The treatments strongly affected anthocyanin compounds in both seasons. In 2019, at harvest, 50 and 100% ETc increased the proportion of peonidins and 25% ETc had a significantly higher proportion of petunidin derivatives. Flavonol composition was only affected by irrigation treatments during the 2020 growing season at harvest . Myricetin and quercetin derivatives were the main flavonols found in Cabernet Sauvignon berry skins and both accounted for about 75% of the total amount. The most restrictive applied water treatment increased proportion quercetins and kaempferols, while 100% ETc increased myricetins and syringetins.This study evaluated the effect of applied water amounts based on the replacement of fractions of the ETc for maintaining berry quality while minimizing yield losses due to the environmental impact . Results covered two seasons that strongly differed in the precipitation supply. Compared with the average total amount of precipitation received by the area in the last decade , 2019 growing season was a rainy period with 970.3 mm precipitation, while 2020 was a hyperarid growing season with only 234.2 mm of precipitation. In spite of the differences in total precipitation, the response of Cabernet Sauvignon grapevines to water deficits was consistent across both seasons and our results corroborated that deficit irrigation may mitigate the effects of water scarcity . The results achieved in this study indicated that 25% and 50% ETc treatments were effective in improving iWUE compared with previous studies reporting a compilation of data from Cabernet Sauvignon and other cultivars . The iWUE decreased when the fractions of appliedETc increased as previously reported by Keller et al. in a 3-year field experiment conducted on the same Cabernet Sauvignon clone as used in this study. Likewise, planting blueberries in containers WUEc calculated as the ratio between yield and water applied was also enhanced with the decreased water supply.

The berry must δ 13C enhanced under stronger water deficits conditions corroborating previous studies with different grapevine cultivars . The iWUE and the berry must δ 13C also indicated a linear relationship in accordance to previous research . Previous work indicated that δ 13C of grape must is a reliable indicator of plant water status and leaf gas exchange in vineyard systems, which in turn, are crucial for the identification of plant water status zones leading to better irrigation decisions and informed management . The present study also provided evidence that δ 13C is a convenient tool without intensive labor and time inputs for the assessment of environmental impacts of deficit irrigation strategies. Increased applied water amounts led to greater canopy size and yields . There was a strong negative relationship between the berry must δ 13C and grapevine vegetative growth measured as LAI. Previous studies reported a linear relationship between the δ 13C and the carbon assimilation rates and consequently with vegetative growth estimated as pruning mass . Yield achieved in this experiment ranged from 4.8 to 10.4 kg · vine−1 in accordance to a previous study conducted in a vineyard at a similar density . Thus, 100% ETc may double the yield compared with the 25% ETc as previously reported by Keller et al. . This suggested that the effect of applied water on yield components is consistent in spite of the climate difference, planting space, and grapevine age. Under our experimental conditions, primary metabolites were affected by applied water amounts in the second season, where 100% ETc accounted for lower TSS but higher pH. Increased water content in berries was associated with a lower concentration of sugars due to a dilution effect . Conversely, the lower pH in 25% ETc grapevines was related to exacerbated organic acid degradation under high temperatures by water deficit . Berry skin flavonol and anthocyanin contents decreased with the 100% ETc in 2019 but not in 2020.

Although several studies reported increases in berry flavonoid content under mild or moderate water deficit , field research conducted in California resulted in contradictory results when severe water deficits were combined with a long hang time . In general, 100% ETc irrigation treatment reduced the proportion of petunidin derivatives and increased the proportion of peonidin derivatives leading to a decreased ratio between tri-hydroxylated and di-hydroxylated anthocyanins, which was suggested to be less chemically stable for winemaking purposes . Likewise, previous studies have reported an increase in the ratio between tri-hydroxylated and dihydroxylated anthocyanins when grapevines were subjected towater deficits given the upregulation of the relevant anthocyanin biosynthetic genes . In addition, these forms were more persistent through hang time, making trihydroxylated flavonoids more abundant as maturity progressed . Flavonol composition was modified by applied water amounts in 2020 growing, where proportions of myricetin and syringetin derivatives increased and quercetin and kaempferol derivatives decreased with 100% ETc. Given that quercetin and kaempferol are important antioxidants in red wines, this shift in the composition may impact the antioxidant properties of wine . In previous work, it was reported that 100% ETc irrigation increased the net carbon assimilation and improved the grapevine water status, leading to higher soluble sugar and starch contents in leaves with the highest yields, and vegetative biomasses . However, the greatest leaf area to fruit ratios measured in this treatment showed a clear sign of disproportionate leaf biomass growth, which presumably impacted berry metabolism. Thus, both studies highlighted the importance of management of water deficits to ensure grape berry composition optimization, improving water use sustainability by rewarding quality over quantity in arid and semiarid regions .Decreasing irrigation amounts increased AMF colonization in accordance with previous studies .

The symbiotic relationship of AMF with grapevines provided several adaptive advantages, such as improved abiotic and biotic stress resistance, enhanced nutrient uptake, and grapevine growth . Previous research suggested that these effects might be related to the altered regulation of nutrient transport, cell wall-related, phenylpropanoid, and stilbene biosynthesis genes driven by AMF colonization . Additionally, it was recently reported that AMF may enhance the content of flavonoids in berries , leading to improved berry composition and antioxidant properties in spite of the lack of effect on petiole nutrient contents . However, vineyard management practices may affect the soil structure and the composition of the rhizosphere-living microbiota , as well as the microbiota associated with grapevine roots, which is mainly composed by Rhizophagus and Glomus genus , likely affecting the effectiveness of the symbiosis. The relationship between AMF and berry must δ 13C suggested that productivity of high quality grapes could still be sustained in this region with less water input because the root system of the grapevines may perform more efficiently due to greater AMF colonization. The totalWF measured in this study ranged between 484.3 and 1237.7 m3 ·tonne −1 across treatments and growing seasons, in accordance with previous studies assessing the WF of grapevine cultivation . This variation in the totalWF was related to the amount applied and the differences in precipitation between the two seasons . Indeed, the previous research speculated that changes in temperature and precipitation may affect the proportional contribution of blue and green WF to the totalWF . Previous studies reported that vineyards accounted for a higher WF compared with other crops such as olives, wheat, and other fruit trees . Wine grape growers require appropriate irrigation schedules that reduce blueWF and increase greenWF leading to a decreased totalWF for increasing sustainability of vineyards. Under our experimental conditions, 25% ETc strongly decreased the blueWF, however, container growing raspberries this came with a dramatic increase in the grayWF component, which led to increased totalWF. Conversely, 100% ETc decreased totalWF to lower values than those reported in Zotou and Tsihrintzis , presumably because of the differences of standard yields recorded in Mesogeia area , where the authors conducted their research, and Napa Valley, CA, USA where this study was performed. A recent study reported that the current values of blueWF and gray WF are unsustainable . The actual runoff of the surface water is not sufficient to satisfy the irrigation requirements and/or dilute the pollutant load associated with the diffuse and point sources to reduce it below the maximum acceptable concentration . These results highlighted that the management of natural resources, specifically water management, is paramount for the sustainability of the wine industry under future constraints . Thus, our data suggested that values ranging between 600 and 1000 m3 · tonne −1 of the totalWF may ensure a high iWUE of grapevines , optimum LAI, and profitable yields, which maintained the balance between vegetative and reproductive growths . Nevertheless, it is noteworthy to address that WF assessment also presents some limitations given that the water consumed by an irrigated crop is often a mix of residual soil moisture from previous precipitation and irrigation events and that the reference ET is strongly dependent on the local climate .Ants benefit plants . Humans have known this for quite a long time. In fact, ants were described as biological control agents in China around 304 AD . Many plants have also evolved to promote the activity of ants on their tissues. Some plants provide domatia as ant housing structures, while others attract ants to their tissues with extra-floral nectaries. Some plants are hosts to honeydew-producing hemipterans that excrete honeydew, a sugary substance consumed by ants. Still other plants are simply substrates for ant foraging.

The majority of studies conducted across these ant–plant groups show that ants benefit plants by removal of herbivores . Nonetheless, in many agroecosystems, the benefits of pest control services by ants are not recognized. Agricultural managers often view them as pests or annoyances to agricultural production because some ants tend honeydew-producing insects that can damage crops . However, a review of the literature on ant-hemipteran associations suggests that even these associations benefit plants indirectly because ants remove other, more damaging herbivores . Regardless, the literature lacks studies investigating ant–plant interactions in agroecosystems. Here, we broadly survey the pest control services provided by a suite of ant species to better understand the role of ant defense of coffee. Coffee is a tropical crop that occurs as an understory shrub in its native range, and coffee plants are therefore often grown under a canopy of shade trees in agroforestry systems in some parts of the world . This canopy layer provides plantatsions with a forest-like vegetation structure that can help maintain biodiversity . Ant biodiversity is high in many coffee plantations and ants attack and prey on many coffee pests, including the coffee berry borer . For example, Azteca instabilis F. Smith is a competitively dominant ant that aggressively patrols arboreal territories in high densities and previous research has found that it impacts the CBB . Some laboratory and observational field studies have found that Pseudomyrmex spp., Procryptocerus hylaeus Kempf, and Pheidole spp. may limit the CBB . However, other field experiments have not found ants to be biological control agents of the CBB . Further, the pest control effects of many ant species on the CBB have not yet been evaluated and it could be that previously documented effects are specific to only a few species. Natural ant pest control of the CBB is particularly important because chemical insecticides used to control CBB are not always effective. This lack of effectiveness is in part because the CBB lifecycle takes place largely hidden within coffee berries and also because the CBB has developed insecticide resistance . Several of the stages of the CBB life cycle make it vulnerable to attack by ants . First, the CBB hatches from eggs within the coffee berry, where it consumes the seeds . Small ants may enter the berry through the beetle entrance hole and predate the larvae and adults inside . Second, old berries infested with the CBB may not be harvested because they often turn black and remain on the coffee branches or may fall to the ground . These old infested berries may act as a population reservoir of borer populations and ant predation at this stage could be very important for limiting CBB populations in the next season. Third, as adult borers disperse to colonize new berries, ants may prevent them from entering new berries . To date, no field experiment has specifically investigated how coffee-foraging ants limit CBB colonization of berries. Here, we studied the abilities of eight ant species to prevent colonization of berries by the CBB. We hypothesized that only species with high activity on branches would limit CBB colonization of berries.