300-400 percent moisture is used.

• Keep 10 trays one over other for 3 to 6 days, depending on the crops. Cover the entire stack with polyethylene sheet. This ensures conservation of moisture until germination. No irrigation is required till seedling emergence. Care must be taken for spreading the trays when the seedling is just emerging, otherwise seedlings will get etiolated.

• Seeds start emerging after about 3-6 days of sowing depending upon the crops. Shift the trays to poly or net house and spread over a bed covered with polyethylene sheet.

• The trays should be irrigated lightly every day depending upon the prevailing weather conditions by using a fine sprinkling rose can or with hose pipe fitted with rose. Never over irrigate trays, as it results in leaching of nutrients and building up of diseases.

• Drench the trays fungicides as a precautionary measure against seedling mortality.

• The media may need supplementation of nutrients if the seedlings show deficiency symptoms. Spray 0.3 per cent (3g/ litre) of 100 percent water soluble fertilizer (19 all with trace elements) twice ( 12 and 20 days after sowing).

• Protect the trays from rain by covering with polyethylene sheets in the form of low tunnel.

• Harden the seedlings by withholding irrigation and reducing the shade before transplanting.

• Spray systemic insecticides like lmidacloprid (0.2 ml/litre) 7 - 10 days after germination and before transplanting, for managing the insect vectors.

• The seedlings will be ready in about 21-42 days for transplanting to the main field depending upon the crop.

Mechanization of vegetable seedling production

     As more and more vegetable farmers are resorting to buy their seedlings from the commercial vegetable nurseries, there is a need to go for the mechanization for mass-production of vegetable seedlings. To address this, IIHR, Bangalore has developed the following machinery to facilitate mechanization of vegetable seedling production by the interested nurseries: a) Media Siever, b) Batch Type Media Mixer, c) Protray Filling Machine, d) Plate Type Dibbler, e) Handle Operated Protray Dibbler, Plate Type Vacuum Seeder, g) Handle Operated Vacuum Seeder for Portrays, h) Automatic Protray Seeding Machine. Using this machine about 200 seedling trays per hour can be filled and seeds sown.

2. Seedling raising by raised bed method Nursery raising

·        Prepare 10 m x 15 m area of land by finely tilling or digging to raise seedling for one hectare area.

·        Prepare beds of 9 m long 1 m wide and 15-20 cm high and number of beds require depends on the crop.

·        Break the clods and bring the bed to a fine tilth.

·        Apply 15 kg well decomposed FYM to each of this bed. Add chemical fertilizers @ 100 g each of nitrogen, phosphorus

         and potash to each bed.

·        Mix 3 g Trichoderma culture in 100 g neem cake/sq mt of nursey area and prepare nursery beds.

·        Sow the seeds on lines with a spacing of 8 cm X 2 cm and cover with a thin layer of a manure.

·        Cover the bed with dry grass or straw until germination.

·        Sprinkle 50 to 100 g of insecticide dust formulations around the nursery beds to prevent ants from eating the seeds.

·        As soon as seeds germinate, drench the nursery with copper oxy chloride (at 3gilitre).

·        Cover the beds with 40 or 50 mesh nylon net to protect against vectors like whitefly and thrips and aphids.

·        Seedlings have to be hardened before transplanting by withholding the irrigation and removing the nylon net.

·        Spray systemic insecticides like Imidacloprid (0.2 ml/litre) 7 -10 days after germination and before transplanting, for

         managing the insect vectors.

·        The seedlings will be ready in 25-42 days after sowing for transplanting depending on the crops.

Use of Nylon net    

It is important to have vegetable seedlings that are free of insect pests and disease problems. The earlier the plants are infected with pests or diseases, the more severe the effect on the field crop growth and yield. Hence, growing vegetable seedling under cover using insect proof nylon net (40-50 mesh) is a good practice. Use Casurina or bamboo poles or GI pipes to support the net. To raise seedlings sufficient for one hectare, a net covered area of about 150 square meter is required, which will require one time expenditure of Rs. 5000 for procuring inputs and stitching the net.

Solarization for nursery bed sterilization

It is a method of heating soil through sunlight by covering it with clear /transparent polythene sheet to control soil borne diseases including nematodes. Other additional beneficial effects include control of weeds, insect pests and release of plant nutrients resulting in increased crop growth. Solarization is a non-chemical alternative for disease, insect pest and weed control. It can be successfully used for disinfection of any seedbed to produce healthy seedlings of vegetable.

Method of soil solarization

• Prepare the raised bed, add organic manure and make the bed ready for sowing.

• Bring the bed to field capacity by irrigating. Cover the nursery beds with 200 gauge transparent polyethylene film as tightly and closely to the ground as possible.

• Leave the beds covered for 30-40 days. The soil temperature of the nursery bed thus covered can go up to 52°C in summer.

• Care should be taken to see that sheets do not tear off.