IN THIS ISSUE:

HORTICULTURE:
- Preliminary results of apple rootstock trials
 
ENTOMOLOGY:
- Moth Capture in Pheromone Traps
- Degree-Day Table
- Percent Egg Hatch
- Pest Activity
- OFM Update
- Second Brood of Tufted Apple Bud Moth Update
- Fruit Section of 1-800-PENN-IPM Available for the Fruit Growers

POSTHARVEST PHYSIOLOGY
- Registration of 1-MCP
- Storage Workshop To Be Held By Cornell University - August 13 & 14, 2001
 
Horticulture:

PRELIMINARY RESULTS OF APPLE ROOTSTOCK TRIALS:  In 1994 a planting of Gala was established at the Horticulture Research Farm at Rock Springs to evaluate rootstocks that were similar to M.9 in size or were different clones of M.9.  The planting was part of a sanctioned planting for the NC-140 Regional Research Project.  At the end of the seventh growing season the smallest trees based on trunk cross sectional area were on M.27 EMLA, Poland 22 and Poland 16 (Table 1).  The largest trees were on Vineland.1 and M.26 EMLA.  Within the M.9 clones there was quite a range of sizes.  The largest M.9 clones were the French clones Pajam2 and Pajam1.  The annual growth increment was similar to the ultimate tree size with the smallest trees having the least amount of trunk area increase.  Suckering was variable by rootstock with M.26 EMLA and Poland 2 having the least number of root suckers, while Ottawa 3 and Poland 16 had the greatest amount of suckers.

All the fruit on each tree was counted and weighed to obtain an average yield by rootstock.  Yields per acre are based upon a tree spacing of eight feet in the row and sixteen feet between trees in adjacent rows for a density of 340 trees per acre.  The cumulative yield is the sum of yields from 1995 through 2000.  Yields in 1995 were included in this analysis although in a commercial orchard the fruit may not have been harvested due to the small amount in the orchard.  As would be expected, small trees had lower yields because they did not have the canopy volume of the larger trees (Table 2).  On the larger trees however there was very little difference in the yield in 2000.  Cumulative yields for the six cropping season shows that trees on Vineland 1 produced the most fruit.

Efficiency can be determined by taking total cumulative yield and dividing by the current trunk cross sectional area.  In many rootstock studies it is usually shown that although the smaller trees produced less on a per tree basis their efficiency is often better than large trees.  In this study however, the smallest trees were the least efficient (Table 3).  There was however a specific impact by rootstock.  M.26 EMLA which was one of the largest trees also had a lower efficiency than all the M.9 clones.  Pajam 1 and NAKB clones of M.9 had the highest efficiency. This is probably due to the fact that the larger trees were taller resulting in overall larger canopy volumes.

The study will be continued for another 3 years but there are certain observations that can be made at this point.
   o M.27, P.22 and probably P.16 induce too much dwarfing for our
     convenionally spaced orchards.
   o Trees on Mark rootstock are starting to show signs of ground line
     swelling and tree decline.
   o V.1 is as large as M.26 but is more productive
   o B.9 in this planting with Gala is 14-18% smaller than M.9 EMLA
     or M.9 NAKB
 

Table 1.  Tree size as measured by trunk cross sectional area (TCSA),
          Growth increase and number of rootstocks in 2000.

Rootstock           200 TCSA, cm2     Growth, cm2     # of suckers
 

B.469                 20.6 ab           4.2 ab         5.3 a-d
B.491                 17.3 ab           3.3 a          1.9 abc
B.9                   30.4 bc           5.9 abc        4.8 a-d
M.26 EMLA             66.6 fg          14.7 e          0.0 a
M.27 EMLA             10.7 a            2.3 a          1.8 abc
M.9 EMLA              35.3 b-e          7.9 a-d        1.3 ab
M.9 NAKB              37.1 b-e          7.3 abc        5.1 a-d
M.9 PAJAM 1           51.2 efg          9.3 cd         5.2 a-d
M.9 PAJAM 2           53.7 efg          9.3 cd         8.6 cd
M.9 RN 29             48.5 c-f          8.9 bcd        7.0 bcd
MARK                  29.4 b            4.4 ab         3.5 a-d
0.3                   50.5 d-g         12.4 de         9.6 d
P.16                  16.4 ab           2.8 a          9.9 d
P.2                   32.3 bcd          6.7 abc        0.5 ab
P.22                  11.2 ab           2.0 a          5.3 a-d
V.1                   67.5 g           15.5 e          1.9 abc
 
P-value              0.0001            0.0001          0.0001
 
 
 
 
 
 
 
 
 
 

Table 2.  Yield of Gala on different rootstocks in 2000 and
          Cumulative yield for 1995-2000.
 

                  Yield 2000          Cumulative
Rootstock            bu/A*           bu/A 1995-2000
 

B.469               242 abc             1033
B.491               205 ab               781
B.9                 361 bcd             1583
M.26 EMLA           734 e               2655
M.27 EMLA            73 a                379
M.9 EMLA            523 cde             1822
M.9 NAKB            589 de              2004
M.9 PAJAM 1         758 e               2785
M.9 PAJAM 2         759 e               2775
M.9 RN 29           649 e               2596
MARK                298 abc             1463
0.3                 539 cde             2614
P.16                194 ab               818
P.2                 364 bcd             1435
P.22                 74 ab               340
V.1                 677 e               2965
 
P-value           0.0001
 

Table 3.  Cumulative yield efficiency of Gala on different rootstocks

                 Cumulative
                 Efficiency
Rootstock          kg/cm2
 

B.469              2.81
B.491              2.53
B.9                2.91
M.26 EMLA          2.23
M.27 EMLA          1.99
M.9 EMLA           2.89
M.9 NAKB           3.03
M.9 PAJAM 1        3.05
M.9 PAJAM 2        2.89
M.9 RN 29          3.00
MARK               2.79
0.3                2.90
P.16               2.79
P.2                2.49
P.22               1.69
V.1                2.46
 
(Rob Crassweller - Horticulture, PSU)
 
 
 
 
 

Entomology:

MOTH CAPTURE IN PHEROMONE TRAPS:
Year 2001 - weekly capture of adult moths in pheromone traps located at PSU FREC Biglerville, PA (Adams County):

Species   5/24   5/31   6/07   6/14   6/21   6/28   7/05   7/12   7/19

RBLR         0      0      0     24     55     77     32     24     12
OFM         28     14     18     31     16     38     30     78     43
CM            1     12     10     20     10     13     3      8     13
TABM         39     47     45     37     22     12     2      0      3
VLR           1      1      1      4     13      3     0      0      0
OBLR          0      2     42     31      3      0     0      0      0
STLM         32     32   1054   2510   3593   2844  3946   2110   3190
LAW           0      1      2      1      3      1     0      1      0
LPTB         19      8      6     31     15      9     2      4      2
DWB           4      5      4      5     34     17    30     26     16
PTB                         0      2      4      2     4      10     9

Key to acronyms: RBLR - redbanded leafroller; OFM - Oriental fruit moth; CM ­ codling moth; TABM ­ tufted apple bud moth; VLR ­ variegated leafroller; OBLR ­ obliquebanded leafroller; STLM - spotted tentiform leafminer; LAW ­ lesser appleworm; LPTB ­ lesser peach tree borer; DWB ­ dogwood borer; PTB ­ peach tree borer.

DEGREE-DAY TABLE: Accumulated degree-days base 43 from Jan 01 (courtesy of SkyBit, Inc.). The accumulated degree-days for the last day (July 31) mentioned in the table are based on the weather forecast.

Site/Date          6/19    6/26    7/03    7/10    7/17    7/24    7/31

Biglerville, 2001  1410    1589    1806    2004    2184    2396    2616
Biglerville, 2000  1674    1888    2090    2278    2468    2642    2836
Biglerville, 1999  1522    1699    1937    2202    2402    2661    2916

Rock Spring, 2001  1220    1378    1586    1744    1904    2110    2308
Rock Spring, 2000  1400    1594    1770    1931    2104    2255    2441

PERCENT EGG HATCH: Below is listed the present and forecasted egg hatch status for five pests in the Biglerville area based on information provided by SkyBit, Inc.  This insect information was based on biofix and weather data taken at the PSU Fruit Research and Extension Center in Biglerville.  Growers should be advised to use local trap capture and accumulated degree-days from their own sites in order to make proper spray decisions.  The percentage egg hatch for the last day (July 31) mentioned in the table is based on the weather forecast.

Species  Biofix    6/26    7/03    7/10    7/17    7/24    7/31
STLM     4/02        41      79      95       0       2      10
OFM      4/22         4      55      96     100       0       2
CM       5/03        94       0       1       4      16      52
TABM     5/09        90       0       0       0       0       0
OBLR     5/29        81      98       0       0       0       0
 

INSECT PEST ACTIVITY FROM VARIOUS PA COUNTIES
Pheromone trap data collected from commercial fruit farms located in various PA counties.  Trap information is provided by participating growers.  The trapping project is partially supported by the Extension Committee of the State Horticultural Association of Pennsylvania and the Pennsylvania IPM Program (PDA/PSU).

Adams County (Fairfield) (data collected in cooperation with Laurie Roth)
Species          6/05   6/12   6/19   6/26   7/03   7/10   7/17   7/24
OBLR                2     30      4      0      1      0      0      1
OFM                 0      3      1      4      5      1      2      2
CM                  0      0      6      0      0      0      0      3
TABM               18     46     24     11      9      2      1      3

Adams County (York Springs) (data collected in cooperation with Laurie Roth)
Species          6/05   6/12   6/19   6/26   7/03   7/10   7/17   7/24
OBLR                3     59      5      3      1      0      0      0
OFM                 6      6      5      7      8     22      9      9
CM                  1      0      1      1      0      0      0      0
TABM               41     56     41     18      7      4      1      0

Allegheny County (data collected in cooperation with Eric Oesterling)
Species          6/05   6/12   6/19   6/26   7/03   7/10   7/17   7/24
OBLR                1      4      2      1      0      0      0      0
OFM                 1      1      2      2      1      1      4      3
CM                  1      8      6      5      2      1      3      7
TABM               10     14     24     14      2      1      0      1

Berks County (data collected in cooperation with Mena Hautau)
Species          6/05   6/12   6/19   6/26   7/03   7/10   7/17   7/24
OBLR                1     11      1      2      0      1    N/A
OFM                 1     17     15      7      5     15    N/A
CM                  1     11     10      5      3      1    N/A
TABM               23     50     63     29     22      1    N/A

Centre County (data collected in cooperation with Tom Ford):
Species          6/05   6/12   6/19   6/26   7/03   7/10   7/17   7/24
OBLR                0      1      6      2      1      2      0      0
OFM                 5     38     44      9     10      2      3     12
CM                  1      9     14      8      4      1      2      4
TABM                1      7     13      9      7      3      1      2

Erie County (data collected in cooperation with Andy Muza)
Species          6/05   6/12   6/19   6/26   7/03   7/10   7/17   7/24
OFM                 1     12     12      5      8      4     22     15

Montour County (data collected in cooperation with Jeff Mizer)
Species          6/05   6/12   6/19   6/26   7/03   7/10   7/17   7/24
OBLR                1      5      5      8      1      1      3      0
OFM                 6     11     10      3      6      3      4      0
CM                  1      4      1      2      2      2      2      1
TABM                4      9      8     14      3      2      5      0

Schuylkill County (data collected in cooperation with George Perry)
Species          6/05   6/12   6/19   6/26   7/03   7/10   7/17   7/24
OBLR                3     20      7      2      2      0      1      1
OFM                 0      3     30     12      9     10      9     15
CM                  2      7      5      5      4      1      3      8
TABM               14     13     15     15      2      2      0      0

York County (data collected in cooperation with Tim Elkner)
Species          6/05   6/12   6/19   6/26   7/03   7/10   7/17   7/24
OBLR               25     13      5      6      0      6
OFM                 8      4      4      8      2      1
CM                  5      8      4      5      5      1
TABM               29     22     41     21      5      0

PSU Experimental Farm Rock Spring (data collected in cooperation with Don Smith)
Species           6/05   6/12   6/19   6/26   7/03   7/10   7/17   7/24
OBLR                 0      0      4      5      2      0      0      0
OFM                  7     26     43     19     19      1      1      0
CM                   1      2      2      3      4      0      0      3
TABM                 1      2      6      3      1      0      0      0
 

PEST ACTIVITY: The total degree day accumulation base 43 for this year (calculated since 01 January) is about 200 DD below last yearís accumulation.  On the other hand, the degree day accumulations for various pests calculated since this yearís biofix, but using respective lower and upper thresholds, are almost identical with last yearís accumulation for this time of the season.  Despite later biofix dates for our major pests, the insect phenologies are almost at the same stage as they were last year.  Larvae from the first brood of both the tufted apple bud moth and the obliquebanded leafroller are completing their larval development and feeding on foliage and fruit.  It appears that the second brood TABM adult flight (and OBLR as well) just started or will start within this week and continue until late September.  Last weekís orchard observations revealed the presence of various larval instars and pupae of OBLR and TABM.  Egg hatch for second generation of both species should occur during August.  Both leafrollers species can be controlled very effectively, but precise timing of insecticide applications will be very important.  Egg hatch of second brood codling moth reached about 15 percent in the Biglerville area on 24 July.  Apple maggot emergence is still underway and it is important to monitor this pest until late in the season, since some additional adult emergence can occur even in late August, especially if we finally receive some rain. For the most up to date information on egg hatch models, adult emergence and trap capture data from FREC in Biglerville please visit our web page at: http://www.frec.cas.psu.edu/

OFM UPDATE:  Despite the fact that some late larvae from the second generation may still be present inside the terminals or fruit on both apple and peaches, the flight of the third generation of Oriental fruit moth adults has already started.  At least two or maybe even three additional generations of OFM will be present in the orchards before harvest is complete.  According to the egg hatch models, the eggs of the third OFM generation will start to hatch within the next few days (July 29-30) in Adams County.  Our observations from previous years indicate, that starting from this OFM generation, in many orchards we can observe continuous flight of OFM adults for the rest of the season.  In areas where peach and apple orchards are localized in close proximity, considerable overlapping of generations may occur.  The capture of moths in pheromone traps should be used as the main factor to properly time treatments.  For good control of OFM larvae an effective insecticide (OPís, carbamates or pyrethroids) should be applied.  In orchards with high OFM pressure higher rates of insecticides should be used: Azinphos-methyl 50W at 1.5-2.0 lb/A, Imidan 70W at 3.0-4.0 lb/A, Lannate 90SP at 0.75-1.0 lb/A , Asana at 8-12 fl oz/A, or Danitol at 16-21 floz/A.  As growers make their decision on what materials to use for the last few applications of the season, they should check their records and the label for the seasonal amount of insecticide they can apply. For example, with recent changes brought on by FQPA, growers can only use 4.5 lbs AI per acre per season of azinphos-methyl.

If pheromone traps are being used for OFM monitoring, please be aware that the sex pheromone for OFM tends to attract another small tortricid moth, the lesser appleworm (LAW).  LAW adult males are smaller than OFM adults and the dominant wing color is brown with a gold/yellowish band evident across its back.  Coloration of adult OFM is composed mostly of different shades of the color gray.  In addition to being attracted to the same pheromone lures, both species have also an analogous host range and cause very similar fruit injury.  Both of them are internal fruit feeders, with LAW feeding mainly just under the skin of infested fruits (shallow tunneling), while OFM feeds deeper inside the flesh of the fruit.

SECOND BROOD OF TUFTED APPLE BUD MOTH UPDATE: Tufted apple bud moth adults from the second brood should start (or already started) to fly in Adams Co. this week and continue until September.  The egg laying period will begin shortly after the beginning of moth flight.  Larvae will feed on both leaves and fruits.  Fruit injury appears as tiny holes or irregular scaring of the fruit surface, often around the stem.  Rarely, the larvae can enter the fruit calyx and feed within the seed cavity.  Usually, the fruit injury caused by the second brood of TABM is at a higher level than the damage done by the first brood TABM and what makes matters even worse, the larvae may still be present on fruit during the harvest.  Please note that a number of loads of fruit were rejected for the presence of TABM larvae in the calyx end of the fruit during last few years.

Monitoring and management: The use of pheromone traps for monitoring TABM is especially useful to determine the right timing for insecticide applications.  The egg hatch models and current moth captures in pheromone traps located at the Fruit Research and Extension Center in Biglerville are updated weekly on the web at: http://frec.cas.psu.edu/.  The Pennsylvania Tree Fruit Production Guide (PA TFPG) lists the recommended spray timings for TABM using conventional pesticides based on degree-day accumulations and application methods (Table 33 p.116 or at the web at: http://tfpg.cas.psu.edu/part2/part23am.htm).  Please remember, that the recommendations in the PA TFPG were prepared for the broad-spectrum insecticides (organophosphate and carbamate insecticides).  For the newer, highly selective insecticides such as Confirm or SpinTor we recommend that two complete applications be used to control the second brood of TABM.  If using Intrepid at the 12-16 fl oz /acre rate, only one application may be necessary.  If using Intrepid at the 8 fl oz/acre two applications are recommended.  The complete spray timings correspond to 20-30% (2355-2435 DD base 45) and 60-70% (2665-2740 DD) egg hatch.  Please also refer to the product label for rates and application timings.  If Confirm, SpinTor or low rate of Intrepid (8 fl oz/acre) are used for leafroller control, please note that these compounds will not provide adequate control of the internal fruit feeders, Oriental fruit moth or codling moth.  Intrepid at the 12-16 fl oz/acre rate is more effective on the CM/OFM complex, but it is not as effective as a broad spectrum insecticide (OPs, carbamates, pyrethroids) especially where insect pressure is high.  In orchards with established OFM and/or CM populations an organophosphate or carbamate insecticide should be added to control these pests. If growers are not monitoring for OFM or CM, we also recommend the addition of an OP insecticide when using these insecticides.  The efficacy of various insecticides for the control of TABM and other insect pests is listed in Table 50 of PA TFPG (p.180 or on the web at: http://tfpg.cas.psu.edu/part4/table50.htm).

It is very important that growers establish a good resistance management program for leafrollers.  One part of that plan calls for alternating between different chemistries for controlling consecutive broods of TABM (i.e., do not use the same insecticide chemistry for both broods).

FRUIT SECTION OF 1-800-PENN-IPM AVAILABLE FOR THE FRUIT GROWERS: The fruit entomology section of PENN IPM phone hot-line is again available at a toll-free 1-800-PENN-IPM phone.  The pre-recorded message includes current pest and beneficial insect information as well as some pest control recommendations.  It is our intention to utilize this tool as a fast and accurate messaging board for communicating with commercial and small-scale fruit growers.  The phone message will be updated weekly during the growing season.
(Greg Krawczyk and Larry A. Hull)

Postharvest Physiology:

THE REGISTRATION OF 1-MCP: (SmartFresh of AgroFresh Inc.) by the EPA has not yet occurred.  AgroFresh had anticipated that registration would be granted in time for a limited commercial launch this fall.  Without registration approval, AgroFresh has delayed their commercial launch until the 2002 harvest.
 
Perhaps an old proverb is appropriate..."good things come to those who wait".

STORAGE WORKSHOP TO BE HELD BY CORNELL UNIVERSITY - August 13 & 14, 2001
Topics to be covered are:
   Scald
   MCP
   CA Systems
   Decay Control
   Bitter Pit
   Food safety for export
   Meeting export quality requirements
 
Registration for the workshop will be:  $60 prior to August 1,  $75 thereafter

The workshop will be held at the following location:
               Ramada Inn - Airport
               2310 N. Triphammer Rd.
               Ithaca, NY
               PH:  607-257-3100
 
The price of the room is $99 and must be booked by July 13th.
 
For further information please contact:
               Maxine Welcome/Storage Workshop
               Dept of Horticulture
               134A Plant Science Building
               Cornell University
               Ithaca, NY  14853
               PH:  607-255-5439

(Nate Reed, Postharvest Physiology, PSU FREC)

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