In black soils

• Starting about three weeks after transplanting of tobacco a number of intercultures are given to drive our moisture in the top soil and induce root growth in deeper layers.
• Mulching with paddy straw @ 3,600 kg/ha after the first interculture was found to be better in the black soils as compared to repeated interculture.
• Mulching with black alkathene film gave better results than paddy straw mulching.
• In the irrigated light soil area of West Godavari district

One or two interculturings are given a month after planting in both directions of the plant row.

• It is to break the hard crust and throw more soil at the base of the plant, so that a broad ridge is formed along the plant row.
• In case of soils with a higher silt content, the crust formation will be more pronounced and interculturing and ridging will be required at the optimum moisture conditions between any two irrigations. This promotes better aeration around the roots and keeps the field ready to get maximum benefit from the next irrigation.

In the unirrigated light soils of southern region

• The crop may benefit by periodic interculture, which keeps the soil in a fit condition to absorb maximum precipitation.

In karnataka during rainy season

• Where the crop is grown during the rainy season, the first interculture is given as early as on 20^th day and followed after each rain till the 45^th day when a final ridging is given by working a couple of country ploughs followed by a ridger so as to earth up the soil on the planting row, leaving furrows in between to facilitate surface drainage.

In West Bengal

• It is a normal practice to work a hand plough at weekly intervals followed by one or two weeding-cum-cold crushing operations.

In case of cigar-wrapper tobacco

• Mulching with black polythene sheet or paddy straw has been found quite beneficial
• In the cigar and chewing tobacco-growing areas of Tamil Nadu.
• A light hoeing is given with hand hoes three weeks after planting; two weeks later, a deep digging is done around the plants with spades and the plants left to wilt for about 7 to 10 days.
• Then the ridges are reformed bringing the plants to the middle of the ridge and giving copious irrigations.
• During this period of mulching and moisture stress, the plants put out a lot of new roots and rate of growth is phenomenal after this period.

• Weeds are generally kept under check by summer cultivation and three or four intercultures given during period of crop growth.
• When weeds become a problem they can be brought under control by use of weedicides.
• In case of tobacco in general and cigarette tobacco in particular use of chemicals which leave a residue on the leaves canot be advocated.
• Weedicides like 2,4 D, 2, 4, 5- T, tafazine have some adverse effect on the chemical and physical attributes.

Some Of the Herbicides Recommended For Tobacco

1. Post emergence (Nursery)
Fluazifop (150 g/ha)	When needed it can be combined with one hand weeding
2. Bidi tobacco (Main field)
Oxyfluorfen (0.1 kg a.i /ha) , Benthiocarb (0.75 kg/ha) , Fluchloralin (1.5 kg a.i/ha)	Apply about 8 days before transpalnting. combine with one inter cultivation.

• Topping is the process of removal of flower heads either alone or with few upper leaves from the plants.
• The main objectives of topping are
  1. To improve the size, body, texture and quality of leaves.
  2. For full development of the top leaves
  3. Finally to increase the leaf yields.
• The height of topping and number of leaves at which topping is done vary with type of tobacco.

The number of leaves left on the plants after topping are as follows for different types:

Type of tobacco	No. of leaves left on the plant
Cigarette & cheroot	8-9
Wrapper (cigar)	10-12
Hookah, Chewing & Bidi	10-14

• It is observed that the energy and nutrients absorbed by the plants are diverted to the leaves rather then flower heads due to topping.
• Thus it helps in the full development of the top leaves or otherwise they will remain relatively shorter when the lower leaves are going to mature.
• It increases the leaf size, thickness and dry weight of the leaves to the extent of 84, 24 and 48 per cent respectively. The effect of topping is more pronounced in younger leaves than older ones.

• Following topping the buds in the leaf axils otherwise dormant become active and put forth branches technically known as suckers.
• To get full benefit of topping, the suckers are to be removed periodically.
• The process of removal of suckers commences after 7 days of topping and 2-3 successive de-suckerings are necessary, otherwise the topping becomes non-effective.
• The manual de-suckering is a time consuming, laborious and more expensive process, therefore, use of chemicals may be practised.

Use of Chemicals for De-Suckering

• Application of coconut oil to the top six axils soon after topping suppresses the emergence of suckers in flue-cured Virginia tobacco.
• In case of Cheroot tobacco in Tamil Nadu, application of 2 per cent (20 g/lit) Naphthalene Acetic Acid in triethenolemin to the topped portion suppresses all the suckers.
• Use of 2 per cent (20 g/lit) of maleic hydrazide or Indole Butyric Acid is also recommended for an effective de-suckering.
• Petroleum jelly, when applied on buds, suppresses suckers.
• Application of neem oil emulsion at 35% immediately after topping completely suppresses the suckers (neem oil 1.75 litre + sandovit 0.5 litre + water 2.75 litre will be sufficient for 1000 plants).
• Piercing of the stem after topping with 20 to 25 cm long needle is found to be beneficial in improving yield and quality of tobacco leaves.
  
  

• Tobacco is an apically dominant plant. If terminal bud is removed lateral buds develop into a reproductive bud that produce flowers when topping is done, the upper 3-4 suckers develop from axils. If these are removed secondary suckers develop.
• A tobacco plant has the potential of producing e suckers at each axil. Topping is essential.

Topping and suckering has the following advantages.

• Increases root growth
• Iincreases water absorption and nutrient absorption
• Reduces top weight - does not lodge
• Reduces drain on certain organic and inorganic compounds used for growth
• Increases the weight and body of leaves
• Improves yield and quality
• Increases nicotine and desirable sugar content of cured leaf.
• The yield increases is much greater for topping and suckering than for topping alone. Marked reduction in yield when topping was delayed beyond early flower stage. The yield was lowered by 10 kg per day.
• Leaves from early topping will be thicker, more oily and good bodied.Due to delayed topping beyond early flower stage,
  1. total alkaloids were reduced
  2. sugar content was lowered
  3. total N affected
  4. reduction in leaf size, length and width
• Low plant population always prefers high topping
• High plant population prefers low topping Spacing, N level, time of topping and variety will decide the height of topping.
• Topping increases nicotine, leaf size, leaf thickness and body.
• The yield was increased with high topping at all population levels and the price tended to be lowered with high topping.