What is DIF?
How greenhouse growers can utilize dif to their advantage
What is DIF, and how do I calculate it?
DIF is short for the difference between daytime temperatures and nighttime temperatures within a greenhouse.
When the temperature during the day is warmer than it is at night, there is a positive DIF. When the temperature during the day is cooler than it is at night, there is a negative DIF. If there is no difference between the daytime and nighttime temperature, there is zero DIF.
The DIF of your greenhouse can be calculated using this formula: DIF = DT – NT, or DIF = day temperature – night temperature.
What is DIF used for?
Growers use DIF to control the height of their plants.
Research shows that having a positive DIF makes plants grow taller, while a negative DIF makes them shorter.
Higher daytime temperatures promote stem height, thickening, and vascular growth.
Lower daytime temperatures prevent stretching and make the plants more compact.
The most effective DIF strategy is called the “cool morning pulse.” Using a cool morning pulse has the same impact as maintaining a negative DIF.
This method saves a lot of energy because it maintains the cooler temperature for only a few hours instead of the entire day.
DIF has the most impact during the crop’s most active grow period, so it doesn’t have to be used throughout the entire grow cycle. That’s why keeping them cool at dawn will show similar results as keeping them cool all day.
Insights
Some plants respond to DIF more than others. Crops that are sensitive to DIF include ornamentals, tomatoes, snap beans, broccoli, cucumber, and different varieties of melons. If you’re growing crops such as tomatoes, you might want to maintain a positive DIF. If you’re growing flowers and ornamentals, your plants would benefit from a negative DIF.
The biggest advantage to using DIF is that it reduces the need for chemicals to control plant height.
The biggest disadvantage is that a negative DIF can reduce plants’ grow rate/development if cooler daytime temperatures are sustained.
Temperature control, including controlling DIF within your greenhouse, is made easy with TC Control Group’s temperature control systems. Our systems are fully integrated, considering humidity and airflow along with temperature. With a TC Control Group system, you have complete control over your growing environment. TC Control Group makes maintaining DIF, positive or negative, easy. Contact our experts to get started today.
