The harmful effect of the excessive humidity is known by man since remote times, the Cuban aborigines told the Canaries who were one of the first European tobacco producers that “water sucked the honey of tobacco" and today our peasants to define this situation refer that in rainy years tobacco is like straw. Next some technical elements will be given that could justify the approaches before outlined.

If the conditions of watering are above the necessities of the producer, in function of the industrial use, serious affectations take place in the chemical composition of the leaf and its physical qualities, influencing directly in the characteristics of the cigar, for what in tobacco for wrappers humidity should not be restricted because thickness, nerviations, development and texture of the leaf would be affected invalidating it, on the other hand tobacco for filler would lose the aroma, scent and its flavor, among other qualities if it is cultivated in a rainy year or with a régime of watering superior to the one required.

Generally the leaves that are produced with high humidity of the ground are characterized by:

• Great size
• Fine texture
• Little development of the nerviations
• Clear and uniform Colors
• Low contents of nicotine
• Low contents of nitrogenous substances.
• Delicate and diminished aroma
• Low contents of essential oils and resins
• Very good combustibility, if the content of chlorine in water is less than 25 parts per million

To know the hydric régime is very important but also to define the adequate moments in which it should be applied to the plants. These moments agree with the following phases of growth and development:

• Phase of adaptation (first 8 days after the sowing of the plant)
• Phase of great period of growth (between 22 and 45 days before the sowing of the plant)
• Maturation phase (from the 45 days after the sowing of the plant to the harvesting of the higher leaves). In this stage watering should not be very frequent and of low norm.

Not all the varieties respond in the same way to the demands of watering, in this sense one can point out that in the varieties `Habana 2000 ', `Criollo 98 ' and ' Corojo 99 ', the yield increases when one waters with a humidity of the ground of 70-75-65% of the capacity of the field during the three cultivation stages (0-20, 21-45 and 46-75 days after the transplant). To achieve these objectives 2 slight waterings, 3 heavy and 2 slight will be applied in each phase respectively.

The variety ' Havana 92 ' doesn't require big volumes of water, mainly in the period of adaptation, where the plants are conditioned easily to the field.

Volumes between 1 200 and 1 300 m3/hectare should be used for a cycle of 75 days, what allows altering the watering régime proposed for other varieties. The distribution of watering in this variety should be:

• Sowing with the finger: 170 m3/hectare (light watering).
• First vivo after 4 days: 110 m3/hectare (light watering).
• Second vivo after 8-10 days: 110 m3/hectare (light watering).
• First watering after 22 days: 200 m3/hectare (average watering).
• Second watering after 35 days: 208 M3 /hectare (average watering).
• Third watering after 55 days: 180 m3/hectary (light watering).

If the year is dry and the rain is considered similar to zero, a slight watering will be applied 65 days after the transplant.
Among other factors the hydric régime of tobacco depends on the qualities of the ground, climatic conditions, date of sowing, and very particularly on the type of dark tobacco that is produced, that is why is offered the information on how is watering carried out in the central and oriental provinces of Cuba.
It is not possible to point out exactly the quantity of water and waterings that should be applied to each variety, because it depends fundamentally on the climatic conditions, characteristic of the ground, type and quality of tobacco that is wanted to obtain, fertilizer applied, etc. Some general recommendations can be pointed out for the central and oriental provinces:

If there is no residual humidity in the ground to sow, water should be applied before. An advice to the producer should be that his experience and observation during several years, makes him arrive at a conclusion about the procedure to follow in each case and that it is better for tobacco to "suffer" because of the lacking of humidity in the first 25-30 days of its development, than to see it grow with vigor for having been watered excessively, what would cause little development of the radical system.

In sun grown tobacco (en palo) in the province of Pinar del Río with possibilities of watering, it will be applied in the following moments:

• In the transplant (slight)
• Tape de palito (when covering the stem of the plants) (slight)
• From 24 to 25 days (heavy)
• From 32 to 34 days (heavy)
• From 38 to 40 days (slight)
• From 50 to 55 days (heavy)

Fertilization According to the Nutritional Demands of Dark Tobacco

In the majority of the agricultural cultivations is admitted that the most appropriate soils be characterized by their high fertility, however, this is not valid when talking on tobacco, because it requires a strict control of the nutritional régime with the objective of producing the leaves with the required qualities for industrial use. The nutritional demands of tobacco depend on multiple factors, being some of them the following:

• Prospective yield
• Quality
• Type of tobacco to be produced
• Physical, chemical and biological characteristics of the soil
• Climatic Conditions and environment
• Use of watering
• Quality and types of fertilizers
• Time or period of sowing
• Quality of the works of cultural attentions
• Execution of the orientations of the Management of Soils and Fertilizers.

During the cultivation independently of the type of tobacco three moments for the application of fertilizers exist, the first one during the sowing, the second one when covering the furrow and the third one when hilling around the plant, in Pinar del Rio the fertilizer containing nitrogen is not applied in the first moment, the biggest quantity of fertilizer coincides with the last application, moment in which the plant is in the beginnings of the great period of growth

The doses of fertilizers to apply depend on many factors as it was stated before. For the different types of tobacco can be offered the following tentative figures (expressed in kg / hectare):

In the last years mainly in tobacco for wrappers the located watering has been introduced with very good results and inside this variant the fertiriego. It has facilitated to elevate efficiency in the use of fertilizers and also yields and quality of tobacco with a minimum of aggression to the environment, nevertheless it is necessary to value the consequences of this type of watering which can favor the salinity of the soil.

Although very well-known the following basic principle of the fertilization of tobacco it is also very interesting and important: “the fertilizer can not contain chlorine", nor in small quantities, this compound affects considerably any type of tobacco, except the one that is used to chew, because this element causes the reduction of the combustibility of the leaf drastically.

The fertilization of tobacco should facilitate the satisfaction of the nutritional demands of the plant without affecting considerably the environment, facilitating the production of the aromatic leaf in a sustained way.

Links & Sources:

• www.guerrillero.co.cu