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Postharvest deficit irrigation (DI) strategies have been proven to advance bloom, harvest dates and economic return in loquat ‘Algerie’ trees because an early harvest results in higher loquat fruit prices. This fact poses the question of whether postharvest DI strategies could have a similar effect on more precocious cultivars than cv . Algerie, providing thus a more profitable option to farmers. In this work, the response of an early- and intermediate-maturing loquat cultivars ( cv . Cardona and Algerie, respectively) to a summer early (DI early ) and late (DI late ) DI strategy was assessed in two parallel studies during three consecutive years. The effects of the DI early and DI late strategies on bloom date, percentage of fruit picked at harvest per picking date and yield of both loquat varieties were studied. Moreover, fruit quality of cv . Cardona at harvest was also assessed. Plant water status was monitored by midday stem water potential (Ψ stem ) measurements. Results showed that DI early and DI late strategies advanced bloom in both cultivars although a higher effect was observed with the DI early than with the DI late treatment. Water restrictions did not increase the percentage of fruit picked at any of the picking dates and did not affect yield or fruit quality in the early-maturing cultivar. In ‘Algerie’ trees, a higher percentage of fruit was generally picked during the first picking dates in the DI early and DI late treatments than in the control although differences were only statistically significant during the last experimental season. Yield was significantly higher in ‘Algerie’ DI late trees than in control or DI early trees two out of the three experimental seasons. Overall, results showed that the DI early and DI late strategies tested here did advance bloom in the early-maturing cultivar but did not have an effect on the percentage of fruit picked per picking date at harvest. Nevertheless, the fact that substantial water savings (>30%) were obtained with no detrimental effect on yield presents the use of postharvest DI strategies as an interesting option to be followed in early-maturing cultivars for a more efficient crop production. [ABSTRACT FROM AUTHOR]

• Water regime and climatic conditions affect aroma composition of "Muscat of Alexandria". • Negative relationships between total volatiles and vine yield were observed. • Pre-veraison water deficits increased glycosidycally-bound compounds. • No water stress during pre-veraison increased free compounds. • Seasonal effects predominated over those of water regimes on grape aromas. Irrigation effects in relation to the environmental conditions on grape aromas are still unknown. This study aims to clarify the effects of water regime on the aromatic composition of "Muscat of Alexandria" grapes under the semiarid climate conditions of eastern Spain and over three seasons. The relationships between total volatile composition in free and glycosidically-bound fractions, vine performance, and grape composition were also assessed. The watering treatments studied were: sustained deficit irrigation (SDI) at 50% of the estimated crop evapotranspiration (ET c); early deficit (EDI), where pre-veraison water deficit was imposed; late deficit (LDI), in which a water shortage was applied during post-veraison; and control (C), irrigated at 100% of ET c during the entire season. The effects of water regimes on volatile and glycosidically-bound composition were different between seasons due to the predominant effect of the environmental conditions on aromatic composition. The seasons with the greater yield were associated to a lower grape aromatic composition, however, this effect at the crop level was less pronounced in the most irrigated treatment. In drier seasons, irrigation delayed ripening and increased the terpene concentration of "Muscat of Alexandria" grapes, showing a high treatment and season interaction. Specific water regimes have the potential to buffer the effects of environmental conditions on the aromatic composition of "Muscat of Alexandria" grapes in a semi-arid climate, as the result of the complex relationships between climatic factors, vine performance and grape maturity. [ABSTRACT FROM AUTHOR]

• Mulching and no-tillage improved vine water status regardless of watering regime. • Alleviations of water stress resulted in decreases in grape phenolic composition. • Soil management and water regime caused interactive effects on water use efficiency. • Bulk density increased at the soil surface due to mulching and no-tillage. Optimizing water use in vineyards is crucial for ensuring the sustainability of viticulture in semi-arid regions, and this may be achieved by minimizing direct water evaporation from the soil through the use of mulching. In this context, the current study aimed at assessing the combined effects of the vine-row application of an organic mulch (vine prunings) and no-tillage under two water regimes on soil properties, plant water and nutritional status, yield and must composition of grapevine (Vitis vinifera L.) cv. Bobal grown under semi-arid conditions. For this purpose, a field experiment in a split-plot design was carried out for three years (2016–2018) in a mature Bobal vineyard located in Eastern Spain. Two soil management strategies (tillage and organic mulching with no-tillage) were assessed under two water regimes (rainfed and deficit drip irrigation) with four replications per combination. Vine responses were determined by measuring midday stem water potential, leaf nutrient concentrations, pruning weight, yield components and grape composition. Soil properties were assessed at the end of the experiment. Mulching and no-tillage positively affected vine water status under both water regimes, resulting in reductions in grape phenolic composition. Interactive effects of both water regime and soil management on water use efficiency were found. Regardless of soil management practice, irrigation increased yield and pruning weight when compared to rainfed conditions. Soil management had slight effects on vine nutritional status. At the end of the experiment, soil compaction increased and infiltration decreased as a consequence of mulching and no-tillage. Organic mulch and no-tillage improved vine water status, however, considering the final soil surface compaction and low water infiltration rate, longer-term studies are necessary to assess the sustainability of combining both practices. [ABSTRACT FROM AUTHOR]

Increasing water-use efficiency (WUE) is mandatory for more sustainable agricultural land use. Here we studied during three consecutive years in a nectarine ( Prunus persica L.) orchard the effects of placing 2 × 40 L coconut fiber substrate (S) bags per tree on the agronomic performance and WUE. Additionally, there were two regimes of watering, control (C), fulfilling 100% of the estimated crop evapotranspiration (ET c ) and a deficit (D) irrigation treatment, replacing the 65% of the ET c . Root colonization of the substrate, changes in the soil and substrate water content and temperature, tree water status (midday stem water potential), shoot growth (trunk diameter and tree volume), fruit yield and fruit quality compounds, were determined. Coconut substrate was colonized by the roots after two months from its installation, and after three years root dry weight in the substrate averaged 172 and 155 g per tree for the control and deficit irrigation treatments, respectively. During the first year, tree growth was enhanced in the C irrigation, while freezing temperatures during fruit set almost totally removed all fruits. In the second year, probably the abundant rainfall disguised the effect of the substrate on the yield parameters. However, this year and the next, deficit irrigation reduced fruit mean weight and delayed fruit harvest. In the third year, the substrate in the deficit irrigation treatment had a positive effect on fruit yield by increasing the number of fruits per tree in comparisons with deficit irrigation trees without substrate. The combination of deficit irrigation and substrate increased the WUE over the rest of the treatments but with no clear improvements in the tree water status. The results suggest that nectarine trees with deficit irrigation and substrate could be benefiting from a more efficient use of nutrients that further increases fruit set or prevent fruit drop. [ABSTRACT FROM AUTHOR]

Vineyards occupy large areas in many Mediterranean agroecosystems, in which their evapotranspiration is a major component of the water cycle. The correct determination of the actual crop evapotranspiration (ET a) is critical for accurate irrigation scheduling, allowing to match irrigation applications to crop water needs. This study was conducted to monitor the vineyard ET a and its partitioning into soil evaporation (E) and plant transpiration (T), under deficit irrigation and rainfed conditions, and to obtain the relationship between the estimated relative water stress coefficient (K s,r) and measured midday stem water potential (Ψ stem). A 2-year field experiment was carried out in a 'Monastrell' commercial vineyard located in Fuente Álamo (Albacete, SE Spain). Thermal infrared radiometers were deployed in both treatments, together with a weather station, to gather all the inputs required in the simplified two-source energy balance (STSEB) approach. Results showed that the accumulated ET a ranged between 183 and 253 mm for the irrigated treatment, and between 121 and 158 mm for the rainfed conditions. Canopy transpiration in the irrigation treatment almost double the value obtained in rainfed conditions for both years, and the ratio T/ET a increases around 8–9% in the irrigation treatment. The E component ranged from 21% for the irrigated treatment up to 50% for the rainfed treatment, confirming its importance in the vineyard water balance. A good linear relationship (r2 =0.650) was obtained between K s,r and Ψ stem , indicating the potential of using a surface energy balance approach in conjunction with plant radiometric temperature measurements to monitor the vines water status. Moreover, the rainfed treatment reduced the values of stomatal conductance (g s), transpiration (E l) and net photosynthesis (A N) compared to the irrigated treatment, whereas no increase in the intrinsic water-use efficiency (WUE i) nor the instantaneous water-use efficiency (WUE inst) was observed. The reported results will be useful for improving deficit irrigation scheduling techniques for 'Monastrell' red grapes. • Surface energy balance has the potential to monitor vine water status. • Transpiration doubles in the irrigation treatment versus rainfed conditions. • Water stress is well captured by the estimated relative water stress coefficient. • Irrigation increased yield but to a lesser extent increased transpiration. • Rainfed conditions did not increase the water use efficiency at the leaf level. [ABSTRACT FROM AUTHOR]