28TH F I ELD
AGRICULTURAL RESEARCH AND EDUCATION CENTER
APRIL 17, 1986
OOT 4 1987
HASTINGS AREC RESEARCH REPORT HAS1986-1
PROGRAM 28TH FIELD DAY
AGRICULTURAL RESEARCH AND EDUCATION CENTER
THURSDAY, APRIL 17, 1986, 1:00 PM
Presiding Jim Dilbeck, St. Johns County Extension Director
Welcome and Potato Outlook
Nitrogen Efficiency Studies 1
D. R. Hensel, Center Director
Improving Energy and Water Use Efficiency of Seepage
Irrigation Studies 2
Dorota Haman, Asst. Prof. Agricultural Engineering Dept.
Potato Variety Development 3
Herbicide Trial and Growth Regulatory Test 6
J. R. Shumaker, Assoc. Professor
Potato Yields Following Use of Soil Fumigants in NEF
during 1984 and 1985 7
Disease and Nematode Control-- Field Experiments in Progress 13
D. P. Weingartner, Assoc. Professor
Cabbage Alternaria Leafspot Studies
Dominic Fontem, Plant Pathology Graduate Student
Tour of plots
Refreshments courtesy of ASGROW FLORIDA CO., FARM CREDIT SERVICE,
HASTINGS FARM CENTER, INC., HELENA CHEMICAL CO. and WISE FOODS.
Nitrogen Efficiency Study on Potatoes
D. R. Hensel, Center Director
Cooperator: S. J. Locascio, Professor, Vegetable Crops IFAS
Nitrogen is a primary nutrient for most horticultural and agronomical
crops. It is usually the most costly nutrient applied in fertilizer. Except
for the mucks and organic soils, Florida soils are deficient in nitrogen
and require heavy applications for maximum yields. Nitrogen is considered
a mobile element in the soil in the form of nitrate. It will move with
the moisture in the soil profile. Excessive applications can result in
nitrates being discharged into drainage waters which could create
environmental concerns. Considering the above factors, the objective of
this study is to determine which rate, form, and time of N application will
achieve the maximum efficiency of N. This may or may not be the maximum
The treatments for this study are:
% N in NO3 form 5, 25, and 45
N application Rate 100, 200, and 300 Ibs/A
% N applied at planting 0, 33, and 67
The treatments were placed in a 3x3x3 factorial design experiment. In
order to monitor N uptake, leaf samples will be taken at three intervals
during the season. Before leaf drop, whole plant samples will be taken
for N content. Yields will be taken at harvest along with specific gravity
and other quality factors. Total N uptake will be determined and compared
with the various treatments to determine which one is most efficient.
Experimental area was treated with Telone 6 gpa soil fumigant 3 weeks
prior to planting. All plots were given a basic application (in Ibs/A)
of 25 P205, 150 K20, 50 MgO, and 25 of micronutrients. The basic application
of fertilizer and appropriate N treatment were mixed and banded at planting.
Atlantic seed (2 oz.) was hand placed 8 inches apart on February 14, 1986.
Temik (3.0 ai/A) was placed on the open rows and covered immediately.
Sencor" (0.5 ai/A) was applied as pre-emergence herbicide. Side dressing
application of the N treatments were made on March 19 which was 33 days
IMPROVING ENERGY AND WATER USE EFFICIENCIES OF SEEPAGE IRRIGATION SYSTEMS
Dorota Z. Haman, Asst. Professor, Agricultural Engineering Department
University of Florida
Cooperators: D. R. Hensel, Center Director, Hastings AREC
Allen G. Smajstrla, Assoc. Prof., Agricultural Engineering Dept.
Fedro S. Zazueta, Asst. Prof., Agricultural Engineering Dept.
Runoff from a seepage irrigated field reduces irrigation system
application. In Florida seepage irrigation application efficiency is often
estimated to be 50%, but it may range from 20% to 60% depending on runoff
and other site-specific factors. Through collection and recycling of runoff
water significant savings of water and energy can be achieved. Early
estimates from this project indicate that approximately 60-70% of the
irrigation water and 30-40% of the energy used for pumping can be saved
through the implementation of a recycling system. The project at the
Yelvington Research Farm demonstrates the functioning and reliability of
a water recycling and control system. The control system has the advantage
of being relatively low cost, so that in many cases its cost can be recovered
in the first year of operation. The system requires a second pump. for
recycling of runoff water. However, because of the low pumping lift, its
pumping cost is less than that of the primary pump (deep well), therefore
the energy requirement for the operation of the recycling pump is
Construction of a collection ditch or pond at the site is necessary.
At the AREC Hastings site, another collection ditch was constructed just
to keep runoff water from this project separate. In most cases the existing
drainage ditch can be used. The recycling pump is placed inside the
collection structure and operates automatically when a float switch preset
for operation of the pump at a given water level closes.
Another major advantage of the system is significant reduction of pumping
from the acquifer. By using runoff water for irrigation, ground water pumping
is reduced, thus conserving a valuable natural resource, and reducing the
deterioration of water quality due to excessive pumping.
The control system at Yelvington Research Farm will operate throughout
the growing season, and data related to water and energy savings will be
collected. Results will be available from the Department of Agricultural
Engineering and the Hastings Agricultural Research and Education Center.
J. R. Shumaker, Assoc. Horticulturist
Methods. Potato varieties and seedlings were tested for their adaptability
and desirable horticultural characteristics at the Agricultural Research
and Education Center, Hastings, Florida. Clones were grown in advanced
trials (four replications). Telone (6 gpa preplant) and Temik (3 Ib
ai/A in-the-row at planting) were applied to all trials. Seed was spaced
12 inches apart in 20 foot single row plots. Between row spacing was 40
inches. The crop was planted in early February and harvested in late May.
Processing Varieties. Sebago and Atlantic are the standard chip processing
varieties in this area (Table 1). Sebago is tolerant to bacterial wilt
(tuber brown rot) disease but susceptible to corky ringspot disease.
Atlantic is susceptible to both diseases, and therefore, should not be
planted on land that has a history of bacterial wilt disease. Belchip
has produced highly desirable tuber yields and chip processing traits when
compared with Atlantic and Sebago. Since it matures about a week later
than either standard variety, Belchip is recommended for grower evaluation
in a late production program. Like Atlantic, it should not be planted
on land that has a history of bacterial wilt.
White Table Stock Varieties. La Chipper, Superior and Late Superior (a
later maturing strain of Superior) are the standard varieties grown for
the white table stock market. While they are generally considered not
acceptable for chip processing, they do demonstrate excellent fresh market
traits. La Chipper has some tolerance to bacterial wilt disease but is
susceptible to corky ringpost disease. Both strains of Superior are
resistant to corky ringspot disease but susceptible to bacterial wilt.
Ontario produced some of the higher yields, has a high degree of tolerance
to bacterial wilt and is recommended for grower trials.
Table 1. Four-year summary comparing potato varieties for yield,
specific gravity and chip color.
Yield US 1A
Variety 85 84 83 82 Mean
Sebago 265 186 217 276 236
Atlantic 256 243 192 293 246
Belchip 248 214 152 246 215
Norchip 205 135 170
La.Chipper 244 296 149 285 243
Late Superior 144 173 86 212 154
Superior 120 176 87 189 143
Ontario 214 249 232
Centennial 175 226 117 184 176
Russette 172 245 151 224 198
85 84 83 82 Mean
Sebago 1.061 1.079 1.066 1.057 1.065
Atlantic 1.076 1.083 1.078 1.074 1.078
Belchip 1.068 1.073 1.074 1.069 1.071
Norchip 1.066 1.078 1.072
La Chipper 1.070 1.071 1.067 1.067 1.069
Late Superior 1.074 1.075 1.069 1.068 1.072
Superior 1.070 1.072 1.067 1.066 1.069
Ontario 1.064 1.072 1.068
Centennial 1.065 1.073 1.062 1.055 1.064
Russette 1.074 1.065 1.076 1.064 1.070
85 84 83 82 Mean
Sebago 3.3 4.0 3.8 3.8 3.7
Atlantic 2.8 3.7 5.5 2.8 3.7
Belchip 3.0 2.3 3.0 2.2 2.6
Norchip 3.8 2.0 2.9
La Chipper 2.6 4.0 3.8 3.0 3.4
Late Superior 2.6 2.7 5.8 3.6 3.7
Superior 3.6 3.7 5.3 2.8 3.9
Ontario 4.8 4.0 4.4
*Chip color determinations made 1, 2 and 3 weeks after harvest. Color
rated 1-2 = very light color, highly desirable; 3-4 = moderately light
color, no marketing problem; 5 = brown color, borderline; 6-9 = brown
to black color, unmarketable.
Russet Varieties. Centennial, standard russet-skin variety, and Russette
produced the highest tuber yields. Tubers from both clones are considered
oblong in shape.
Current Studies on Potatoes.
Potato Variety Trials
Sponsored by Potato Chip/Snack Food Association
Raw product quality is of major importance to the potato chip industry
and potato plant breeders are continuously striving to develop new cultivars
with improved production, storing, and processing qualities. The objective
of these trials will be to cooperate with potato breeders in the enhancement
of the testing, development of management profiles, and the introduction
of advanced seedlings--which are the most promising-for the potato chip
Clone No. Clone
Red La Soda
Pre March 4
Post March 19
Planting date February 14
Growth Regulatory Test
On Seed Piece
1 qt. Compleasal/A
16 fl. oz. Respond
24 fl. oz. Respond
16 fl. oz.
24 fl. oz.
Planting date February 18
Potato Yields Following Use of Soil Fumigants in NEF during 1984 and 1985.
D. P. Weingartner Assoc. Prof. (Plant Pathologist)
J. R. Shumaker Assoc. Prof. (Horticulturist)
Introduction: Nearly all of the potato acreage in northeast Florida (NEF)
is treated with nematicides. Nematicides available to growers can be divided
into two categories: soil fumigants and nonfumigants. Based on efficacy
and handling characteristics, both groups of nematicides have strong points
and short comings. Soil fumigants: must be applied several weeks before
planting due to phytotoxicity; are most effective when soil is warm and dry;
provide rapid, effective control of all nematodes found in NEF-soils; are
mainly dissipated by planting and therefore provide no additional residual
control of nematodes and other pests during the growing season; delay onset
of bacterial wilt; reduce incidence of verticillium wilt; do not control
corky ringspot disease (CRS) and can actually result in an increase in
incidence of CRS. Nonfumigant nematicides: can be applied at planting; are
most effective when soil is moist; remain residual during the season. and
systemically control some insects; provide varying degrees of nematode control
depending upon nematode group; some provide effective control of CRS; do
not provide effective control of bacterial wilt. Chemicals belonging to
both categories of nematicides have been detected in groundwater adjacent
to or within potato fields in some potato producing areas.
Use of nematicides was gradually adopted as a standard practice by NEF potato
growers during 1968 1978. Soil fumigants were the first nematicides
commercially available. DD and EDB were vigorously marketed in NEF during
the late 1960's and early 1970's. Phytotoxicity associated with use of EDB
during the 1971 potato season temporarily restrained its acceptance by growers.
The fumigant of choice by potato growers during 1971-73 was DD. Subsequently
DD was replaced by Telone and EDB because lesser volumes of the latter two
fumigants were required and EDB had a decided price advantage. During 1974
and 75 the nonfumigants ethoprop (Mocap) and carbofuran (Furadan ) received
state labels for use in Irish potatoes, however, before either was widely
used, aldicarb (Temik) received nationwide clearance and was available for
grower use in 1975. Temik rapidly gained acceptance and within three years
was used on >80% of the NEF potato acreage. It is presently used on nearly
all nonrestricted potato acreage in NEF. Some growers striving for top tuber
quality as well as tonnage have used soil fumigants, notibly EDB (until its
removal from use in 1983) and Telone II in combination with Temik.
Both soil fumigants and nonfumigant nematicides play important roles in
managing soil borne diseases of potatoes in NEF. Our long term data document
that loss of all nematicides would result in a yield reduction of 15-20%
for the entire NEF production area. Due to reports of groundwater
contamination, toxicity and/or carcinogenicity to laboratory animals use
of many soil applied chemicals has been restricted or eliminated by regulatory
agencies. The soil fumigants DD, EDB, and DBCP either due to regulation
or manufacturer withdrawal are no longer available. Aldicarb, 1,3D and some
other nematicides have been under intense scrutiny. Because of public and
legislative concern for potential contamination of potable water with
pesticides and other chemicals and high solubililty and mobility of most
nematicides in water, long term availability of some nematicides is
uncertainl. For this reason one short range objective of nematode and soil
borne disease control research for the past three years has been to determine
the relative efficacy of nematicides not previously tested in NEF. This
report summarizes portions of data obtained on use of Busan 1020.
The chemical name of Busan 1020 is metham sodium and it is chemically
identical to the widely known Vapam. Metham sodium is widely used in potato
production in Washington and Oregon where it is applied in large volumes
of water using central pivot irrigation systems. It is applied at 50 to
>75 gallons chemical/acre for nematode and soil borne disease control at
a cost of $300 >450/acre. This method of application both from economic
and practical standard points is not suited to NEF. Even though metham sodium
has generally been ineffective in other areas of the US when soil injected
it was decided that injection of low rates of the chemical using multiple
chisels/row might be effective in the ridged row system of production used
1/ In Florida groundwater is defined as water in the first saturated zone.
The water table in most NEF potato fields is maintained at <20 in.during
the production season, with the first saturated zone being several inches
above the water table. Therefore, by definition, any pesticide applied
to the soil in NEF potato production could be found in groundwater. To
date, however, no pesticide has been found in any shallow drinking wells
adjacent to or within NEF potato fields. Aldicarb, however, has been
detected in runoff water from potato fields following rain.
Although there is some variation in the yield data presented in Tables 1-3,
several generalizations can be made:
1. During 1984 yields following application of the 15 gallon
rates of Busan 1020 were less than those following the
45 gallon rate.
2. Yields following application of Busan 1020 during 1984
were > those following applications of Telone II or Telone
3. Yields following applications of the 10 gallon rate of
Busan 1020 during 1985 were < than those following use
of the 20 and 30 gallon rates. There were no differences
in yields following applications of the 20 and 30 gallon
4. Yields of the 20 gallon and 30 gallon rates of Busan 1020
during 1984 (Tables 3 and 4) were > those of the 10 and
15 gallon Telone II treatments.
to Potato Growers
Based on these observations metham sodium is suggested for grower trial using
a minimum rate of 20 gallons/acre delivered by at least two chisels/row.
Metham sodium has not controlled CRS at any rate tested. Control of bacterial
wilt is inconclusive. Therefore metham sodium is suggested for nematode
Table 1. Yields (cwt/A) of Atlantic and Sebago Size A potato tubers following
fumigation with two dosages of Busan 1020, Telone II and Telone C-17 both alone
and in combination with Temik 15G. 1984 Experiment.
Low High Low High Fumigant
Nematicidel/ 2/ 3/ rate rate rate rate averages
Busan 1020 122 154 141 184 150
Busan 1020 + Temik 133 149 153 184 155
Av. Busan rates 128 152 147 184 153
Av. cultivars 140 166
Telone II 117 125 140 130 128
Telone II + Temik 127 135 137 141 135
Av. Telone rates 122 130 139 136 132
Av. cultivars 126 138
Telone C-17 141 138 129 152 140
Telone C-17 + Temik 145 144 135 141 141
Av. Telone C-17 rates 143 141 132 147 141
Av. cultivars 142 140
Av. cultivars/exp 136 148
1/ Respective low and high in-row (row spacing of 40 in) rates of fumigants
were Busan 1020 15 and 45, Telone II 6 and 12, and Telone C-17 7.25 and
14.5 gallons/acre. Low rates of all fumigants were applied with a single
chisel/row. High rate of Busan 1020 was applied using three chisels/row
whereas Telone II and Telone C-17 were applied with two chisels. Temik
15G was applied at 20 Ib acre in-the-row.
2/ Yields were reduced due to crop injury resulting from allowing insufficient
waiting period between fumigation (2/3-6/84) and planting (2/20/84). The
test was replanted 3/9/84.
3/ The only significant (P = .05) treatment effects among treatments were
those of fumigants and rates of fumigants. Additional data are shown for
comparison with 1985 data.
Table 2. Yields (cwt/A) of Size A Atlantic and Sebago potato tubers following
fumigation with three rates of -Busan 1020 and Telone II both alone and in com-
bination with Temik 15G. 1985 Experiment. 1/
Atlantic Sebago Nematicide
Nematicide IX 2X 3X 1X 2X 3X averages
Busan 1020 168 178 172 144 151 148 160
Busan 1020 + Temik 182 189 193 162 175 174 179
.--Av. Busan dosage 175 .184- .183-.--. 153 163 161 .. ..170 _.
Av. cultivars 181 159
Telone II 145 161 -161 136 131 140 146
Telone II + Temik 177 167 169 159 154 157 164
Av. Telone II dosage 161 164 165 148 143 149 155
Av. cultivars 163 147
Temik 184 145 165
Nontreated 154 141 148
1/ Yields are not corrected for incidence of corky ringspot disease. Data
shown were taken from an experiment having three additional fumigation
treatments. Analyses of variance showing significant fumigant, rate of
fumigant, nematicide, variety and variety x nematicide effects was performed
on the entire experiment.
2/ Busan 1020 1X = 10 gallons/acre delivered via one chisel; 2X = 20 gallons/
acre via two chisels; 3X = 30 gallons/acre via three chisels; Telone II
1X = 5.0 gallons/acre via one chisel; 2X = 10 gallons/acre via two chisels
and 3X = 15 gallons/acre via three chisels. Temik 15G applied at 20 lb/acre
in-the-row. A 40 in row spacing was used.
Table 3. Yields (cwt/A) of US Size A Atlantic and Sebago
following use of nematicides. 1985.
Nematicidel/ 2/ Atlantic Sebago Average
Busan 1020 279 248 264
Busan 1020 + Temik 15G 302 268 285
Telone II 301 241 271
Telone II + Temik 15G 294 245 270
Temik 15G 301 235 268
Control 176 151 164
1/ Busan 1020 applied at 20 gallons/acre using two chisels/row; Telone
II applied at 6.0 gallons/acre and Temik 15G at 20 Ib, all rates
expressed as in row rates using a 40 inch row spacing.
2/ Nematicide treatments during previous seasons are not considered
in this table and data are means of all plots receiving nematicides
during 1985. Temik 15G is average of three, Telone II two, Temik
15G + Telone II two, controls three, and Busan 1020 and Busan
1020 + Temik 15G average of one plot, respectively.
Disease and Nematode Control Field Experiments in Progress
D. P. Weingartner
Long term use of nematicides Beds 3, 4, 5 OL
Various sequences and combinations of Temik, Telone II and other fumigants
have been applied in large plots each year since 1977. The objective is
to compare potato yields and nematode control following the various treatments
to those of nontreated controls over long periods of time.
Benalaxyl Residue Study Beds 6 and 7 OL
Soil samples are being taken monthly for an 18 month period. The purpose
is to monitor fate of an experimental systemic fungicide, benalaxyl, in soil
following use in a potato crop. Supported by Montedison Corp.
Fungicide Efficacy Experiment Cabbage Bed 11 OL
Efficacy of fungicides against downy mildew and alternaria leat spot is being
evaluated. Supported in part by SDS Biotech.
Epidemiology of Early (and Late) Blight. Beds 1 and 4 NL
Relationship of disease progress of early blight is being related to potato
yields in six potato cultivars (Superior, Atlantic, Ontario, Sebago, Red
La Soda and La Chipper). The objective is to determine effects of early
blight on potato yields and develop data for making spray advisories for
controlling early blight.
Fungicide Efficacy Experiment Potatoes Beds 1 and 4 NL
Efficacy of fungicides against early and late blights is being evaluated.
Supported in part by Ciba Geigy and SDS Biotech Corps.
Soil Fumigation Experiment Bed 2 NL
J. R. Shumaker, Cooperator
Several soil fumigants (chlorpicrin, three rates of methyl bromide, Telone
II, two rates of Telone C-17, and Busan 1020) are being evaluated alone and
in combination with Temik for nematode, corky ringspot, and bacterial wilt
control in Atlantic and Sebago cultivars. A deep chisel placement of a slow
release formulation of methyl bromide is being tested. Supported in part
by Great Lakes Chemical Corp.
Calcium Cyanamid Trial Bed 3 NL
Six rates of calcium cyanamid (Perkla) are being evaluated in a nonreplicated
trial for nematode control.
Bacterial Wilt Resistance Bed 3 NL
J. R. Shumaker, Cooperator
Resistance of USDA seedlings to bacterial wilt (caused by Pseudomonas
solanacearum) is being evaluated. Approximately 1043 seedlings have been
individually inoculated with the pathogen.
Mocap Residue Study Bed 1 NL
The nematicide Mocap has been applied at increased rates and as a side dress
treatment. The objective is to determine maximum rates which can be used
on Irish potatoes. Supported by Rhone Poulenc Corp.
Interaction of Pseudormonas solacearum with Root-knot Nematodes Bed 3 NL
In co-operation with R. McLaughlin
Effects of root-knot nematodes on bacterial wilt development will be followed.
Cover Crop Experiment Long Term Use of Temik and Telone. Bed 5 NL
- This bed has been treated with Telone and Temik in various combinations. A
summary test is being considered in cooperation with D. D. Beltonsperger
(Agronomy, University of Florida). The objective would be to determine effect
of hairy indigo on summer build up of nematodes.
Calcium Tuber Rot Experiment. Bed 6 NL
S. Locascio and J. A. Bartz, Cooperators
Calcium levels of tuber periderm has been shown to be related to tuber rot
in Wisconsin. Rot potential of potato tubers following applications of
different levels of calcium will be studied. This is the third and final
season for this experiment.
Alternaria Leaf Spot Disease of Cabbage
These studies are being performed by Dominic Fontem, a graduate student in
plant pathology. Disease progress is of Alternaria leaf spot in time and
space (ie rate of disease spread from a line source in the crop and rate
of spread from time of inoculated) is being studied.