AK Bijaya Devi, Sinam Sharmila Devi and Mrinalini Longjam
Contd from prev issue
C. SEED SOWING:
Treat the seed with Captan or Thiram @ 3g per kg of seed before sowing. Seeds are sown either by broadcasting or sowing in rows/lines. Later one is more advantageous due to easiness in weeding, application of plant protection chemicals and uprooting for seedlings. After preparation of nursery bed, shallow furrows are made with finger or sticks at a distance of 5-10 cm. on levelled beds. Seeds are sown uniformly in furrows. Furrows can be made with special furrow making frames. Small sized seeds are sown by mixing with fine sand. Sowing should be thin so as to have 2-4 a seed per cm. Depth of furrow is kept at four times the diameter of seed. Seeds of cabbage, cauliflower, chilli, brinjal, tomato, etc. are sown 1.0-1.5 cm. deep. Cover the furrow with a thin layer of paddy straw to avoid crust formation and irrigate the nursery bed with water so as to keep the nursery bed moist. During the peak summer season raise the nursery under shade net to protect seedlings from hot weather conditions. Nursery can be made in ploy house made up of transparent UV stabilized polythene film which provide a controlled and favourable environment for proper germination of seeds and also checks incidental entry of insect pest.
D. DISEASES AND INSECT PESTS OF NURSERY PLANTS:
DAMPING OFF SEEDLINGS: This disease commonly occurred in poorly managed nursery beds. The symptoms of disease occur in two phases i.e. pre-emergence and post-emergence death of seedlings. In the former, there is failure of seedling emergence from soil either due to seed rots or killing of young seedlings before their emergence from soil, hence resulting in patchy appearance of seedling stands in nursery. In post emergence damping off, the disease outbreak is characterized by toppling over the infected seedlings at any time after their emergence from soil.
1. Treat the seeds with Captan or Thiram @ 3 g per kg of seed before sowing.
2. Drench the nursery beds with 0.4% Captan or Thiram (400g in 100 litres of water) 5-7 days after germination. Repeat the drenching after 7 to 10 days if necessary.
3. If there is an attack of insect spray recommended insecticide to control the insect.
E. ESSENTIAL OPERATIONS IN NURSERY RAISING:
1. MULCHING: Immediately after sed sowing about 5 cm. thick layer of mulch (farm residues, saw dust, ash, polythene etc.) should be applied over the bed to conserve moisture in the soil. When the seed germinates, the layer of mulch should be removed.
2. PRICKING: The transferring of young seedlings into another bed, pan or tray is termed as pricking. This operation is practiced when the seedlings at two leaves stage and the seedlings become large enough to handle. It is done with the objective of fast and vigorous development of seedling and minimizing transplantable time.
3. HARDENING OFF: This is a practice of exposing the plants to full sunlight and withholding the irrigation for seven to ten days before transplanting so as to make the plant able to tolerate external growing conditions.
F. UPROOTING OF SEEDLING:
One or two weeks before transplanting restrict or withhold irrigation for 7-10 days for hardening of seedlings. Hardened seedlings withstand transplanting shock better than in the main field. Irrigate nursery beds heavily on the previous day of uprooting to facilitate easy uprooting of seedlings without damage to roots of seedlings. Seedlings should always be transplanted at their suitable age. Generally, it has been seen that over-aged seedlings have a high percentage of mortality and a slow established rate. Bolting in onion and premature seeding in cabbage are the best examples of negative effects of planting over-aged seedlings in the field. Suitable ages for transplanting seedlings of some crops are given below.
Sl. No. Vegetable crops Age in weeks
1. Brinjal (3-4)
2. Tomato (3-4)
3. Brussels sprouts (6-8)
4. Cabbage (4-6)
5. Cauliflower (3-4)
6. Sprouting broccoli (3-4)
7. Celery (6-8)
8. Leek/lettuce/Parsley (4-5)
9. Onion (6-8)
For further details contact:-
Public Relation & Media Management Cell,
CAU, Imphal. Email: [email protected]