A notably short and productive flowering period in most crops across much of the country has been very welcome this year
By Will Vaughan-France, Dekalb technical specialist
A notably short and productive flowering period in most crops across much of the country has been very welcome this year. In many cases, full flowering lasted barely 4-5 weeks, rather than the 6-7 we’ve often seen of late, coming to a rapid end as I write at the start of the second week in May.
Far steadier development than last year in a later and much drier spring has allowed our vigorous hybrids, in particular, to produce well-structured canopies with plenty of strong side branches that are none too tall. Just the way we like them.
As expected, our low biomass hybrids with the semi-dwarf character have caught up rapidly over the past month, with an especially short, sharp flowering flourish.
Following an autumn and winter in which rooting was unhindered by water-logging in many cases, the dry spring has been no bad thing; especially not with the early May rain coming at just the right time to favour pod-fill rather than further canopy development.
Good photosynthetic and pollination conditions in an April in which most parts of the country saw 40 per cent more sunshine hours than the 30-year average, have been very beneficial too. As a result, we’re seeing excellent, even pod set across the vast majority of our small plot and commercial scale trials.
The short flowering period means far less late pod creation. So it looks like we’ll see more sensible levels of pod density this season, with greater numbers of seeds per pod – I’ve already been counting between 20-30 in the earliest set – and potentially far bigger seeds. Especially so as the early end to flowering leaves a good two months of pod fill.
Lack of moisture in March and April could well also give us a valuable extra pod-fill bonus of late nitrogen release from earlier-applied fertiliser now we’ve had a decent amount of rain.
Of course, the dry spring hasn’t helped crops with thinner areas fill-in as well as we’d hoped. In some areas flea beetle larvae damage has been serious enough for crops to be pulled out in April. And we’re likely to see more extended flowering and less even crop development where late frosts have hit.
The surprisingly high levels of seed weevil I’ve seen in a few crops may also cause them to suffer more pod midge damage than usual. While reports of high turnip yellows virus (TuYV) incidence cannot be ignored, our untreated UK variety development work against a continued background of the virus suggests this is unlikely to have a major impact on yield.
Overall, therefore, the bulk of the national crop looks well set for the run-in to harvest.
Generally more even crops should make Roundup timing for harvest management a good bit easier this season too. In modern, well-structured crops it’s more important than ever we have patience, only spraying when the pods in the part of the canopy carrying the bulk of the yield are ready.
Relatively few late pods on lower branches will mean less of a maturity range across most crops. So there shouldn’t be nearly such a risk from not rushing into pre-harvest spraying as soon as the pods on the main raceme are ready. All the more so with pod-shatter resistant varieties.
Being in no hurry with the Roundup will, in turn, enable the best yields, oil contents and sample qualities to be secured in a year in which the greatest gross output will be more critical than ever to crop profitability.