When to score heading: planning scoring days in field trials

Heading notes are quick to take per plot. They're expensive in visits. You have to be at each site while the plots are heading, go back again and again as more of them head, and do it at every station in the same few weeks. Miss a hot week and half a trial heads between visits.

This article is about planning those visits: when to start, how often to go, what to write down, and how to give the work to technicians so that nothing falls through.

Agree on what "headed" means

Before you plan the days, agree on the note. A common definition is the day half the heads in the plot have fully emerged from the boot. Some programs use first heads visible instead, or full heading. Any of these works if everyone uses the same one.

Write it in your protocol, with a photo of a plot that just counts and one that doesn't yet. If two people score the same trial, have them walk a few plots together on the first day and compare. Scorers drift apart more than they think.

When to start

Start a few days before the earliest plots are due. There are three ways to know when that is.

Your early checks. When the earliest check starts heading, the window is open. Walk past the trial every couple of days from about a week before you expect it.
Thermal time. If you know roughly how many GDD from sowing your early lines need, track the GDD at each site and start when it's close (see predicting heading date).
Last year's dates, adjusted for this year's sowing date. The weakest of the three, but better than nothing.

Sites don't head together. A warmer station, or one sown earlier, will be ahead of the others. Plan travel so one person isn't needed at two stations on the same day.

How often to go back

During the window, plots move fast, especially in heat. The time between visits is the precision of your notes. If you visit every three days and write down the visit date, a plot's recorded date can be two or three days after the day it really headed.

Every day gives the tightest dates. It's worth it for genetic studies of heading, or for crossing block parents.
Every two or three days is a common compromise for yield trials.
More often in a hot spell. Heat speeds development, so the window gets shorter just when you might be tempted to skip a visit.

What to write down

The simplest method: on each visit, write today's date for every plot that has reached your definition since the last visit. Then skip those plots next time.

Two small additions help a lot.

Mark the plots that are close. A quick "nearly" mark tells you which plots to look at first next time. It also lets you put a plot that passed between visits on the middle day, rather than on the visit day.
Mark the plots you were too late for. If a plot was already well past heading on your first visit, its note only says "on or before this date". Mark it, rather than writing the visit date as if it headed that day. Analyses and forecasts can then treat it differently.

Walk in field order, carry the list of plots still to score, and note anything that will affect the data: hail, lodging, a rep that was missed.

Weather and safety

You can score heading in light rain. It's slower, the tablet gets wet, and notes get sloppier. Heavy rain and thunderstorms are different: stay out of the field. Lightning on open ground is a real risk. In hot weather, start early, carry water and take breaks.

Check the forecast when you plan the week, not just on the morning. A visit pushed back by a wet day eats into the next one.

Organising the work for technicians

Heading notes go wrong more often for organisational reasons than scientific ones. Nobody was asked. Two people each thought the other was going. The paper sheet was never typed in.

A good scoring task says five things:

What: the trait, by its agreed name and definition.
Where: the site, and which plots. Usually the ones not yet scored.
When: a window, not a single day. "Any day between 8 and 12 July" is honest about how heading works.
Who: a named person, or anyone in the crew.
Done: a tick, with the time it was really done, even if the phone had no signal at the time.

Look over the list at the end of each day. Plots that should have headed by now but haven't been scored are the ones to check first tomorrow.

A week in practice

Here's how that can look for a made-up program with trials at a warm southern station and a cooler northern one.

Monday. The early check is starting to head at the southern station. A scoring task goes out for the next four days there, given to the technician based nearest.
Wednesday. Most early lines in the south are done. The forecast shows rain on Friday, so the next visit moves up to Thursday.
Friday. The northern station's early check shows its first heads. A second task goes out for that station, starting Monday, to the same crew.
Each evening. Anyone who scored ticks the task off, or leaves a note on what's left. The breeder looks at the plots still to score at each site.

Nothing here is clever. It works because the window, the plots and the person are written down in one place.

How Crossling helps

Crossling joins the forecast, the task and the scoring screen.

A heads-up on Today. From the Outlook's heading model, Today says when plots at each site should start reaching the stage, up to two weeks ahead: "Heading starts at Lacombe around 12 Jul", with how many plots fall between which dates and when most are expected.
Overdue plots. If plots should have reached the stage by now and haven't been scored, Today says so and asks you to check them.
One tap to a task. Any of these becomes a field task. The forecast's window becomes the due dates, and the trait and the plots still to score come with it. The same suggestion never becomes two tasks.
Tasks for the crew. Give a task to a person or to anyone in the program. Breeders and admins give out tasks; technicians add their own, and tick off theirs or anyone's. On the phone the list reads Overdue, Today, This week, Later and Done.
Works with no signal. The task list opens offline, and ticks wait on the phone, sent later with the time they were made. Scores entered offline wait the same way.
The weather for the day. Scoring tasks show what the forecast says about the day they're due, such as heavy rain, real cold or heat, and thunder where the forecast gives it, and which day looks better when it's a poor one.
Scoring in field order. The scoring screen walks the plots in the order you walk the field, with big buttons, voice entry and barcode scanning.

As plots are scored, the forecast for the rest of that site gets sharper. Try the demo to see Today and the task list, or create an account and plan your own scoring days.