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To: sanet-mg@ces.ncsu.edu
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From: Charles Benbrook <cbenbrook@igc.apc.org>
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Date: Mon, 18 Apr 1994 08:15:50 -0700
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Cc: atl@igc.apc.org, cbenbrook@igc.apc.org, ccof@igc.apc.org, cmellinger@igc.apc.org, jcbloome@ucdavis.edu, liebman@uclink.berkeley.edu, mmellinger@igc.apc.org, psyltie@igc.apc.org, pweddle@igc.apc.org, tforster@igc.apc.org
4/18/94
Note to Sanet --
From: Chuck Benbrook
A very important article has recently been published as a
letter in the journal "Phytopathology" (Vol. 84, #3, 1994, pages
222-225), entitled "Root Camouflage and Disease Control" (by
Gregory Gilbert; Jo Handelsman; Jennifer Parke). It explains a
mechanism whereby certain soils can become disease suppressive.
The implications are exciting, and make a great deal of sense in
light of the insights emerging in the growing literature on
microbial biocontrol of plant pathogens. While there has been a
resurgence of interest in disease suppressive soils (actually,
farming systems that render plant-soil interactions less vulnerable
to yield loss caused by disease), there is little understanding of
the mechanisms within soil microbial communities that give rise to
observed instances in which some soils, under certain
circumstances, become disease suppressive. Scientists world wide
are searching for answers to what characterizes a disease
suppressive from a disease supportive soil, for obvious reasons
(they want to replicate via management or an input the state that
gives rise to disease suppressiveness). The above letter provides
a cohesive explanation for a process that may, in fact, be one of
the major mechanisms of disease suppressiveness.
I don't want to spoil the show or steal their punch-line, but
the letter explains the differences between bacteria populations in
the rhizosphere in contrast to root-free soil. Certain ubiquitous
pathogens are clearly "turned on by" the exudates and other
microbial activity unique to the rhizosphere. But when the
microbial activity in the root-free portions of the soil profile is
closer to the activity in the rhizosphere, pathogenic
microorganisms seem less inclined to attack roots, hence the use of
the word "camouflage" in the letters title. Any management
practice that elevates general microbial activity and complexity
throughout the soil profile will tend to contribute to this effect.
I recommend this article to anyone interesting in the science base
of disease suppressive farming systems. And congrats to the
authors for breaking some real ground!
Article 417 of triangle.gardens:
Path: bigblue.oit.unc.edu!concert!news.duke.edu!acpub.duke.edu!pdrh
From: pdrh@acpub.duke.edu (Peter Doyle Higgins)
Newsgroups: triangle.gardens
Subject: seed starting by presprouting
Date: 2 Apr 1994 12:59:08 GMT
Organization: Duke University; Durham, NC; USA
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Keywords: seeds, germination, presprouting
I'm experimenting with presprouting, a method I read about in *Square Foot
Gardening*, by Mel Bartholomew. So far, I seem to be having excellent success.
The idea is that it is difficult to put seeds directly into the ground and
maintain the appropriate temperature and moisture to achieve germination,
yet many plants' root systems don't tolerate transplanting very well. This
method is supposed to produce maximum germination under controlled conditions
before transferring sprouts to the ground.
You start by wetting a paper towel and wringing it out to dampness,
then folding it to a size that will fit into your ziplock bag. Slide the paper
towel into the bag, spread your seeds on top of it, seal the bag ad put it in a
warm place - top of a refrigerator or a hot water heater. On my hot water
heater, I'm getting 90-100% germination, and I've just moved these sprouts to
the outdoors, where I've spaced them for their eventual size (no thinning)
three seed widths below the surface in some moist seed starting mix.
According to Mel, these sprouts should push through to the surface in just a
few days, and be off and running.
I've always hated low germination rates and thinning perfectly good
plants - what a waste of seed! This seems to be an excellent solution. As
Mel would say (it really is a good book to get from the library), why use
high volume commercial methods for your low volume home garden?
I just hope we've seen our last frost - last night, April 1 in Durham,
we saw Frosty again!
(1845) Mon 20 Apr 92 22:02
Re: Florida Commercial Vegetable Transplant Producers (from PennPages)
FLORIDA COMMERCIAL VEGETABLE TRANSPLANT PRODUCERS
Florida Cooperative Extension Service, University of Florida
Charles S. Vavrina
Greater than 200 million total production volume:
Speedling, Inc. P.O. Box 7220, (813) 645-2543
Sun City, 33570 FAX 645-1906
Vegetables, Tobacco, Ornamentals
Speedling, Inc. P.O. Box 307 (904) 793-6700
Bushnell, 33513 FAX 793-3410
LaBelle Plant P.O. Box 399 (813) 675-2020
LaBelle, 33935 FAX 675-6052
Tomato, Tobacco, Pepper, Watermelon, Cantaloupe
100 to 200 million total production volume:
CollierGro Hwy 29, P.O. Box 379
Immokalee, 33934 (813) 657-6141
Watermelon, Cantaloupe, Tomato, Pepper, Cabbage
Plants of Ruskin P.O. Box 994
Ruskin, 33570 (813) 645-2528
Vegetables
50 to 100 million total production volume:
Bonnie Plant Farm 3505 Lake
Tohopekaligs Rd.
St. Cloud, 32769
Broccoli, Cabbage, Cauliflower, Eggplant, Lettuce,
Pepper, Tomato
Classie Plants Inc. P.O. Box 1653
Palmetto, 34220 (813) 723-1804
Tomato, Pepper, Cabbage, Watermelon, Broccoli, Onion, Celery
Johnny Johnson Greenhouses P.O. Drawer Zero
Immokalee, 33934 (813) 657-4779
Tomato, Pepper, Watermelon, Cantaloupe, Lettuce, Beets
Knox Nursery, Inc. 4349 N. Hiawassee Rd.
Orlando, 32818 (407) 293-3721
Pepper, Tomato, Squash, Watermelon
The Plant Farm 12638 Fruitville Rd. (813) 371-1179
Sarasota, 34240 (813) 371-1174
Tomato, Pepper
Redi Plant #21 6-L Farm Rd.
Naples, 33961 (813) 774-6030
Tomato, Pepper, Watermelon
1 to 50 million total production volume:
ABC Farms, Inc.
Veg. Transplant Div. 807 E. Main St.
Immokalee, 33934 (813) 675-1394
Tomato, Peppers
Barfield Produce P.O. Box 1089
Immokalee, 33934 (813) 657-3611
Tomato, Peppers
Chastain Farms 37800 Wash. Loop Rd.
Punta Gorda, 33982 (813) 639-6861
Watermelon, Cabbage
A. Duda & Sons, Inc. P.O. Box 95
Lake Jem, 32745 (904) 383-6111
Celery, Carrots, Corn, Lettuce
Elsberry Farms 101 Big Bend Rd.
Ruskin, 33572 (813) 677-6221
Tomato, Pepper, Onion, Strawberry
Harlee Farms Rt. 1, Box 437-G
Myakka City, 34251 (813) 722-7747
Tomato, Watermelon
Hyatt Farms 26689 E. Hwy. 60
Lake Wales, 33853 (813) 692-1361
Watermelon, Pepper, Eggplant, Tomato
Jack Lee Farms Rt. 1, Box 418
E. Palatka, 32131 (904) 328-5315
Potato, Squash
Long & Scott Farms P.O. Box 65
Mt. Dora, 32757 (904) 383-6900
Cabbage, Onion, Corn, Potato
S. Authur Peterson of Florida 5530 W. Atlantic Ave.
Delray Beach, 33484 (407) 498-3500
Tomato, Pepper, Eggplant, Cabbage
Picolata Produce P.O. Drawer 200
Elkton, 32033 (904) 824-1600
Potato, Broccoli, Turnip, Pepper, Collard, Mustard,
Spinach, Kale
Putnam Farms Rt. 1, Box 229
San Mateo, 32187 (904) 328-4553
Cabbage, Potato
Slingerland's Flower Haven 175 S. Orchard St.
Ormond Beach, 32174 (904) 677-4481
Tomato, Pepper, Broccoli, Brussel Sprouts, Tomato
Superior Plant Co. Jim Myers
15000 Old Rt. 41 N.
Naples, 33963 (813) 455-1560
Tomato
Canal Road Greenhouse P.O. Box 1087
Palmetto, 34220 (813) 722-8697
Tomato
Earl Williams Farms Rt. 3, Box 95
Graceville, 32440 (904) 638)7452
Cole Crops, Chinese Cabbage
Zarella Farms P.O. Box 1139
Stuart, 34997 (407) 287-0707
Cabbage
Zellwin Farms Co. P.O. Box 188
Zellwood, 32798 (407) 886-1891
Escarole, Endive, Lettuce, Napa, Cabbage, Onion, Cauliflower
Less than 1 million total production volume:
Benedict Farm 3605 Darby Rd.
New Smyrna Beach, 32168 (904) 427-1410
Cabbage, Pepper, Kale, Lettuce, Watermelon
Brown's Farm Rt. 2, Box 127
Hawthorne, 32640 (904) 475-2015
Onions, Peppers
Flint Farms Rt. 2, Box 675
Arcadia, 33821 (813) 494-5277
Tomato, Watermelon, Cabbage
Marion & Marvin Fussell, Jr. Rt. 2, Box 252
Webster, 33597 (904) 793-2142
Eggplant, Pepper
Carlow Gutschlag Farm P.O. Box 1067
Fairfield, 32634 (904) 629-6358
Pepper, Eggplant, Tomato
Hart's Plant Nursery 1404 Blair Rd.
Jacksonville, 32221 (904) 781-7910
Mixture of Vegetables
Chapman Lewis Farms 2930 SE 41st Pl.
Ocala, 32671 (904) 694-4737
Tomato, Pepper, Eggplant
Libby Nursery Rt. 1, Box 295-B
Hilliard, 32046 (904) 845-3543
Tomato, Pepper, Eggplant
Bruce McElroy Farms Rt. 1, Box 520
Newberry, 32669 (904) 493-1088
Muskmelon, Watermelon
Morton's Greenhouses Rt. 10, Box 956
Lake City, 32055 (904) 752-9280
Tomato, Pepper, Eggplant
Norris Plant Farm Rt. 1
Chipley, 32428 (904) 638-1074
Tomato, Pepper
Plant Labs was (Tri-W Farms) 5720 Hamilton Bridge Rd.
Milton, 32570 (904) 994-6022
Cabbage
Plants Inc. of Sarasota 13011 Fruitville Rd.
Sarasota, 34240 (813) 371-8998
Tomato, Pepper
Eddie Roberts Farms P.O. Box 184
O'Brien, 32071 (904) 935-1416
Pepper, Eggplant
Scherer's Plant Farm 2030 30th St. N.
Clearwater, 34620 (813) 531-2973
Vegetables
Sheffield Nursery 400 W. Ash St. (904) 584-2088
Perry, 32347 (904) 584-2914
Tomato, Pepper, Squash, Cucumber
Sunshine State Growers Rt. 5, Box 941
Tallahasee, 32301 (904)421-8444
Tomato, Pepper, Squash, Eggplant
Gary Zachary Farms P.O. Box 33
Bushnell, 33597
Eggplant, Pepper
----------------------------------------------------------------
Where trade names are used, no discrimination is intended and no endorsement by
the Cooperative Extension Service is implied.
Authors: M. D. Orzolek, Prof. of Vegetable Crops
P. A. Ferretti, Prof. of Vegetable Crops
Department of Horticulture, Penn State
Janaury 1992
PENpages Number: 09401226
-------------------------------------------------------------------
Horticulture Vegetable Newsletters
Michael D. Orzolek and Peter A. Ferretti
Department of Horticulture
Penn State University
1. Vol. 4, No. 1, 1992
(1846) Mon 20 Apr 92 22:07
Re: Environmental tips for greenhouse transplant growers (from PennPages)
ENVIRONMENTAL TIPS FOR GREENHOUSE TRANSPLANT GROWERS
Vegetable Views, University of Maryland, December 1991
David S. Ross
A number of vegetable growers have built small film plastic greenhouses to
use during the winter and spring months to start vegetable transplants needed
for their summer production. While many of these ventures have proved to be
successful, some have had problems and others might be able to make
improvements
to get better production. This article will discuss factors relating to the
structure, cover, heating, ventilation, air circulation and other environmental
control considerations. Growers should evaluate their greenhouses in terms of
the considerations given in this paper.
Structure and Cover: Simple wood frame or metal pipe frame greenhouses
can
be used, but they must be strong enough to withstand high winds or a heavy wet
snow lead. An air-inflated double poly cover gives a 30 percent energy savings
over a single cover. Air for inflating a double cover should come from the
outside to reduce the condensate between the two poly covers. Air circulation
for maintaining temperature uniformity may be difficult in long narrow
greenhouses.
Heatingthe combustion process and pollutants: Several problems can be
related to the heating system. Tomato transplants are very sensitive to some
combustion pollutants as growers have found out in recent winters.
One major source of problems in some greenhouses is the use of unvented,
direct-fired propane or kerosene space heaters. Impurities in the fuel can
cause toxic combustion products. In a tight plastic greenhouse, the oxygen may
eventually be consumed during the combustion process, leaving incomplete
combustion products and toxic pollutants. The flame may actually go out and
let
the greenhouse freeze. The use of unvented heaters is risky; at some time the
environmental conditions may be right for disastrous results to occur. In an
emergency, clean or pure fuel and extra ventilation may be adequate precautions
for short term use.
In plastic greenhouses where a vented heating system is used, a proper
flue
must be used to achieve success. The flue should extend outside and up two
feet
above the peak or ridge of the greenhouse so there is a good "draw." Heated
combustion gases must rise by convection to escape. A hot exhaust helps; an
insulated flue pipe maintains the temperature needed to cause the exhaust gases
to rise. Pollutants are largely formed at the "startup" and shutdown" of the
burner. It is important that exhaust gases flow up the flue and not be forced
back down and out into the growing space.
Sufficient oxygen must be available for complete combustion in the heating
units. A plastic greenhouse can be made very air tight. A duct from outside
the greenhouse to the rear of the combustion chamber is recommended to provide
the air (oxygen) needed. A pipe about the size of the flue pipe is adequate. A
general rule of thumb is to provide 1 square inch of fresh air inlet for each
50,000 BTU per hour capacity of the direct-fired unit.
Regular servicing of the burner, heat exchanger and air-fuel ratio
adjustment to avoid incomplete combustion will reduce ethylene production and
release of unburned hydrocarbon fuels.
Heating and air circulation: The heating unit is controlled by a
thermostat. The thermostat must be located in the interior of the greenhouse
(in the air stream but not directly in the heated air discharge). Do not mount
the thermostat on the outside wall of the greenhouse where the cold air near
the
wall will adversely affect it.
Uniform air temperatures in the greenhouse help to maintain uniform plant
growth. Wire the heater fan to operate continuously while the burner unit is
controlled by the thermostat. Add additional fans (horizontal air flow) or a
fan-perforated tube to provide continuous air circulation during the heating
season. See Agricultural Engineering FACTS 170, Greenhouse Air Circulation,
for
specific details.
Check the heater air throw distance capability to see if it is adequate to
move the heated air to the far end of the greenhouse.
Ventilation: Solar radiation can cause high temperatures in a greenhouse
during winter months. Temperature control is needed for control of plant
growth. Ventilation rates of 2 cubic feet per minute (CFM) per square foot of
greenhouse floor space for minimum winter ventilation and 8 CFM per square foot
of greenhouse floor space for summer ventilation should be provided.
Greenhouses under 5000 cubic foot in size need up to 12 CFM per square foot of
floor space for adequate ventilation.
Two speed fans or small and large fans can be used to allow different
rates
of ventilation. Motorized inlet louvers of a slightly larger size than the
fans
should be provided. Keep doors and windows closed on the end of the greenhouse
where exhaust fans are located while ventilation is occurring.
All thermostats should be located together in a shaded box about one-third
of the way across the width and down the length of the greenhouse. An
aspirated
box with a small fan blowing air across the thermostats is desirable.
Summary: Inexpensive greenhouses can be built for growing vegetable
transplants, but their success depends on the ability to control the
environment
properly. The functions of heating, ventilating, air circulation, and control
must be adequately provided.
-----------------------------------------------------------------
Where trade names are used, no discrimination is intended and no endorsement by
the Cooperative Extension Service is implied.
Authors: M. D. Orzolek, Prof. of Vegetable Crops
P. A. Ferretti, Prof. of Vegetable Crops
Department of Horticulture, Penn State
Janaury 1992
PENpages Number: 09401226
-------------------------------------------------------------------
Horticulture Vegetable Newsletters
Michael D. Orzolek and Peter A. Ferretti
Department of Horticulture
Penn State University
1. Vol. 4, No. 1, 1992
Reprinted without permission from the Fall, 1992 Bio-Dynamic News & Events
newsletters Published by the Bio-Dynamic Farming and Gardening Associaton,
Kimberton, PA (2185) 935-7797
A Report on the Seed Growing Work at Ekkharthof Farm in Switzerland:
Seed work at Ekkharthof began around the initiative of one man, Limar Randuja.
Now it is in its 19th year, but Limar began seed work in 1952, long before
coming to Ekkharthof. The seed catalog is actually in its 28th year. Only very
gradually has the seed work expanded to a wider circle of involvement. There
are now about 20 growers ranging from gardeners growing a few varieties to
farmers who plant and combine a field of a variety needed in large quantities.
The bulk of the varieties are still grown only at Ekkharthof. Originally the
hope was to provide biodynamic seed to market growers. At the time they proved
not a large or dedicated enough body of support, but there was a great interest
among home gardeners, so the seed company focused on serving the latter. Most
varieties are available in limited quantities and customers are restricted to
home garden size portions. This is gradually changing as the company expands
and a number of main crop varieties are available in commercial size lots.
The enterprise at Ekkharthof is quite small by commercial standards but well
beyond cottage industry scale. Gross sales are about 250,000 Swiss Franks (160,
000 U.S. dollars). 267 varieties of vegetable, herb, flower and cover crop
seeds are offered. Growers receive 213 bulk retail price for their seed. One
kg. is bulk size for most seed. For the last two years they have collectively
decided to put 10% of this in a fund to be redistributed yearly to help cover
unforeseen losses to growers or to the seed company. Prices of seed are high by
American standards. The seed enterprise is combined with a market garden and
with herb growing, processing and marketing. The herb business dovetails nicely
with the seed company, sharing equipment, facilities and marketing. The garden
covers about 12 acres and there are eight gardeners.
Seed cleaning at Ekkharthof involves a combination of handwork and small scale
mechanization. All of the seed cleaning can be done by hand and it is often
more practical for small batches than setting up the machinery and doing the
absolutely thorough cleaning of the machines that is necessary between batches.
Careful hand threshing and cleaning is gentler on the seed than mechanical
means and usually results in better germination and longer seed life. Timely
and careful harvesting also make a big difference with seed quality and ease of
cleaning. The primary equipment for hand cleaning is a set of round sieves
similar in size and construction to old fashioned wood and mesh garden sieves.
To handle the full range of seeds from 20 to 40 sieves of various mesh sizes
are needed. One can get by with 20 sieves and one would be very well set up
with 40 sieves. Sieves from a Swiss maker of sturdy high quality construction
cost about $35 U.S. a piece. Sieves are used for several techniques besides
screening and grading, and diameter and height of wooden hoop frame are
important as well as mesh size. There are also other very effective hand seed
cleaning devices that are easily constructed of wood, fabric, and cardboard. A
common hand cranked fanning mill with a good set of screens is also very
helpful.
Power seed cleaning machinery at Ekkharthof consists of a small but versatile
thresher, the Pelz Saatmeister, and an air, screen and indented drum cleaner,
the Mini.Petkus made by Rober of Germany. Most batches of seed larger than 2 or
3 kg. go through these two machines. All seed to be sold is brought to at least
98% purity. Most batches require additional handwork to be brought to top
market grade. Some require a great deal of handwork. There are machines that
can replace the additional handwork. Ekkharthof has not felt it necessary to
mechanize further with their scale of cleaning, but any substantial increase in
volume or batch size would require it. The next stage of mechanization would be
to add a specific gravity separator which effectively separates objects of the
same size but different densities, and an endless belt cleaner that separates
objects according to their ability to roll or slide down an inclined surface.
This would replace the bulk of further hand cleaning for most seeds. Exceptions
are damaged or moldy seeds that must be sorted out on the basis of visual
appearance. And occasionally a particular weed seed will require more
sophisticated or different cleaning methods or devices.
Further facilities include: a 16X20' room for seed cleaning; a 14X20' room with
double doors and a smooth floor for threshing; a large loft for curing and
drying; a dry cellar room with dehumidifier for drying and short-term storage
of threshed seed; another such room for longterm storage of seed stocks and
accessions; a small room for germination tests; a large room for filling seed
packets, filling orders, packaging and shipping, catalog production, record
keeping, etc.; a small office; a cool greenhouse for overwintering half-hardy
biennials and perennials, and cold frames for the same purpose.
Small equipment includes: accurate scales; dehumidifiers, hygrometers,
thermometers; drying screens and a large dryer shared with herb and food
processing; a large collection of tubs and trays, cloth bags, canisters and
crates; a computer for address labels, records, catalog production, etc.; and
there is also all the equipment that goes with an intensive diversified 10 acre
market garden, all of which contributes to the seed growing as well.
Considerable shed and cellar space is devoted to storage of packaging and
shipping supplies, crates, nets, fabric, plastic tunnel and greenhouse
supplies, stakes, trellises, irrigation equipment, etc.
All breeding work done at Ekkharthof is pretty much standard line selection.
Some growers do a little breeding work and some maintain their own stock seed,
while others use stock seed Ekkharthof provides. Some intensive breeding work
is done, for example 26 lines from one original Brussels sprout variety, two of
which are now quite distinct selected varieties. Some things are simply grown
and harvested with no selection work at all. Garden cress and some of the
herbs, flowers and cover crops fall into this category. Some varieties have
been intensely rogued for a number of years until they reached a desirable
stable condition, and will probably not be selected again unless and until they
show characteristics that would warrant it. Examples are some of the beans. For
some of the varieties there is ongoing breeding work and selection, but some or
all of the final multiplication is done without selection. Most vegetable
varieties have ongoing breeding work. Most intensive positive selection is for
breeding work and stock seed, but there is some surplus that goes into the mix
to be sold. Most seed sold has had at least negative selection (roguing) in its
final multiplication. Seeds selected out of produce plantings are positively
selected but the intensity of selection varies widely according to size of
planting and number of seeds produced per plant.
As a seed company with a cooperative of growers, Ekkharthof is not without its
problems: Things like crop failures; seeds that come back from growers full of
dirt or weed seeds; seeds damaged by combining, moisture or insects; seeds a
grower has taken on but never managed to plant or forgot to harvest in time;
and so on. There are safety measures like keeping reserve seed and spreading a
variety among more than one grower. The cooperative of growers also becomes
more experienced, dependable and professional every year. Despite these
problems Ekkharthof is known as an excellent source of high quality, dependable
open-pollinated organic/biodynamic seeds. Ekkharthof is large and diversified
enough, and well enough organized and managed to weather these problems and
still maintain its reputation.