3,610 research outputs found
Machine Vision System for Early-stage Apple Flowers and Flower Clusters Detection for Precision Thinning and Pollination
Early-stage identification of fruit flowers that are in both opened and
unopened condition in an orchard environment is significant information to
perform crop load management operations such as flower thinning and pollination
using automated and robotic platforms. These operations are important in
tree-fruit agriculture to enhance fruit quality, manage crop load, and enhance
the overall profit. The recent development in agricultural automation suggests
that this can be done using robotics which includes machine vision technology.
In this article, we proposed a vision system that detects early-stage flowers
in an unstructured orchard environment using YOLOv5 object detection algorithm.
For the robotics implementation, the position of a cluster of the flower
blossom is important to navigate the robot and the end effector. The centroid
of individual flowers (both open and unopen) was identified and associated with
flower clusters via K-means clustering. The accuracy of the opened and unopened
flower detection is achieved up to mAP of 81.9% in commercial orchard images
Spatio-temporal Diptera visitation to Silene acaulis flowers studied with time-lapse cameras in Svalbard and Greenland
Flower visitation by flying arthropods has mainly been studied by direct human observation, which usually neglects seasonal development of flower abundance even though this is known to be important for visitor dynamics and match between trophic levels. In the present study, the arthropod visitor community focusing on Diptera was investigated on the cushion plant Silene acaulis (L.) Jacq. in relation to the available flower area. This was done using time-lapse cameras at one sub-Arctic, one low Arctic, and two high Arctic sites at Svalbard and Greenland. The S. acaulis flower visitor match at the Svalbard site was in addition characterized by using independent invertebrate traps located next to the camera site. Image annotation of cushion’s visitors ensured a high temporal resolution of data throughout the flowering season and showed a highly increased visitation frequency when more flowers were open. Individuals from several trophic levels visited S. acaulis, supporting the claim of S. acaulis as nursing plant and community hotspot. True flies (Diptera) were by far the most abundant visitors of the visitors identified. The Diptera visitor abundance per unit flower area showed large variations and varied over seasonal development, years, and between sites. Image-annotated visitors were observed both on open flowers and the remaining image. In average 40 % of Diptera visitors were observed on flowers. This percentage followed the increase in image area with open flowers and peaked the same time as flowering peak, thought the number was also site and year specific. For the largest camera site in Svalbard, this percentage of visitors on flowers strongly decreased during the three-year study period. The decrease may have been enhanced by delays in flowering onset that led to increased competition with other flower species, making S. acaulis flowers less attractive to visitors
Edna metabarcoding of avocado flowers: ‘Hass’ it got potential to survey arthropods in food production systems?
In the face of global biodiversity declines, surveys of beneficial and antagonistic arthropod diversity as well as the ecological services that they provide are increasingly important in both natural and agro-ecosystems. Conventional survey methods used to monitor these communities often require extensive taxonomic expertise and are time-intensive, potentially limiting their application in industries such as agriculture, where arthropods often play a critical role in productivity (e.g. pollinators, pests and predators). Environmental DNA (eDNA) metabarcoding of a novel substrate, crop flowers, may offer an accurate and high throughput alternative to aid in the detection of these managed and unmanaged taxa. Here, we compared the arthropod communities detected with eDNA metabarcoding of flowers, from an agricultural species (Persea americana—‘Hass’ avocado), with two conventional survey techniques: digital video recording (DVR) devices and pan traps. In total, 80 eDNA flower samples, 96 h of DVRs and 48 pan trap samples were collected. Across the three methods, 49 arthropod families were identified, of which 12 were unique to the eDNA dataset. Environmental DNA metabarcoding from flowers revealed potential arthropod pollinators, as well as plant pests and parasites. Alpha diversity levels did not differ across the three survey methods although taxonomic composition varied significantly, with only 12% of arthropod families found to be common across all three methods. eDNA metabarcoding of flowers has the potential to revolutionize the way arthropod communities are monitored in natural and agro-ecosystems, potentially detecting the response of pollinators and pests to climate change, diseases, habitat loss and other disturbances
Geomagnetism review 2014
The Geomagnetism team measures, records, models and interprets
variations in the Earth’s magnetic field. Our data and research help to
develop scientific understanding of the evolution of the solid Earth and its
atmospheric, ocean and space environments, and help develop our
understanding of the geomagnetic hazard and its impact. We also provide
geomagnetic products and services to industry and academics and we use
our knowledge to inform the public, government and industry
Spatiotemporal variation in the pollination systems of a supergeneralist plant: is Angelica sylvestris (Apiaceae) locally adapted to its most effective pollinators?
Background and Aims: In terms of pollination systems, umbellifers (plants of the carrot family, Apiaceae) are regarded as generalists, since their (usually dichogamous) flowers are visited by a wide range of insects representing several taxonomic orders. However, recent analyses of insect effectiveness revealed that these plants may be pollinated effectively by a narrow assemblage of insect visitors. Of particular interest was whether populations of an umbellifer species varied in pollinator assemblages and whether this could lead to local specialization of the pollination system. We also explored whether variation in pollinator assemblages was associated with variation in floral traits, and whether this variation influences reproductive output. Methods: The focus was on Angelica sylvestris, a common European species visited by a taxonomically diverse insect assemblage. In three populations, located along an ~700-km transect, over three growth seasons insect visitors were identified, their effectiveness was assessed by surveying pollen loads present on the insect body, insect activity on umbels, nectar and scent composition was studied, and transplantation experiments were performed. Key Results: The populations investigated in this study differed in their nectar and scent profiles and, despite the similar taxonomic composition of insect visitor assemblages, were effectively pollinated by disparate pollinator morphogroups, i.e. flies and beetles. Although this suggested local adaptations to the most effective pollinators, analyses of body pollen loads and behaviour on umbels demonstrated functional equivalency of the visitor morphogroups, which is probably related to the fact that A. sylvestris bears few ovules per flower. The transplantation experiments confirmed that reproductive success was not related to the source of experimental plants and that the insects do not exhibit preferences towards local genotypes. Conclusions: Angelica sylvestris is morphologically well adapted to ecological generalization, and there is little evidence that the surveyed populations represent distinct pollination ecotypes. Most likely, the observed variation in floral characters can be interpreted as 'adaptive wandering'. Specialization in this family seems possible only under very special circumstances, for example when the pollinator community comprises insect visitor groups that clearly differ in their pollination capacity (e.g. due to differences in their functional morphology) and/or have different perceptional biases (e.g. for colour or scent). However, the barrier to the evolution of morphological adaptations resulting in the fine-tuning of the flower towards particular pollinator types may arise from the architectural constraints on the floral bauplan that make umbellifers so uniform in their floral displays and so successful in attracting large numbers of pollinators
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