Summary:

Fifty research tasks are conducted within 2008 - 2014 Multi-Year Pro-gramme. One of them (2.2) is: Optimization of irrigation of fruit crops in Poland considering weather condition and soil water resources in major fruit production regions. The aim of this task is to develop internet service of irrigation recom-mendations and to develop and implement with the use of Internet simple methods of water requirement calculation for fruit crops. The test version of the service was launched in 2012. The web address of the service, which is located on a server belonging to Research Institute of Horticulture is: http://www.nawadnianie.inhort.pl. It is also possible to access the service from the main web site of the Institute: http://www.inhort.pl using "Serwis Nawodnieniowy" link. The web service contains current and historical meteorological data measured by several weather stations belonging to the Institute. Climatic water balance is also calculated. The web also contains glossary and scientific literature on irrigation and water management. Software applications for calculation of plant water needs and irrigation rates are important elements of the service. Using these calculators it is possible to determine evapotranspiration and plant water requirements computed with the use of measured weather parameters. They are designated for users who do not have access to data from meteorological stations. Initial analyses demonstrated a high correlation between water requirements calculated using the internet application and the actual quantities of water which were applied through irrigation system controlled by soil moisture sensors.