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Sustainable vineyard management in inter-rows may improve biodiversity and ecosystem service provision in landscapes with a high density of vineyards. The current work investigates the effect of three inter-row ground cover treatments (bare soil by tillage, alternating and complete vegetation cover) on carabid beetle communities and vine vitality, in relation to climatic, soil and landscape parameters. Pitfall traps were used to collect carabids in the spring and autumn of 2016 from nine Austrian vineyards, with all three ground cover treatments established in each vineyard. Additionally, grape berry samples were collected before harvest in order to determine juice quality parameters. Generalized linear mixed models revealed that complete vegetation cover, the most extensive vineyard inter-row management, decreased both carabid density and species richness. The variables hours of sunshine, vineyard cover at the landscape scale and mesofauna abundance had negative impacts on species richness. The largest differentiator of carabid communities was the sampling timepoint, and we observed clustering associated to vineyard manager, whereas ground cover treatment played no significant role. The importance of treatment on vine vitality parameters was low; however, complete vegetation cover was detrimental to vine vegetative growth and berry weight. On the basis of our results, we conclude that although community composition may be influenced by pedo-climatic conditions and landscape components, alternating vegetation cover is an option for maintaining both carabid diversity and high-quality berries in vineyards. [ABSTRACT FROM AUTHOR]

Berry shrivel (BS) is a ripening dysfunction resulting in grapes with low sugar content, high acidity, reduced anthocyanins and flaccid berries. In this study we challenge the K + -deficiency hypothesis as underlying cause for BS in grapevine. The hypothesis is based on empirical vineyard studies and proposes that K + -deficiency or a disbalance of K + /Mg 2+ in plant content cause of BS. Recent studies on more grapevine varieties and further geographical locations lack supporting evidence for the K + hypothesis. Here we review existing evidence from the field and apply physiological analyses to study processes involved in K + and nutrients transport in BS and non-symptomatic clusters. For the first time the molecular background of K + transportation is being studied over the course of BS disorder. Our objectives were (1) to determine the distribution of nutrients in BS vines and clusters and (2) to evaluate the role of selected potassium transport proteins and channels during grape berry development and BS induction in pedicels and berries. Our results with ICP-MS show a strong and significant reduction of K + concentration in rachis and pedicels of BS grapes, whereas boron, zinc, copper and aluminum were increased. Concentration of nutrients in BS berries were either not changed or increased compared to non-symptomatic clusters. Expression analyses with qPCR in pedicels revealed no pre-symptomatic differences of genes involved in potassium transport (VviKUP1, VviKUP2 and VviK1.2), but later during ripening reduced expression was observed. In BS berries the expression of VviK1.2 was reduced before veraison. We show significant K + deficiency in BS rachis and pedicels along with partial reduced expression of K + transporter genes. Consequently K + phloem transport is involved in BS induction, however our study did not provide conclusive evidence to support the K + deficiency hypothesis as a single factor for BS induction. Instead the idea that a combination of further stress factors influences K + and assimilates translocation towards sink organs before veraison is proposed. [ABSTRACT FROM AUTHOR]

Grapevine (Vitis vinifera L.) is the most economically important deciduous fruit crop in the world. Iron (Fe) is an essential micronutrient for plant development since its active form is involved in several biochemical processes, e.g., chlorophyll synthesis. The uptake of the elements depends on individual elements' interactions. Iron (Fe) nutrition of plants can be significantly affected by different nitrogen (N) forms through altering the uptake ratio of cations and anions, and changing rhizosphere pH. It is known, that most crop species grow best with access to nitrate (NO3 -) as well as ammonium (NH4 +) nitrogen, but little attention has been paid to changes in iron uptake under supply of different nitrogen (N) forms. The presented study aimed to decipher the specific interaction of different nitrogen (N) forms on Iron uptake of different grapevine rootstocks on the physiological as well as on the biochemical and molecular level. Four NH4 +: NO3 - ratios (0:1,1:5, 1:3, 1:1) were tested with a modified half-strength Hoagland solution with and without FeNa(III)-EDTA, summing up to eight treatments within a hydroponic system (Kick-Brauckmann, 7.5 L) under semi-controlled climatic glasshouse conditions in 2021. Rooted woody cuttings of the rootstocks Fercal (V.berlandieri x V. vinifera) and Couderc 3309 (V. riparia x V. rupestris) were used for the experiment. The results could differentiate iron deficiency effects, nitrogen form effects and rootstock effects. Biomass of leaves was negatively influenced by iron absent in both rootstocks with nitrate as only N source. This effect was observed for 3309C for all NH4 +: NO3 -ratios, while with Fercal the biomass of leaves increased with increasing amount of NH4 +. A similar trend was overserved for root biomass, promoting in Fercal with increased NH4 + amount and not response in 3309C. The efficiency of the photsystem II (Y(II)) decreased under iron deficient conditions in both rootstocks showing the strongest effect with only nitrate as N source especially with rootstock 3309C. Increasing ammonium levels in the nutrient solution lead to a higher pH reduction by the rootstocks probably enhancing the Fe2+ availability and uptake. The ferric chelate reductase (FCR) activity was specifically increased in Fercal under irondeficient conditions, while no effect was observed for 3309C in comparison to control plants. These first results of the study indicate that rootstocks differ in their preference on both the physiological and molecular level depending on the nitrogen form and in interaction with iron deficiency stress. In a next step the molecular mechanism will be analysed. [ABSTRACT FROM AUTHOR]