What fungicide control Pythium root disease ? How can I reduce the risk of damping - off in propagation ?
From recent discussion with grower , it seems more are likely to be raising their own flora to fill at least some of their production requirements this season , rather than being as reliant on importee as in former year . Thisadvisory blogby Syngenta Ornamentals tells us more about successful extension .
Whatever propagation system you ’re using , and whether your starting stuff is seminal fluid or cuttings , one of the key challenges will be manage the risk of root diseases , particularly those normally known as damp off which are because of specie of Pythium .
weaken - off really is a disease where bar is better than cure – indeed , once a tray has run low over with dampen off , it ’s had it . By the time you see symptom , it ’s already too late and your only pick is to bin it .
The pathogenPythium is an oomycete , a group of organism we ’ve met before in these blog . Although they share some characteristic with fungi they are completely unrelated and any similarities have evolved independently . Many aspect of oomycete biochemistry are all different , which is why only a few antifungal have modes of action that pretend them .
Pythium spread by spores capable of ‘ swim ’ in the tenuous film of water that surrounds the speck in the grow medium , but it can also be transfer by pests such as sciarid and shore fly .
SymptomsThe first augury of a Pythium infection on a harvest in propagation range from leaf yellowing , wilting or stunting to complete flora collapse . Seedlings may break to emerge , or do so unevenly across a tray ; infected cuttings may miscarry to take root .
Sometimes a light infection goes unnoticed but the crop will belike never make a marketable grade after pot on .
bar : culturalAs always your starting point is practiced greenhouse hygiene , paying peculiar attention to prop benches and other surface , and implementing an in force plan against sciara and other pests likely to bear ancestor - disease spores .
apply a free - enfeeble generation medium and store it so it ’s protected from potential contaminant . Be aware , too , of any sources of contamination if you take cut or roll up seeds from your own stock plants .
Use mains or treat water in prop unit . It ’s in all likelihood serious to deflect recycle piss in this situation .
Propagation , perhaps more than any other stage in the crop hertz , demands environmental experimental condition for strong , active maturation . The skill is in striking the right balance in humidity and root - geographical zone wet level that encourage maturation without favor Pythium or other root - zone or foliar pathogen . Modern environmental monitoring equipment , which we ’ve talked about before in these blog , is well deserving considering , especially to help annul an over - moist grow medium .
Prevention : fungicide applicationSubdueis specifically designed to control oomycete ascendant disease . Its dynamic ingredient is mefenoxam , the most active form of metalaxyl ( you may see it write as metalaxyl - M , for illustration in databases and on the production recording label ) . It run by inhibiting the mechanics oomycetes use to interpret genetic information to produce proteins . That micturate it effective against several stage in the pathogen ’s ontogeny , including the increase of mycelium and the formation of spores .
Subdue must be utilise to the growing medium – either as a drench or by internalization – from where it is rent up by the etymon and moves systemically within the works . It ’s active against class Oomycetes that may be present in the growing culture medium as well as in flora tissue .
We ’ve talk in old blogs about trying to cut spray mass rate to keep more combat-ready element on the leaf . When using a drench , however , you in reality require to moisten the fungicide off the leafage into the root zone , so this is one example where you require a comparatively high diligence volume . The label recommends drenching with between 6.25 and 9.4ml of Subdue in 100 cubic decimetre of H2O and apply a total spray volume tantamount to 10 % of the mass of media in the tray . Apply when the medium is already moist , as this will aid ingestion into the roots , and give a burst of overhead irrigation immediately after to lap the fighting off the leaves and into the etymon zone .
Ideally you should train to get an covering on early , before any disease present takes hold . We all desire to keep our economic consumption of chemic fungicides to a minimum but in the case of oomycete root word diseases , particularly in propagation , one preventive coating early on may preserve the financial and environmental costs of a wasted crop .
Another option is to contain it before filling tray or pots – by spray the want amount over the sensitive and commingle through as evenly as possible .
Subdue is in effect against class Oomycetes but remember fungal pathogens can also cause tooth root equipment casualty during propagation . handling against these include Trichoderma - based biofungicides such as T34 , supplied by our partner atFargro , which can be used preventively in junction with Subdue .
With respect to merged crop management , Subdue appears not to harm soil - dwelling predatory hint , insect - kill nematodes ( such as Steinernema feltiae ) and biofungicides ground on the bacterium B subtilis .
For more information : Syngenta Ornamentalswww.syngentaornamentals.co.uk
