---

Delivering Weather, Climatological, and Environmental Information Pertinent to Tree Fruit Management in Northern Ohio

---

 

PRINCIPAL INVESTIGATOR:      Ted W. Gastier, Huron County Agricultural Agent

 

COOPERATING

ORCHARDS:            Burnham Orchards, Berlin Heights, OH 44814

                                    Eshleman Orchards, Clyde, OH 43410

 

SCOUT TECHNICIANS:     Eugene Horner, Extension Program Assistant

                                                James Mutchler,  Extension Program Assistant

                                   

ABSTRACT: Thirty-one apple and peach growers in fourteen Ohio counties, including five of the top ten apple producing counties, plus five Extension Agents and two industry reps received apple disease prediction products by e-mail.  These products were supplemented with weekly orchard visits to thirty-five production blocks.  The objectives of this project were; 1). To expand a weather-based predictive system for pest management in northern Ohio orchards 2). To initiate practice change by growers in their selection process for for pest management based on lowering orchard Environmental Impact Quotients (EIQs) to reduce non-target impacts.

 

METHODS:  Disease products for apple scab, fire blight, and sooty blotch were purchased from SkyBit, Inc. of Bellefonte, PA for two orchard locations which were representative of ten apple producing counties.  The products were received through e-mail by the Huron County Extension office and forwarded to growers and agents twice each week during the growing season.  These products were supplemented with National Weather Service wind, temperature, and precipitation forecasts for seven Ohio locations.  The NWS Web site is available at no cost to growers and the general public at <http://www.nws.noaa.gov/mdl/forecast/text/state/OH.MRF.htm>

 

Three temperature/leaf-wetness Spectrum Technologies monitors where positioned at eye-level within the apple tree canopies at three locations.  The apple scab computer Specware,  based on the Modified Mills Chart (available from Spectrum Technologies of Plainfield, IL) was utilized to indicate expected apple scab infection periods.  In addition, daily temperature and precipitation data from twelve Ohio weather stations were recorded to collaborate wetting periods.

 

Two scout/technicians made weekly orchard inspections in 24 apple blocks and 12 peach blocks to determine pest pressures through pheromone traps and visual observation of insects, mites, and diseases as well as populations of beneficial insects and predatory mites. In addition, the principal investigator made weekly visits to 4 apple blocks and three peach blocks for this project and mating disruption trials in cooperation with Eshlemans and Dave O’Brien of UAP.  Fruit quality was checked for disease-caused blemishes as apples were placed into storage at eighteen locations.  Peach fruit quality was assessed on several dates during the harvest season.

 

RESULTS:

            Fruit Quality Harvest Survey – Apples (sample size = 10 growers)

Defects noted and level of incidence:

                        1). Climatological – soft hail damage (3 orchards)2).

                        2). Physiological - fruit russet (5 orchards)

                        3). Insect – codling moth (9 orchards)

                                            San Jose scale (2 orchards)

                                            redbanded leafroller (1 orchard)

                                            plum curculio (1 orchard)

                        4). Disease – scab insignificant (10 orchards)

                                              fire blight significant (2 orchards)

                        5). Other pests – crows (2 orchards)

multi-colored Asian ladybird beetles (2 orchards although present in all orchards.)

                        6). Tree leaf injury noted during growing season –

spotted tentiform leafminer (two orchards)

 

            In cooperation with Dr. Celeste Welty, approximately 13,700 apples were examined in two non-destructive surveys with the fruit found to 99.6% free of defects.

 

            Fruit Quality Harvest Survey – Peaches (sample size = 4 growers)

            Defects noted and level of incidence:    

                        1). Disease – bacterial spot (two orchards)

                                             brown rot (one orchard)

                        2). Internal fruit feeders – mainly Oriental fruit moth (one orchard)

                        3). External fruit feeding – mainly redbanded leafroller (two orchards)

 

Non-destructive surveys were conducted during the harvest season with 725 peaches being examined indicating the following:

Clean	Internal feeding	Surface feeding	Mechanical damage	Bacterial spot	Brown rot	Over-ripe	Split pit	Unknown
90.8%	1.8%	1.5%	2.9%	1.1%	1.2%	0.1%	0.1%	0.1%

 

Late Season Multi-colored Asian Ladybird Beetle (MCALB – Harmonia) Survey – Specimens were found in 55 MultiPher III traps set for apple and peach pests.  No fruit feeding was observed.  The September 26^th observation also included 9.6 adults/trap of family Hemerobiidae (brown lacewing) and syrphid flies too numerous to count.

Date	September 5	September 12	September 19	September 26
MCALB/trap	0.02	0.18	1.04	6.31

North Central Ohio Pesticide EIQs, DEs and Costs for 1999 and 2003-12-11 (Averages for 10 apple producers and 5 peach producers.)

	Apple						Peach
	EIQ		DE		Cost $		EIQ		DE		Cost $
Year	1999	2003	1999	2003	1999	2003	1999	2003	1999	2003	1999	2003
Average	1733	1610	17	22.5	306.53	610.05	1744	2553	10	18	176.78	356.51

EIQ – Environmental Impact Quotient,   DE – Dosage Equivalent (explanation at: http://www.nysipm.cornell.edu/publications/EIQ.html )

SkyBit and SpecWare  Apple Disease Predictions (percent days reported, indicated or predicted)

Month	SpecWare scab infection  indicated	SkyBit Scab Rpt	SkyBit 3-day scab Pdt	SkyBit 4-10 day scab Pdt	SkyBit fire blight Rpt	SkyBit 3-day fire blight Pdt	SkyBit 4-10 fire blight scab Pdt	SkyBit sooty blotch Rpt	SkyBit 3-day sooty blotch Pdt	SkyBit 4-10 day sooty blotch Pdt
April	na*	26%	50%	89%	-	-	-	-	-	-
May	23%	71%	65%	100%	35%	76%	77%	-	-	-
June	27%	60%	57%	100%	50%	53%	100%	0	0	67%
July	45%	65%	58%	55%	81%	81%	100%	100%	100%	100%
August	71%	87%	84%	100%	87%	84%	100%	100%	100%	100%

            na* equipment failure     Rpt = reported     Pdt = predicted

 

DISCUSSION:

            Codling moth management continues to challenge apple growers and researchers throughout the Midwest.  Timing of spray application will become more important as newer, more environmentally friendly materials supplement and/or replace organophosphates.  Dependable timing is provided by establishing Biofixes with pheromone traps.  Newer materials will help lower the Environmental Impact Quotients.  A combination of factors contributed to control failures in two blocks:  inadequate coverage in older, standard trees; storage of apple bins in or near orchard perimeter; high resident populations; nearby woods; and inattention to late-season control during the peach harvest.  Codling moth mating disruption is not “ready for the big-time” in the Midwest. 

 

            Apple scab pressures were heavy this season due to a cooler and wetter than normal growing season.  Our growers had good control using a combination of standard and newer, softer materials.   Continued movement away from the standards will lower future EIQs.  Fire blight severity was lessened with the wide-spread  use of a twig growth inhibitor except where later applications of foliar nutrients were added in cover spray applications.

 

            For the most part, the peach crop was abundant with good quality.  However, bacterial spot was diagnosed in two orchards by Dr. Mike Ellis.  Oriental fruit moth damage was considered excessive in later varieties in one block due to several factor.  The block has a history of damage, we have no way to monitor mated-females with mating disruption, and extremely high populations were present in the early season.  Heavy disease pressures lead to heavier usage of control materials compared to 1999.

 

            The SkyBit scab prediction product has been used for several years to assist growers with apple scab.  Because of the low predictability (25% accuracy) of precipitation for any given point, the product errors on the safe side as shown for the 4 to 10 day prediction in the table above which could lead to over-application.  The SpecWare monitoring and analysis is subject to equipment failure and depends on downloading by growers on a timely basis. 

 

EXTENSION PROGRAM IMPLEMENTATION:

Specific recommendations for the 2004 growing season:  1) Replace SpecWare and SkyBit with direct-reading Weather Tracker Apple Scab Alert devices, 2) Substitute SkyBit weather forecasts with the National Weather Service forecasts available on the Web, 3) Emphasis EIQs for specific products in the Ohio Fruit ICM News, 4) Recommend  San Jose scale control in early season, and 5) encourage softer products for codling moth, and apple and peach disease control.