disease management programs. These products provide post-infection
management options; however, they should be integrated with all other
depending on timing of the application and the physical mode of action of the
of inoculum. All of these products should be used following recommended
rates and application frequencies, and within all labeled requirements. It is
important to consider the cost of these products and what average yield savings
will equal the cost of a product application. In general, the most costly
product application is when there is no disease present or a product does
disease assessment is critical for any management strategy.
SUMMARY
Successful disease management starts with assessing the economics
of the cropping system combined with an understanding of the disease
it can affect the techniques that can be used in the current growing season
as well as the future. There are many pre- and post-planting management
techniques available to producers that can be used to reduce disease risk.
Ultimately, integrated plant disease management strategies provide producers
with the tools to obtain acceptable yields with adequate economic
returns that are more sustainable than the results achievable with a single
management method.
Insect Management
The management and control of insects and mites can be challenging,
even under optimum conditions. Integrated pest management (IPM) is a
useful approach for producing vegetables. It involves integration of cultural,
physical, biological, and chemical methods to maximize productivity in a
way that is ecologically sound and safe. Often, but not always, it means
limiting the use of broad-spectrum insecticides and miticides. IPM implies
management of all crop pests, including insects, mites, diseases, nematodes,
and weeds; however, only insects and mites will be considered here.
Where possible, the effects of measures to control diseases and weeds
should enhance or, at least, not interfere with the management of insects
and mites.
Many of the general IPM principles and tactics that apply to the control
of plant diseases apply to the management of insects and mites. These
include regular scouting or monitoring for problems, identifying pests and
their life stages, keeping good records of pest management practices,
using exclusion techniques, practicing good sanitation, testing soil or plants
for nutrients, using biological controls when possible, and using selective
pesticides, properly timed and applied.
CROP SCOUTING AND MONITORING
In order to detect pests and the damage they cause before a problem
becomes serious, growers must visually inspect plants once or twice a
, growers should observe the overall plant, looking for
speckling or bronzing on leaves, holes and other damage caused by chewing
insects, distorted growth, and fruit damage. The next step is to carefully
inspect all plant parts from ground- or stem-level up to the growing tip.
plant parts and recognizing the presence of pests and the damage they
cause. Workers engaged in cultural practices should be trained to recognize
insects and the damage they cause.
Both the upper and lower leaf surfaces must be thoroughly inspected.
Many insects, as well as some diseases, begin their infestation or infection
from the lower side of the leaf. Many insects and mites only feed on the
underside of the leaf and may never move to the upper leaf surface or other
plant parts until populations become so great that overcrowding forces
movement. Attention should be given to the midrib area under the leaf
and along large, lateral, lower-leaf veins. The leaf axils, growing tips, and
terminal buds should be carefully inspected. Often weeds serve as hosts for
insects, mites, and diseases that can move to vegetable crops and should
be removed (see section on Sanitation).
Some insects, particularly thrips, will be found within the blossoms, so
these should be included in the inspection. Tap the blossoms over a white
pan or card to see these tiny insects. The area under the calyx or stem
end of tomatoes and cucumbers can also be an attractive hiding place for
insects. Generally speaking, insects inhabit secluded areas of the plant that
provide protection.
many insects. Blue is more attractive to thrips, but yellow works well also.
Traps are usually placed vertically at or just above the plant canopy. Some
insects, such as thrips and leafminers, can be caught just above the surface
of the growing medium. One recommendation is to use one to three cards
per 1000 sq ft. Traps should be inspected weekly and replaced regularly.
A system of numbered traps can facilitate sampling and simplify record
keeping. Yellow sticky tape can be used on a larger scale to reduce insect
populations by trapping. Yellow sticky traps and tape are available from
many online distributors.
Many of the arthropod pests that infest vegetable crops are very small.
the eggs of other harmful insects are not much larger. Growers should have
at least a 10x hand lens (jeweler’s hand lens), but a 16x–20x is preferred.
With a hand lens, a grower can quickly identify many of the arthropod pests
that are otherwi
learn to use a common dissecting microscope. These microscopes can be
purchased either as a monocular (one barrel) or binocular (two barrel) type.
grower can see small mites, such as broad mites, and disease lesions clearly.
This tool can be very helpful in detecting and diagnosing problems early.
IDENTIFICATION OF INSECTS AND MITES
is absolutely critical. If the grower knows exactly which pests are present,
proper chemical or biological controls can be selected and steps taken to
RECORD KEEPING
Good records can help growers see trends in pest infestations, keep
track of the success or failure of control efforts, and determine how the environment
affected the crop. Of course, pesticide application records are essential
and should include the time and date of application, product name,
EPA registration number, active ingredient, amount used, the target pest,
and effectiveness. Some things that general records should include are
daily minimum and maximum temperatures, measurements of plant growth
and development, the pH of the growing medium, soluble salts, general root
health, and other speci
plants and sticky cards are also useful for identifying trends over time and
for determining the effectiveness of control efforts. Over several seasons, it
may be possible to see that certain problems occur at the same time each
20 2019 Vegetable Production Handbook of Florida