Effects of regulated deficit irrigation on physiology, yield and fruit quality in apricot trees under Mediterranean conditions

Scarce water resources mainly in arid and semi-arid areas have caused an increasing interest for applying irrigation protocols aiming to reduce water spends. The effects of regulated deficit irrigation (RDI) on the performance of apricot trees (Prunus armeniaca L. cv. “Búlida”) were assessed in Murcia (SE Spain), during three consecutive growing seasons (2008-2010). The hypothesis was that RDI would not restrict yield but increase fruit quality while saving water. Two irrigation treatments were established: i) control, irrigated to fully satisfy crop water requirements (100% ETc) and ii) RDI, that reduced the amount of applied water to: a) 40% of ETc at flowering and stage I of fruit growth; b) 60% of ETc during the stage II of fruit growth and c) 50% and 25% of ETc during the late postharvest period (from 60 days after harvest). Stem water potential, gas exchanges, trunk cross-sectional area (TCSA), fruit diameter, yield and fruit quality traits were determined. Vegetative growth was decreased by the use of RDI (12% less TCSA on average for the three years), whereas yield was unaffected. In addition, some qualitative characteristics of the fruits, such as the level of soluble solids, sweetness/acidity relation and fruit colour, were improved by the use of RDI. These results and average water savings of approximately 30%, lead us to conclude that RDI strategies are a possible solution for irrigation management in areas with water shortages, such as arid and semi-arid environments

Agronomic Practices for Reducing Soil Erosion in Hillside Vineyards under Atlantic Climatic Conditions (Galicia, Spain)

Water erosion is a severe threat to soil resources, especially on cultivated lands, such as vineyards, which are extremely susceptible to soil losses. In this context, management practices aiming at reducing erosion risks must be favored. This current study aimed at estimating soil losses in two vineyards under Atlantic climatic conditions (Galicia, North West Spain). The capacity of two management practices for reducing soil erosion was tested and compared with tilled soil in the inter-rows: (i) application of mulching, and (ii) maintaining native vegetation. Soil losses were assessed using erosion pins and micro-plots. In addition, the improved stock unearthing method (ISUM) was employed in one of the vineyards to estimate soil remobilization since plantation. Soil loss rates in one of the vineyards were lower when soil was managed under mulching (0.36 Mg ha−1) and native vegetation (0.42 Mg ha−1), compared to tilled soil (0.84 Mg ha−1). Sediment losses measured in the second vineyard ranged between 0.21 and 0.69 Mg ha−1, depending on the treatment, but no clear conclusions could be drawn. Long-term soil loss, as estimated by ISUM, was of the same order of magnitude than that obtained by erosion pins and micro-plots. In both vineyards, soil loss rates were lower than those registered in Mediterranean vineyards, and were below the limit for sustainable erosion in Europe. Nevertheless, soil management practices alternative to tillage in the inter-row might reduce erosion risks under Atlantic climate conditionsThis research was funded by Interreg Atlantic Area with European Regional Development Fund, grant number EAPA_272/2016 project Risk-AquaSoilS

Efeitos da rega superficial e subsuperficial sobre a fisiologia e produção da variedade ‘Godello’ na Galiza, Noroeste de Espanha

Irrigation has been considered a controversial practice in European traditional viticulture due to potential alterations in the balance between vegetative growth and yield. In this regard, the influence of surface (DI) and subsurface (SDI) drip irrigation on physiological performance of the ‘Godello’ grapevine (Vitis vinifera L.) cultivar was compared with a non-irrigated control (R) over three consecutive growing seasons (2012- 2014) in NW Spain. Irrigation improved vine water status; R plants reached a minimum of midday leaf water potential of –1.5 MPa, whereas DI and SDI plants reached –1.3 MPa. Stomatal conductance was unaffected by irrigation as well as chlorophyll a fluorescence. However, photosynthetic pigments were present at higher concentrations in leaves from irrigated plants than in those from R plants in 2013. In addition, R plants showed higher values for the indicators of oxidative damage. No significant yield improvements were observed for irrigated plants, although the trend was to obtain slightly higher yields under irrigation in years with low rainfall amounts. This may not encourage growers to establish irrigation systems on their vineyards. However, these results may be important with the objectives of stabilizing yield from year to yearA rega tem sido considerada uma prática controversa na viticultura tradicional Europeia devido a potenciais alterações no equilíbrio entre crescimento vegetativo e rendimento. A este respeito, a influência da irrigação por gotejamento superficial (DI) e subsuperficial (SDI) sobre o desempenho fisiológico da variedade ‘Godello’ (Vitis vinifera L.) foi comparada com uma testemunha em condições de sequeiro (R) ao longo de três anos consecutivos (2012-2014) no noroeste de Espanha. A rega melhorou o estado hídrico da videira; as plantas do tratamento R atingiram potenciais hídricos foliares ao meio-dia de –1.5 MPa, comparativamente a um valor de –1.3 MPa para as plantas dos tratamentos DI e SDI. A conductância estomática e a fluorescência da clorofila a não foram afectadas pela rega. No entanto, os pigmentos fotossintéticos apresentaram maiores concentrações em folhas de plantas regadas quando se comparam com as plantas do tratamento R em 2013. Além disso, as plantas do tratamento R apresentaram valores superiores para os indicadores de danos oxidativos. Não foi detectado nenhum incremento do rendimento nas plantas regadas, embora se tenha observado uma tendência para obtenção de rendimentos ligeiramente mais elevados sob rega em anos com baixa pluviosidade. Tal poderá não encorajar aos viticultores a implementar sistemas de rega nas suas vinhas. No entanto, estes resultados podem ser importantes para a estabilização do rendimento de ano para anoThis research was supported by the Spanish Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria (INIA), Project nº RTA2011-00041-C02-00, with 80% FEDER funds. J.M. Mirás-Avalos and E.M. Martínez thank Xunta de Galicia for funding their contracts through the “Isidro Parga Pondal” and “Isabel Barreto” Programmes. E. Trigo-Córdoba thanks INIA for their PhD scholarship (FPI-INIA)S

Grape Composition under Abiotic Constrains: Water Stress and Salinity

Water stress and increasing soil salt concentration represent the most common abiotic constrains that exert a negative impact on Mediterranean vineyards performance. However, several studies have proven that deficit irrigation strategies are able to improve grape composition. In contrast, irrigation with saline waters negatively affected yield and grape composition, although the magnitude of these effects depended on the cultivar, rootstock, phenological stage when water was applied, as well as on the salt concentration in the irrigation water. In this context, agronomic practices that minimize these effects on berry composition and, consequently, on wine quality must be achieved. In this paper, we briefly reviewed the main findings obtained regarding the effects of deficit irrigation strategies, as well as irrigation with saline water, on the berry composition of both red and white cultivars, as well as on the final wine. A meta-analysis was performed using published data for red and white varieties; a general liner model accounting for the effects of cultivar, rootstock, and midday stem water potential was able to explain up to 90% of the variability in the dataset, depending on the selected variable. In both red and white cultivars, berry weight, must titratable acidity and pH were fairly well simulated, whereas the goodness-of-fit for wine attributes was better for white cultivars

Effects of the Annual Nitrogen Fertilization Rate on Vine Performance and Grape Quality for Winemaking: Insights from a Meta-Analysis

Sustainability in grapevine cultivation requires the precise use of water and fertilizers, particularly nitrogen (N), to produce grapes of the highest quality for winemaking, while simultaneously avoiding harm to the surrounding waters and atmosphere by reducing NO3− losses and N2O and NH3 emissions from the vineyards. To address the challenge of optimizing N use in viticulture, many N fertilization trials have been carried out over the last decades, and a compilation and analysis of worldwide trials was therefore needed. The present study tackled this challenge through a meta-analysis of published research, which included 374 fertilization trials. From the compiled data, six vine production parameters and eight grape quality traits were extracted and normalized to enable comparisons between experiments. The Mitscherlich law of diminishing returns was able to satisfactorily describe the set of vine production parameters against nitrogen application rate, and the same occurred with the yeast assimilable nitrogen (YAN). In vines, both reproductive and vegetative growth similarly responded to the N application rate. In general, the nitrogen requirements for 95% of the maximum grape yield amounted to rates between 30 and 40 kg·N·ha−1, which increased nitrogen use efficiency (NUE) to values between 0.27 and 0.36 t·kg·N−1. Although several grape quality traits could not be described against the N rate in terms of any mathematical relationship, an N rate between 20 and 25 kg·N·ha−1 could be considered as maximizing grape quality for winemaking. Such N fertilization range increases NUE up to values between 0.41 and 0.47 t·kg·N−1, thus almost doubling the known NUE standards when grape quality is targeted instead of yield, although soil fertility could be exhausted in the mid-to-long term. Whatever the case, anthocyanins and polyphenols are well preserved in red grapes at such low N rates, although YAN is not. The results of this work will be useful for guiding new vine N nutrition research and N nutrition management in vineyards, thus increasing wine growing sustainability

Response of grapevine cv. ‘Brancellao’ and ‘Sousón’ to supplementary irrigation: Water relations, vine growth, yield and berry and wine composition

Growers are concerned about the negative impacts on vine yield and berry quality caused by global warming. Irrigation systems are increasingly being installed in vineyards in order to counteract those problems. Therefore, an efficient irrigation management is required. In this context, a field experiment was carried out over three years (2012-2014) on red Vitis vinifera (L.) cv. ‘Brancellao’ and ‘Sousón’ in order to assess the effects of supplementary irrigation on vine performance and must and wine composition. Rain-fed vines were compared with a treatment irrigated to 40% of potential evapotranspiration (ET0) from bloom to two/three weeks before harvest. Both cultivars showed less negative stem water potentials under irrigation than under rain-fed conditions; however, stomatal conductance was similar between treatments. Yield was unaffected by irrigation, whereas pruning weight tended to increase in both cultivars. Must and wine composition, including amino acids and volatile compound concentrations, were mostly unaffected by irrigation. Water productivity was higher under rain-fed conditions and, as a consequence, gross incomes were not increased by irrigation. Therefore, irrigation does not seem an economically viable agricultural practice under the conditions of this trial

Irrigation effects on the sensory perception of wines from three white grapevine cultivars traditional from Galicia (Albariño, Godello and Treixadura)

This study aimed to assess the effect of irrigation on the sensory profile of wines from three Galician white grapevine cultivars. Field experiments were carried out in 2011 and 2012 at the research farm of the Estación de Viticultura e Enoloxía de Galicia (EVEGA), where two treatments were imposed: rain-fed and irrigation to the 50% of potential evapotranspiration. A panel of seven judges tasted the wines in six sessions (one per cultivar and year) for evaluating their sensory profile. In the case of ‘Albariño’, three descriptors, although not the same for both years, were significantly different between treatments. For ‘Godello’, several descriptors differed between treatments, and citric was present in both years. In ‘Treixadura’ white fruit and persistence were present in 2011 and 2012. Several descriptors contributed to the hedonic index, but differed between wines; however, balance was common for all the cultivars and years. In conclusion, ‘Albariño’ and ‘Godello’ wines from the rain-fed treatment received higher marks than those from the irrigation treatment; whereas Treixadura wines from the irrigation treatment were better valued

Sublethal effects of insecticides used in strawberry on Trichogramma pretiosum (Hymenoptera: Trichogrammatidae)

7 Pags.- 2 Tabls.- 1 Fig. Copyright © 2021 INIA. This is an open access article distributed under the terms of the Creative Commons Attribution 4.0 International (CC-by 4.0) License.Aim of study: Assessment of toxicity and sublethal effects of registered insecticides currently used in strawberry cultivation in Brazil on Trichogramma pretiosum Riley adults. Area of study: The study was conducted under laboratory conditions in Paraná (Brazil). Material and methods: Previously non-parasitized Duponchelia fovealis Zeller (Lepidoptera: Cambridae) eggs were dipped into insecticide dilutions or control solution. Seven active ingredients were tested: thiamethoxam, abamectin, azadirachtin, spinetoram, chlorfenapyr, lambda-cyhalothrin and chlorpyriphos. Side-effects of pesticides were quantified by measuring mortality on T. pretiosum females in 24 h, longevity after exposure to the insecticides, parasitism and emergence rates, and offspring sex ratio. These traits were also measured on the second generation. Main results: According to IOBC criteria, thiamethoxam was classified as harmless; abamectin, chlorfenapyr and spinetoram as slightly toxic; azadirachtin and lambda-cyhalothrin as moderately toxic and chlorpyriphos as toxic. The emergence rate of T. pretiosum second generation was not significantly affected by thiamethoxam, abamectin, azadirachtin, and chlorfenapyr. Sublethal effects caused by azadirachtin, abamectin and chlorfenapyr were verified in the second generation. Research highlights: The information generated by this study is useful for designing future biological control strategies in integrated pest management programs against D. fovealis.Coordenação de Aperfeiçoamento de Pessoal de Nível Superior – CAPESPeer reviewe