Wild grapevine (Vitis vinifera subsp. sylvestris Gmel Hegi) is dioecious with male and female plants, whereas domesticated grapevine is mostly hermaphrodite with self-fertile hermaphrodite flowers. The pollen morphology of wild grapevine has been poorly studied. There is no detailed palynological study of V. sylvestris in Croatia and neighboring countries. Here, scanning electron microscopy (SEM) was used to analyze the pollen of V. sylvestris from male and female individuals growing at two natural sites in Croatia. The selective APT3 marker was used to confirm the flower phenotype with the genetic background. SEM analysis showed that the pollen grains of V. sylvestris were isopolar and radially symmetrical, with foveolate perforated ornamentation, regardless of the flower type of the individuals. All male flowers were 3-colporate and prolate in shape, whereas female individuals varied from subprolate to spheroidal and had inaperturate pollen grains. Pollen shape, dimensions and exine ornamentation proved very informative, and here we address the most polymorphic traits in the analyzed V. sylvestris individuals. Principal component analysis (PCA) and clustering based on pollen morphology variables clearly differentiated individuals by their flower type, and no grouping specific to population was observed, pointing to the conserved pollen structure of V. sylvestris. The results indicate the need to continue the palynological study of V. sylvestris and serve as a good phenotypic basis for functional genetic studies on genes involved in pollen morphology and function.
The flowering and fruit set of grapevines are determined by many morphological, physiological, and environmental factors. Although the elemental composition of pollen grains plays a crucial role in the fruit set, there is still a considerable gap in our knowledge. To date, no study has been conducted on the elemental composition of Vitis vinifera subsp. sylvestris (hereafter V. sylvestris) pollen grains. The aim of this work was to investigate the elemental composition of pollen grains of V. sylvestris using scanning electron microscopy with energy dispersive X-ray spectroscopy (SEM-EDX). The pollen grains of ten V. sylvestris individuals (eight male and two female) and one hermaphrodite cultivar ‘Plavac mali crni’ were analyzed. SEM-EDX analysis revealed the presence of eight elements (carbon—C, oxygen—O, magnesium—Mg, phosphorus—P, potassium—K, calcium—Ca, molybdenum—Mo, and aluminum—Al) in the pollen grains. Interestingly, aluminum was detected exclusively in the pollen of the cultivated grape cultivar ‘Plavac mali crni’, while it was not present in the genotypes of V. sylvestris. No significant differences between genotypes were found for oxygen and phosphorus, while significant differences were found for other elements. Pollen dimorphism was not associated with differences in element composition, although principal component analysis separated the genotypes into two distinct groups, with two female individuals (Pak10 and Pak12) and one male (Im19) tending to form separate clusters. This study is the first report on the elemental composition of pollen grains of V. sylvestris genotypes and provides valuable insights for further studies on pollen functionality.
The Integrated Agrometeorological Prediction System (IAPS) was a two-year project for the development of the long term forecast (LRF) for agricultural producers. Using LRF in decision-making, to reduce the risks and seize the opportunities, represents short-term adaptation to climate change. High-resolution ensemble forecasts (51 forecasts) were made for a period of 7 months and were initiated on the first day of each month. For the initial testing of the capacity of LRF to provide useful information for producers, 2017 was chosen as the test year as it had a very hot summer and severe drought, which caused significant impacts on agricultural production. LRF was very useful in predicting the variables which bear the memory of the longer period, such are growing degree days for the prediction of dates of the phenophases’ occurrences and the soil moisture of deeper soil layers as an indicator for the drought. Other project activities included field observations, communication with producers, web portal development, etc. Our results showed that the selected priority forecasting products were also identified by the producers as being the highest weather-related risks, the operational forecast implementation with the products designed for the use in agricultural production is proven to be urgent and necessary for decision-making, and required investments are affordable. The total cost of the full upgrade of agrometeorological climate services to meet current needs (including monitoring, seamless forecasting system development and the development of tools for information dissemination) was found to be about three orders of magnitude lower than the assessed losses in agricultural production in the two extreme years over the past decade.
The productivity and quality of grapes and wine are significantly influenced by changing climate conditions in vineyard regions worldwide. This study assesses changes in temperature, precipitation, and viticultural indices between the periods of 1971–1990 and 2000–2019 in Trebinje, a vineyard area located in the Herzegovina region of Bosnia and Herzegovina. Between the two periods, mean annual temperature increased by 2 °C and mean vegetational temperature by 2.4 °C, while mean precipitation remained within the range of climatological variability, with annual values increasing by 6% and vegetational values decreasing by 4.6%. Warming resulted in a longer duration of the vegetation season by 23.7 days, a reduced risk of late spring frosts, and an increased risk of very high temperatures during summer. These changes led to the reclassification of Trebinje vineyards’ climate from Region III to Region V, based on the Winkler index values, from a “temperate warm” to a “warm” category, based on the Huglin heliothermic index, and from “cool nights” to “temperate nights” based on the cool nights index. The category of the dryness index remained unchanged between the two periods. The findings emphasize the necessity for a renewal of the viticultural zoning and the development of climate change-adaptation plans for this region.
28 December 2022 in "Annals of the University of Craiova - Agriculture, Montanology,Cadastre Series "
The research was carried out at University of Belgrade Faculty of Agriculture experimental station “Radmilovac” on table grape Victoria cv with aim to improve grape quality and with consideration the introduction of these ampelographic measures in regular grapevine growing. The research included two treatments of berry thinning (thinning bunch tip - BtT and first lateral wink -BtW), girdling (G) and control (C). Combined effect of berry thinning and girdling were not examined. The following features were examined: fertility and yield, bunch and berry dimensions, bunch and berry structure, sugar content and total acidity. The thinning treatments did not have significant effect on uvometric parameters and grape quality, but they improved the yield by 41.7% (BtW) and 51.4% (BtT) in comparison to the control. It can be explained by bad fruit set influenced by unfavourable meteorological conditions during floweringin control treatment. Berry thinning achieves a better fruit set. Berry thinning should be applied as a regular ampelographic measure according to weather conditions during flowering phonological stage. Results confirm the positive influence of girdling. The yield was increased by 88,34% compared to control, berries had a higher diameter (for about 1mm with respect to control), fruit set and bunch mass were in higher level against other treatments, sugar content (17,00%), total acidity (5,75 g/L) were improved too. Girdling can be introduced as a regular ampelographic measure in the table cultivars vineyards, in order to obtain higher yields and better quality of table grape.
1 January 2024 in Zbornik Matice srpske za prirodne nauke
Viticulture production, like the entire agriculture, is subject to climate changes related to a significant increase in air temperature. High air temperatures during the ripening period negatively affect the yield and quality of grapes. Apart from the increase in air temperature, grape production is also affected by rainfall and the frequency of extreme events. Climate projections for the future predict a further increase in air temperature and a change in the most important viticultural indices. The analysis shows that there has been a change in the climate category according to WI and HI values, and in some areas also CI. The Drought Index (DI) does not show significant changes in the first two periods (2021- 2040; 2041-2060), in contrast to the increased frequency of droughts and the extension of the duration of the dry period during the year. Since the most significant risks in viticulture come from high temperatures during the grape ripening period and from hail and stormy weather during the growing season, appropriate adaptation measures are needed.