RESPONSE OF YOUNG SOUR CHERRY TREES TO WOODCHIP MULCH AND DRIP IRRIGATION

The productivity of sour cherries grown in Latvia is insufficient. Yielding of sour cherries can be advanced providing appropriate soil moisture and control of diseases. Cherry leaf spot as well as spur and twig blight are the most important sour cherry diseases which cause economical losses of the yield. The influence of woodchip mulch and drip irrigation on sour cherry yielding and resistance to the diseases is investigated. The drip irrigation and woodchip mulch increased the yield of cherries. The cultivar ‘Bulatnikovskaya’ was the most productive. Drip irrigation slightly improved resistance to cherry leaf spot for the cultivars ‘Zentenes’, ‘Orlica’ and ‘Tamaris’

DIGITAL TWIN: ORCHARD MANAGEMENT USING UAV

Orchard management can benefit greatly from the use of modern technology to reach higher yields, decrease costs and achieve more sustainable farming. Implementation or such a smart farming approach into orchard management can be realised via application of unmanned aerial vehicles (UAV) for data collection and artificial intelligence (AI) for yield estimation and forecasting. On top of that, a digital twin of the orchard can be implemented to represent the physical system of the orchard in the digital format allowing implement modern data-driven decision-making based on fruit-growing automation.The aim of this study is to present a digital twin based on application of UAV and AI for orchard management that is being developed as part of a research project lzp-2021/1-0134. At this moment, we are developing a user-centred design which is oriented to satisfy horticulture specialists’ needs for an autonomous monitoring system and to help them in decision-making. Within the framework of this study an enterprise model of orchard management is designed, which supports the digital twin concept and provides autonomous orchard monitoring. The study is scoped with subjects: apples, pears and cherries, and yield management based on orchard monitoring using UAV.

Risks and returns in strawberry, raspberry and cherry production with various methods

Horticultural production in Latvia has always been subject to numerous and diverse risks similar to other branches of crop plant production in Latvia. On the other hand, the climate of Latvia is favourable for plant crop growing but the value of production depends on climatic condition as well as field management and competence of the farmers. The markets of inputs used in strawberry, raspberry, and cherry farming have a direct impact on risks through unexpected rise in prices. Similarly, returns from horticultural outputs are affected by high volatility of fresh farm produce markets. Besides that, growers face the inevitable yield risks induced by adverse weather conditions, pests, and diseases. There are a few systems used in production of strawberries, raspberries, and cherries - extensive and intensive growing both in open and covered areas. These methods vary by the level of risks and necessary investments. The production of berries and stone fruit in areas covered by polyethylene tunnels is expanding. The tunnel method of production provides better climatic conditions and reduces the damage by pests and diseases, thus, contributing to a longer and more predictable shelf life of the fruit. Production in tunnels extend the harvest season. High tunnels, in turn, can advance harvest dates earlier. Beyond the normal season, there is less competition and producer prices can be set higher. The aim of the study is the assessment of general risks in strawberry, raspberry, and cherry production, risks in production with various methods at farm level and evaluation of the tradeoffs among farming risks and expected returns

SSR-Based Analysis of Genetic Diversity and Structure of Sweet Cherry (Prunus avium L.) from 19 Countries in Europe

Sweet cherry (Prunus avium L.) is a temperate fruit species whose production might be highly impacted by climate change in the near future. Diversity of plant material could be an option to mitigate these climate risks by enabling producers to have new cultivars well adapted to new environmental conditions. In this study, subsets of sweet cherry collections of 19 European countries were genotyped using 14 SSR. The objectives of this study were (i) to assess genetic diversity parameters, (ii) to estimate the levels of population structure, and (iii) to identify germplasm redundancies. A total of 314 accessions, including landraces, early selections, and modern cultivars, were monitored, and 220 unique SSR genotypes were identified. All 14 loci were confirmed to be polymorphic, and a total of 137 alleles were detected with a mean of 9.8 alleles per locus. The average number of alleles (N = 9.8), PIC value (0.658), observed heterozygosity (H-o = 0.71), and expected heterozygosity (H-e = 0.70) were higher in this study compared to values reported so far. Four ancestral populations were detected using STRUCTURE software and confirmed by Principal Coordinate Analysis (PCoA), and two of them (K1 and K4) could be attributed to the geographical origin of the accessions. A N-J tree grouped the 220 sweet cherry accessions within three main clusters and six subgroups. Accessions belonging to the four STRUCTURE populations roughly clustered together. Clustering confirmed known genealogical data for several accessions. The large genetic diversity of the collection was demonstrated, in particular within the landrace pool, justifying the efforts made over decades for their conservation. New sources of diversity will allow producers to face challenges, such as climate change and the need to develop more sustainable production systems

SSR-based analysis of genetic diversity and structure of sweet cherry (Prunus avium L.) from 19 countries in Europe

Sweet cherry (Prunus avium L.) is a temperate fruit species whose production might be highly impacted by climate change in the near future. Diversity of plant material could be an option to mitigate these climate risks by enabling producers to have new cultivars well adapted to new environmental conditions. In this study, subsets of sweet cherry collections of 19 European countries were genotyped using 14 SSR. The objectives of this study were (i) to assess genetic diversity parameters, (ii) to estimate the levels of population structure, and (iii) to identify germplasm redundancies. A total of 314 accessions, including landraces, early selections, and modern cultivars, were monitored, and 220 unique SSR genotypes were identified. All 14 loci were confirmed to be polymorphic, and a total of 137 alleles were detected with a mean of 9.8 alleles per locus. The average number of alleles (N = 9.8), PIC value (0.658), observed heterozygosity (Ho = 0.71), and expected heterozygosity (He = 0.70) were higher in this study compared to values reported so far. Four ancestral populations were detected using STRUCTURE software and confirmed by Principal Coordinate Analysis (PCoA), and two of them (K1 and K4) could be attributed to the geographical origin of the accessions. A N-J tree grouped the 220 sweet cherry accessions within three main clusters and six subgroups. Accessions belonging to the four STRUCTURE populations roughly clustered together. Clustering confirmed known genealogical data for several accessions. The large genetic diversity of the collection was demonstrated, in particular within the landrace pool, justifying the efforts made over decades for their conservation. New sources of diversity will allow producers to face challenges, such as climate change and the need to develop more sustainable production systems