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Ravni Kotari is registered as an area important for the conservation of endangered species and habitat types in Zadar County extends from Town of Nin and the Karin Sea in the northwest to the Krka River in the southeast, Bukovica region in the northeast and the City of Zadar in the southwest. It is an area characterized by agricultural production, especially in fruit and vegetable growing and more recently in viticulture, winemaking and olive growing. For the purposes of this work, scientific data and other sources were collected and analyzed, and the state and challenges in conservation and agricultural use were determined. The goal is to preserve a mosaic of agricultural areas with sustainable production as suitable habitats for the conservation of target species.

Olive (Olea europaea L.) is a Mediterranean fruit crop that requires irrigation to achieve optimal yield and quality. Irrigation practices and damage of olive fruit curculio (Rhodocyrtus cribripennis (Desbrochers, 1869)), a pest of olive fruit, may be an important factor in determining the stage of fruit maturity, one of the main indicator of of fruit quality. The aim of this paper is to determine how different practices, through the amount and frequency of irrigation, with presence of olive fruit curculio, affect the maturity index of olive, variety ‘Coratina’. The research was conducted on 24 olive trees at two locations in Zadar County: Žman (Dugi otok) and Novigrad. Irrigation was performed with a drip system with four variants in three replicates: K (0%) rainfed olives; T1 (PP) irrigation set according to grower experience; T2 (SAN) irrigation set according to evapotranspiration and olive phenology, at up to 80% of field capacity and T3 (100%) where 100% of calculated evapotranspiration was added. Soil analysis determined the field capacity, and evapotranspiration was read from the Pinova™ meteorological station. Harvests was conducted in October 2020 and 2021. For determination of olive fruit curculio infestation and maturity index, 100 fruits per sample were harvested. By processing the data with one-way analysis of variance (ANOVA) and return test (Tukey), the significant effect of irrigation practices on the olive fruit maturity index by treatments, years and locations, single and interdependent, was determined. No effect was found between the presence of olive fruit curculio and the maturity index.

Olive groves in the Mediterranean may lose production sustainability because of their vulnerability to climatic change. Irrigation is an important measure that could significantly affect fruit yield, olive fruit fly infestation, and oil characteristics. The aim of paper was to compare the regulated deficit irrigation with different water management practices, in consecutive years, in two locations in Zadar County (Croatia), affecting fruit morphology, olive fruit fly infestation, and quantity and quality of the extracted Coratina cultivar oil. Treatments, namely C—rainfed, T1—deficit irrigation (produce’s practice), T2—regulated deficit irrigation, and T3—full irrigation (100% ECTO), were established. Irrigated treatments had a positive effect on all morphological characteristics of the fruit. The pulp mass, independently of the year, increased in irrigated treatment (ranging from 1.04 to 1.65 in C to 2.25 and 2.30 in the irrigated treatments) and resulted in a higher oil content on a fresh weight basis (ranging from 16.39% to 17.85% in C to 19.48% to 23.26% in the irrigated treatments). However, fruit yield per tree was only location-dependent. When olive fruit fly presence was high, fruit infestation was greatest in the irrigated compared to the rainfed treatment. According to quality parameters, all oils were classified as EVOO. Individual phenols were influenced by irrigation, while the composition of fatty acids was more influenced by location than treatment. The sensory characteristics of the resulting oil were slightly reduced compared to rainfed treatment. The results indicate that regulated deficit irrigation benefits water use sustainability without compromising the quality of the oil.

Croatian islands are olive growing areas characterized by poor conditions for olive trees because of karst soil and a precipitation deficiency. Under these conditions, irrigation is a very important factor for constant olive oil production. This paper aims to investigate the effects of different watering regimes on quantity, sensory and chemical quality and composition of Coratina cv. olive oil obtained from trees grown on ameliorate karst soil during two harvesting years. Olive trees were subjected to rainfed conditions and three different irrigation treatments (T1—deficit irrigation representing the usual producer’s practice, T2—regulated deficit irrigation in respect to phenological stages, T3—full irrigation). Irrigation treatments increased oil yield compared to rainfed conditions (T1 + 58%, T2 + 66% and T3 + 74%, representing average values for both studied years). All olive oil samples were of extra quality. Irrigation led to a decrease in carotenoids, volatiles, polyunsaturated fatty acids and linolenic acid contents, with no difference found among irrigation treatments. Total phenols and secoiridoids concentration was not affected by irrigation, indicating that similar oil quality could be achieved with less demand on the water supply. Obtained results could help producers to define a suitable irrigation management in particular conditions of ameliorate karst.