PLANT PROTECTION 1 – Pests, Diseases and Weeds

PLANT PROTECTION 1 – Pests, Diseases and Weeds
Control methods
CONTROL
REMINDER
Relative humidity,
wind and high
temperatures.
Lack of moisture in
the atmosphere (low
RH) is usually
temporary and seldom
causes damage but
when combined with
high wind velocity and
high temperatures
may lead to excessive
loss of water from the
foliage and may result
in leaf scorching or
burning, shriveled fruit
and temporary or
permanent wilting of
plants (Agrios 2005).
LEGISLATION, REGULATIONS, ETC
Various Food Acts, Pesticide Acts, Pollution Acts, Environment Protection Acts, etc
prescribe and regulate residues in food, and in food and feed products. Restrictions
apply to the application of hormone herbicides, eg 2,4-D, MCPA, within a
prescribed distance of grapevines which are extremely sensitive to such herbicides.
Quarantine Acts reduce the risk of introducing exotic non-parasitic living agents, eg
algae and mosses.
Standards are available for pruning certain plants, quality of tomatoes, etc.
CULTURAL METHODS.
Environmental factors. Temperature and moisture are the most important
environmental factors affecting plants, pests, diseases and weeds. Environmental
factors are used to control growth and flowering. Always be aware of the weather
conditions prevailing before or during the appearance of symptoms.
– Weather warning programs provide information on weather events, for
particular crops/different regions, eg temperature ranges, rain, hail and dew points,
etc. During transport and storage of temperature-sensitive goods such as flowers
and plants, various systems monitor temperature, sounding a warning alarm when
conditions stray outside a predetermined range.
– Plant Efficiency Analysis measures and interprets chlorophyll fluorescence
emissions from leaves of plants before visible symptoms of stress appear. Trees
showing symptoms of dead branches in the canopy, sparse leaf cover, curling
browning or drooping leaves, earlier than normal autumn colours, deep bark cracking,
need watering long before these symptoms are visible. Many young trees newly
planted need special attention by watering. Public tree plantings may need watering.
– Temperature requirements influence planting dates, eg varieties of pome and
stone fruits that flower later may miss late spring frosts. High temperatures may
slow ripening of tomato and increase a plant’s need for water, etc.
– Water management programs and initiatives. Most states/territories and crops/
situations have water management progams. Use computerized systems if available.
The National Water Initiative (NWI) is Australia's enduring blueprint for
water reform. Through it, governments across Australia have agreed on actions
to achieve a more cohesive national approach to the way Australia manages,
measures, plans for, prices, and trades water.
AQUAMAN, AQUA SPY takes the guess work out of irrigating; details are set
up for each paddock, including location and soil type. Reports can be
generated instantly for each paddock taking into account the holding capacity
and other features of the soil as well as recent rainfall and weather conditions.
A major cause of lower yield in peanut crops is a lack of timely and adequate
irrigation 2007.
'Global drying' describes three types of water (Ridout, Landline
16/8/2009). Green water is the rainwater that hydrates food crops. Blue
water comes from surface or underground resources; it's the rivers and
reservoirs on which the irrigated regions rely. Esoteric grey water, which
could be called diluted water; it's the amount needed to dilute waste water from
industry and crops.
Australia Golf Course Environmental and Water Initiatives, AGCSA
Water/irrigation provides advice on irrigation regimes and drainage.
Waterwise programs are available for home gardeners (Walsh, 2004).
Six vital principles include reduce areas of lawn, group plants according to
water needs, use drought tolerant plants, maintain the garden, use mulch, water
efficiently. Know the aspect of your garden, eg winter sunshine, etc. Identify the
plants with high water needs and group them in an area where they can receive
the extra water. Place plants in groups of 3 or more for maximum effect.
Soil moisture probes and sensors connected to irrigation controllers assist
with scheduling of irrigation in shallow rooted crops.
Water quality. All water sources should be analyzed. Water testing of
recycled is readily available, eg www.lanfaxlabs.com.au/
Follow water restrictions guidelines and consult with water authority or
industry specialists about efficient irrigation products and how to use them,
‘More crop for the drop’ (Landline 21/9/2008)
Soil mulch Know your soil how it drains or holds water, adding composted
organic matter is one of the best ways to increase water retention plus there are
commercial water saving products available.
– Light, eg primary factors regulating flowering are daylight (photoperiod) and
temperature. Many shrubs and other plants require a certain amount of sun to grow
and flourish. However, many plants require shade - make a shade map of you
garden and utilize shade of surrounding plants, grow trees to increase shaded areas.
Indoor plants may suffer from insufficient light.
– Other environmental factors include wind, mechanical injuries, and soil
structure.
400 Non-parasitic pests and diseases