Diseases | Credits

SCAFFOLDS Fruit Journal, Geneva, NY                Volume 4
 Update on Pest Management and Crop Development    August 21, 1995 


                                                     43F       50F
Current DD accumulations (Geneva 1/1-8/21):         2943      2149
                       (Highland 3/1-8/21):         3142      2231

Coming Events:                              Ranges:
Peachtree borer flight subsides                2230-3255   1497-2309
San Jose scale 2nd flight subsides             2494-3191   1662-2302
Oriental fruit moth 3rd flight peak            2549-3267   1845-2326
Obliquebanded leafroller 2nd flight peak       2634-3267   1789-2228
Redbanded leafroller 3rd flight peak           2775-3174   1863-2169
Apple maggot flight subsides                   2775-3174   1958-2169
Lesser peachtree borer flight subsides         2782-3328   1796-2359
Codling moth 2nd flight subsides               2782-3624   1796-2582
Lesser Appleworm 2nd flight peak               2961-3328   1927-2359
American plum borer 2nd flight subsides        3005-3587   2154-2497
STLM 3rd flight subsides                       3235-3471   2228-2472

TRAP CATCHES (Number/trap/day)
                                   8/7   8/10   8/14   8/16   8/21
Redbanded Leafroller               0.4    0.2    0.3    0.3    0.3
Spotted Tentiform Leafminer         24     28    204    550    184
Oriental Fruit Moth (apple)        6.5    5.0    7.0   11.3    6.2
Lesser Appleworm                   0.8    0.7    2.1    3.0    1.8
Codling Moth                       7.5    7.0    6.3    2.8    1.1
San Jose Scale                     5.4   16.2    4.6    4.0    3.1
American Plum Borer (cherry)       3.1    1.8    2.0    1.0    0.5
Lesser Peachtree Borer (peach)     4.0    2.7    5.0    8.8    2.6
Lesser Peachtree Borer (cherry)    2.3    1.0    2.3    3.8    3.8
Peachtree Borer                    1.0    1.5    1.1    1.0    0.6
Obliquebanded Leafroller             0      0    0.8    0.3    0.7
Apple Maggot                       0.6    0.9    0.6   0.06   0.08

Highland (Dick Straub, Peter Jentsch)
                                  7/24   7/31    8/7   8/11   8/21
Redbanded Leafroller               0.6      0      0    0.2    2.3
Spotted Tentiform Leafminer       20.8   20.3   42.8   33.9   57.8
Oriental Fruit Moth                1.1    1.7    1.6      0    0.1
Codling Moth                       1.1    1.1    0.6    2.4    0.7
Lesser Appleworm                   0.6    1.6    0.7    1.1    0.4
Sparganothis Fruitworm               0    0.3    0.2    1.9    1.3
Tufted Apple Budmoth                 0      0    0.6    0.3    0.8
Variegated Leafroller              0.1      0    1.1      0    0.4
Obliquebanded Leafroller           0.2    0.3    0.1    0.1    0.3
Apple Maggot                       0.2*   0.1    0.3    0.4    0.7

                                                        * = 1st catch


By:Dave Rosenberger, Plant Pathology, Highland

This year there is good news and bad news about postharvest fungicides for apples. The good news is that three new postharvest fungicides have recently been registered for apples and pears. The bad news is that none of them are likely to be available for use in the northeast this year. Why aren't the new fungicides available? The answer provides an interesting case study on problems associated with commercialization of new biorational and biotechnology products.

All three of the new fungicides that have been registered are "biocontrols". This means that the products are not traditional fungicides that act by killing fungal spores or inhibiting spore germination. Instead, the three new products are formulations of bacteria or yeasts -- living organisms that actually grow on the fruit after they are applied. These biocontrol organisms control decays by colonizing wounds on the apple fruit where decays are initiated. The biocontrol organisms apparently use up all of the available nutrients in the wounds, leaving nothing to support germination of the spores of the decay fungi.

The three new postharvest fungicides registered for apples and pears were all registered by relatively small companies with little or no experience in marketing fungicides. Two products, BioSave-10 and BioSave-11 have been registered by EcoScience Corporation. EcoScience was formerly headquartered in Worcester, MA, but recently moved to New Jersey. Both BioSave-10 and BioSave-11 are bacteria. BioSave-11 is targeted for pears, whereas BioSave-10 has better activity on apples. The third biocontrol is Aspire, which has been registered by Ecogen Inc., Langhorne, PA. Aspire is a yeast, Candida oleophila.

Extensive company testing and limited university trials have shown that all three of these new products have reasonably good activity against postharvest decay fungi. The level of control achieved is sometimes slightly better than and sometimes slightly less than that achieved with thiabendazole (TBZ). The real benefits from these products become apparent when they are combined with TBZ. Combinations of the biocontrols plus TBZ have frequently provided better control than can be achieved with either TBZ or the biocontrol used alone. In many trials, reduced rates of TBZ (20% of the recommended rate) combined with the biocontrols provided exceptional decay control.

If these products can be used to improve decay control, what is the hold-up in getting them into commercial use? As stated above, the products may not be available in the northeast this year. The companies are just now gearing up their production lines, but they are targeting initial sales toward the citrus and west coast apple markets. Neither company was certain that there would be any product available in the northeast this fall, and it appears that neither company has determined how their product will be distributed in the northeast after it does become available. Both companies have apparently applied for labels in New York State, but I could not get clear answers on the status of those labels.

Another reason for not recommending these products at this time involves pricing. The rumored price for BioSave-10 is $25/lb and the application rate for drenchers is 1 lb/10 gallons. (No, we didn't miss a zero: the price would be $250 per 100 gal of drench solution.) The company feels that it can get this price in citrus and west coast apple and pear operations where the product will be applied as a non-recirculating spray to bushes on pre-sizer lines. In my opinion, they need to do some more homework if they expect to see their product used in the east. I have not heard a price for Aspire, but the company said they will be "competitive".

Even if the biocontrols were available this year, growers might wish to proceed with caution because no one can be certain about public acceptance of food products sprayed with bacteria and yeasts. This may be a case where we should be happy to let the west coast get into the action ahead of us. I do not mean to imply that there are any safety concerns with using these new products. The products have been tested and approved by EPA. They are perfectly safe for their labeled uses. However, as we learned with Alar, public perceptions are not always based on facts.

Before recommending the new fungicides for general use in eastern packinghouses, I believe additional testing should be done in university trials. Results of company-run trials have generally looked quite good, but I am reluctant to recommend expensive new products based solely on the data presented by the manufacturer.

If Aspire or BioSave-10 become available during the 1995 harvest season (and if they are affordable), packinghouse operators may wish to try these products on limited quantities of fruit. However, I suspect that it will be another year or two before these products can be broadly recommended for apple storages in the northeast.

The scenario I have described for the new postharvest fungicides for apples is likely to be repeated many times over the next few years as more biological control and biotechnology products reach the marketing stages. The small companies that develop these products may succeed in speeding their products through the EPA labeling process because EPA is making an effort to put bicontrol and biorational products on a fast track for registration. However, the label itself is of little value if there is no distribution network for getting the product to the commercial end-user. Whereas large agrichemical companies experience lengthy delays in getting traditional fungicides registered, it appears that the delay with the new fungicides may occur between labeling and development of effective distribution and usage patterns.

Next week: A review of the recommendations for using TBZ in postharvest apple drenches.

Scaffolds is published weekly from March to September by Cornell University -- NYS Agricultural Experiment Station (Geneva), and Ithaca -- with the assistance of Cornell Cooperative Extension. New York field reports welcomed. Send submissions by 3 p.m. Monday to:

Scaffolds Fruit Journal
Editors: A. Agnello, D. Kain
Dept. of Entomology, NYSAES
Geneva, NY 14456-0462
Phone: 315-787-2341 FAX:315-787-2326

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