Citation: Walsh, K.B. In-Field
Estimation of Fruit Quality and
Quantity. Agronomy 2022, 12, 1074.
https://doi.org/10.3390/
agronomy12051074
Received: 19 April 2022
Accepted: 25 April 2022
Published: 29 April 2022
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agronomy
Editorial
In-Field Estimation of Fruit Quality and Quantity
Kerry B. Walsh
Institute for Future Farming Systems, Central Queensland University, Rockhampton, QLD 4701, Australia;
k.walsh@cqu.edu.au
Every new tool gives humankind a new capability or capabilities, as a new tool finds
a range of applications. For example, the production of a magnifying lens allowed a new
look at the natural world. Every generation of scientists since has accessed some new tool
allowing a different view of the same subjects, from a compound microscope to a confocal
microscope and beyond. Each new view enables new interpretations.
This evolution also applies to agricultural applications. On a dairy farm, the pro-
duction of every cow can now be monitored daily, and the herd can be managed at the
level of the individual beast. In a wheat field, a satellite-acquired vegetation index map
can be used for a variable-rate fertilizer application program. However, until now, fruit
production has been based on a per-orchard basis rather than a per-tree basis. Technol-
ogy advances, however, are throwing up a range of capabilities that allow for change in
orchard management.
Agriculturalists are both an inventive and adaptive lot. They are inventive in the sense
that technology advances sometimes come from agricultural applications and are then
applied elsewhere. For example, the field of near-infrared spectroscopy was pioneered in
the 1960s context of an agricultural product quality control by Karl Norris of the United
States Department of Agriculture. The technology soon flourished in other application areas
and is heavily used today in a range of disciplines, from petrochemical to pharmaceutical,
as well as agricultural industries such as diary, forage, and grain. Its use in the assessment
of intact fruit, both on fruit pack lines and in the orchard, using handheld devices came
later, beginning in the 1990s.
However, agriculturalists are more commonly an adaptive lot, taking advantage of
technologies developed for other applications, particularly from the medical, space, and
defense sectors, given the well-funded R&D programs in those areas. Yield forecasts based
on satellite- or drone-assessed vegetation indices are now commonplace for broadacre
crops. Such technology-enabled forecasts of tree fruit harvest timing and load are yet
to be widely commercially implemented, although advances in a range of technologies,
including machine vision, image processing, LiDAR, and spectroscopy, hold promise for
in-orchard assessment of various fruit crop attributes.
The need to forecast tree fruit harvest timing and load has increased due to scale and
distance factors. Scale refers to the increase in size of fruit production systems, with a
time-poor orchard manager relying on forecasts in harvest resourcing decisions. Distance
refers to the increasing length of global value chains, with the managerial need to forecast
harvest timing and volume increasing with the complexity of the value chain.
Relevant technologies used in the controlled environment of the packhouse are being
shifted to use in the field environment of the orchard to address these needs. Examples
include near-infrared spectroscopy (NIRS), used in assessment of fruit attributes relevant
to the estimation of the optimum harvest timing, and machine vision techniques that allow
for automated assessment of the flowering stage and level and fruit detection, sizing, and
counting. These tools can inform farm management decisions on flower thinning, harvest
timing, harvest resourcing (labour and materials), and marketing.
Agronomy 2022, 12, 1074. https://doi.org/10.3390/agronomy12051074 https://www.mdpi.com/journal/agronomy