Volume 15 -Number 12
View from the Field
Potato Leafhopper (Empoasca fabae) populations in alfalfa continues to increase across the state. Several extension educators report populations rising and some new seedings over threshold. With the hot dry weather potato leafhopper populations will continue to increase. Sometimes if you’re lucky and get a thunderstorm or a very heavy rain it can reduce a population. All alfalfa field should currently be monitored for potato leafhoppers.
We have a training video on IPM for Potato Leafhopper in Alfalfa (8 minutes long). The video helps you understand how to monitor and determine thresholds for potato leafhopper. It also has IPM methods of control of potato leafhopper including harvesting early, planting resistant cultivars and insecticides. There is a short survey to evaluate the video.
Mike Hunter (CCE Northern NY) reports Phytophthora root and stem rot a field of soybeans in Jefferson County. The strange thing is that this disease is normally a problem in wet fields. This field was very dry.
Above Ground Symptoms (Photo by Mike Hunter, CCE Northern NY)
The fungal pathogen that causes phytophthora root rot is Phytophthora sojae. The spores can survive in the soil or on previous crop debris. Normally when there is high moisture in the soil the spores can germinate. Reduced and no-tillage tend to have more occurrence of the disease than conventional tillage systems. There are many races of Phytophthora sojae that can infect soybeans. The symptoms show up from emergence through late season plants. Seed rot, damping off and wilting of young plants is common early in the season. When the plant is more mature leaves start turning yellow/wilting to brown/dry as it progresses. If you cut open the root will show a dark brown color and rotted.
There are a few management strategies that can be employed:
- Rotate soybeans every year. This helps break the disease cycle. It is best to rotate with corn, wheat or some other non-host.
- Use Resistant Cultivars. They are race specific and would be good to know what races of the disease are in your area to better select a resistant cultivar.
- Use of fungicide seed treatment
- Good soil management practices
- Reduce soil compaction
- Do not work wet soils
- Improve soil health/structure and drainage
- Plant when soil temperature is 55 F or above
- Proper soil pH
Weather Outlook – July 21, 2016
NOAA Northeast Regional Climate Center, Cornell University
Last week temperatures ranged from normal to 4 degrees above normal. Precipitation ranged from a tenth to 2 inches. Base 50 growing degree-days ranged from 110 to 170.
Heat & humidity return…
Today will be sunny with temperatures warming into the 80’s and low 90’s. Overnight lows will be in the 60’s and low 70’s with strong thunderstorms possible (gusty winds).
Friday will be humid with highs in the mid 80’s to low 90’s with showers and thunderstorms likely with a passing cold front, some possibly severe (large hail, damaging winds possible). Lows will be in the 60’s to low 70’s.
Saturday high pressure will bring sunny, still humid conditions with temperatures in the 80’s and low 90’s. Overnight temperatures will be in the mid 60’s to low 70’s.
Sunday highs will be in the mid 80’s to low 90’s with continued high humidity. Overnight temperatures will be in the mid 60’s to low 70’s with a chance of showers and thunderstorms.
Monday the chance of showers and thunderstorms continues in the morning, highs will continue to be above normal in the mid 80’s to low 90’s. Lows will be in the mid 60’s to low 70’s.
Tuesday temperatures will be more seasonable in the 80’s. Lows will be in the 60’s.
Wednesday temperatures will be in the 80’s. Lows will be in the 60’s.
The five-day precipitation amounts will range from ¼” to 1.5” .
The 8-14 day outlook (July 28 – August 3) shows an increased chance (50-60%) for above normal temperatures and an increased chance (33-40%) for above normal precipitation.
The Drought Monitor: For the last 30 days, precipitation is below 25 percent of normal. Stream flows at all levels (1-, 7-, 14-, and 28-day) are reaching into the tenth percentiles. Moderate to Severe drought (D1-D2) was expanded to cover these high impact areas in western NY. New York issued the first statewide drought watch since 2002.
Western Bean Cutworm Update (7/22/16)
Ken Wise-NYS IPM
The western bean cutworm moth catch increased dramatically this week. Last week we were at 89 moths across the state, this week it was 720 moths with 85 percent of the 62 traps catching at least 1 moth. The highest number caught was 148 moths/trap in Riga, Monroe County. You could start seeing some egg masses on corn leaves. In the next week or so start scouting for the egg masses on a weekly bases. The economic threshold is when 5% of plants have egg masses and/or young larvae. Once larvae enter the corn ears insecticide is not effective at control. The following is the moth counts per trap location.
|St. Lawrence||South Colton||1||2|
|St. Lawrence||North Lawrence||0||6|
|St. Lawrence||Chase Mills||4|
|Steuben||North Cohcoton Hill||0||0||4||4|
Western bean cutworm updates will be available at this blog throughout the season and the NYS IPM Sweet Corn Pheromone Trap Network Report.
Partial Alfalfa Field Harvest Increases Potato Leafhopper Risks
Keith Waldron-NYS IPM
Are potato leafhoppers (PLH) in your alfalfa fields? If so, avoid partial field harvests to best manage PLH populations. Clean harvest of whole alfalfa fields is optimal, however our recent stretch of rainy weather has surely messed up more than one harvest schedule sometimes stopping a hay harvest in mid-stride. These partially harvested fields can set the stage for future PLH problems. In situations where edges or portions of alfalfa fields have been harvested but other areas of the field are left intact watch closely for PLH populations and potential injury to the regrowth.
Adult PLH in the standing portion of the field can easily relocate to the shorter portion of the field and attack the vulnerable regrowth. The shorter alfalfa has a lower threshold for PLH than taller alfalfa so is at much higher risk for injury.
Harvest remaining portions of the field as soon as is practical to minimize PLH population buildup and their easy movement to adjacent portions of the field.
Keith Waldron, NYS IPM
*Walk fields to check general field condition, weed issues
*Watch for crop maturity, stand assessments, weed escapes, nutrient deficiencies, lodging issues
*Evaluate established legume stands for approximate days until harvest
*Monitor potato leafhopper, foliar, systemic and crown rot diseases.
*Monitor new seedings for potato leafhopper, pythium blight, phytopthora root rot.
*Monitor grain fields for growth stage, disease and lodging issues, grain maturity, harvest timing
*Record diseases present, location and types of weed escapes
*Make sure grain storage bins are cleaned and repaired before storing new grain to avoid insect pests.
*Do not add new grain to last year’s grain in storage bins. This can cause insect pests to infest new grain in the old grain was infested.
*Monitor for mid-season corn pests including European corn borer, corn rootworm, western bean cutworm, slugs, foliar diseases such as northern corn leaf blight and gray leaf spot, weed issues, nutrient deficiencies, vertebrate damage.
*Monitor for crop growth stage, soybean aphid, defoliators, foliar diseases, white mold, weed issues, vertebrate damage
*Check water sources, mend fences as needed.
*Check crop growth, clip pastures between grazing as needed
*Monitor for invasive species, plants harmful to livestock
* Check stored grain bins for temperature, moisture and signs of mold and insects. Aerate, core, transfer grain or treat as necessary
* Clean and disinfect empty storage bins in preparation for grain harvest
*Check forage allocation and anticipate feed program adjustments as forages from previous year are used up
*Mow around storage bins and facility to minimize pest hiding places
Dairy Cattle Barn Fly Management:
*Monitor animals and barn area for house fly, stable fly and other pest management needs including presence of rodents and birds.
*Check facilities for favorable fly breeding conditions: (organic matter + moisture): leaks in watering systems, roof gutters for leaks and potential overspill, drainage,
*Sanitation, sanitation, sanitation – clean animal resting areas, feed troughs, minimize source of moist organic matter i.e. fly breeding areas in barn and in adjacent animal loafing yard
* Continue fly monitoring: install “3X5″ index card fly speck monitoring cards throughout barn
*Use, replenish, replace fly management materials: sticky fly tapes/ribbons, insecticide baits, natural enemies (parasitoids), fly population monitoring (3 x 5) spot cards
*Consider purchase and release of Muscidifurax raptor and/or M. raptorellus natural enemies of house and stable fly pupae.
Dairy Cattle on Pasture:
*Monitor animals for presence of face flies, horn flies and stable flies. Action guidelines: face flies (average 10 per animal face), horn flies (average 50 / dairy per animal side, 200 / beef cattle per animal side), stable flies average 10 per animal (all four legs)
*Check feed bunk / water source locations for signs of stable fly breeding (moist undisturbed organic matter – spilled feed, round bales, etc.), minimize source of moist organic matter i.e. fly breeding areas in barn and in adjacent animal exercise yard.
*Check pasture for forage quality / quantity, rotate as appropriate
*Check pasture for vegetation poisonous to livestock
*Consider use of pasture fly traps to help reduce deer, horse and stable fly populations