Commodity canola and seed canola visitation and plant data
Data files
Aug 03, 2023 version files 165.25 KB
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commodityPlants.csv
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README.md
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seedPlants.csv
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seedVisitation.csv
Abstract
Insect-mediated pollination of crops is an important service to agriculture, as increased insect visitation can increase fruit production by increasing pollen deposition. Unfortunately, pollination is often treated as a “black box”, and pollination management suffers from key knowledge gaps that hinder its greater utility, particularly the specific mechanisms underlying the processes of visitation, pollination, and fruit production. We present a causal model that links insect visitation to pollination to three separate components of yield, using field data from two types of canola (Brassica napus) production systems. Our results demonstrate that yield in commodity canola fields is primarily determined by plant size, and we found no relationship between honey bee (Apis mellifera) visitation and pollen deposition, or pollen deposition and seed yield. In contrast, yield in seed production canola fields was similarly controlled by plant size, but there was also a strong relationship between alfalfa leafcutting bee (Megachile rotundata) visitation and pollen deposition, as well as pollen deposition and seed yield. Leafcutting bee visitation in particular strongly increased pollen deposition in seed canola fields, whereas honey bee visitation did not. This model serves as a step towards a dynamic model of pollination services and highlights the relative importance of bee pollination in canola production.
Methods
Visitation and pollen data were collected from hybrid seed canola fields in Alberta, Canada during the summers of 2015 and 2016. Observers watched 1m2 plots for 5 to 10 minutes and recorded the number of visits to within each plot. They then sampled stigmas from five random flowers and counted the density of flowers and plants per m2. Stigmas were mounted on slides and Brassica pollen was counted. Three plants were collected from the same plots at the end of the season; the vegetative mass and seed mass were recorded, and seeds per pod and seed mass was counted for five pods per plant. Additionally, we counted the number of pods per plant, number of primary branches, and the number of pedicels without a pod (flower was aborted).
Similar visitation data was collected from commodity canola fields during the summers of 2014 and 2015 (see https://doi.org/10.5061/dryad.vhhmgqnvj). Three plants were also collected from the same plots at the end of the season, and the same metrics of plant mass, seed mass, and pod counts were recorded.
Usage notes
See README.md for column metadata. All missing data are represented as NA.