27 April 2012: We've had enough rain now but unfortunately we have more to come if the weather man is to be believed. High winds and rain has lead to delays to T1 fungicides in winter wheat and triazole rates are being increased as Septoria risk goes critical. Sclerotinia control in oilseed rape crops also delayed. High winds and heavy rain have knocked down some crops of winter oilseed rape in the West Midlands.
Septoria: risk increases with recent rain.
T1 fungicide: timing in winter wheat a priority.
Flag leaf: tip visible in some forward wheat crops.
Yellow rust: returns where T1s delayed.
Flag leaf: emerging in winter barley.
Sclerotinia: control delayed by weather.
Winter wheat leaf emergence: as the flag leaf begins to emerge in forward crops the date for T2 fungicides will depend on temperatures from now on. The typical phyllochron (the thermal time taken for a wheat leaf to emerge) is about 108 day degrees. Forecast temperatures for the next two weeks suggest that if the tip of the flag leaf is visible now then expect full flag leaf emergence in about 10 days time.
Wet weather raises Septoria risk.
(courtesy of Farming Online).
South East: Final leaf 3 between 75% to fully emerged, and Leaf 2 up to 75% emerged now on main shoots of Gallant/Solstice, with tips of flag leaf visible in Gallant. Very Wet!! We must be enduring the wettest drought ever as have now had >125mm of rain in last 3 weeks. T1 applications are now delayed by 7-10 days in some cases. Soils now very wet in places with standing water not uncommon.
Brown rust: odd pustules can be found in thicker crops and more particularly in September sown crops of Claire, Target and Solstice.
Mildew: since February frosts, most crops remain free of any re-infection to date - only exception is a few lush and forward crops of Gallant/Solstice.
Yellow rust: no foci or leaf pustule stripes seen, but remain vigilant particularly on varieties that may be prone to the Warrior race.
Septoria: current conditions with frequent rain splash events are very favourable for infection and any crops not yet sprayed with a T1 will have significant latent infections now in unprotected leaves, which unless applications are made within the next 4-5 days are likely to result in significant infection of final leaf 3. This looks potentially the worst Septoria year since 2008.
Eyespot: quite a lot of stem based browning now appearing in many September/early October sown crops.
Weed control: all spring applications of herbicide have now been completed - so far control of black grass is looking perhaps more comprehensive than some Autumn applications have been.
Eastern Counties: Probably 60 - 70% crops at GS 32 final leaf 3 emerging. Crops are very tall and thick crops will require a second growth regulator.
Brown rust: no new infection seen since application of T0 fungicides.
Yellow rust: high levels on untreated susceptible varieties.
Mildew: the more backwards crops showing quite a lot of mildew.
Eyespot: showing on crops but is not really penetrating the leaf sheath.
Septoria: showing in the older leaves and with wet weather it has a lot of potential to spread. Invicta seems to be quite badly affected.
Weed control: the mild winter has given rise to more cleavers this year than usual.
East Midlands: Nearly all crops now have final leaf 3 emerging with forward ones showing final leaf 2. After recent heavy rain soils now wet with water in tramlines causing some damage on headlands.
Brown rust: none seen.
Yellow rust: seen in Oakley at low level where T1 delayed due to rain.
Mildew: levels remain low although a bit on the lower stems of Humber but not a significant level.
Septoria: all T1 now beefed up as interval between T0 and T1 gets to 4 weeks.
Eyespot: levels still remain of concern particularly as T1 sprays delayed and spray penetration to the base of the crop gets compromised.
Weed control: Fumitory appears to be the crop of the moment but easily controllable.
West Midlands: Final leaf two is a third out on some of the early sown crops after oilseed rape or potatoes. Pretty much all other crops can find final leaf 3 either out or emerging, T1 down for this week and next week, weather permitting, quite a few crops treated at the beginning of this week, but it has been raining ever since. Some BYDV patches starting to become more obvious.
Brown rust: none seen.
Yellow rust: no new infections seen.
Mildew: levels have declined in the last week and new growth is clean.
Eyespot: some lesions in early drilled crops but not developing.
Septoria: lots of septoria in the base of many crops.
Weed control: rain has encouraged a recent emergence of broad leaved weeds including cleavers and volunteer oilseed rape.
North East: Despite the below average temperatures crops are developing quickly, and are now at GS 31-32. Final leaf 2 at 50% emerged in some Duxford and Scout crops. It has been another difficult week for spraying, but the beginning of the week provided some good gaps between showers and most growers are up to date now on their wheat crops. The target at T1 was final leaf 3, but for many crops final leaf 2 also has good protection now.
Brown Rust: low levels seen in the most susceptible varieties, such as Duxford and Grafton but well controlled so far by the T0 fungicide.
Yellow Rust: traces of rust just re-appearing as T1 applied. In some Oakley, Robigus and Santiago.
Mildew: only the most resistant varieties are clean such as Warrior and Viscount. All the rest have varying levels of infection.
Eyespot: more lesions penetrating the outer leaf sheath seen this week.
Septoria: fairly high levels seen on older leaves of most forward crops, but development halted for now by T0 fungicide.
Weed control: cranesbill is the most common broad-leaved weed, and there are some severe infestations.
Winter Oilseed Rape
Heavy rain and high winds takes its toll.
(courtesy Farming Online).
South East: All crops now between first flowers to mid - flowering. No reports of any lodging.
Phoma: no significant renewed spotting seen to date.
Light Leaf Spot: no new infections seen.
Seed Weevil: first adults seen in last few days.
Sclerotinia: with petal sticking in leaf axils now evident and sclerotinia ascopspores detected on petals at monitoring sites, infection looks to be well synchronized with the vulnerable early to mid-flowering stages of the crop this year.
Eastern Counties: More flowers are slowly appearing and crops look overall yellow except for some late fields of DK Cabernet or a few pigeon damaged areas. Still some final applications of nitrgoen to go on planned for full flower or just afterwards.
Light leaf spot: remained at low levels none on upper leaves, recent conditions have not been conducive to spread of this disease.
Mealy aphids: in small clusters scattered in some crops.
Sclerotinia: some first Sclerotinia sprays have been applied to earliest fields. Other fields now due to be sprayed but forecast not good. However, temperatures are low and spores unlikely to be released just yet from germinating sclerotia. However, all crops will be targeted in full flower and we will probably go back with a later spray for sclerotinia also aimed at alternaria which may be more of threat than usual following the wet conditions.
East Midlands: Rape flowering well and first pods forming. All sclerotinia sprays now on, with safety being the main theme and getting on when conditions allow even if it means a second spray. Anyone waiting for a one hit spray may get caught out this season and rape is too valuable.
Light Leaf Spot: just odd pieces but nothing of concern.
Seed Weevil: no weevil seen yet - probably blown away or drowned!
Sclerotinia: Sclerotinia sprays completed.
West Midlands: All crops now at green to yellow bud stage to early flowering. The colder days over the last week have put crops on hold so many are very slow to come into full flower. However, some fields now have a good overall yellow appearance to them, and some petal fall can be found. Most forward crops are Cubic, Excalibur and Vision particularly where on lighter land. Heavy rain (up to 8 cms in places on Wednesday) and high winds have taken their toll on some crops causing root lodging in places.
Phoma: no new infections.
Light Leaf Spot: very low levels which have not developed.
Pollen beetle: majority of crops now out of danger.
Sclerotinia: rain over the last few days has increased the risk of disease.
North East: Cabernet still slow coming into flower, and have a few missing pods. These are due to a combination of late frosts and a flush of Pollen Beetle just before the weather deteriorated. There is no concern over yield penalties. DK ExPower and Excalibur are mid-flowering and have pods well set on the main stem. Some crops on the lean after recent rain.
Phoma: no further infections seen.
Pollen Beetle: crops coming into flower are no longer at risk.
Sclerotinia: many crops have been treated at the beginning of this week. The rest should be done next week.
South East: Crops continue to develop steadily and now range in growth stage from GS 32-33 with flag leaf emerging in many crops now - late PGR applications urgently need completing on more advanced crops within next 7 days.
Eastern Counties: Forward crops at GS 32 and quite tall.
Net-blotch: at treatable levels in some varieties such as Flagon and Cassata
Brown rust: present in Carat and Pearl.
East Midlands: Growth has slowed down and generally crops at final leaf two emerging. Diseases development controlled by T1 fungicides so far. BYDV obvious in some crops.
West Midlands: Final leaf two emerging on many crops. Disease levels still low and being kept under control by earlier fungicide applications. BYDV now becoming obvious in some crops.
North East: Flag leaf is a bit slow to emerge now, but final leaf 2 is emerged so expect GS 37 within next 7 days. T1 fungicide applied this week.