Rutgers University | New Jersey Agricultural Experiment Station | Pesticide User Responsibility

Organic Farm Advisory

The Plant & Pest Advisory serves NJ growers by reporting on important pests and recommending responses that are grounded in reproducible trials.

Articles in this section contain information helpful to the NJ commercial organic grower.

Sharing organic practice trial results between land-grant universities is a cost effective way to create a common knowledge base built on the strengths of individual programs. In the sidebar, find institutions with programs in organic agriculture which augment knowledge developed at the Rutgers New Jersey Ag Experiment Station.

Rutgers Cooperative Extension Field Guides: These concise guides help with decision making from pre-planting to harvest. For each crop listed, learn what pests to proactively look for as the season progresses, how to look for them, and when to take action.

June 28, 2023

Vegetable IPM Update 6/28/23

Sweet Corn

Low numbers of European corn borer (ECB) moth activity has declined to very low levels in areas where blacklight traps are operating in the northern and central counties.  Feeding in whorl and pre-tassel stage corn has increased only slightly over the past week, with many plantings exhibiting no ECB injury at all.    While ECB has become something of a local phenomenon in NJ, growers should not assume that feeding is below economic levels in their area.

European corn borerLook for the characteristic “shot-hole” type of feeding (photo  below at right) and consider treating when infested plants exceed 12% in a 50 plant sample.  As plantings proceed to the pre-tassel stage, ECB larvae may be found in emerging tassels (see photo at left).  It is a good idea to treat individual plantings as they move into the full tassel/first silk stage one time.  This eliminates any ECB larvae that have emerged with the tassels as they begin to move down the stalk to re-enter near developing ears.

 

Useful insecticides for this particular application include synthetic European corn borerpyrethroids (IRAC Grp 3), spinosyns (including OMRI approved Entrust) IRAC Grp 5), and diamides such as Coragen or Vantacor (IRAC Grp 28) or materials such as Besiege which include the active ingredient in Coragen.  Synthetic pyrethroids alone should NOT be used for corn earworm (CEW) protection on silking corn.  Control with these materials is very inconsistent.

The highest nightly trap catches of ECB for the week ending 6/28/23 are as follows:

Califon   1 Sergeantsville   1
Pennington   1 South Branch   1
Princeton   1

[Read more…]

Filed Under: Organic Production, Vegetable Crops
June 21, 2023

Vegetable IPM Update 6/21/23

Sweet Corn

Low numbers of European corn borer (ECB) moths remain active in areas where blacklight traps are operating in the northern and central counties, although feeding in whorl and pre-tassel stage corn is low and sporadic in occurrence.  The highest feeding levels are in southern Hunterdon and Monmouth counties.   ECB injury around 20% of plants infested has been found in those areas recently.  While ECB has become something of a local phenomenon in NJ, growers should not assume that feeding is below economic levels in their area.   It is typical for feeding percentages to rise as the moth catch declines.  We expect feeding to increase for the next 1-2 weeks before peaking.

European corn borerLook for the characteristic “shot-hole” type of feeding (photo  below at right) and consider treating when infested plants exceed 12% in a 50 plant sample.  As plantings proceed to the pre-tassel stage, ECB larvae may be found in emerging tassels (see photo at left).  It is a good idea to treat individual plantings as they move into the full tassel/first silk stage one time.  This eliminates any ECB larvae that have emerged with the tassels as they begin to move down the stalk to re-enter near developing ears.

 

Useful insecticides for this particular application include synthetic European corn borerpyrethroids (IRAC Grp 3), spinosyns (including OMRI approved Entrust) IRAC Grp 5), and diamides such as Coragen or Vantacor (IRAC Grp 28) or materials such as Besiege which include the active ingredient in Coragen.  Synthetic pyrethroids alone should NOT be used for corn earworm (CEW) protection on silking corn.  Control with these materials is very inconsistent.

The highest nightly trap catches of ECB for the week ending 6/21/23 are as follows:

Bellemeade   1 Oldwick   1
Califon   1 Pennington   1
Clinton   1 Sergeantsville   1
Lawrenceville   1 South Branch   1

[Read more…]

Filed Under: Organic Production, Vegetable Crops
June 21, 2023

Webinar: Managing Food Safety Risks in Hydroponic Operations

Incorporate food safety into your hydroponics setup and worker training.

August, 17, 2023 12:00 – 1:00 p.m. Free!
Register online
You will get the link to sign on or call in a few days before the event.

Hydroponic growers use a variety of methods to grow, harvest, and pack produce. This webinar will focus on general best practices in the hydroponic growing environment to reduce the risk of human pathogen growth and spread.
This webinar will focus on risk assessment and management through:
1. Appropriate worker training
2. Evaluation of growing and harvest processes
3. Identification of food contact surfaces
4. Development of a cleaning and sanitation process

Filed Under: Food Safety, Organic Production, Vegetable Crops
June 14, 2023

Vegetable IPM Update 6/14/23

Sweet Corn

Low numbers of European corn borer (ECB) moths continue to be captured in a few of the remaining blacklight traps in the northern and central counties, although feeding in whorl and pre-tassel stage corn is low and sporadic in occurrence.  The highest feeding levels are in southern Hunterdon County.   ECB injury over 12% of plants infested has been found in that area recently.  While ECB has become something of a local phenomenon in NJ, growers should not assume that feeding is below economic levels in their area.   It is typical for feeding percentages to rise as the moth catch declines.  We expect feeding to increase for the next 1-2 weeks before peaking.

Look for the characteristic “shot-hole” type of feeding (photo  below at right) and consider treating when infested plants exceed 12% in a 50 plant sample.  As plantings proceed to the pre-tassel stage, ECB larvae may be found in emerging tassels (see photo at left).  It is a good idea to treat individual plantings as they move into the full tassel/first silk stage one time.  This eliminates any ECB larvae that have emerged with the tassels as they begin to move down the stalk to re-enter near developing ears.

 

Useful insecticides for this particular application include synthetic pyrethroids (IRAC Grp 3), spinosyns (including OMRI approved Entrust) IRAC Grp 5), and diamides such as Coragen or Vantacor (IRAC Grp 28) or materials such as Besiege which include the active ingredient in Coragen.  Synthetic pyrethroids alone should NOT be used for corn earworm (CEW) protection on silking corn.  Control with these materials is very inconsistent.

The highest nightly trap catches of ECB for the week ending 6/14/23 are as follows:

Allamuchy   1 Hillsborough   1 Sergeantsville   1
Bellemeade   1 Pennington   1 South Branch   1
Clinton   1 Port Murray   1
Farmingdale   1 Princeton   1

[Read more…]

Filed Under: Organic Production, Vegetable Crops
June 8, 2023

Magnesium Deficiency in Tomato and the Relationship with other Important Nutrients

How can growers prevent nutrient deficiencies in crops? Soil testing and tissue testing for fertility management of vegetable crops is key to having the correct levels of nutrients to have a high yielding, high quality crop to harvest and market. Soil testing is best done in fall so that pH levels can be adjusted with soil amendments like lime that correct pH levels for maximum return on fertilizer uptake. Why adjust pH to proper levels? Plant nutrients are hindered in availability when soil pH is too high or too low. Besides pH, fertility levels are important to monitor and adjust pre-plant for the best start to new seedlings and transplants.

With tomato production it is widely known that calcium (Ca) levels in soil are important for prevention of blossom end rot. Therefore, tomato growers have focused on application of adequate and even high levels of calcium to prevent this fruit disorder. Another primary nutrient, potassium (K) is also important for plant and fruit quality for regulating water movement/water loss in the plant and other functions. In addition, it is important to also pay attention to magnesium (Mg) levels. Ca, K, and Mg are all important in successful tomato production. It is important to know these nutrients compete with each other for plant uptake and their proper levels based on soil and tissue testing.

Even though blossom end rot resulting from Ca deficiency can cause tomato fruit to be unmarketable, Mg deficiency can reduce overall plant health and ultimately quality and yield. Low K in the plant can make the plant less tolerant of heat and drought stress. Magnesium in tomato plants plays an essential role in photosynthesis (the process of the plant to make energy to fuel growth), protein synthesis (necessary in cell formation), activation of plant enzymes (necessary for many cellular and growth functions), and chlorophyll synthesis (the green pigment in plants that is essential for optimum plant growth).

Magnesium deficiency can occur, especially in sandy soils, when soil is overwatered or after heavy rainfall events. However, when Ca and Mg levels are out of balance, deficiencies can still occur even when both are showing adequate levels in the soil. It is more important to look at the actual levels. If one is significantly higher than the other deficiency symptoms may occur. Since both Ca and Mg are +2 ions in soil when taken up by plant roots, the plant indiscriminately takes up these two nutrients. Therefore, if there is abundant Ca and lower Mg, Mg deficiencies may be seen. Conversely, when Mg levels are higher than Ca levels blossom end rot may be seen. It is best to have these two nutrients in soil at the same levels to keep a balance in uptake and ultimately promote both healthy fruit formation and foliage growth. Allowing Mg levels to remain deficient in the plant will result in lower yields and less energy for fruit production later in the plants lifecycle.

Magnesium deficiency is first seen on tomato plants as interveinal chlorosis – yellowing of leaf tissue between the veins of older leaves. Eventually the leaves become mostly yellow and purplish-red spots that become necrotic on the interveinal tissue may occur. See photos taken in the field on June 7, 2023.

Deficiency symptoms can be seen at any stage of growth, but are generally first seen when plants begin to flower, start fruit set, and fruit enlargement. When plants change from vegetative growth (production of leaves and stems) to reproductive growth (flowering and fruiting) leaves are stressed and energy and resources are reallocated into growth and development of new progeny (seed and fruit).

Fortunately, Mg deficiency is easily corrected when caught early in the tomato plant’s growth by the application of Epsom salts. Rates differ depending on soil type, soil levels, and plant tissue levels. Mg rates can vary from 5-25 pounds per acre. Application can be done through drip irrigation systems or applied on the soil surface by spraying near the rootzone. When applying through the drip tape, be sure to run the lines with clean water for at least 20 minutes after the salts have gone thorough to prevent salt build up in the emitters. Foliar applications of Mg can be sprayed on plants, but are not as efficient as soil application and root absorption. There are other products available to correct low levels of Mg, but most data available for the use of Epsom salts to raise Mg levels. Pre-plant, the use of high Mg liming products can balance Ca and Mg levels in soil if Mg levels are lower than Ca levels. Therefore, when lime is needed to raise pH it is very important to look at Ca and Mg levels on the soil test results before selecting which type of lime will work best for adjusting the levels of these two very important plant nutrients.

When managing fertility levels for successful crop production, it is important to know the levels of plant nutrients in soil and tissue tests. It is as important to understand the interactions between plant nutrients and how they affect plant growth. Seeing an “optimum” or “sufficient” level on a soil or tissue test report is not enough to fully determine what is needed for high yielding, high quality crops.

Filed Under: Organic Production, Vegetable Crops Tagged With: ,
June 7, 2023

Vegetable IPM Update 6/07/23

Sweet Corn

Warmer evening temperatures have resulted in modest increases in European corn borer (ECB) moth catches in blacklight traps in the northern and central counties.  Whorl corn is the primary target for egg laying, and injury over the 12% threshold has been found in Hunterdon County this week.  It is likely that there are pockets of feeding throughout the southern counties.  Despite relatively low numbers, this pest still poses a threat to plantings now approaching full tassel.  It is typical for feeding percentages to rise as the moth catch declines.  We expect feeding to increase for the next 1-2 weeks before peaking.

Weekly distribution of European corn borerLook for the characteristic “shot-hole” type of feeding (photo  below at right) and consider treating when infested plants exceed 12% in a 50 plant sample.  As plantings proceed to the pre-tassel stage, ECB larvae may be found in emerging tassels (see photo at left).  It is a good idea to treat individual plantings as they move into the full tassel/first silk stage one time.  This eliminates any ECB larvae that have emerged with the tassels as they begin to move down the stalk to re-enter near developing ears.

 

Useful insecticides for this particular application include synthetic European corn borerpyrethroids (IRAC Grp 3), spinosyns (including OMRI approved Entrust) IRAC Grp 5), and diamides such as Coragen or Vantacor (IRAC Grp 28) or materials such as Besiege which include the active ingredient in Coragen.  Synthetic pyrethroids alone should NOT be used for corn earworm (CEW) protection on silking corn.  Control with these materials is very inconsistent.

The highest nightly trap catches of ECB for the week ending 6/07/23 are as follows:

Sergeantsville   2 Oldwick   1
Asbury   1 Port Murray   1
Hillsborough   1 South Branch   1

[Read more…]

Filed Under: Organic Production, Vegetable Crops