Carbon dioxide enters into the plant through the stomatal openings by the process of diffusion. Stomata are specialized cells located mainly on the underside of the leaves in the epidermal layer. The cells open and close allowing gas exchange to occur. The concentration of CO2 outside the leaf strongly influences the rate of CO2 uptake by the plant. The higher the CO2 concentration outside the leaf, the greater the uptake of CO2 by the plant. Light levels, leaf and ambient air temperatures, relative humidity, water stress and the CO2 and oxygen (O2) concentration in the air and the leaf, are many of the key factors that determine the opening and closing of the stomata.
Very high or very low RH is not conducive for high grain yield. Under high humidity, RH is negatively correlated with grain yield of maize. The yield reduction was 144 kg/ha with an increase in one per cent of mean monthly RH. Similarly, wheat grain yield is reduced in high RH. It can be attributed to adverse effect of RH on pollination and high incidence of pests. On the contrary, increase in RH during panicle initiation to maturity increased grain yield of sorghum under low humidity conditions due to favourable influence of RH on water relations of plants and photosynthesis. With similar amount of solar radiation, crops that are grown with irrigation gives less yield compared to those grown with equal amount of 'water as rainfall. This is because the dry atmosphere, which is little affected by irrigation, independently suppresses the growth of crops.
fruit production Factors that affect ..
Photosynthesis is the plant process that uses radiant energy, carbon dioxide, and water to form sugar and oxygen. This basic process occurs in special leaf cell structures called chloroplasts. Chlorophyll (the green pigment) absorbs light energy initiating the process.
Non Pathogenic Diseases in Plants - Gardenerdy
Temperature can affect the rates of growth, development, and mortality of pests. Elevated temperatures may result in population increases due to shorter life cycles and faster generation times. Higher temperatures result in less cold stress and longer growing seasons for warm climate pests and more heat stress for temperate species.
whether due to plant diseases …
Stem Canker: In general, cankers are dark, oval or elongated stem lesions that may be sunken with a raised edge. With time, the canker may develop into a gall (a swollen area resulting from infection). Cankers are most often found on stems (especially near soil level) of a gardenia; however, leaves and roots are also susceptible. They are caused by the fungus, Phomopsis gardeniae, which gains access to the plant through wounds. The fungus remains localized near the canker and with high humidity will produce spores that are easily spread by rain or overhead irrigation. The fungus survives the winter within the canker.
how different nutrients affect different types of plant diseases ..
To provide a guideline for CO2 addition, a theoretical calculation is given below for a glass house of 100 m2, with a growing crop, on a day with average light intensity. In this calculation, a level of 1,000 ppm CO2 will be supplemented to maintain 1,300 ppm during the day. Normally CO2 supplementation is not required at night as no photosynthesis occurs. Actually, the CO2 concentration will tend to build up naturally as a result of plant respiration. Therefore, it is not uncommon to find elevated levels (500600 ppm) early in the morning. Growers using high-pressure sodium lighting during the night should maintain at least 400 ppm of CO2.