This blog provides in-depth details on the effects of fog and frost on crops and the best techniques for farmers to shield their crops from freezing damage in winter.

As the air is turning colder, now is the time to get your crops ready to fight against winter frost. Frost is a severe challenge for farmers during the winter season. It has harmed crop productivity in numerous regions of the world. Many farmers suffer significant losses as a result of frost damage. Farmers must set up their fields to safeguard frost-sensitive crops during anticipated freeze warnings. Don’t worry! This blog will provide you with the best techniques to protect your crops this winter.

What are Frost and Fog?

The term “frost” technically refers to the development of ice crystals on surfaces, either by dew freezing or a phase transition from vapour to ice.

Frost forms at below-freezing temperatures of 0°C. Growers use the terms “light frost” and “hard freeze” in relation to farming.

Water molecules condense into ice crystals in and around your plants when the temperature falls below 0°C. A hard freeze usually occurs when the temperature is below -3°C for more than four hours.

A cloud forming at ground level is commonly referred to as fog. It takes sufficient moisture in the air to cool or be chilled to a temperature suitable for condensation. Visibility drastically declines once condensation starts to happen. As a result, it becomes difficult to carry out day-to-day farming operations.

Impact of Frost and Fog on crops

Ice crystals develop in plant cells when the temperature falls to freezing. The plant is deprived of water because the ice crystals obstruct the movement of water and other fluids.

For this reason, damaged plants’ leaves frequently seem withered and dehydrated after a winter. Eventually, the affected leaves will turn brown. Dehydration of plant cells that results in freezing intracellular water is the leading cause of frost damage. 

Crops particularly vulnerable to injury in freezing weather include beans, cucumbers, muskmelon, okra, peppers, pumpkins, squashes, winter sweet corn, sweet potatoes, tomatoes, watermelons, etc. 

Different crops exhibit different signs of frost damage. Cole crops, for instance, frequently show severe signs of frost damage; these symptoms range from interveinal chlorosis to necrosis, mainly affecting older leaves. 

Heavy fog also can cause damage to fruits and vegetables if it lasts several days. In certain situations, they show evidence of stunted growth and the onset of withering.

List of crops sensitive to the freezing temperatures

Best ways to protect your crop from frost and fog

1. Select the appropriate crop and site. 

Proper site selection is the best means of protecting crops against frost. It is critical to select plants that bloom later to lessen the likelihood of freezing damage and cultivars that are more tolerant of freezing. For example, The citrus fruits more resistant to frost damage are limes, grapefruit, tangelos, and oranges, with lemons being the least tolerant. A site with good cold air drainage makes it an excellent production site for avoiding frost freeze damage. In low areas, where frost damage is most likely, cold air flows downhill and settles.

2. Cover your crops

• Since plant covers are warmer than the open sky, they help lower convectional heat losses to the air. Cover the crop with a tent to keep heat within and stop heat transfer into the atmosphere. This could be made of blankets, plastic sheets, or tarps. 

• You can also construct a frame out of wood and cover it with cloth or plastic or use giant cardboard boxes or trash cans. Wind will undoubtedly be an issue, so secure your tent using poles, buckets of water, bricks, or logs. 

• Always use the covering as a tent. Its ends should touch the ground and cover the crop. One should not wrap the plant like a lollipop. The radiant heat rising from the ground is not utilised in this manner. The tent technique will trap this heat, allowing your plants to withstand the frost.

3. Mulching 

• In simple terms, mulching is the process of covering agricultural beds with a substantial layer of organic material. This prolongs the harvest season for crops, protects bare soil from harsh winter temperatures and helps winter crops withstand freezes and thaws.
• In the case of fruit orchards, mulching should be done after the first hard frost, typically after temperatures have fallen below -3°C and the annuals have died back. The idea is to prevent soil from warming so that plants stay dormant. Hence it is crucial to wait until the earth has frozen before planting.
• Before the ground freezes, cover plants with a 1 to 2 feet layer of straw, leaves, or other organic material to prepare crops for a prolonged harvest. A row cover, old bed sheet, or garden blanket placed on top can help hold everything in place.
• Mulch helps protect vegetables from freezing temperatures. The plant’s crown and roots will survive the winter because of the mulch’s insulating qualities.

4. Irrigation

• It’s likely the last thing on your mind to go outside and water the crops when a significant freeze is expected. Water, contrary to popular belief, can protect plants. Drought-affected plants are less resistant to the cold and are injured at lower temperatures than usual. Several days before the winter weather arrives, irrigate your crops. 
• Additionally, water absorbs solar energy, stores it, and then gradually releases the warmth. Greater air gaps in dry soils prevent heat from being stored and transferred. Therefore, moistening dry soils in colder months improves frost protection. 
• If you irrigate your crops before a freeze, a source of warmth will be created above the freezing point and continue to transfer heat throughout the night. While doing this on its own won’t preserve your tree, pairing it with tenting should yield positive effects.

5. Use of water containers

Compared to air, water cools slower. You can protect your crops from frost damage using water gathered in barrels, buckets, or other storage containers. The containers of water, when placed near plants during the day and under a cover at night, will give out modest amounts of heat as they cool.

It is a technique used to fill 5-gallon buckets or huge trash cans with water. Make sure the lid is on because doing so reduces heat transfer. This has been demonstrated to be a successful strategy for saving the plant, together with tenting.

For example, to produce a warmer microclimate, place a bucket of water close to little tomato transplants and cover the plants as well as the bucket with tents.

Conclusion

There are numerous methods through which frost can be managed. Each grower must select the ideal frost protection strategy for optimum results. Farmers should use all of these techniques carefully. Numerous microclimatic forecasts assist in foreseeing frost in advance. For frost protection, forecasting the minimum temperature and how it might fluctuate overnight is helpful since it aids growers in determining whether protection is required.

How can Fasal assist?

Fasal is a comprehensive platform for horticulture growers that is based on an AI-driven platform. Every Fasal sensing hub has various sensors, including weather sensors, in addition to micro-climatic, macro-climatic, and below-ground characteristics. It assists in lessening the strain that unpredictable weather puts on your crops. 

The Fasal System assists you in managing each stage of your crop’s growth as efficiently as possible. This not only results in high-quality produce but also increases yield.

We think farmers should have access to solutions that can improve their lives by lowering their risks and costs while increasing their income.