Terroir 2020 banner
IVES 9 IVES Conference Series 9 Plant nitrogen assimilation and partitioning as a function of crop load

Plant nitrogen assimilation and partitioning as a function of crop load

Abstract

Aims: The optimization of nitrogen use efficiency (NUE, i.e. uptake, assimilation and partitioning) is a solution towards the sustainable production of premium wines, while reducing fertilization and environmental impact. The influence of crop load on the accumulation of N compounds in fruits is still poorly understood. The present study assesses the impacts of bunch thinning on NUE and the consequences on the free amino N (FAN) profile in fruits.

Methods and Results: A large crop load gradient was imposed by bunch thinning (0.5 to 2.5 kg m–2) in a homogeneous plot of 225 vines. Isotope-labelled foliar urea (10 atom % 15N) was applied on the canopy of the fertilized treatment at veraison. The plants were excavated at four phenological stages over the two seasons (bud burst, flowering, veraison and harvest) and were individually split into five plant parts (roots, trunk, canopy, pomace and must). Total nitrogen and its stable isotope composition were determined in each part, with the aim of monitoring NUE as a function of crop load and fertilization.

The N concentration in fruits either at veraison or at harvest was not related to crop load variation. N concentration was maintained in the must to the detriment of N content in the roots. The root dry weight was 15 % lower and the root N quantity 27 % lower under high yielding conditions (HYC, compared to low yielding conditions LYC). The fertilizer N uptake was 41 % higher under HYC than under LYC. Consequently, urea supply had a positive impact on the yeast assimilable N concentration in the must (+55 mg L-1) only under HYC. However, the must FAN profile was significantly affected by the crop load, suggesting a possible modification of the aroma potential, independently from fertilization and grape maturation.

Conclusion: 

Using a 15N-labeling method, we demonstrate that grapevine has a strong ability to regulate nitrogen uptake and reserve mobilization to maintain a constant fruit N concentration despite changes in crop load. Foliar-urea fertilization at veraison was more efficient under HYC and helped to fulfill grape N demand, while limiting the mobilization of N reserves. However, the crop load affected the must FAN profile, inducing a possible modification of the fruit aroma. 

Significance and Impact of the Study: These findings highlight the great capacity of plants to adapt their N metabolism to constraints, e.g. bunch thinning in this case. These results are important to improve perennial fruit crop production through higher fertilization efficiency and lower environmental impact. Without fertilization, plant nutrition can be enhanced through the optimization of agricultural practices. The root activity appears to be key for understanding the mechanisms that balance N nutrition in plants

DOI:

Publication date: March 25, 2021

Issue: Terroir 2020

Type : Video

Authors

Thibaut Verdenal1, Vivian Zufferey1, Agnes Dienes-Nagy1, Olivier Viret2, Cornelis van Leeuwen3, Jorge Spangenberg4, Jean-Laurent Spring1

1Agroscope Institute, Av. Rochettaz 21, CH-1009 Pully, Switzerland
2Direction générale de l’agriculture, de la viticulture et des affaires vétérinaires (DGAV), Av. de Marcelin 29, CH-1110 Morges, Switzerland
3EGFV, Bordeaux Sciences Agro, INRAE, Univ. Bordeaux, ISVV, F-33882 Villenave d’Ornon, France
4Institute of Earth Surface Dynamics, University of Lausanne, CH-1015 Lausanne, Switzerland

Contact the author

Keywords

Nitrogen partitioning, crop load, isotope labelling, amino acids, vines

Tags

IVES Conference Series | Terroir 2020

Citation

Related articles…

Moderate wine consumption as part of a Mediterranean diet and lifestyle under debate

Moderate wine consumption – with the meals – represents one of the beneficial components of the traditional mediterranean diet (med diet) and a positive item in the med diet score [1,2, 3]. The med diet is considered one of the best diets in the world and the world health organisation (who) identified this eating pattern as an effective strategy to prevent non-communicable diseases (ncd), since it is associated with lower disease occurrence and all-cause mortality [4] . Numerous well-conducted epidemiological studies have also reported that light-to-moderate intake of wine/alcoholic beverages is not only related to a reduced risk of cardiovascular disease, but also to all-cause mortality.

The terroir of winter hardiness: a three year investigation of spatial variation in winter hardiness, water status, yield, and berry composition of riesling in the niagara region using geomatic technologies

Grapevine winter hardiness is a key factor in vineyard success in many cool climate wine regions. Winter hardiness may be governed by several factors in addition to extreme weather conditions – e.g. soil factors (texture, chemical composition, moisture, drainage), vine water status, and yield– that are unique to each site.

Cumulative effects of repeated drought stress on berry composition, and phenolic profile: Field experiment insights

Drought stress has a profound impact on grapevine productivity and significantly alters key quality-related traits of berries. Although research has been conducted on the effects of individual drought events, there is still a knowledge gap regarding the cumulative consequences of repeated exposure to water scarcity and the influence of the timing of stress imposition. To address this gap, a field experiment was conducted to investigate the impacts of repeated drought stress on yield, berry composition, and the phenolic profile of grape berries. The results indicate that yield is primarily influenced by pre-veraison water deficit. Although the number of clusters was only slightly reduced, a substantial decrease in berry size was observed, resulting in a notable reduction in overall yield.

Elementi in traccia e ultratraccia nell’uva: possibili applicazioni ai fini della tracciabilità geografica

Nel presente studio si è ricercata la possibilità di associare l’uva al territorio mediante parametri chimici indipendenti da variabili climatiche ed antropiche.

Scalable asymptomatic grapevine leafroll virus complex-3 detection through integrated airborne imaging spectroscopy, autonomous robotics, and cloud computing

The past three decades of terrestrial remote sensing research have delivered unprecedented insights into our fundamental ability to detect, quantify, and differentiate plant disease (Gold 2021). However, much of our fundamental knowledge in this domain has come from studies in non-agricultural systems and until recently, most agricultural studies, when extant, have focused on tree crops where canopy closure and large plot and plant size facilitate stress detection at low spatial resolution. Recent engineering innovations and advancements in constellation architecture design have refined the accuracy and scalability of airborne and spaceborne sensing platforms, enabling us to monitor diverse specialty crops, including grapevine, planted in smaller, spatially varied fields.