IPM Notes for July 25, 2013

Pheromone Trap Results
Trap #1 - Black Cutworm
2 moths – Black cutworm, 7 chaffer beetles, 1 bee, 1 lightning bug

Trap #2 - Corn Ear Worm
1 Corn Ear Worm moth, 9 noctuid moths, 1 chaffer beetle

Trap #3 - European Corn Borer
Inactive

Trap #4 - Fall Army Worm
1 chaffer beetle, 3 ground beetles, 1 undetermined beetle (due to deterioration), 1 mosquito 


Helios Trap
Inactive

Field Corn
In the field corn, we looked at an example of plant growth when reaching for sunlight. We looked at a velvet leaf plant that was nearly 6 feet tall and mostly stalk. Leaves were few and far apart. It is a very different growth pattern from velvet leaf plants on the edge of the field.

We looked at the milk line on the kernel. At this time it is clearly visible. The kernel is wet when crushed, but will change to a doughy starch when the corn is ready for harvest.
This field corn variety has the end of the ear exposed when the silks fall away. This makes it susceptible to many pests and conditions including, bugs, worms, moisture, fungus.
There is a disease beginning to show on the stalks. If this progresses sufficiently the stalks will become weak and may break in wind or heavy downpour conditions.

Popcorn
Noted some leaf damage but could not locate an agent. Popcorn is at a stage where the whorl is open to environmental and insect impact.

Note: Erosion after the 4” rain received has reached depths of 4 – 8 inches with clear gullies and rills. Some plants are having sediment buildup above the roots, while others are having soil taken from the root system leaving roots exposed.

Wheat/Soybeans
This field is at stage V2 or the 2nd trifoliate stage. The root system is strong but no nodule formation yet. Soybeans are sensitive to the length of the day, so it is a race to see if the plants will fully develop and fruit before the lack of daylight shuts the plants down.

Sweet Corn
All varieties are tasseled, but there is little silk showing. The tassels have not started shedding pollen, so there is still some time. Most of the varieties are putting down brace roots.

Hay Field
The hay has been cut down and is drying. 2nd cutting is considered to be a good hay for its smoothness in the mouths of the feed animals.

Soybeans
These soybeans are now classified as being in the reproductive stage and would have an R-number instead of a V-number (see above). They are setting bean pods and still blooming. There is evidence of leaf hoppers (from the cut hay field) and thrips (leaf curling).

Demonstration Gardens

• Peanuts - Plants were showing signs of needing calcium and potassium. Calcium was added without incident. Potassium was applied at the recommended rate but still burned the leaves. Plants are recovering and showing growth with the added nutrients. The plants should have more flowers but may be being affected by the lack of heat. There is not much evidence of pegging from existing flowers.

• Peppers are recovering nicely. 

• Tomatoes – next thing to watch for will be late blight.

Thanks to Roger for compiling this week's notes.

 

Late Blight Update

There is an update from Rutgers Cooperative Extension Plant and Pest Advisory regarding late blight.  Late blight is a fungus-like disease caused by the pathogen Phytophthora infestans that mainly attacks tomatoes and potatoes.  Late blight was one of the factors that contributed to the Irish Potato Famine.

For more information on the late blight update, visit the Plant and Pest Advisory link.

Link:  Plant and Pest Advisory - Late Blight Update  
 

IPM Notes from July 18, 2013

Pheromone Trap Results
Trap #1 - Black Cutworm
1 ladybug, 1 juvenile green stinkbug, 1 Japanese beetle, 3 European Chaffer beetles, 4 click beetles, 1 cucumber beetle.
Trap #2 - Corn Earworm
1 ladybug, 1 corn earworm moth, 2 unknown beetles
Trap #3 - European Corn Borer
Inactive
Trap #4 - Fall Army Worm
1 cereal leaf beetle, 1 corn borer moth

Helios Trap
Inactive



Field Corn Field
Firing on lower leaves is still present – lack of nitrogen – and moving to higher leaves.
Tassels are breaking – no insects so it may be a weakness in the variety.

We looked at one ear. It is full, all kernels are formed and it has good size. Next week we will learn to calculate the expected yield from the number of kernels and rows.

Popcorn Field
Areas where there was standing water are now crusting. This would be a problem for germinating seeds, but not for growing plants. Buggy whipping is still present on a significant percentage of plants. There will be stunting of plant growth. It is also very visible the difference in plant height between those plants that were water stressed and those that were not. We will now need to watch for moths coming over from other fields. 

We looked at signs of erosion – rilling and gullying. We talked about ways that farmers use to combat erosion. Unless there are continued heavy rains and runoff, this will not be a problem in this field.

Wheat Field now a Soybean Field
Soybeans are up and at the unileaf stage also called mid group 3 stage. It will be a race to see if we get full maturity and what kind of yield by October.

Hay Field
Not yet harvested for 2nd cutting.

Sweet Corn Field
Some varieties have begun to show tassels, but not showing ears. Because all the varieties were planted at the same time in close proximity there will be some cross-pollination. Because of all the moisture at the beginning, the roots of this crop have not grown deep. During these last days of hot, dry weather they are now showing the leaf curling signs of drought stress. They may need to be irrigated. Rule of Thumb for sweet corn; tassels and silks = 21 days.

Soybean Field
Soybeans are flowering and setting on bean pods. There are leaf hoppers present, possibly thrips (though we did not find any). We also found a green ‘clover’ worm or ‘inch’ type worm.

In the demonstration plots:

• Peanuts are beginning to peg.
• Hops can be harvested.

Community gardens
Green bean yellowing possibly from potassium deficiency.

Weeds reviewed

• Ragweed
• Barnyard grass
• Foxtail
• Velvet leaf
• Jimson weed
• Yellow nut sedge
• Goose grass

Special thanks to Roger for compiling this week's note and to Ramona for the photos.

IPM Notes for July 11, 2013

Pheromone Trap Results
Trap #1 – Black Cutworm
5 click beetles, 1 corn earwig, 12 European Chaffer beetles, 3 lady bugs, 4 chaffer-related beetles.

Trap #2 – Corn Ear Worm
2 European Chaffer beetles, 2 click beetles, 3 lady bugs, 6 juvenile moths (not corn ear worm)

Trap #3 – European Corn Borer
Pheromone has been removed due to high attraction for bumble bees. Trap still contained many bumblebees.

Trap #4 – Fall Army Worm
2 Alfalfa Weevil, 1 Lightning bug, 1 click beetle

Helios Trap
The corn has overtopped the trap, so no analysis done.



Corn Field
The corn is in the ‘Tassel’ stage. Also, we are seeing the development of the ‘brace’ roots or adventitious roots. Many of the tassels are not only out, but the pollen is out also. However, many of the ears have not yet put out their silk. This will mean undeveloped ears. This is possibly due to the stresses of the rain and low nitrogen. Because of the rain and wet conditions leaf spot is now developing. 

Brace roots in corn field

Popcorn Field
Buggy whipping is occurring in the popcorn – perhaps as much as 10%. This can be from herbicide damage, flea beetle (no evidence), and environmental causes. Most likely it is from late germination with twisting in the ground before emergence.  We are noting the growth of algae on the top of the ground due to the wet weather and presence of standing water in the fields.

Buggy whipping

Algae in popcorn field

Sweet Corn Field
Noted areas of stunting due to wet conditions. Noted presence of ‘suckers’ (extra stalk coming up from the root). Noted nitrogen deficiency with some evidence of ‘firing’ on the lower leaves.

Wheat Field
Wheat has been harvested. Field has been replanted with soybeans. Straw was not harvested. Due to the wet weather, harvesting and planting was delayed by approximately 6 days from the optimal. This may mean a 6% loss in yield at harvest. (1% per day after optimal planting day)

Soybean Field
Herbicide applied – particularly for horsetail (Equisetum species). Soybeans are flowering. There is a stem and leaf disease developing.

Hay Field
Behind time for the 2nd cutting. (time is determined by alfalfa bloom @ 10%) Need 3 good drying days.



Demonstration Gardens

• Peppers are still water-stressed. Seeing fungal/mushroom growth from the woodchip mulch.

• Tomatoes are showing leaf curl with the presence of lace wings, thrips, and leaf hoppers. Tomato harvest is expected to be much lowered by the wet weather this season.

• Peanuts are still blooming but are not pegging. This is possibly due to the wetness and possibly to a calcium deficiency.

• Cowpeas look great.

• Buckwheat was planted too thickly. Stems were spindly and long and the center of the plot has been laid over by the wind.

• Blueberries – 2 plants are showing Scorch or Fire Blight.

• Hops cones are ready for harvest.

Community Garden Plots
Evidence that powdery mildew has begun.

Other Notes
Bill noted that he is receiving reports from farmers that potatoes are rotting in the ground.


Thank you Roger for compiling this weeks notes.

Pest of the Week - Leafhopper

A leafhopper, Graphocephala sp. (Homoptera: Cicadellidae). Photo by C. L. Barr.

Natural History

Leafhoppers are insects belonging to the family Cicadellidae in the order Hemiptera.  They are recognized by their piercing-sucking mouthparts and by the presence of rows of spine-like setae (hairs) in their hind tibiae.

Leafhoppers go through incomplete metamorphosis in their development. Female leafhoppers insert tiny eggs in tender plant tissue, causing pimplelike injuries.  Overwintered eggs begin to hatch in mid-April. Wingless nymphs emerge and molt four or five times before maturing in about 2 to 7 weeks.  Nymphs resemble adults except that they lack wings; later-stage nymphs have small wing pads.  Leafhoppers overwinter in the Gulf States and migrate north each year.  They usually arrive in New Jersey in June.  There are two to three generations per year in New Jersey.

Leafhopper feeding causes leaves to appear stippled, pale, or brown, and shoots may curl and die. Some species cause a diamond-shape yellowing from the leaf tip. A few species secrete honeydew on which foliage-blackening sooty mold grows. Black spots of excrement and cast skins may be present on leaves and/or fruit. Some leafhopper species transmit plant diseases, but this is troublesome mostly among herbaceous crop plants. 

Potato Leafhooper Empoasca fabae Life Cycle - University of Kentucky

Potato leafhopper, Empoasca fabae, causes hopper burn on red maple and other important shade trees and shrubs. 

 
Leafhoppers can carry the bacterium, Xylella fastidiosa, which causes bacterial leaf scorch in elms, oaks, maples, and sycamores. Leafhoppesrs can also carry a phytoplasma which causes the disease known yellows, ash yellows affects ash, and elm yellows affects elms. Aster yellows affects coneflower, Echinacea. Aster yellows is spread from plant to plant by the leafhopper, Macrosteles phytoplasma. Once infected, diseased plants should be promptly removed and discarded to reduce further spread.

Managment Strategies

On maple, look for leafhoppers on the leaf underside. Look for stippling of leaves and curled or stunted shoot tips. Inspect trees regularly looking for leafhoppers feeding on the lower surface of leaves. Look also for distorted or stunted growth and yellow leaves.
 
Remove plants exhibiting the scorch-like symptoms or the distorted and stunted growth of aster yellows.

Avoid over fertilization, which may cause populations of leafhoppers to increase. ‘Autumn Blaze’, a hybrid of silver and red maple, is highly resistant.

Spray where needed, concentrating on regions where leafhoppers prefer to feed, particularly on new growth.

Bigeyed bugs, damsel bugs, assassin bugs and lacewings are common predators of leafhoppers.

Precautionary Statement on Pesticide Use

All pesticides have both benefits and risks. Benefits can be maximized and risks minimized by reading and following the labeling. Pay close attention to the directions for use and the precautionary statements. The information on pesticide labels contains both instructions and limitations. Pesticide labels are legal documents, and it is a violation of both federal and state laws to use a pesticide inconsistent with its labeling.  Always read and follow the label.



Additional Information

Leafhoppers Fact Sheet 237 - NJAES - Rutgers University

Leafhopper - Department of Entomology - Texas A&M University

Potato Leafhopper on alfalfa - Penn State University

Virginia Alfalfa IPM Source - Virginia Tech

IPM Notes for June 27, 2013

Pheromone Trap Reports

Trap #1, Black Cutworm – Earwig – 1; black cutworm – 1; European chafer – 1; lady bug – 1.

Trap #2, Corn EarWorm – Corn earworm – 2; noctuid – 5; European chafer – 1.

Trap #3, European Corn Borer – Bumble bee – 26; European chafer – 1; corn rootworm – 1.

Trap #4, Fall Army Worm – Fall armyworm – 2; cereal leaf beetle – 4.

Setting pheromone trap

Helios Trap Contents

earwig – 3
bumble bee – 4
striped cucumber beetle – 1
cabbage looper – 1

Examining contents of helios trap

Field Corn

• All the rain we are having is draining the soil nutrients. Some corn is firing, leaves yellowing at bottom, brown (dead) in middle of leaf. Firing starts with an inverted “V” in the leaf. When loosing nitrogen, leaves are yellow and green. When the stalk is getting yellow, which will weaken it, the stalk will snap off when the weight of the corn is on it. 50-60 pounds of nitrogen were put down the weekend of June 22.

• Corn does not grow in temperatures over 90 degrees. 

• Corn is at 8 leaf stage (V-8 – vegetative growth 8). 

• When hail hits corn, it strips the leaves completely and the corn will have no crop. 

• Reddish color brace roots were observed on the top of the soil and over the root ball. These hold the corn in the soil.

• Insects damaging to corn: Flea beetle – causes Stewart’s Wilt, usually when corn is under a foot high.

• Cereal leaf beetle – feeds on veins causing slits; if there are 10 or more per plant, there could be severe damage to the corn. Cereal leaf beetle is usually on wheat; migrating to corn and now laying eggs on leaves.

• Overall, corn looks good

Popcorn

• Two varieties, red and yellow, planted next to field corn a few days ago. 

• The wet spots are showing saturated soil causing nitrogen to leach and the corn will not germinate.

Sweet Corn

• Sixteen rows of corn were planted; each a different variety.

• To estimate number of corn plants per acre: measure 17.5 feet and count the number of plants in that space and count the number of 17.5” rows. Multiply that by 1000. (25 plants in a 17.5” row = $25K plants/acre; if 21 plants = 21K plants/acre)

• The sweet corn is planted in time blocks so it produces corn for the market each week.

• The large space between the rows is so the corn can be fertilized.

• Silver Queen corn no longer exists but the name is synonymous with sweet corn. Many varieties have replaced silver queen such as Argent or Supersweet which are not know to the public; so, for marketing purposes farmers advertise they are selling Silver Queen. These new varieties have a gene that keeps it sweet longer (7-10 days) so it stays fresher/sweeter in supermarkets.

Soybeans

• Some plants have bacterial disease with the yellowing.

• Nodules on roots are pink 

• Plants are at 5 leaf stage (V-5).

• If weather gets really hot soybeans abort their flowers; when it is cooler they will flower again. 

• Soybeans flower by the amount of daylight and shut down when the days are shorter. They have maturity groups. The group range in the Burlington County area is 2.8 to 4.2; 2.8 beans are ready in September and 4.2 are ready in October.

Wheat

• Not resprouting yet; the radical is not coming out. If there is sponginess is in the grain, wheat is not ready to be harvested. The grain must be hard. 

• Awn wheat has spikes (hairs) on each grain. Deer do not like to eat it with the spikes sticking them in the face. There are two kinds of wheat – awn and awnless.

• When wheat is harvested, it is sent to market in bushels. An average bushel weighs 60 pounds; it may be lighter 5 pounds or so because of rain causing mold spores and micro toxins on the wheat. Mold spores cause the wheat heads to be empty of grain so the bushel is lighter and must be mixed with good wheat. Some micro toxins are toxic to humans and animals.

•  Mold spores on the wheat cause the top of the plant to be darker, it has no grain, there are no roots and the stalk is hard. Several plants were noted with the darker tops.

Demonstration Gardens

• Peppers like to dry out so the mulch was pushed away from the plants. The leaves were sprayed with Epsom salts which makes magnesium and greens them. Use 1 teaspoon per gallon of water. Spray once or twice only per season.

Pepper plants

• Tomatoes should not be watered with Miracle Grow. It makes the plants grow tall without fruit. On the tomato insect sticky paper were a slug and Syrphid flies (hoverflies). Hoverflies help pollinate. Leafhoppers on the plants suck the sap out of the leaves and cause them to curl. Several plants had curled leaves. Leafhoppers spread viruses and tomatoes are susceptible to viruses. Leafhoppers love alfalfa and tomatoes and hops are close to alfalfa. Of the three systems used for tomatoes, the stake or trellis is nice for picking. This system is used commercially. Suckers should not be pruned from the tomatoes. As the plants grow, additional string rows should be added to the stakes. The effect of the straw laid around the tomatoes should be checked regarding disease on the plants.

Examining tomato demo plot

• Hops are yellowing from leafhopper damage.

• Quinoa seed replanted in half of the garden.

Special thanks to Marylin for the IPM notes and Ramona for the photographs.

Too Much of a Good Thing

June has been a very wet month in New Jersey.  Statewide the average rainfall was 9.75", a state record for any June since 1895.  Frequently, plants in wet and soggy soils exhibit the same symptoms as plants in drought conditions.  It's not unusual to see plants "wilt" on the first  sunny day after a prolonged period of cloudy wet weather.

Plant cells respire and need oxygen to survive and grow.   Plant cells must get oxygen from the air that is close to the cells. The concentration oxygen in the soil is not as high as oxygen around us.  If soil become saturated with excess water. the excess water in the soil forces out soil air. When there is less air available, the oxygen is rapidly used and becomes inadequate for good root growth. Also, in very wet soils organic matter begins to decompose and this process also further depletes oxygen in the soil environment.

In addition to root problems other diseases get established on plants during wet periods.  Many foliar  diseases may form during this period.  Close observation of your landscape and plants is important after an excessive wet period.  If any dead spots, die-back, leaf spots or other disease problems become apparent, whatever the plant, prompt action is important to prevent more severe damage.

Here are some tips for dealing with too much rain in your garden:

• Cut off or cut back on automatic irrigation systems during periods of heavy rain.


• Keep gutters, downspouts, ditches, drainage grates and culverts clear of debris so water can move.


• Channel flooded waters away from garden beds and plants in the landscape by digging temporary small trenches so standing water will run away from the roots of plants that are not tolerant of “wet feet.”


• Make sure all drainage holes in containers are clear and water can move through the pots.


• Empty pot saucers regularly or remove during times of excessive rain to prevent containerized plant roots “standing in water.”


• Consider installing a rain barrel to catch and recycle this natural resource. This was once a common practice and there are many home “rain barrel” kits and instructions on the internet.


• Consider installing a rain garden in those areas of the yard that tend to hold water during heavy rainfall. 

Additional Information

Office of the New Jersey State Climatologist at Rutgers University

Rain Gardens - Rutgers University

Stormwater Management in Your Backyard

Rain Barrels - Rutgers University

Phytophthora Root and Crown Rot - UC Davis IPM Online