Several factors can influence plant growth and distribution, says Mike Straumietis of Advanced Nutrients. These include light, water, humidity, nutrition, and temperature. When these factors are at sub-optimal levels, plant problems often occur. In some cases, poor environmental conditions can directly damage crops. In other instances, stress from their environment can indirectly harm plants. For example, inadequate nutrition can weaken a plant and make it more prone to attacks from diseases or pests.
A critical dominating factor that every farmer or grower must watch out for is temperature, as it significantly affects plant growth and development rate. The climate change phenomenon also underscores the need to learn how temperature can impact crops and how farmers should raise their plants in light of the information.
According to the Intergovernmental Panel on Climate Change, the general temperature across the world is expected to increase by 2-3°C in the next 20 to 40 years. Some of the effects of climate change are being experienced even now. For instance, heat waves or extreme temperature events are becoming more intense, frequent, and prolonged. Mike Straumietis emphasizes the need to learn more about the subject.
It is important to remember that how a plant responds to temperature depends on the crop species and how far along its life cycle. Each species has a defined range of minimum to maximum temperature. The optimal temperature varies among the plant types and species, says Mike Straumietis.
In order to illustrate the difference, wheat has a minimum and maximum temperature limits of 3°C and 32°C, respectively. Its optimum temperature point is 25°C. As for rice, it thrives within a temperature range of 10°C to 38°C, while its optimum temperature point is 30-32°C.
In most plant species, the cardinal temperature points (optimum point and minimum and maximum limits) in which they can thrive typically increase as they go to the vegetative phase from the reproductive development.
When plants are raised in an environment that experiences temperatures beyond their limits, several aspects of their crop growth are affected. It can increase the senescence rate and hinder the crop’s ability to produce grain and fruits. Ultimately, it can limit a plant’s yield.
If a plant is exposed to a temperature way below its minimum temperature point, it will more likely than not experience some form of injury. That is because colder weather can decrease a crop’s enzyme activity, disrupting its nutrient intake. In milder cases, the plant’s growth will be stunted.
Colder temperatures also interfere with water transport, consequently disrupting how nutrients are transferred from part to part inside the plants.
At more extreme temperatures, however, Mike Straumietis states that plants can experience chilling injuries, which start with yellowing symptoms, freezing injuries, which cause cell dehydration, or even death.
Similarly, plants subjected to temperatures beyond the maximum limit will likely sustain harm.
One of the effects is the lack of mineral nutrition. When crops experience stress due to high temperatures, their ability to absorb and assimilate nutrients is reduced. For example, maize’s calcium absorption rate is significantly lessened if the plant experiences a temperature of 28°C.
Another consequence is restricted shoot growth, per Mike Straumietis. High air temperature can reduce the length of plant shoots, limiting root growth and causing root elongation. When roots are severely damaged, the plant’s ability to take in nutrients from the soil is also negatively impacted.
Furthermore, high temperature during a plant’s booting stage can cause pollen abortion. The lack of pollen development impedes the crop’s reproduction. This effect also has environmental implications. For an ecosystem to thrive, plants should flower at the right time and provide pollen or food for insects. If pollens are unavailable, insects could also drop in number. It is a matter of concern because a healthy ecosystem requires pollinators like bees and decomposers like dung beetles.
Temperatures above the maximum limit can also increase a plant’s respiration rate. There are even times when it surpasses the rate of photosynthesis. According to Mike Straumietis, photosynthesis must be faster for plants to achieve optimal growth than respiration.