Preface

I. introduction
II. Light
III. Precipitation
IV. Temperature
V. Atmospheric Humidity
VI. Wind
VII. Atmospheric Gases
VIII. Conclusion

Preface
The success or failure of farming is intimately related to the land use prevailing climatic conditions. So a farmer should have an elementary knowledge as to how the climate has a bearing on plant growth and development. This article describes the different activities climatic factors such as light, precipitation, temperature, humidity, storage of wind and atmospheric gases and its influence on plant life

Introduction
Climate is one of the main natural factors governing the plant growth and development. It is also a primary factor which determines , tile success or failure of the plant life. Climate can be defined as the sum total of all atmospheric or meteorological influences, Ii principally temperature, moisture, wind, pressure and evaporation which combine to characterize a region and give it individuality by influencing, the nature of its land forms, soils, vegetation and to the land use.

Climate has a great role to play in almost all the agricultural different activities from the initial preparatory tillage to the harvesting and storage of produce. Even the price trends of agricultural products life. are also controlled a lot by the climate. Climate and weather are the two major limiting factors (in crop production) to be considered in the matter of the time of sowing, transplanting, scheduling of irrigation, timing of fertilizer application, using of pesticides etc. Weather is the day to day condition of the atmospheric temperature and the presence of rain, sunshine and wind. Thus weather of a place is said to be dry, cold, hot, warm, sunny, wet, cloudy, clear, windy etc. whereas climate is the, regular pattern of weather, conditions extending over a period of time in a particular region. The climate of a particular region is fairly uniform over a wide variety and area. However, variation in the climate can take place in relatively small areas mainly due to the topographical or other factors. These local variations which are limited to small areas and create a small climate are called micro-climate.

A sound knowledge or the climatic factors and understanding of the complex processes of interaction between climate and biological processes of the plant are essential for a scientific approach to farming The following are the climatic factors that affect the crop plants in their growth and development.

II. Light (Solar radiation)

Light is the most important abiotic (non-Living) factor without no Life can exist. Climatic factor also accelerates many vital processes of the plant. The chief natural sources of light are sunlight, moon light and star light. Of these sunlight has the greatest ecological significance. In fact, farming is simply the harvesting of solar energy through crop plants.

Solar energy meets two essential needs of plants: (I) Light required for photosynthesis; and (2) thermal conditions required for the normal physiological functions of the plant. These are needed for the functions such as seed germination, leaf expansion, growth of stem and root, flowering, fruiting, and reduces the dormancy.

Light is an indispensable factor for the synthesis of increases the carbohydrate in plant cells. This sunlight is absorbed by the green, pigment of the plant i.e. chlorophyll. Chlorophyll captures the solar energy from sunlight and preserves it in the form of carbohydrates which are the chemical compounds produced inside the leaves by the process called photosynthesis. The carbohydrate manufactured by by the plants during photosynthesis is the only link between the solar energy and the living world.

Photosynthesis consists in the building up of simple carbohydrates such as glucose and fructose in the green leaf by the chloroplasts in the presence of sunlight by using carbon dioxide and water as raw material.

All the four characteristics of light namely light intensity, light quality, light duration and light direction influence plant growth and development These are discussed below:

A. Light intensity

The variation of light intensity takes place when there is a the change in temperature and relative humidity, which controls the process of photosynthesis very much. The very low light intensity reduces the rate of photosynthesis and may even result in the closing of stomata. This will retard the growth of the plant. Similarly, very high light intensity is also detrimental to plant in many ways. It increases the rate of respiration and this disturbs the photosynthesis-respiration balance. It causes rapid loss of water from plant leaves resulting in the closure of stomata thereby blocking the entry of CO2 into the leaves. The high light intensity also causes the by phenomenon of solarization in which the cell contents are oxidised by atmospheric oxygen resulting in the loss of CO2 from plant the leaves.

Most of the crops show marked response to change of light the intensities. During cloudy weather the production of dry matter is limited. It also depends on the type of plants. Some plants are heliophytes (sun loving) and some are sciophytes (shade loving). Most of the species produce maximum dry matter under high light intensity if water is available in plenty. However, crops like betel, sunflower, wheat and tobacco, grown during summer, produce greater dry matter if slightly shaded.

B. Quality of light

When light is passed through a prism it is dispersed into wave lengths of different colours viz., violet, indigo, blue, green, yellow, orange and red. The most effective wave length for the growth and development of a plant is red light followed by violet and blue. Red light is especially important for the photosynthesis.

Many factors such as amount and kind of cloud cover, fog, hence they air pollution and the colour of the foliage, influence the light and its impact on plant growth and development.


Next : Climatic Requirement of Plants - Duration of Lights