BSPP ‘Plant Doctor’ Quiz #10 – January 2022

The correct answer is:

Septoria apicola:

You are probably not familiar with the spores of Septoria, but none of the other pathogens produces spores so it has to be the fungal pathogen.

The incorrect answers were:

Cucumber mosaic virus; viruses have no resting structures such as spores and almost all of them (TMV is a major exception) have no survival outside a host or vector.

Erwinia amylovora; a very common bacterial pathogen, bacterial plant pathogens do not produce spores.

Xanthomonas campestris; see above.

The correct answer is:

Provides the operator with a false sense of security:

Unless the PPE is actually fit for purpose, it may provide the illusion of protection to the operator so they will believe they are protected and change their behaviour and ultimately become more exposed.

The incorrect answers were:

Provides limited protection to the operator; there may be very limited protection offered but this is often tiny compared to the extent the operators believe they are protected. It is my personal opinion that these masks that offer almost no protection should be banned.

Reminds the operator that the chemical is potentially hazardous; this could be the case but it also reminds the operator that they think they are protected when they are not.

Has no effect on the behaviour of the operator or their exposure; providing a mask will alter the behaviour of the operator exposing themselves to greater hazard.

The correct answer is:

Use another pesticide container of a different type:

This is not good practice, but if a farmer is to split a pack, at least get them to use a pesticide container. That way, if there is a mix up, the worst that can happen is that the wrong chemical is sprayed onto a crop.

The incorrect answers were:

Use plastic fizzy drinks bottles as they are tough and will withstand pressure; this is very common behaviour in some regions but is the worst choice. It can easily lead to accidental death when the pesticide is drunk by a third party.

Use containers that cannot be sealed in-case pressure builds up inside the container; any container containing a pesticide should be sealed.

Use metal food containers as they are the strongest; the strength of the container can be an issue but, most importantly, it should NOT be an old food container.

The correct answer is:

All three can generally cross a graft:

The graft is generally not a barrier to pathogens.  A few viruses cannot cross the graft, but they are the exception and most can.

Photo by kind permission from the real English fruit company. https://realenglishfruit.co.uk/

The correct answer is:

Chemical.

This may seem a surprise, but an extract from a plant contains chemicals that will control the pests and diseases.  The origin of the chemical (in this case a plant) does not alter the fact that chemicals are being used to control the problem.

The incorrect answers were:

Biological; no, even though the chemical is from a biological source, it is not biological control.

Cultural; it may be part of the local culture, but this is not how the word “cultural control” is used.

Organic; there are very strict rules with regard to what can be sprayed onto crop plants when in an organic regime.   Just because the chemical is from a natural source does not make it approved for organic use.

The correct answer is:

The decision as to what to do will depend on the crop and pest:

Generally, it is appropriate to destroy the crop trash after harvest (ploughing or composting or burning), however there are times when it may be appropriate to remove it and store it.  If the pest is not mobile; the natural enemies are mobile and there is no threat from other pests or diseases, then this may be a sensible strategy.

The incorrect answers were:

Burn it or compost it as far as is practical; this is a safe option and is usually the correct one.

Store the debris nearby to allow the natural enemies to emerge; this can be a good practice but should not be universally adopted unless you are aware of all the pests and diseases on the trash.

Take it to a field where the same crop is being grown and spread it onto the soil; this is never appropriate and would completely undermine most of the benefits of crop rotation.

The correct answer is:

Powdery mildew:

They are very unusual pathogens and will prosper under dry conditions.  Free water will actually inhibit the germination of powdery mildew spores.

The incorrect answers were:

Downy mildew; all downy mildews require free water and high humidity to grow and spread.

Bacterial disease; bacterial diseases are seldom a problem in dry weather.

Rusts; once inside the leaf, rust pustules will develop within a dry leaf, but spore germination requires free water.

The correct answer is:

One sprayer is required:

Provided the sprayer is well washed out between use, there is no requirement to have more than one sprayer on the farm.

The incorrect answers were:

See above.

The correct answer is:

There is nothing that can be done to prevent the spread of a virus within a plant:

There are no chemicals that will prevent the spread within a plant and there are many areas that are symptomless but still carry the virus.

The incorrect answers were:

Antiviral sprays work well and should be applied as soon as symptoms are seen; they do not work.

Cut off the regions showing symptoms to prevent the spread to healthy areas; there will be areas of the plant infected but not showing symptoms.

Insecticide sprays will prevent insects from transferring the virus to new areas of the same plant; repeated infection from outside is not necessary for a virus to spread within a plant.

The correct answer is:

The walking speed of the operator:

The speed at which the operator walks through the crop will affect the volume of diluted spray applied to an area of land.

The incorrect answers were:

The concentration of the mix in the tank; this will not affect the amount of diluted liquid exiting the nozzle.

The size of the crop; the spray operator would have to slow down for a larger crop if it was to be fully coated, but the size of the crop will not affect the amount of spray required.