Influence Of Environmental Climate On Pathogen Populations

INFLUENCE OF ENVIRONMENTAL CLIMATE ON PATHOGEN POPULATIONS Fertilization Fertilizing can help control disease and sensitize plants to other diseases. Example: poor plant condition either due to lack of minerals, poor soil structure, lack of sunlight or similar to lack of fertilizer. A disease that develops in poor conditions is brown spot disease on rice Drechslera oryzaewhereas in good plant conditions, blast disease develops Pyricularia oryzae. Irrigation Irrigation of plants can increase yields but on the other hand, it can affect several diseases. Groundwater is an important but little-known environmental aspect of soil that influences the growth and survival of pathogens in soil. Knowledge of groundwater in relation to: growth of microorganisms, antagonists, host exudation, other factors that influence the development of pathogens in the soil is very useful for preventing or controlling plant diseases. Groundwater energy, better known as groundwater potential, is determined by the forces that bind the soil. If living organisms, both pathogens and those that are antagonistic to pathogens, cannot overcome the forces that bind water in the soil, then they cannot obtain water for their life processes. Living organisms differ in their ability to take up bound water, so that the water potential that is critical for one pathogen species may not be so for another pathogen. Therefore, knowledge of the relationship between soil water potential and the growth or reproduction of microorganisms in the soil is very necessary to determine the influence of soil water on plant diseases caused by pathogens in the soil. Irrigation of plants can encourage increased yields because irrigation can dissolve minerals in the soil that plant roots need for growth and facilitate the transportation of minerals from the roots to the top of the plant. Microclimate (humidity, light, wind) The term humidity is often associated with water contained in the air between plants, rain, dew, exudation which causes free water in plants. Soil moisture that does not match plant needs can result in poor growth and will not produce satisfactory results. Areas that lack water can cover large areas, where plants will grow miserable and for plants that cannot stand it will cause death. It often happens that this water shortage is only limited to certain types of soil, topography and the state of the soil structure. In such circumstances, the symptoms of the disease will be visible in limited areas, whereas in nearby areas where sufficient water is available, plant growth will be normal. Plants that lack water show symptoms of stunting, the color is pale green to yellowish, the leaves are smaller and not fresh. Such symptoms are also visible in the flowers and fruits. If this lack of water lasts for a long time, the plants will wilt and die. Plants that are weakened by drought will be more sensitive to various pathogens that in a healthy state cannot attack them.Lack of air humidity will be very damaging if it occurs together with strong winds and high temperatures. In such situations, the plant will lose a lot of water, which will cause the leaves to burn and the plant will wilt, although often not for too long.Too much water in the soil, often caused by poor drainage or waterlogging, will result in quicker death. This is because the plant roots become rotten due to a lack of oxygen in the soil which is needed by the plant. Apart from that, there are also changes in the condition of the microflora in the soil. Wet soil allows the growth of anaerobic microflora which excretes toxic substances to plants. Damaged roots can be further damaged by facultative parasites which may develop better due to environmental changes in the soil. Thus, plants wilt as a result of too much water in the soil causing root death or often because it is accompanied by the uptake of toxic substances from the soil. Light or radiation Radiation absorbed by the plant canopy is related to heat, especially chemical energy (hydrocarbons), another part of which is used in evapotranspiration to convert liquid into water vapor. Lack of light can inhibit the formation of chlorophyll and result in elongated growth so that the plant falls over easily. This condition is called etiolation. Planting that is too closely spaced or in fairly dark conditions can cause etiolation. Excess lightactually rarely occurs in nature, what is important is the quality of light that reaches the surface of the plant. Although much damage to plants is caused by light, it is most likely a result of high plant temperatures due to high light intensity. Wind Plants will catch spores that are blown by the wind and then deposit them. The strength of the wind gusts, the direction of the wind determines the distance the fungal spores or mycelia travel, as well as helping the spread of disease vector insects to farther places so that they spread the disease more quickly to a wider area.