Fertilization of nursery bed

• 200-840 g/m2 of fertilizer with 4.8% N, 4-12% P and 3-12% K.
• Higher rates required for flue-cured, medium rates for cigar and Turkish and lower rates for fire-cured and Burley tobacco.
• In Nepal, fertilizers @ 75g/m2 with 6.4% P, 20% K and 4% N.
• In poor soils general recommendation is 50 kg ammonium sulfate and 300 kg SSP per ha should be applied.
• In late sown conditions, in sandy soils, Mg deficiency is observed, thus application of dolomite lime stone @100 kg/ha is desirable in such conditions.

Seed rate and seed treatment

• Generally, 2-3.5 kg/ha of seed rate is required depending on the type of tobacco.
• However, under hot conditions the seed rate may be increased up to 4-5 kg/ha, but considerations must be kept to avoid overcrowding of seedlings that may result in higher incidence of damping-off of seedlings.
• The seeds can be treated with 2.5% Formalin solution or 0.25% of Dithane Z-78 or Dithane M-45 for protection from seed-borne diseases.
• A pre-sowing soaking in 50 ppm Gibberellic acid for 48 hours increases and synchronizes germination and seedling stand.

Sowing time

• Tobacco is usually seeded in beds 6-12 weeks before transplanting.
• In Nepal, the sowing time ranges from 3rd week of July to 2nd week of August and transplanting is done from 3rd week of September to 2nd week of October.

Method of sowing and after care of seedlings

• Before sowing, the seeds are mixed with ash or fine sand in the ratio of 1:15 to 1:20 for uniform broadcasting.
• The treated seeds are sown by broadcasting and later mixed with soil up to depth of 1.5-2 cm with the help of rake and compacted.
• Watering of nursery must be regular. Before formation of 1st pair of leaves, the plants are watered several times a day at small rates, to keep the surface moist, but excess water must be avoided.
• When 2nd and 3rd pair of leaves begin to develop, water is less frequent but the rates is increased.
• Usually, 6-8 weeks are required to obtain the transplantable seedlings in case of N. tabacum, while that of N. rustica is prepared in 5-6 weeks.

Main field preparation

• A well-prepared field for transplanting of tobacco seedlings can be achieved by one deep (15-25 cm) primary tillage and subsequent harrowing to make the land clod-free.
• It must always be cared that the soil consists of solid particles and the pores.
• In uncompacted soils, the pores make up about 50% of the total soil volume.
• Too wet fields lead to compaction and therefore reduce root growth.
• Tillage contributes to soil compaction in at least one of the two ways, viz; by destroying soil OM and weakening the soil structure.

To overcome such problems, following ways can be practiced during the field preparation of tobacco:

– Deep tillage to break up the compacted layer. However, deeper tillage does little to improve the growth and results in higher cost of production.

–  Shallow-in-row tillage is found effective in reducing the negative effects of compaction.

Transplanting

• Transplanting of tobacco seedlings is more or less similar to other garden crops.
• The optimum time of transplanting and spacing varies with the type of tobacco.
• Generally, transplanting is done in the month of Sept-Oct in case of winter crop and during late March to beginning of April in case of summer crop.
• Good stocky plants with a healthy root system are essential in obtaining a full stand without replanting.
• Plants 15-20 cm in height with stem diameter about a pencil live better and grow more rapidly than smaller or larger plants.

• As different types of tobacco are grown at different plant population, the spacing between the rows ranges from 50-100 cm and that between plants ranges from 10-60 cm.
• Oriental tobacco with small leaves (Dubee, Samsun) are grown at the plant density of 150-200 thousand per ha while those with medium leaves at 80-90 thousand per ha and the broad leaved strains of Virginia type at 25-40 thousand per ha.
• In Nepal, flue-cured Virginia type tobacco is planted at the spacing of 100 x 60 cm where as Natu tobacco and Belachhapi-1 at 80 x 80 cm spacing.
• The seedlings are transplanted manually or with the help of seedling planters.