Verticillium wilt in osr

[moretimeforgolf]

I've cut 25ha of Popular on heavy ground so far and has yielded a disappointing 3.3t/ha (roughly). There was barely a green stem in sight despite only having been sprayed with glyphosate 14 days earlier. From looking fairly decent, it ripened very rapidly from the top down, especially the side branches. Having spoken to my agronomist and done a bit of research it appears to be verticillium wilt ... not been a problem before. Does this mean the end of rape for this farm or are there ways to minimise the impact?

 

[Badshot]

I think this is more widespread than we realise, I have rape on virgin ground this year and it's as green as anything in the stems still, 2 and a half weeks since dessicating, might get to it later this coming week but not holding my breath at the minute.

 

[Northdowns Martin]

Didn't your neighbour RS have problems with wilt some years back. From memory Wilt is recognisable by silvery grey stems.

 

[moretimeforgolf]

Didn't your neighbour RS have problems with wilt some years back. From memory Wilt is recognisable by silvery grey stems.

Seems to match the symptoms, yes silvery grey in the stems. 4 years since those fields had rape.

 

[DrWazzock]

My pods have ripened from top down, turning white and desiccating quickly while lower pods are still green and healthy.

Been a nightmare to judge when to desiccate.

A crop that looked good until post flowering now looks poor. MIght just have been drought though.

 

[moretimeforgolf]

We tend to suffer from drought most springs but rape seems relatively resilient . The fields cut so far this year have been on heavy ground, some subsoiled and some direct drilled.

 

[JACK F]

Variety seems to make an impact on its severity. Had it last year on our fields of Quartz and devastated them. They yielded over half tonne acre less than any of our other varieties on neighbouring fields. Not sure how susceptible Popular is though.

 

[moretimeforgolf]

The only variety list I've come across (Elsom seeds data) shows Catana least affected and Excalibur most affected. Unfortunately the trial list is a bit out of date and doesn't include Quartz or Popular. Would be good to see an up to date trial.

 

[Fish]

I have see some upto date data on wilt scores,
On a 1-9 rate, 1= low infection

Catana @ 1.5
Popular@ 3.75
Quartz @ 7.5

 

[moretimeforgolf]

I think that Popular score needs updating !

 

[Barry]

Data on Verticillium is very thin, but you are correct there is some data from a few trials that suggest Catana is about the best and Quartz is about the worst but there is no guarantee on any variety and the disease is not easy to identify so there may be instances of infection that have been missed.

Barry

 

[RBM]

Sometimes it depends upon the time of year the infection comes in, late infections have less impact than early infections, think there was a variety trial on Tom H's last year that showed Incentive & Extrovert coping better with verticillium. Extrovert has Catana in it's parentage and has performed considerably better where we have had a history of it in on some blocks than other varieties.

 

[Neddy flanders]

why think 3.3t/ha is disappointing!!!
For a 1 in 2 rotation it's the norm. Widen it to 1 in 3 or 1in 4 and you'll get 3.75.
Plenty Of agronomists are using Wilt as a reason to placate farmers who read forums with big Knobs shouting about 6t/ha crops. Rape is a Basxxxd of a crop to grow. If it doesn't want to yield it won't, and it won't tell you why it hasn't.

 

[Wheatseeker]

I've cut 25ha of Popular on heavy ground so far and has yielded a disappointing 3.3t/ha (roughly). There was barely a green stem in sight despite only having been sprayed with glyphosate 14 days earlier. From looking fairly decent, it ripened very rapidly from the top down, especially the side branches. Having spoken to my agronomist and done a bit of research it appears to be verticillium wilt ... not been a problem before. Does this mean the end of rape for this farm or are there ways to minimise the impact?

Main sign of verticillium would be a brown stripe down the side of the main stem. Late infection sclerotinia that catches the last flowers on the side branches can cause a similar symptoms to those you are seeing.

 

[dirty harry]

Our incentive struggled to do 4ton despite looking like a 5 + tonner all year, disappointing really, done some troy on Virgin ground which is running at 3.5ton ish, also cut some trinity in same field as troy(same treatments etc) and this was doing 5ton + The stubble was a lovely healthy green colour compared to dead ish in the troy?

Trouble is I haven't much trinity (Sod's law)!! But will be planting more next year.......

Heard some good reports on campus locally Aswell.

Have some harper to do when it dries up Aswell which has looked less than average all year but looks ok now so fingers crossed......!!


Cheers dh

 

[dirty harry]

Before you ask why troy anyway, it's virgin "growy" land so wanted a dwarf, and it did really well here last year.

I also wander if the hgca and other trials are done on Virgin land and whether they should do a virgin trial and a 2/3yr osr gap trial to see the difference?

And reading the farming press over the last few weeks/ months who are these bloody osr "experts" who keep re conning we should easily do 6ton plus blah blah blah......!!!!
Do they consistently do this on their own farms?!!

Cheers dh

 

[Badshot]

I did comment years ago that I thought it was possible for a farm to become sick to a particular variety after a few years growing it, maybe that was caused by verticillium wilt that was affecting that particular variety.

 

[moretimeforgolf]

I shall try to get my suspicions confirmed before the weather allows me to harvest the rest of it! Have already cancelled my Popular order.

 

[Brisel]

Before you ask why troy anyway, it's virgin "growy" land so wanted a dwarf, and it did really well here last year.

I also wander if the hgca and other trials are done on Virgin land and whether they should do a virgin trial and a 2/3yr osr gap trial to see the difference?

And reading the farming press over the last few weeks/ months who are these bloody osr "experts" who keep re conning we should easily do 6ton plus blah blah blah......!!!!
Do they consistently do this on their own farms?!!

Cheers dh

Are you a member of NIAB TAG? They have done long term repeated replicated trials on osr yields in different rotation lengths. Virgin was best, then unsurprisingly yields dropped away the closer you got between crops. There wasn't a big difference in 1 in 4 to 1 in 3, nor any major gains for 1 in 6+.

There are more & more reasons for osr yields to reduce over time from diseases we don't know enough about, like Olpidium Brassicae, Verticilium WIlt etc. Many of these don't grow in agar in a lab so we weren't really aware of them until recently.

http://cereals.ahdb.org.uk/media/418246/RIF-April-2014-soil-borne-osr-pathogens.pdf

It's a crop I love to hate. That got forgotten about when osr was £400/t and yielded 5 t/ha for a couple of years, but now we're back to the long term average of 1.5 t/ac with ever increasing costs of production from disease, charlock, slugs, pigeons etc

 

[hybrid vigour]

Here is some independent data from the AICC. Incentive top 'resistant' hybrid.

HV