2.1.3. Climatic Data

The data on climatic conditions were collected by Croatian Meteorological and Hydrological Service. The climatic conditions were monitored by the nearest climate stations (Virovitica for Lukaˇc and Gradište for Tovarnik). The distance between the meteorological stations and the experimental sites was not more than 20 km. For the period from April to September, data on mean air and soil temperatures and total precipitation were collected and analyzed for Virovitica and Gradište in both years under investigation.

#### 2.1.4. Design of Experiments

At each site, sugar beet seed was sown in three treatments, one of which was untreated seed (0 mg a.i./seed), the second treatment was sugar beet seed treated with imidacloprid (0.91 mg a.i./seed) and the third treatment was seed treated with thiamethoxam and teflutrin (0.36 + 0.036 mg a.i./seed). In both years sowing was done in regular spring terms (2015: 9 April—Lukac, 10 April—Zagreb, 11 April—Tovarnik; 2016: 26 March—Tovarnik, 1 April—Lukac, 7 April—Zagreb). In field trials, each treatment was sown on 1.000 m<sup>2</sup> in three repetitions. Each repetition was 123 m long and was sown with a six-row sowing harrow (i.e., 333 m2) at a depth of 3 cm, the distance between rows was 45 cm and the distance in one row was 18 cm (i.e., 123,321 seeds/ha). In the greenhouse research the sowing conditions in the arable layer (30 cm) were simulated. The same treatments were sown in plastic containers of 90 cm × 50 cm × 38 cm (length × width × height) filled with 100 L Klasmann-Deilmann GmbH Supstrat 1 (EN Standard). The substrate used was a mixture of white peat (H2–H5) and black peat (H6–H8) with a pH value (H2O) of 5.5–6.5 and 14:10:18 NPK fertilizer. The amount of heavy metal was significantly below the maximum permissible concentration. The sowing was done by hand at a depth of 3 cm and the distance between the seeds was 5 cm with an approximate quantity of 45 seeds per container. A total of six containers were sown per treatment (2 per repetition).
