Phoma is probably the most significant and costly rape disease, says Neil Groom
widespread disease. It was record- ed in all regions at high levels of incidence, confirms Crop Monitor. Phoma could become even more prevalent in the future as climate changes, suggests Mr Groom. There are some varieties with good resistance ratings to this disease, says Mr Groom. But he warns: “Phoma is probably the most significant and costly dis- ease of rape, causing premature death and yield losses up to 0.5 to 1t/ha.” The AHDB list for 2018/2019 details 20 rape varieties. But only two have an 8 rating for phoma resistance. Of the others, two have a 7 rating, three a 6 rating, five a 5 rating, six a 4 rating and two have a poor 3 rating. Grainseed rape variety Mam- bo has a rating of 7.8, Alegria 7.4, Decibel CL 8 and Aquarel CL 8. “This resistance is also multi- gene and is resistant to all known strains of Phoma stem canker, so is unlikely to break down in the field,” says Mr Groom.
“Choosing a variety with a high resistance rating to Phoma
can protect the crop and save you money. It has been calculated that each resistance rating point is worth at least £20/ha benefit.”
Highest incidence Light Leaf spot is the next most widespread disease and affected 68% of crops and 15% of plants within the crop last spring, ac- cording to Crop Monitor. The north of England showed the highest incidence, with 88% of crops infected and 36% of plants. Light Leaf spot can also be a
costly disease, and has the ability to stunt plants and cause prema- ture pod ripening which can lead to large yield losses, Mr Groom explains. “A couple of years ago most va- rieties had a 5 or 6 rating but now many more have a 7. However 7 is the highest rating out of a 1-9 rat- ing system. Mambo has a 6.4 rat- ing for Light leaf Spot and Aquar- el CL a 6, Alegria has a 5.4 and Decibel CL a 5.” Varietal resistance is also very important when it comes to Verti- cillium wilt which is more wide-
spread, probably due to it being a soil-borne disease and tighter crop rotations. The first option is grow- ing a resistant variety and the sec- ond is widening crop rotations. That is because are no ap-
proved chemical solutions to Verticillium, which can cause heavy yield losses due to lower seed weight, fewer pods and seeds per pod, premature ripening and plant death. As a result, resist- ant varieties play a key part in combating the disease.
“CropMonitor doesn’t look at this disease nor do AHDB publish resistance ratings on their list. But the Association of Independ- ent Crop Consultants and ADAS have been investigating and as- sessing varietal differences. “Our varieties Mambo, Alegria
and Alienor have all come out very well in terms of resistance to this disease in these assess- ments.” says Mr Groom. Growers should choose a rape variety with robust disease resist- ance across the most important diseases – as they would do when selecting wheat.
GET MORE FROM YOUR
OILSEED RAPE
TALK TO THE HEAR SPECIALISTS 02392 632883
info@premiumcrops.com www.premiumcrops.com WHITEDALE FARM EAST STREET HAMBLEDON HAMPSHIRE PO7 4RZ Premium Crops a division of Cefetra Ltd
JULY 2018 • ANGLIA FARMER 31
On average
HEAR growers earn £100 per hectare more from their
Oilseed Rape crops
Page 1 |
Page 2 |
Page 3 |
Page 4 |
Page 5 |
Page 6 |
Page 7 |
Page 8 |
Page 9 |
Page 10 |
Page 11 |
Page 12 |
Page 13 |
Page 14 |
Page 15 |
Page 16 |
Page 17 |
Page 18 |
Page 19 |
Page 20 |
Page 21 |
Page 22 |
Page 23 |
Page 24 |
Page 25 |
Page 26 |
Page 27 |
Page 28 |
Page 29 |
Page 30 |
Page 31 |
Page 32 |
Page 33 |
Page 34 |
Page 35 |
Page 36 |
Page 37 |
Page 38 |
Page 39 |
Page 40 |
Page 41 |
Page 42 |
Page 43 |
Page 44 |
Page 45 |
Page 46 |
Page 47 |
Page 48 |
Page 49 |
Page 50 |
Page 51 |
Page 52 |
Page 53 |
Page 54 |
Page 55 |
Page 56 |
Page 57 |
Page 58 |
Page 59 |
Page 60 |
Page 61 |
Page 62 |
Page 63 |
Page 64 |
Page 65 |
Page 66 |
Page 67 |
Page 68 |
Page 69 |
Page 70 |
Page 71 |
Page 72 |
Page 73 |
Page 74 |
Page 75 |
Page 76
