Critical temperatures of crops

Temperature is certainly one of the factors that directly affect crops and plantations worldwide, since all processes that take place during the growth and development of plants depend on it. 

Aware of that, producers are always trying to implement new strategies and sustainable models that allow them to prevent the arrival of critical temperatures on the crops by providing the necessary conditions, so the processes involved are developed in an optimal way and comply with quality standards.

But what are critical temperatures of the crops all about? Simply put, each plant has an optimal temperature point that is ideal for its growth process to take place naturally and without inconveniences. However, when that point deviates above or below its ideal level, the plant can enter into a zero-growth stage, in others words, the plant stops its development, in such a way that the more extreme the deviation from its ideal point, the plant will reach a temperature threshold point that is critical for its survival.

How to calculate the critical temperatures of crops?

It is possible to calculate those thresholds for plants, for example, regarding the cold it is as simple as monitoring the freezing point of the plant, while for the heat it is important to review the denaturation of proteins.

The critical temperature of crops is something that shouldn’t be taken lightly, since making the right decisions timely can prevent entire crops from being affected negatively, which will translate into countless economic losses.

It is worth mentioning, that the yield potential of each crop will depend greatly on the weather and the changes that take place during each sowing and harvest season. According to information published on the webpage Agritech TNAU, more than 50 per cent of the variation in crops will be determined by weather. In addition, the most important climatic factors that end up affecting the growth, development and yield of crops are solar radiation, temperature and the amount of precipitations that take place in an area.

 Types of plants and the ideal temperature for development

In the realm of plants, there are some types that tend to be less demanding in terms of temperature, which at the same time are the ones that will set the trend for the production, considering the time of year the crops are going through. 

There are plants specifically set for winter production, such as cauliflowers and peas, while for summer production there are others that are more appropriate for tropical weathers or weathers with a higher temperature, such as tomatoes and cantaloupes. However, there are other fruits and vegetables that can be produced without inconveniences through the entire year, such as lettuce.

 

What happens when climatic factors such as frosts arise?

This is a very important factor that affects the critical temperature of crops, since the climatic phenomenon known as frosts takes place when the temperature of air reaches 32ºF. The more severe the frost and thus, the decrease of the temperature, as well as its duration, the more extreme the effect on the plant will be. It will all depend on the minimum temperature of survival of each plant.

When temperatures are extremely low, there are several factors related to the growth of crops that are affected in a negative way, such as:

• Survival of the plant
• Cell division
• Photosynthesis
• Water transportation
• Growth and yield

On the other hand, high temperatures greatly affect the mineral nutrition of plants, the growth of new sprouts and the development of pollen, which translates into low yield. Therefore, the critical temperature of crops above which plants reach the point of death is called precisely thermic “death point.”

When can we say that the temperature is high? When it is above 122°F, which generally kills many crops annually in areas where the temperature increases considerably. We must consider that the threshold will be different for each plant and will depend on the conditions of the same.

In general, and to get a better idea about the subject, here is an article about the similarities between plants and human beings that experience thermal stress or that need sunlight exposure for their development and health. 

Use of thermal cover plastic films 

One of the tools that horticulture producers have handy is being able to intervene in the temperature changes of their plantations. To achieve these changes it is necessary, among other techniques, the creation of forced or protected horticultural crops, which basically implies setting up designed small greenhouses that include thermal cover plastic films that allow to reach temperatures that are better and more favourable, so that plants that require an early production can develop normally and in less time. 

With the use of modern agricultural plastics we can, for example, extend the farming season of blackberries or table grapes, reduce energy costs in crops in countries with extreme temperatures such as Canada  or cultivate against natural seasons.

Greenhouse plants frequently harden due to the exposure to external conditions before being transplanted to the field. It has been demonstrated that the treatment of seeds with certain chemicals increases the resistance in some plants. The application of the right amounts of nutrients required can help maintain the resistance of the plant.

Another ideal alternative that many producers have implemented to avoid excessive temperature peaks is having always handy a sowing seasons calendar where they can carefully specify the optimal periods for planting the most delicate plants, which require more monitoring, as well as to keep a log of the periods that are more prone to experiences factors such as frosts or a considerable temperature increase, as a way to protect crops and keep them healthy.

Even though there are several methods designed to prevent the damage caused by frosts and the excess of temperature in the crops, it is essential for agricultural producers to be up-to-date in terms of knowing which procedures are feasible, sustainable and more economical to prevent the damage done by frosts and extremely high temperatures.

Recommendations when it comes to thermal cover plastic films:

• Gama TRC
• Plastermic Range
• Duratermic Range 

Likewise, if you need advice regarding your crops, you can get in touch with us to receive additional information that is more suitable to your needs.