Spinach Pre Emergence Pest Control By Tim Braun
Spinach became a major fresh vegetable crop until the outbreak of
E-coli contamination during the last two years. The demand for vegetables like spinach with high levels of beneficial
carotenoids especially the antioxidant luttein had created a large consumer market. Clearance for the use of pest
control products for spinach lagged behind the increase in crop production.
Spinach is listed in the Chenopodiaceae (Goosefoot) family. The other agriculturally grown vegetables in this family
include beets. Weeds in the Goosefoot family of plants include pigweed, lambs’-quarters, and Russian thistle
“tumbleweed”.
The spinach plant grows well in many areas of the country. A cool weather plant with many shallow feeder roots
near the soil surface making it susceptible to shallow applied herbicides.
Spinach is a dicotyledon. It has two seed leaves. Spinach does have a tap root. It is a broadleaf and is susceptible
to broadleaf herbicides.
Spinach is grown year round in the coastal area of California. In the southwest deserts and central valley of
California spinach is grown in the fall and winter. In the eastern area of the United States, New Jersey, spinach is
grown in the fall, winter and spring.
There are two basic leaf types: smooth or flat and crinkled. The newer hybrids are less crinkled and smoother. The
leaves are triangular, oval, round or arrow shaped. The stems are edible and from 1 to 6 inches long.
With new varieties and hybrids being planted in new areas, new pest control problems have increased. These pest
problems include diseases, weeds, insects, and nematodes.
Before planting spinach on a piece of ground several things should be considered. The weed history of the field is
very important. The surrounding crops that may carry virus infestations should be noted. Nematode infestations of
previous crops should be investigated. This is especially true of sugarbeets and previous crops of spinach.
With the advance of new housing in rural areas any new zoning for roads or buildings should be investigated.
Building equipment can create a great deal of dust that could destroy a field of spinach before harvest.
Spinach is very susceptible to herbicide residues. The plant back restrictions on herbicides that were recently used
on the field should be taken into account.
The type of spinach cultivar should be chosen to overcome the various diseases that exist under the weather
conditions that the crop will grow in. The time needed for land preparation should be considered. Some diseases
build up as crop residues rot in a soil. Depending on weather some previous crop residues should be turned under a
month or more before planting to prevent diseases like damp-off.
Nematode in Spinach
Spinach is a host for the sugarbeet cyst nematode. If a field about to be planted with spinach had sugar beets with a
history of cyst nematode infestations the chances of damage from sugarbeet cyst nematode should be considered.
This nematode is a microscopic round worm that exists in the soil and roots of spinach. The nematode worm is
pinhead size, white and oblong in the early stages of growth. They turn brown as they mature.
Soil sampling for nematode infestations is a way of being sure of the pest problem. These soil samples should be
taken during the months of June through October. Sugarbeet cyst nematode activity occurs in soil temperatures
above 77 degrees F. This temperature is taken at the 4 inch depth.
At soil temperatures below the 77 degree F temperatures, spinach crops grow without damage occurring from
sugarbeet cyst nematode infestations. The nematode cysts and eggs can be present in the crop below this
temperature, but the nematode is not active enough to damage the spinach.
As soils warm up in the spring of the year spots in the fields may have damaging infestations. This can happen in the
late summer and fall of the year if soil temperatures stay above the 77 degree F level.
Infestations of sugarbeet cyst nematode can take over the entire field or be located in specific areas of the field.
Infested spinach plants are smaller and do not mature as rapidly as the plants that aren’t infested. The spinach
seedlings can be killed or emerge slowly. The yield and quality will be damaged.
Sugarbeet cyst nematodes are plant parasites that infest a wide variety of plants both cultivated crops and weed
pests. The infested pests (weeds) are hosts and are a source of infestations.
Preplant applications of the soil fumigant Telone II is used to treat nematode infestations. Use only as directed on the
label.
The cultural control of this pest includes crop rotation. Host crops are beets, sugarbeets, spinach and cole crops.
Weeds that host these nematodes are mustards, sheperd’s purse and wild mustard. Intermediate hosts are the
weeds, common lambsquarters and redroot pigweed.
Wireworms in Spinach
Wireworm larvae are hard-bodied, slender, yellow to brown, shiny and cylindrical. Depending on the species
wireworms are about 0.5 to 1.25 inches in length. The adults are tan to black beetles that are from 0.25 to 1.0 inch
in length. They are called “click” beetles because when they are turned upside down they can snap and flip their
bodies into the air.
Wireworms eat seeds and damage roots . By feeding on rootlets, tap roots and the lower part of the stems of
spinach seedlings they damage the vascular system of the plant. This stops the flow of water and nutrients to the
upper portion of the plant resulting in death or stunting. The wireworm damage to the epidermal tissue of the plant
will result in the entry of diseases into the plant .
Wireworms are found in every kind of soil and exist throughout the year. Wireworms can last for several years in the
soil in their beetle larval stage. Wireworms are most prevalent in fields with high levels of organic matter. Crops of
turf, alfalfa, vineyards, citrus and grains leave high residues of organic matter.
Reducing the crop residue and allowing enough time before planting to decompose organic matter will produce an
environment where wireworm will not multiply. If possible avoid planting in cold, wet soils.
Baited traps may be used to monitor wireworms. Treating the seed with Lindane and the soil with Metam fumigant
or Diazinon are chemical pest control methods.
The Seedcorn Maggot
Seedcorn maggots are a white, legless larvae of adult, small, light gray flies. The larvae will over winter in the soil or
the adult may lay eggs in late winter. Three to four generations occur per year, but the first generation is economically
destructive to young seedlings and seeds.
Seedcorn larvae bore into the seed and feed on germinating seedlings. The plants yellow and die within a few days.
Cool wet weather combined with high organic matter where the adult maggot can lay eggs are ideal situations for
populations of maggots to establish themselves.
Avoid planting in fields with high crop residues. Allow a period of time for residues to decompose. Apply manure
months before planting. All of these cultural practices will reduce the organic matter that seed corn maggots thrive in.
Chemical control of seed corn maggots includes the use of the seed treatments, Lindane and Lorsban. Soil
incorporation of Diazinon before planting is a chemical control method for seedcorn maggot. Read and follow label
directions.
Pre Plant Weed Control
Weeds are one of the major pests of spinach. Weed competition will do the following to a spinach crop:
Buyers will reject the crop because they cannot sell spinach with weeds in it.
Weeds in nearby fields, and on the edges of the field are a source of insect pests, diseases, vertebrates and
nematodes.
Spinach is a poor competitor against weeds resulting in loss of nutrients, water, space and sunlight to the growing
crop.
Harvest of a weed infested spinach crop is too costly for the grower. The crop is often destroyed.
Because of the thickness of the fast growing spinach crop, cultivation is not possible and expensive hand weeding is
required.
There are weeds that are considered to be spinach production problem weeds. These include: burning nettle; little
mallow; chickweed, London rocket and sheperd,s purse. There are several others, but these thrive under the same
growing conditions that spinach grow in. Spinach is a broadleaf plant and so are most of these weed pests.
Economical cultural and chemical types of weed control have to be managed in a year round planned program to
produce the desired weed free spinach crop. If the crop is organically grown, the chemical type of weed control is
replaced by costly hand weeding.
The management program starts when the grower picks the field where the crop of spinach will be grown and
continues even after the spinach crop is harvested. Mapping and recording of the weeds in a field includes the
conditions that caused them to grow in that field. These conditions include weather, moisture (irrigation or rainfall),
soil and air temperature, calendar dates when the weeds grow, cultural practices, soil type and so on.
This also includes the name of the weeds. There are several web sites that contain pictures of weeds for
identification. This type of information gives you an idea of what the field’s weed seed bank contains.
This seed bank of the field contains weed seeds that have been there for several years. Weed seeds will not
germinate until they encounter specific environmental cues. This means the conditions (temperature, moisture, salt,
acid, nutrition and other stimulants) will make these specific weeds germinate.. You may have seen flushes of
different weeds growing in a field where you haven’t seen them before.
These weed flushes often appear in fields that have recently received an application of manure. Research has shown
that the nutrient stimulation from the manure causes seeds in the field’s seed bank to finally grow. In many situations
the weed seeds are already in the field and the manure application doesn’t put them there. Manure nutrition can
stimulate the fields old weed seeds to germinate.
A good pre-irrigation can give your field a wide variation of stimulation that weeds seeds might like. If there are
several weeds after pre irrigation you may need to spray them with a herbicide before you disc them.
Spinach is sensitive to Balan, Glean, Gallery, Prowl, Treflan, Kerb, and Prefar. The labels on all of these products
will give you the length of time needed for these herbicides to dissipate before planting your spinach crop. There are
plant back label instructions that can reduce the plant back period by plowing. Check the labels.
Preplant Herbicide Control In Spinach
There are a limited number of herbicides used in spinach weed control.
California allows growers to use Ro-Neet which is incorporated before bedding or applied on the beds after they are
formed. Ro-Neet can be applied after planting and before emergence and incorporated with sprinklers.
The fumigant Metam Sodium can be applied pre-plant by injection or sprinkler irrigation.
Glyphosate (Round Up) can be applied to weeds that have emerged after preirrigation.
Pelargonic Acid a contact herbicide can be applied to weeds that have emerged after prerrigation.
Cultural preplant weed control includes:
1.) Field selection. Weed free fields or fields that have been planted to cool season crops and have been observed
without weeds. 2.) Sanitation. Try to keep weeds from going to seed. 3.) Rotation. Follow crops that have low
weed problems. 4.) Land preparation. Uniform beds that allow cultivation and well tilled fields (no clods) where
herbicides do their best job.
5.) Solarization. In warm areas this technique will control several weed species.
6.) Preirrigation. Encourage as many weeds as possible to emerge and destroy them before planting.
Preplant Disease Control
One type of pests often overlooked is soil-born diseases. These are treated before a crop is planted. As with most
diseases, the pest control for spinach is done on a preventive basis. We buy seed that has been treated for soil-born
disease.
Soil-borne diseases that infect spinach include: pythium, rhizoctonia, Phytophthora and fusarium. They are present in
fields for years and only infect the plants when conditions are favorable for their growth.
Crops like spinach that are planted and grown in cool moist soils are susceptible to these diseases. These diseases
grow best under these conditions.
We manage these diseases in our normal growing practices which include: planting in soils with good drainage,
leveling and irrigating so that flooding doesn’t occur, crop rotation and choosing cultivars that are resistant to these
diseases. University extension services recommend these growing practices. They call them “Cultural Methods of
Disease Pest Control”
These soil borne diseases are parasites that exist in the soil in different forms: spores and hardened tubes or
mycelium masses. When a source of food is available these parasites come out of their dormant stage and begin
feeding.
Healthy fast growing crops grow away from these diseases. Healthy spinach roots are difficult for the parasites to
penetrate. Slow growing emerging spinach seedlings have weak tender roots that the parasitic fungus disease can
penetrate. Spinach seeds that are slow to germinate soften and can be penetrated by the parasitic diseases.
Pre-Plant Fungicides For Damping Off Diseases
Buy spinach seed that is treated.
Ridomil Gold is sold in various formulations:
The emulsifiable concentrate is registered for spinach. For spinach Ridimil Gold E can be applied to the soil only. It
can be incorporated or injected with liquid fertilizer. It can be banded over the row.
A granular formulation registered for use in spinach as a soil application only. It can be preplant incorporated or
preemergence.
Do not use in greenhouses. Always read the label.
The use of trade names in this course is solely for the purpose of providing specific information. It is not a guarantee
or warranty of the products named, and does not signify that they are approved to the exclusion of others of suitable
composition. Use pesticides safely. Read and follow directions on the manufacturer’s label.
Acknowledgements:
Authored by University of California faculty, specialists, and farm advisors, produced and edited by IPM Education
and Publications, University of California Statewide IPM Program. Guidelines Coordinator: Barbara Ohlendorf;
Technical Editor: Mary Louise Flint.
"/PMG/selectnewpest.spinach.html"
Trujillo, Linda Speaking of Spinach , Master Gardener
Monterey County Managing Diseases for the Rapidly Increasing Spinach Industry
http://www.ipmcenters.org/cropprofiles/docs/NJspinach.html
Crop Profile for Spinach in New Jerseyc
Spinach became a major fresh vegetable crop until the outbreak of
E-coli contamination during the last two years. The demand for vegetables like spinach with high levels of beneficial
carotenoids especially the antioxidant luttein had created a large consumer market. Clearance for the use of pest
control products for spinach lagged behind the increase in crop production.
Spinach is listed in the Chenopodiaceae (Goosefoot) family. The other agriculturally grown vegetables in this family
include beets. Weeds in the Goosefoot family of plants include pigweed, lambs’-quarters, and Russian thistle
“tumbleweed”.
The spinach plant grows well in many areas of the country. A cool weather plant with many shallow feeder roots
near the soil surface making it susceptible to shallow applied herbicides.
Spinach is a dicotyledon. It has two seed leaves. Spinach does have a tap root. It is a broadleaf and is susceptible
to broadleaf herbicides.
Spinach is grown year round in the coastal area of California. In the southwest deserts and central valley of
California spinach is grown in the fall and winter. In the eastern area of the United States, New Jersey, spinach is
grown in the fall, winter and spring.
There are two basic leaf types: smooth or flat and crinkled. The newer hybrids are less crinkled and smoother. The
leaves are triangular, oval, round or arrow shaped. The stems are edible and from 1 to 6 inches long.
With new varieties and hybrids being planted in new areas, new pest control problems have increased. These pest
problems include diseases, weeds, insects, and nematodes.
Before planting spinach on a piece of ground several things should be considered. The weed history of the field is
very important. The surrounding crops that may carry virus infestations should be noted. Nematode infestations of
previous crops should be investigated. This is especially true of sugarbeets and previous crops of spinach.
With the advance of new housing in rural areas any new zoning for roads or buildings should be investigated.
Building equipment can create a great deal of dust that could destroy a field of spinach before harvest.
Spinach is very susceptible to herbicide residues. The plant back restrictions on herbicides that were recently used
on the field should be taken into account.
The type of spinach cultivar should be chosen to overcome the various diseases that exist under the weather
conditions that the crop will grow in. The time needed for land preparation should be considered. Some diseases
build up as crop residues rot in a soil. Depending on weather some previous crop residues should be turned under a
month or more before planting to prevent diseases like damp-off.
Nematode in Spinach
Spinach is a host for the sugarbeet cyst nematode. If a field about to be planted with spinach had sugar beets with a
history of cyst nematode infestations the chances of damage from sugarbeet cyst nematode should be considered.
This nematode is a microscopic round worm that exists in the soil and roots of spinach. The nematode worm is
pinhead size, white and oblong in the early stages of growth. They turn brown as they mature.
Soil sampling for nematode infestations is a way of being sure of the pest problem. These soil samples should be
taken during the months of June through October. Sugarbeet cyst nematode activity occurs in soil temperatures
above 77 degrees F. This temperature is taken at the 4 inch depth.
At soil temperatures below the 77 degree F temperatures, spinach crops grow without damage occurring from
sugarbeet cyst nematode infestations. The nematode cysts and eggs can be present in the crop below this
temperature, but the nematode is not active enough to damage the spinach.
As soils warm up in the spring of the year spots in the fields may have damaging infestations. This can happen in the
late summer and fall of the year if soil temperatures stay above the 77 degree F level.
Infestations of sugarbeet cyst nematode can take over the entire field or be located in specific areas of the field.
Infested spinach plants are smaller and do not mature as rapidly as the plants that aren’t infested. The spinach
seedlings can be killed or emerge slowly. The yield and quality will be damaged.
Sugarbeet cyst nematodes are plant parasites that infest a wide variety of plants both cultivated crops and weed
pests. The infested pests (weeds) are hosts and are a source of infestations.
Preplant applications of the soil fumigant Telone II is used to treat nematode infestations. Use only as directed on the
label.
The cultural control of this pest includes crop rotation. Host crops are beets, sugarbeets, spinach and cole crops.
Weeds that host these nematodes are mustards, sheperd’s purse and wild mustard. Intermediate hosts are the
weeds, common lambsquarters and redroot pigweed.
Wireworms in Spinach
Wireworm larvae are hard-bodied, slender, yellow to brown, shiny and cylindrical. Depending on the species
wireworms are about 0.5 to 1.25 inches in length. The adults are tan to black beetles that are from 0.25 to 1.0 inch
in length. They are called “click” beetles because when they are turned upside down they can snap and flip their
bodies into the air.
Wireworms eat seeds and damage roots . By feeding on rootlets, tap roots and the lower part of the stems of
spinach seedlings they damage the vascular system of the plant. This stops the flow of water and nutrients to the
upper portion of the plant resulting in death or stunting. The wireworm damage to the epidermal tissue of the plant
will result in the entry of diseases into the plant .
Wireworms are found in every kind of soil and exist throughout the year. Wireworms can last for several years in the
soil in their beetle larval stage. Wireworms are most prevalent in fields with high levels of organic matter. Crops of
turf, alfalfa, vineyards, citrus and grains leave high residues of organic matter.
Reducing the crop residue and allowing enough time before planting to decompose organic matter will produce an
environment where wireworm will not multiply. If possible avoid planting in cold, wet soils.
Baited traps may be used to monitor wireworms. Treating the seed with Lindane and the soil with Metam fumigant
or Diazinon are chemical pest control methods.
The Seedcorn Maggot
Seedcorn maggots are a white, legless larvae of adult, small, light gray flies. The larvae will over winter in the soil or
the adult may lay eggs in late winter. Three to four generations occur per year, but the first generation is economically
destructive to young seedlings and seeds.
Seedcorn larvae bore into the seed and feed on germinating seedlings. The plants yellow and die within a few days.
Cool wet weather combined with high organic matter where the adult maggot can lay eggs are ideal situations for
populations of maggots to establish themselves.
Avoid planting in fields with high crop residues. Allow a period of time for residues to decompose. Apply manure
months before planting. All of these cultural practices will reduce the organic matter that seed corn maggots thrive in.
Chemical control of seed corn maggots includes the use of the seed treatments, Lindane and Lorsban. Soil
incorporation of Diazinon before planting is a chemical control method for seedcorn maggot. Read and follow label
directions.
Pre Plant Weed Control
Weeds are one of the major pests of spinach. Weed competition will do the following to a spinach crop:
Buyers will reject the crop because they cannot sell spinach with weeds in it.
Weeds in nearby fields, and on the edges of the field are a source of insect pests, diseases, vertebrates and
nematodes.
Spinach is a poor competitor against weeds resulting in loss of nutrients, water, space and sunlight to the growing
crop.
Harvest of a weed infested spinach crop is too costly for the grower. The crop is often destroyed.
Because of the thickness of the fast growing spinach crop, cultivation is not possible and expensive hand weeding is
required.
There are weeds that are considered to be spinach production problem weeds. These include: burning nettle; little
mallow; chickweed, London rocket and sheperd,s purse. There are several others, but these thrive under the same
growing conditions that spinach grow in. Spinach is a broadleaf plant and so are most of these weed pests.
Economical cultural and chemical types of weed control have to be managed in a year round planned program to
produce the desired weed free spinach crop. If the crop is organically grown, the chemical type of weed control is
replaced by costly hand weeding.
The management program starts when the grower picks the field where the crop of spinach will be grown and
continues even after the spinach crop is harvested. Mapping and recording of the weeds in a field includes the
conditions that caused them to grow in that field. These conditions include weather, moisture (irrigation or rainfall),
soil and air temperature, calendar dates when the weeds grow, cultural practices, soil type and so on.
This also includes the name of the weeds. There are several web sites that contain pictures of weeds for
identification. This type of information gives you an idea of what the field’s weed seed bank contains.
This seed bank of the field contains weed seeds that have been there for several years. Weed seeds will not
germinate until they encounter specific environmental cues. This means the conditions (temperature, moisture, salt,
acid, nutrition and other stimulants) will make these specific weeds germinate.. You may have seen flushes of
different weeds growing in a field where you haven’t seen them before.
These weed flushes often appear in fields that have recently received an application of manure. Research has shown
that the nutrient stimulation from the manure causes seeds in the field’s seed bank to finally grow. In many situations
the weed seeds are already in the field and the manure application doesn’t put them there. Manure nutrition can
stimulate the fields old weed seeds to germinate.
A good pre-irrigation can give your field a wide variation of stimulation that weeds seeds might like. If there are
several weeds after pre irrigation you may need to spray them with a herbicide before you disc them.
Spinach is sensitive to Balan, Glean, Gallery, Prowl, Treflan, Kerb, and Prefar. The labels on all of these products
will give you the length of time needed for these herbicides to dissipate before planting your spinach crop. There are
plant back label instructions that can reduce the plant back period by plowing. Check the labels.
Preplant Herbicide Control In Spinach
There are a limited number of herbicides used in spinach weed control.
California allows growers to use Ro-Neet which is incorporated before bedding or applied on the beds after they are
formed. Ro-Neet can be applied after planting and before emergence and incorporated with sprinklers.
The fumigant Metam Sodium can be applied pre-plant by injection or sprinkler irrigation.
Glyphosate (Round Up) can be applied to weeds that have emerged after preirrigation.
Pelargonic Acid a contact herbicide can be applied to weeds that have emerged after prerrigation.
Cultural preplant weed control includes:
1.) Field selection. Weed free fields or fields that have been planted to cool season crops and have been observed
without weeds. 2.) Sanitation. Try to keep weeds from going to seed. 3.) Rotation. Follow crops that have low
weed problems. 4.) Land preparation. Uniform beds that allow cultivation and well tilled fields (no clods) where
herbicides do their best job.
5.) Solarization. In warm areas this technique will control several weed species.
6.) Preirrigation. Encourage as many weeds as possible to emerge and destroy them before planting.
Preplant Disease Control
One type of pests often overlooked is soil-born diseases. These are treated before a crop is planted. As with most
diseases, the pest control for spinach is done on a preventive basis. We buy seed that has been treated for soil-born
disease.
Soil-borne diseases that infect spinach include: pythium, rhizoctonia, Phytophthora and fusarium. They are present in
fields for years and only infect the plants when conditions are favorable for their growth.
Crops like spinach that are planted and grown in cool moist soils are susceptible to these diseases. These diseases
grow best under these conditions.
We manage these diseases in our normal growing practices which include: planting in soils with good drainage,
leveling and irrigating so that flooding doesn’t occur, crop rotation and choosing cultivars that are resistant to these
diseases. University extension services recommend these growing practices. They call them “Cultural Methods of
Disease Pest Control”
These soil borne diseases are parasites that exist in the soil in different forms: spores and hardened tubes or
mycelium masses. When a source of food is available these parasites come out of their dormant stage and begin
feeding.
Healthy fast growing crops grow away from these diseases. Healthy spinach roots are difficult for the parasites to
penetrate. Slow growing emerging spinach seedlings have weak tender roots that the parasitic fungus disease can
penetrate. Spinach seeds that are slow to germinate soften and can be penetrated by the parasitic diseases.
Pre-Plant Fungicides For Damping Off Diseases
Buy spinach seed that is treated.
Ridomil Gold is sold in various formulations:
The emulsifiable concentrate is registered for spinach. For spinach Ridimil Gold E can be applied to the soil only. It
can be incorporated or injected with liquid fertilizer. It can be banded over the row.
A granular formulation registered for use in spinach as a soil application only. It can be preplant incorporated or
preemergence.
Do not use in greenhouses. Always read the label.
The use of trade names in this course is solely for the purpose of providing specific information. It is not a guarantee
or warranty of the products named, and does not signify that they are approved to the exclusion of others of suitable
composition. Use pesticides safely. Read and follow directions on the manufacturer’s label.
Acknowledgements:
Authored by University of California faculty, specialists, and farm advisors, produced and edited by IPM Education
and Publications, University of California Statewide IPM Program. Guidelines Coordinator: Barbara Ohlendorf;
Technical Editor: Mary Louise Flint.
"/PMG/selectnewpest.spinach.html"
Trujillo, Linda Speaking of Spinach , Master Gardener
Monterey County Managing Diseases for the Rapidly Increasing Spinach Industry
http://www.ipmcenters.org/cropprofiles/docs/NJspinach.html
Crop Profile for Spinach in New Jerseyc
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