Effect of Climatic Conditions and Irrigation on Sugar beet Production in Serbia and Montenegro

1. Effect of Climatic Conditions and Irrigation on Sugar beet Production in Serbia and Montenegro Dr. Livija Maksimovic, Prof. Dr. Svetimir Dragovic Institute of Field and Vegetable Crops, Novi Sad, Serbia and Montenegro

2. INTRODUCTION The sugarbeet is the main raw material for the sugar industry of Serbia and Montenegro. In the Vojvodina Province, sugarbeets are grown at 80-100 000 ha and are processed by 11 refineries. Because of the insufficient amount and unfavorable distribution of rainfall during the growing season, resulting sugarbeet yield losses that are often as high as 50% and may reach as much as 80% in extremely dry years. We need high and stable yields each year, which is not possible under natural water supply conditions, so irrigation has to be used.

3. MATERIALS AND METHODS The effect of irrigation on sugarbeet yield performance are regularly monitored on a loamy soil with favorable water-physical and chemical properties At experiment fields ofInstitute of Field and Vegetable Crops in Novi Sad. This paper reviews the results of a 38-year experiment (1966-2003) on rainfall amounts and distribution during the growing season, plant water requirements, yields with and without irrigation and the effects of irrigation on sugarbeet yields.

4. RESULTS The values established for the period 1966-2003 indicate that the average sugarbeet water requirement (ETP) was 578 mm. Potential evapotranspiration of sugarbeet changes with stage of plant development: - 78 mm in May (15% of the total requirement), -118 mm in June (22%) -139 mm in July (27%), -129 mm in August (25%) - 60 mm in September (11%). The actual consumption, of water was 398 mm. The yearly average water deficit, was in this period 185 mm, ranging annually from 28 in 1991 to 427 in 2000.

5. - Water balance of sugarbeet in the location of Novi Sad (1966-2003) ETP - potential evapotranspiration, R - rainfall (IV-IX), ETR - real evapotranspiration

6. Table 1 - Water balance of sugarbeet in the location of Novi Sad (1966-2003) - Water balance of sugarbeet in the location of Novi Sad (1966-2003) ETP - potential evapotranspiration, R - rainfall (IV-IX), ETR - real evapotranspiration Water deficit was especially high in July and August, when the average shortage in rainfall reached 131 mm, with the annual variations from 0 to 282 mm.

7. Average sugar beet yields in trial with and without irrigation conducted at Novi Sad on a loamy soil at the experiment field of Institute of Field and Vegetable Crops in Novi Sad Sugarbeet root yields witought irrigation depend directly on the amount of growing season rainfall and the amount of available water spent on evapotranspiration.

8. In the trials conducted on a loamy soil over a period of 38 years (1966-2003), the average yield in irrigated conditions was 80.7 t ha-1, ranging from 58.2 to 124.0, whereas in non-irrigated conditions it was 60.9 t ha-1 and ranged between 33.2 and 93.7.

9. Sugar beet yields as affected by the sum of precipitation and irrigation Max 181% Min 4% Irrigation effects for the analyzing period were 37% (20 t ha-1) on average, varying from 4% in 1966 to highest effect (75,7 t ha-1)181%.The extremely dry year was 2000, in which the water deficit during the growing season was 427 mm.

10. Effect on irrigation relative to non-irrigated condition After a long period of research (almoust 40 years) conclusion is: Natural precipitations are not enough for high and stabile yields and for that reason irrigation is nessesery for suger beet production.

11. Thank you for attention!