Rapeseed: Stabilise using early growth regulation
The rapeseed stocks on the fields made it through the Winter well. There is no winter damage because there was not any severe frost period. However, a lot of stocks were damaged by pests such as cabbage flies (Mecklenburg-North Pomerania and Saxony-Anhalt) as well as flea beetles. What should be done? AGRAVIS's expert Franz Schulze-Eilfing has some tips.
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In northern Germany, there was massive amounts of beetles flying in, a part of which was due to the long vegetation periods in the winter that just came to an end as well as the 2013/2014 winter that helped these insects multiply enormously. The high temperatures also gave a lot of time for these insects to lay their eggs. That turned into a massive plague of flea beetle larvae.
Phorma infection blocks
The plague of flea beetles and cabbage fly larvae in Mecklenburg-North Pommerania and Schleswig-Holstein was sometimes so serious that stocks had to be ploughed up. Added to that were two worst-case scenarios of large-scale Phoma infection blocks caused by a warm autumn with a lot of humidity. This was mostly in northern Germany in September of 2014, whereas it was almost everywhere in Germany in October. There was even another extreme weather period in the Christmas season with mild temperatures and a lot of rain.
The humidity provided Phoma pathogens with good conditions where susceptible rapeseed sorts were affected most. This shows that the damage from Phoma infestation is greatest where there is a great density of stock (second growth of old rapeseed) with sorts that have no resistance to Phoma were sowed. Phoma infestation is particularly substantial with rapeseed plants simultaneously weakened by pests. It would have made a lot of sense to target Phoma lingam in September and October in a lot of locations.
Using an important growth regulator
What can we do in this situation? Franz Schulze-Eilfing is the manager of the plant cultivation consultation department at AGRAVIS Raiffeisen AG. "We advise using an early growth regulator with a good fungicidal effect to keep your plants healthy and stabilise them. Of course, applying an early growth regulator with a good fungicidal effect cannot combat the autumn infection any longer at the begin of the longitudinal height. However, it does make a contribution to the stabilisation of the lower stem area by shortening, thickening and deep branching and it protects from other early infections that are likely after the substantial precipitation of recent days – also from other rapeseed diseases. The stems of the plants can still be reached easily for any treatment after they turn green again and at the beginning of shooting. Products such as Tilmor, Toprex and Efilor are a natural for this. For a later time, the expert recommends a growth regulator such as Carax to shorten the stocks more in this spring after a brief vegetation rest since a higher storage susceptibility can be expected like last year.
More efficient seed dressing
Altogether, AGRAVIS's expert believes there is greater cabbage fly infestation in rapeseed than in previous years without dressing with neonicotinoide ingredients. In past, the dressing intercepted the early wave of beetles flying in. More frequent treatment was necessary against the flea beetles last autumn, although the added spraying did not reduce the environmental pollution in comparison to the neonicotinoides. Instead, it endangered the soil life and beneficial organisms, since a relatively large amount of active ingredients gets onto the soil with the early application that was needed then against the rapeseed flea beetles. Schulze-Eilfing also thinks that the spraying was less efficient than seed dressing because it covered a much greater spectrum of pests in early stages with significantly less and well-placed quantities of active ingredient.