July 18, 2007
In this issue
§ Insect update
§
Downy mildew confirmed in
§ Passive solar greenhouses for year-round production and risk management
§ New bulletin helps farmers fight honeybee problems
Dear readers,
Several events have conflicted with publishing regional reports and the weather news this issue. Please see our Enviro-weather web site for updated agricultural weather: http://www.enviroweather.msu.edu . We will return to our standard content with next week’s issue. – Joy N. Landis, editor.
Beth Bishop
Entomology
The second flight of European corn borer moths has begun in
southern
The number of aster leafhoppers present in celery and carrot
fields in
Mary Hausbeck
Plant Pathology
Downy mildew was confirmed on cucumber in a third
§ Fungicides should be applied to cucumbers every FIVE to SEVEN days.
§ Fungicides should be applied to pumpkins, melons, cantaloupes, squash, zucchini and gourds every SEVEN to TEN days.
|
Applied before disease (7-day intervals) |
Applied after disease (5-day intervals) |
|
— Gavel 75WG (5 day PHI) |
— Previcur Flex 6SC (2 day PHI) |
|
— Previcur Flex 6SC (2 day PHI) |
— Ranman 3.6SC (0 day PHI) |
|
— Ranman 3.6SC (0 day PHI) |
— Tanos 50WG (3 day PHI) |
|
— Tanos 50WG (3 day PHI) |
|
|
Alternate products and mix each with either: — Dithane (mancozeb) 3 lb or — Bravo (chlorothalonil) 1.5 pt |
Alternate products and mix each with either: — Dithane (mancozeb) 3 lb or — Bravo (chlorothalonil) 2 pt |
Table 2 summarizes the spore numbers that have been counted so far for 2007 in the highlighted columns. For comparison purposes, spore counts from 2006 are in the adjacent, non-highlighted columns. The entire table containing all of 2006 data is available at my website http://plantpathology.msu.edu/labs/hausbeck/Hausbeck%20Lab%20For%20Growers.html, click on link to Downy mildew news). This table is continually being updated as new counts are completed.Table 2. Daily spore trap totals by county and year.
|
Date |
|
|||||||||
|
Allegan |
Bay |
|
|
|
||||||
|
2007 |
2006 |
2007 |
2006 |
2007 |
2006 |
2007 |
2006 |
2007 |
2006 |
|
|
Jun 8 |
– |
– |
– |
– |
S 2 |
– |
– |
– |
– |
– |
|
9 |
– |
– |
– |
– |
2 |
DM – |
– |
– |
– |
– |
|
10 |
– |
– |
– |
– |
6 |
– |
– |
– |
– |
– |
|
11 |
– |
– |
– |
– |
2 |
– |
– |
– |
– |
– |
|
12 |
S 0 |
– |
– |
– |
0 |
– |
– |
– |
– |
– |
|
13 |
2 |
– |
– |
– |
0 |
– |
– |
– |
– |
– |
|
14 |
0 |
– |
– |
– |
3 |
– |
– |
– |
S 0 |
– |
|
15 |
2 |
– |
S 2 |
– |
2 |
– |
S 2 |
– |
5 |
– |
|
16 |
5 |
– |
0 |
S 0 |
2 |
S 27 |
2 |
– |
2 |
S 6 |
|
17 |
0 |
S 3 |
0 |
0 |
2 |
54 |
0 |
– |
2 |
0 |
|
18 |
2 |
0 |
2 |
2 |
0 |
24 |
2 |
– |
2 |
5 |
|
19 |
2 |
8 |
2 |
2 |
0 |
5,072 |
2 |
– |
0 |
10 |
|
20 |
140 |
3 |
2 |
0 |
2 |
1,886 |
3 |
– |
0 |
14 |
|
21 |
12 |
2 |
2 |
5 |
2 |
30 |
0 |
– |
0 |
5 |
|
22 |
30 |
0 |
0 |
14 |
0 |
597 |
0 |
– |
0 |
19 |
|
23 |
108 |
5 |
2 |
0 |
2 |
6 |
3 |
– |
2 |
11 |
|
24 |
102 |
0 |
0 |
3 |
0 |
5 |
2 |
– |
3 |
8 |
|
25 |
‡0 |
5 |
2 |
11 |
DM 0 |
3 |
3 |
– |
5 |
13 |
|
26 |
– |
0 |
2 |
2 |
0 |
6 |
2 |
– |
0 |
3 |
|
27 |
– |
2 |
0 |
5 |
0 |
5 |
2 |
S 6 |
0 |
5 |
|
28 |
‡12 |
0 |
0 |
2 |
0 |
5 |
0 |
42 |
0 |
10 |
|
29 |
70 |
0 |
0 |
3 |
0 |
54 |
0 |
38 |
65 |
3 |
|
30 |
63 |
2 |
2 |
5 |
0 |
3,336 |
0 |
24 |
131 |
11 |
|
Jul 1 |
10 |
0 |
0 |
10 |
0 |
*52 |
0 |
12 |
388 |
7 |
|
2 |
27 |
2 |
0 |
8 |
0 |
115 |
0 |
8 |
145 |
2 |
|
3 |
0 |
0 |
0 |
5 |
0 |
8,933 |
0 |
32 |
5 |
0 |
|
4 |
0 |
2 |
0 |
8 |
‡2 |
4,345 |
0 |
12 |
0 |
0 |
|
5 |
2 |
– |
0 |
2 |
– |
2,448 |
7 |
3 |
17 |
0 |
|
6 |
0 |
– |
2 |
2 |
– |
1,045 |
0 |
8 |
3 |
5 |
|
7 |
2 |
0 |
2 |
5 |
– |
*1,557 |
2 |
2 |
68 |
13 |
|
8 |
2 |
2 |
0 |
8 |
– |
6,268 |
0 |
8 |
20 |
20 |
|
9 |
7 |
5 |
0 |
5 |
– |
*122 |
3 |
3 |
5 |
0 |
|
10 |
2 |
3 |
0 |
0 |
– |
*93 |
2 |
5 |
0 |
3 |
|
11 |
2 |
2 |
0 |
13 |
|
3,970 |
3 |
5 |
|
0 |
|
12 |
0 |
2 |
|
2 |
|
48,878 |
|
5 |
|
5 |
|
13 |
0 |
12 |
|
23 |
|
48,230 |
|
7 |
|
18 |
SSpore trapping started on this date.
DMDisease was found in the county on this date.
*Spores present but soil
prevented accurate count.
‡Partial day.
Adam Montri and
John Biernbaum
Horticulture
Using protected cultivation for extended season production is not a new
idea. But given the current environment of reduced availability and increased
cost of fuel together with increased emphasis on farm profitability and local
economy, it is one that has the potential for new impact. Farmers and
researchers alike have recognized the benefits these simple structures provide.
There are a number of reasons why we would be interested in growing
year-round, but some of the main points often cited include increasing farm
viability by creating income throughout the year; increasing availability of
fresh, healthy, local produce; decreasing farmer workload in the summer months;
decreasing energy dependency for food transportation; and keeping dollars in
the local economy to name a few.
While there are many names to describe season extension structures
including hoophouse, hightunnel, coldframe and unheated greenhouse, we tend to
use the title Passive Solar Greenhouse (PSGH). While all are typically metal
framed, poly-film covered structures, a PSGH is covered by two layers of
inflated 6-mil greenhouse plastic. Most importantly, PSGHs are unheated,
passively ventilated, have no supplemental lighting, and are designed with the
intent to grow throughout the year, even in northern climates. PSGH may conjure
the image of a custom built “bioshelter” with an insulated north wall and water
for heat storage to prevent freezing. That
is not what we mean! We want off-the-shelf, low cost, simple construction (View images of the PSGH
at the MSU Student Organic Farm.) Freezing conditions are not a problem for
winter crops. The structure and moisture on the plastic film work like a cloud
to trap the heat of the soil in the greenhouse so the soil does not freeze.
Risk management reduction is also a major reason for employing these
structures. While risk management can mean many things, we think of 1) soil
health/organic matter, 2) crop diversity, 3) direct marketing and 4) season
extension.
Promoting soil health is a basis of organic production systems and is
integral to successful agriculture regardless of production system. Increases
in soil organic matter, often through compost applications in the PSGHs and by
cover cropping in the field, can improve soil health and subsequently benefit
plant health. Increases in soil organic matter improve water absorption and
water holding capacity, thereby mitigating runoff common during heavy rains and
buffering the effects of drought. In the PSGH, soil organic matter
contributions to moisture availability are important for the rapid growth under
the protected conditions. The soil organic matter is also the primary source of
nutrients. A steady and somewhat limited supply from biological availability
can maintain production without leading to lush, damage susceptible growth.
From experience, it is safe to say that nearly all crops grow better in
the properly managed PSGH than in the field. That being said, it is important
to determine which crops are worthwhile to grow in such valuable space. While
we could grow only tomatoes in the spring, summer and fall, by doing so we risk
losing the entire crop if there is a crop failure. By increasing crop diversity
in the PSGH we are able to reduce risk. Peppers, summer squash, eggplant,
melons and basil are crops that do well in the summer season PSGH. Cutflowers
and herbs can also be profitable. What we are growing is dependant upon the
season. We are not talking about tomatoes in December. For the winter, cold
tolerant crops like spinach, kale, chard and dozens more are good choices.
There is still time for early tomatoes—our first this year were harvested on
June 14.
By selling directly through CSAs, farmers’ markets, restaurants, and
on-farm markets, more of the dollar comes back to the farmer. While this is not
exclusive to PSGH producers, the structures allow farmers to offer customers
something unique and to keep customers buying all year. Production in the PSGH
is still susceptible to weather variations and can be used as a tool to teach
customers about the impacts of weather on production.
Another advantage of the PSGH is the potential to decrease disease and
insect pressure. Many of the fungal diseases common in the field have lower
incidence in the properly managed PSGH as the plastic covering excludes rain
and therefore minimizes the wet foliage environment under which fungal diseases
prosper. There is also a marked decrease in insect pressure within the PSGH
with good techniques such as sanitation and crop rotation.
As the use of these structures increases, more questions have been asked
about the economics of year-round production. The C.S. Mott Group for
Sustainable Food Systems at
For technical assistance related to structures, crops or other questions
about year-round production in PSGHs, please contact Adam Montri at
517-432-3381 or admontri@anr.msu.edu.
One quarter of the
“Conserving Native Bees on Farmland” (E-2985) provides straightforward information about creating attractive environments for native bees. The bulletin teaches the reader about various native bee species and gives recommendations about nesting sites and food resources.
Honeybees are the most economically important pollinator and are used widely for pollinating crops, but they are also susceptible to diseases and parasites. Colony collapse disorder is a mysterious condition that has appeared recently in which adult honeybees abandon their hives for what appears to be no reason at all.
“With honeybee health problems, focusing on native bees is a strategy to reduce the risks of sole dependence on honeybees,” said Rufus Isaacs, associate professor of entomology. “Our goal is to help growers make sure they can pollinate their crops and have reliable production on their farms every year.”
Entomology graduate student Julianna Tuell did native bee research with 13 growers in conventional blueberry farms and semi-abandoned blueberry fields. She studied a variety of native bees, their habitat needs and feeding preferences. The bulletin compiles her research into recommendations for farmers, gardeners and anyone growing crops that rely on bees for pollination.
“The native bees contribute to pollination, but they won’t replace honeybees,” Tuell said. “The good news is that native bees do not seem to be affected by colony collapse disorder, perhaps because they do not live in large colonies.”
“Conserving Native Bees on Farmland” (E-2985) can be purchased through the MSU Bulletin Office for $2 per copy by calling 517-353-6740 or visiting http://www.emdc.msue.msu.edu/. Discounts are available if the bulletin is purchased for use with MSU Extension programming. You can also print and view a copy through the pdf file at: http://www.nativeplants.msu.edu/pdf/E2973.pdf
Project GREEEN (Generating Research and Extension to meet Economic and Environmental Needs) funded the entomology research and also supported another new bulletin describing the relationships between native plants and beneficial insects. “Attracting Beneficial Insects with Native Flowering Plants” (E-2973) was written by Isaacs and Tuell, along with MSU entomology researchers Douglas Landis and Anna Fiedler.
Visit http://www.nativeplants.msu.edu for more information on MSU native plant and beneficial insect research. A companion site helps identify natural enemies in crops.
(This news release provided by one of the project funders,
Project GREEEN, a cooperative effort between plant-based commodities and
businesses together with the Michigan Agricultural Experiment Station, MSU
Extension and the Michigan Department of Agriculture. To learn more about