Cut Foliage Technical
Update
June 2013
Weed Control Update
Its been a long lingering spring and we eagerly await some decent summer weather.
Growers have been taking advantage of any suitable days for spraying and you will
have received a detailed note earlier in the year on weed control programmes. Now
that planting of new crops has commenced I thought short summary update might
be helpful:
New Plantings
Planting continues and a lot will be taking place within the next few weeks.
For most of the key species you can apply Butisan S (2 l/ha) + Stomp Aqua (2.9l/ha)
immediately on planting (within 48 hours) - This is critical as Stomp Aqua has to go
on before the growing out of any new roots from the plants.
If spraying is delayed - use Butisan S (2 l/ha) + Lenacil/Venzar (2l/ha)
Top ups will be required in the Autumn/early winter.
If weed seedlings appear in any crop then depending on what’s present—use Betanal
max Pro @ 2l/ha or Goltix @ 2 l/ha.
Sites vary and can have particular weed issues at times—please contact me if you
want to discuss you own situation.
Year 2 plantations & older
Work continues on some sites—this has been a difficult spring and spray days were
scarce and wind & rain has caused difficulties in the last while. Depending on
condition of site – following clean up using directed applications of Roundup, Basta,
Spotlight Plus or MCPA/24D etc as detailed in earlier editions of notes you should
aim to apply a residual to maintain weed control on sites through the summer.
Consider Ronstar @ 5 l/ha as a directed spray OR Lenacil/Venzar @ 2l/ha + Stomp
Aqua @2.9l /ha overall as long as site is clean.
Pest Activity Update
Things are relatively quiet on the pest front at the moment directly as a result of
the long winter and late spring but that can quickly change once temperature start
to increase. We are seeing aphids on some ornamental species and migration of
other pests from winter hosts has commenced albeit slowly. While all foliage
species are susceptible to aphids, unless there is extremely high numbers,
treatment is not generally necessary .Our main concerns are with pests such as
Capsid and Caterpillar particularly on Laurel & Viburnum.
Species of Psyllid can be problematic on Pittosporum & Eucalyptus. It is important
that growers monitor for pest & disease in their own crops by walking them
regularly. A colour guide was recently sent to growers to help with this
identification (attached again). If you see anything unusual that you don't
recognise or are unsure about please contact me and either send me a photograph
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or sample for identification.
Laurel
We are monitoring for some insect pests in the main growing areas and given stage
of crop development and trap catches, growers of laurel and in particular crops 2
years & older should now apply the following tank mix:
Decis @ 300 mls/ha (capsid & general insects)
plus
Ridomil Gold @ 2 kg/ha or Acrobat @2 kg/ha (clean up any lingering downy mildew)
plus
Cuprokylt @0.35 kg/ha ((bacterial shot hole). Other Copper products can also be
used.
Continued spray programme:
Generally speaking, a routine application at 3 week intervals will be necessary over
the summer months particularly for pest control and bacterial shot hole on laurel.
Diseases such as Downy mildew on laurel are totally weather related and this will
influence what’s used and when.
To avoid resistance problems with pesticides it is advisable to alternate pesticides
of different modes of action and from different chemical groups.
For insect control choose from insecticides such as Decis, Toppel, Karate & Calypso.
For disease control (specifically Downy Mildew) choose from Ridomil Gold, Acrobat
& Infinto. Always include Copper in the programme.
Water volume-Apply in 300—400 l/ha. Spray onto dry foliage and allow to dry on.
I will issue updates on recommendations if there will be a need for any major
changes given pest or disease activity.
Slugs on all species
In unsettled weather, it is important to monitor new & established plantings of all
foliage species for slug activity and be prepared to treat with Methiocarb (Draza)
slug pellets accordingly. Rate—5 kg/ha.
You can monitor for activity by using a bait trap (place a tea spoon full of slug
pellets under a piece of plywood or slate slightly risen off the ground). Take a
couple of sections of a crop and put 1 or 2 traps in a 20—30 m² area. Check for
slugs the following morning and if you find more than 4 or 5 dead per trap you need
to treat.
Psyllid on Pittosporum & Eucalyptus
Two unrelated Psyllid species are primary pests of Pittosporum and Eucalyptus for
cut foliage. A detailed note on Pittosporum Psyllid is included in this update. Whilst
growth of Pittosporum is behind normal this year, I suggest Pitto growers aim to
apply an early insecticide of either Decis @ 300 mls/ha or Calypso @ 400 mls/ha
before mid June on crops destined for harvest later this summer and Autumn.
Eucalyptus Psyllid generally migrates from mid July onwards when insecticide
treatment will be necessary. We will monitor and keep you updated.
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Pittosporum Psyllid
Background & Life Cycle
Pittosporum Psyllid (Triosa vireoradiata) is the most
serious threat to the quality of Pittosporum when
grown for cut foliage. It is widely distributed in New
Zealand and is established in Ireland since 2003. It
causes serious damage to the young growth. The complete life cycle takes 60 days or more. There is an
early summer generation on the young leaves followed
by another generation later in the summer and autumn
in which the adults breed and overwinter. Nymphs
feed by penetrating the leaf tissue with their piercing
and sucking mouthparts. Plants react by creating a hollow blister or gall best described as pitting of the leaf.
The nymphs usually live sedentary lives attached to
both surfaces of the leaves within the shallow hollow
blisters that they cause. The adults are poor fliers
but are excellent jumpers, using their enlarged hind
legs and will overwinter on previous year’s growth. The
new spring growth is particularly susceptible to attack,
and retains the galls throughout life reducing its commercial value as a foliage. With heavy attacks, sooty
mould grows on the honeydew deposits. The combination of extensive galling and build up of sooty mould
further lowers or removes the market value of plant
material grown for the cut flower industry.
Advisory Information
Pittosporum cut foliage growers are recommended to check young plant growth
which is most susceptible to attack. As with other sap sucking insects, systemic &
contact insecticides can provide control. Systemic products include Dimethoate
(Dimethox), Acetamiprid (Gazelle) or Thiacloprid (Calypso). Effective contact insecticides include Deltamethrin (Decis) or Cypermethrin (Toppel 10).
Any chemical products mentioned are provided as a guide only. Always follow product label directions before use.
Further information from Andy Whelton on 087 7848065
June 2013