1. ABOUT THE DATASET ------------ Title: Avocado supply chain dataset Creators: Jessica Austin Organisations: University of Reading Rights-holders: This dataset is copyright Jessica Austin. Fruit samples used in the creation of the dataset were generously donated by Greencell (Westfalia Fruit UK) Publication Year: 2023 Description: These data support the PhD thesis 'Epidemiology and community analysis of stem end rot-associated fungal pathogens and their impact on postharvest disease of commercial avocado (Persea americana)'. Fruit physiological and disease symptom data were collected from avocados provided by the Greencell fruit distribution centre at the end of the supply chain. Fruit mesocarp was imaged and samples from the stem end were plated for each avocado to match disease symptoms to potential pathogenic fungal morphotype. Cite as: Austin, J. (2023): Avocado supply chain dataset. University of Reading. Dataset. https://doi.org.10.17864/1947.000434. Related publication: Austin, J. (2022). Epidemiology and community analysis of stem end rot-associated fungal pathogens and their impact on postharvest disease of commercial avocado (Persea americana) [PhD thesis, University of Reading]. https://doi.org/10.48683/1926.00113324 2. TERMS OF USE ------------ Copyright 2023 Jessica Austin. This dataset is licensed under a Creative Commons Attribution 4.0 International Licence: https://creativecommons.org/licenses/by/4.0/. 3. PROJECT AND FUNDING INFORMATION ------------ Title: Epidemiology and community analysis of stem end rot-associated fungal pathogens and their impact on postharvest disease of commercial avocado (Persea americana) Dates: 2017 - 2021 Funding organisations: University of Reading, University of East Anglia, Greencell (Westfalia Fruit UK) 4. CONTENTS ------------ File listing 1 File: supplychaindataset.xlsx (3 tabs + ReadMe tab) 1. Fruit Quantity Data – Physiology data such as fresh weight, dry mass, firmness, and mesocarp browning 2. Fungal Species Data – Fungal morphotype isolated from each fruit 3. Fruit Code Masterlist – Grower locations and harvest time 5. METHODS ----------- Fruit Code - Every individual avocado fruit is given an alphanumeric code. The letters are a shipment designation and the number is a fruit. For example, AR25 is the 25th avocado fruit from box AR. I receive a box of avocados each week on Monday. Total fruit fresh weight (g) - Total weight of an avocado using a standard laboratory balance. Button (1/0) - When avocados are harvested, the stem remnant is often left on the fruit in the form of a small 'button'. This can affect how easily a disease organism can enter the stem end. Sometimes avocados are plucked from the tree, or the button falls of during transport. Avocados with the stem button intact are designated '1', while those with the button missing are designated '0' (binary data). Firmness (kg) - Two firmness measurements were averaged as indicated by a penetrometer (Firmness 1 and Firmness 2). This instrument measures the amount of force needed before the inner tissue (mesocarp) collapses. This is a measurement of force in kilograms. Mean Firmness is the average of the two firmness measurements. Dry matter content (%) - One half of the avocado sample is dried at 60C for five days, until all water is removed from the sample. The dry matter is a percentage of the final dry mass (Weight after drying) divided by the original fresh weight of the avocado half (Weight before drying). Avocados typically have a dry mass of 20-30%, but vary widely by the season. Much of this is oil. Browning Symptoms - Each avocado was halved and photographed. The browning symptoms are divided into five different categories: • FB = Fungal Browning (SER) • VD = Vascular Discoloration (SER) • M = Mycelial (SER) • B = Bruising/Internal Chilling (non-fungal browning) • BR = Body Rot (non-SER) SER categories means that it is POSITIVE FOR STEM END ROT; any category that is non-SER did not have a fungal rot on the stem end, but it had another type of browning, such as bruising. Browning Score - This is a measure of rot progression. The length of the avocado was divided into thirds. For example, considering a 9 cm avocado, if the fungal browning or vascular discoloration is within 3 cm from the top, I assign it a 1, if the rot extends 3 to 6 cm from the top I assign 2, and beyond that, I assign 3. This records a categorical value. To convert it to numerical, a score of 1 indicates 1-10% rot, a score of 2 indicates 11-60% rot, and a score of 3 indicates 61-100% rot. (Rot progresses more rapidly as the fruit ages and cellular integrity degrades. Storage - When avocados first arrive in the laboratory, about half of the shipment is processed on the day of arrival, the other half is stored in a food processing laboratory for four days, which mimics grocery store conditions. The fruit processed at the end of the shelf life test show how the rot progresses over time. It is important to separate these two batches! (use Sort to create separate sheets for the fruit processed immediately '0' and those processed at the end of the week '1'. Primary Phenotype - A core of mesocarp is removed from the stem end of the avocado and placed on malt extract agar plates. The resulting fungus is assigned a name based on its colour and phenotype. When the plate did not culture a fungus, it is assigned 'blank'. Secondary Phenotype/ Tertiary Phenotype - Sometimes the avocado core sample cultured more than one fungus. The second or third fungal phenotype on the plate is recorded in these two columns. Shipment Information: (Fruit Code Masterlist) - Records the origin, orchard, and processing date of each avocado shipment. The avocado batches are split into two groups of usu. 25. The first 25 fruit are processed on the day of intake, and the second 25 is processes four days later to serve as a shelf life test (designated as a 'yes' on the shelf life column).