Abstract & Overview
The experiments showing the effect of drip irrigation on yield, evapotranspiration and water productivity of sweet basil (Ocimum basilicum L.) were conducted at the experimental field of the Alternative Crops Department, Institute of Field and Vegetable Crops, Novi Sad. Irrigation was scheduled on the basis of the water balance method. Daily evapotranspiration (ETd) was computed from the reference evapotranspiration (ETo) and crop coefficient (kc) in May, June, July and August of 0.5, 0.6, 1.1 and 1.0, respectively. ETo was calculated using Hargreaves equation. The irrigation depth was restricted to the soil depth of 0.3 m. In other words, irrigation started when readily available water in the soil layer of 0.3 m was completely depleted by plants. The irrigation rate was 30 mm (30 l m-2) while the amount of water added by irrigation during the season was 140 mm. Basil sensitivity to water stress was determined using a yield response factor (Ky). According to the results, the yield of fresh herb of basil under irrigation (32.015 t ha-1) was higher by 9% compared to non-irrigated, control variant (29.364 t ha-1). Worthy of note, basil essential oil yield was significantly affected by irrigation (35.329/28.766 kg ha-1). The content of essential oil was significantly higher in irrigated (6.45 g kg-1 ) than in non-irrigated variant (5.33 g kg-1) in the first harvest, while no significant difference between irrigated and non-irrigated variants was obtained in the second harvest (6.83 and 6.62 g kg-1 , respectively). Water used on evapotranspiration in irrigation conditions (ETm) was 431 mm and 270 mm in non-irrigated, control variant (ETa). The values of irrigation water use efficiency (Iwue) and evapotranspiration water use efficiency (ETwue) were 1.89 kg m-3 and 1.65 kg m-3 respectively. Ky value (0.22) exhibits all essential characteristics of climate conditions of 2016 rainy year. These preliminary results could be used as a good platform for basil growers in the region, in terms to optimize the use of irrigation water.