Crop Watch – Farmers Weekly
Crop Watch – Farmers Weekly ...
Catchy weather has been the theme of late. If it hasn’t been wind, it has been rain. The combination has been a driver for increased pressure from septoria tritici.
Rain splash has moved spores onto newer leaves, while the wind has driven spores up the plant by blowing upper leaves against infected lower ones.
This has seen the disease more prevalent than in recent years, and infection in some varieties with good disease scores is higher than one would have expected.
On the back of this, in most cases, T1 chemistry to protect leaf three has been based on mefentrifluconazole to hit the disease hard and take it out. Fenpicoxamid has also been used to achieve the same goal in several cases.
Where broad-leaved weeds are emerging in cereal crops, a herbicide is being added at T1 timing to take these out.
Where oilseed rape is being planned as the following crop, sulfonyl-urea based chemistry is being omitted where possible, to negate the risk of herbicide residue affecting the following crop.
Herbicide residue
In these situations, florasulam + halauxifen-methyl is being employed.
Slower emergence of broad-leaved weeds in some cases is seeing the need to hold off on a herbicide application, and potentially return at a later date if weed pressure increases.
Most spring crops are now in the ground. Earlier drilled spring barleys which were established in late February, have suffered on heavy land.
Heavy rains after drilling compacted and waterlogged turning headlands, to the extent that most of the seed rotted in wet soil.
Re-drilling or planting a cover crop in these areas, to establish a root system to benefit soil structure, would be a good plan.
Later drilled crops are slower to emerge and grow away due to recent cooler conditions. This is not helpful in sugar beet, where rapid growth to the 12-leaf stage is desired to reduce the risk of yield loss from virus yellows.
It has been a long time since we last had such a cold, wet spring, and the effect of the weather has been quite profound.
Spring drillings of cereals, maize and beet have all been delayed as we wait for the soil to warm and dry out to an extent where a seed-bed can be produced.
It is for seasons like this that the old expression “Better to be out of season than out of reason” was used to warn about mucking crops into the ground.
Timings of many fertiliser and agchem products have been compromised by the weather, as ground conditions have been too wet to travel and spray days at a premium.
It is always the case that the very weather that is putting a delay into fungicide applications, is the same weather that is causing the disease situation to worsen.
Most wheat crops are carrying worryingly high levels of septoria and with fungicides providing far less “kick-back” than they used to, delayed T1s will inevitably lead to poorer disease control than we would hope for.
Some of the more forward wheat crops have been at growth stage 33 before they received their T1.
Cold, wet soil conditions have lead to slow responses to nitrogen applications when they have gone on, with wet areas in fields looking much paler than the more free draining ones. In all, the situation at present is looking very average, but as we all know this can change dramatically with a few dry, warm days.
We just have to hope that they appear pretty quickly now.
Phoma
Winter OSR crops are looking quite promising, with most crops now in full flower. There is, however, evidence of phoma in the few crops that did not receive an autumn fungicide for one reason or another.
The dilemma now is, will a treatment be effective or will the disease have made it from leaf to stem to become full blown stem canker. Only time will tell.
Spring cereals that were planted in the dry February are looking reasonably well and are currently at the mid-tillering stage.
They should have received all their nitrogen by now and be set fair, but again will, like the winter crops, want to see some drier and warmer weather.
With a lot of spring planting left to happen, I would just like to take the opportunity to wish everyone good luck and to remind people that often the most important day in the life of a crop is the day it goes in the ground.
The better the planting conditions, the better the crop, so please exercise patience as well.
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