As every year, nature reminds us not only of its beauty, but also of its destructive power.
Although frost protection in Poland is usually assessed only towards the end of May, this season was different. By the end of April, many orchards already knew their real yield potential — or, more precisely, the scale of losses caused by a severe abiotic stress: temperatures dropping below 0°C.
It is fair to say that, considering both the geographical scale of the frosts, which affected virtually all major fruit-growing regions in Poland, and their intensity, we are facing one of the most serious disasters in Polish fruit production in recent decades.
Low temperatures, regardless of the developmental stage of the plants, damaged many species of fruit trees and berry crops with devastating force. The consequences will certainly be reflected in the financial condition of many farms.
From the perspective of our farm, and based on observations from Powiśle, one of the largest fruit-growing regions in Poland several important conclusions emerge, similar to last year.
The first and most important one: when planning investments, frost protection systems should be treated as a priority. A farm can maintain profitability for one season without a new tractor, sprayer, or another machine. It is much harder to do so when yield losses reach 80–100%. This is the path many growers in our region have chosen, investing primarily in overhead sprinkler systems. In the case of Powiśle Lubelskie, the natural advantages of the location play a major role, especially the relatively easy access to water, which makes it possible to build effective frost protection systems.
The second key element is a proper measurement base. Under frost conditions, a standard thermometer often does not tell the whole story. This season, during several frosty nights, the same pattern repeated itself: the temperature on a standard sensor was still around +4°C, while the wet-bulb temperature had already dropped below 0°C.
This was caused by a drought lasting more than two months, another abiotic stress factor weakening plants that were often already in poorer condition after a winter with temperature drops reaching -30°C. In practice, this detail can determine the effectiveness of frost protection. It is also a very misleading situation. Under moderate humidity conditions, as the air temperature approaches 0°C, the wet-bulb temperature usually becomes very close to the dry-bulb temperature due to humidity rising above 90%. This was not the case this season.
Starting the sprinkler system too late means failing to build the necessary thermal energy early enough through the process of water freezing. With temperature drops to -1°C or -3°C, such a delay may not always have dramatic consequences. But when temperatures fall to as low as -10°C at ground level, the safety margin practically disappears.
We are now observing the effects of such decisions across Poland. Too often, the effectiveness of frost protection sprinkler systems is reduced to a simple statement: “they did not work.” But very rarely does anyone ask whether their full potential was actually used.
The third issue is the quality and selection of high-pressure pumps. Petrol and diesel pumps are very popular, especially in areas where a high water table in wells allows them to be used effectively. However, practice shows that technical parameters on paper are not enough. Not every pump that theoretically meets the requirements of an installation performs well in real conditions — during many hours of operation under heavy load. There have been cases of breakdowns, excessive vibration, and even mechanical failures during operation. With every frost event, we hear more and more stories of almost absurd pump failures.
That is why, when designing a sprinkler system, it is worth leaving a sufficient safety margin in water capacity. Not so the system looks good in a calculation, but so the pump can operate under optimal conditions and the installation can maintain stable pressure. Based on our observations, proper pressure affects not only sprinkler output, but also the quality and speed of sprinkler movement. On a frost night, when every minute matters, these are critical factors.
The fourth conclusion concerns delaying vegetation. It seems that in seasons like this one, delaying the start of vegetation may bring significant benefits especially in floricane raspberry varieties, but also in other fruit crops. The more advanced the plant’s developmental stage, the harder it becomes to protect it effectively against frost damage.
Early vegetation also increases the risk of plants entering their most sensitive stage during a period of highly unstable weather. Strong wind gusts, and in extreme cases even snowfall, add another layer of difficulty something we experienced during last season’s temperature drops.
This year once again shows that frost protection is not an optional addition to fruit production. It is one of the foundations of risk management in modern horticulture.
There is no single technology that solves every problem. However, there are decisions that significantly improve a farm’s chances of surviving extreme seasons: the right investments, precise measurements, a well-designed system, reliable equipment, and decisions based on data — not only intuition.
To sum up, we continue to assess frost protection sprinkler systems very positively, both on our farm and in other farms in our area. However, this comes with one important reservation: we also witnessed cases where an overly relaxed approach to delaying the start of irrigation led to the opposite of the intended effect — not only yield loss, but also damage to the leaf mass.
For another year in a row, Rivulis 233B, Flipper, and Super XL sprinklers performed very well on our farm. During the last frost event, we also started testing relatively new solutions from Netafim — specifically Pulsar x StripNet X and Pulsar x GyroNet SR. Based on our first observations, they appear to be very interesting design solutions, and we will certainly continue testing them in the coming seasons.
I am also convinced that we need to further expand our temperature and air humidity measurement base. The technology has already been selected, and I hope that next season I will be able to share the results of this work as well. Moreover, after managing several sprinkler systems on a single farm for several consecutive nights, I am fully convinced of the need to monitor their operation remotely from a mobile device. For this reason, each pump will most likely be equipped with its own pressure sensor. This should significantly reduce the resources needed to supervise pump operation, while also shortening the response time in the event of a potential failure.
Polish fruit production is facing difficult months ahead, but also a time to draw conclusions. Everything indicates that, in horticulture, success will increasingly belong not to those who farm the largest number of hectares, but to those who manage production risks and costs most effectively.