Group Title: Annual rice field day ...
Title: Annual rice field day
ALL VOLUMES CITATION THUMBNAILS PAGE IMAGE ZOOMABLE
Full Citation
STANDARD VIEW MARC VIEW
Permanent Link: http://ufdc.ufl.edu/UF00054448/00010
 Material Information
Title: Annual rice field day
Series Title: Belle Glade EREC research report
Physical Description: v. : ill. ; 28 cm.
Language: English
Creator: Belle Glade AREC
Belle Glade EREC (Fla.)
Publisher: University of Florida, Institute of Food and Agricultural Sciences, Cooperative Extension Service, Agricultural Research and Education Center.
Place of Publication: Belle Glade, FL
Publication Date: 1990
Frequency: annual
regular
 Subjects
Subject: Rice -- Field experiments -- Periodicals -- Florida   ( lcsh )
Rice -- Diseases and pests -- Periodicals -- Florida   ( lcsh )
Rice -- Periodicals -- Florida   ( lcsh )
Genre: government publication (state, provincial, terriorial, dependent)   ( marcgt )
 Notes
Dates or Sequential Designation: Began 1978?
Dates or Sequential Designation: Ceased in 1991 or 1992.
Issuing Body: Prior to 1984 this was issued by the Agricultural Research and Education Center (Belle Glade, Fla.), which changed its name to the Everglades Research and Education Center.
General Note: Description based on: 4th (1981); title from cover.
General Note: Latest issue consulted: 11th (1991).
 Record Information
Bibliographic ID: UF00054448
Volume ID: VID00010
Source Institution: University of Florida
Holding Location: University of Florida
Rights Management: All rights reserved by the source institution and holding location.
Resource Identifier: oclc - 40942624
lccn - 2006229205
 Related Items

Full Text




BeIle Glade EREC Resc c Eort EV-1984-10
HUME LIBRARY


I r" A .<- . A


SEVENTH ANNUAL RICE FIELD DAY


UNIVERSITY OF FLORIDA
EVERGLADES AGRICULTURAL RESEARCH AND EDUCATION CENTER
INSTITUTE OF FOOD AND AGRICULTURAL SCIENCES
COOPERATIVE EXTENSION SERVICE
BELLE GLADE, FLORIDA
JULY 18, 1984










RICE FIELD DAY


9:30 A.M.


9:40 A.M.


10:00 A.M.


10:20 A.M.


10:40

10:55

11:15



11:45

11:55

12:30

1:15


A.M.

A.M.

A.M.



A.M.

A.M.

P.M.

P.M.


EVERGLADES RESEARCH AND EDUCATION CENTER

BELLE GLADE, FLORIDA

JULY 18 1984

William C. Donovan, Presiding
State Extension Specialist, Sugarcane and Rice

Page
Welcome Remarks
W. C. Donovan

Rice Fertility Studies 1983 1
G. H. Snyder and D. B. Jones

Rice Diseases in the Everglades: 1984 Update 6
D. F. Myers and D. B. Jones

Weed Management Systems for Rice. in Florida 9
J. A. Dusky

Break

1983 Stink Bug Studies 17

Activities of the Rice Council for Market
Development
Charles Wilson, Rice Council Representative

Closing Remarks

EREC Rice Field Tour

Dutch Treat Lunch (Catered)

Tour of Glades Area Rice Fields










Rice Fertility Studies 1983

G.H. Snyder and D.B. Jones



NITROGEN FERTILIZATION

Two studies were conducted at the Everglades Research and Education

Center in 1983 to determine the optimum time for applying N to rice drill seeded

in organic soil. The rice (Lebonnet) was drill seeded in mid-March and mid-April

for the two studies, respectively, and flooded approximately one month later.

The flood was maintained without interruption until harvest. Nitrogen from urea

was applied at 60 kg/ha at one of the following stages: a) emergence, b)

flooding, c) one week prior to panicle initiation, d) panicle initiation, and e)

fully extended flag leaf prior to heading. Averaging across both studies, only c

and d, above, resulted in yield increases over the check (no N) treatment, and

the greatest yield was obtained for application at panicle initiation. This

experiment, combined with studies conducted in previous years, has led to the

following suggestions for N fertilization of drill seeded Lebonnet rice grown on

organic soils. When drill seeded rice is flooded 3 to 6 weeks after emergence,

use no N at planting. Apply N from urea or ammonium sulfate at panicle

initiation at 60 kg/ha (approximately 50 lb/acre). In our studies, N

fertilization in this manner has consistently resulted in increases in rough

rice dry (12%) weight yield of 15 to 20%. However, growers should apply this

information with caution. The effects of N fertilization on such production

problems as lodging, blast and other diseases, insect infestations, and

sterility, have not been adequately investigated. It is suggested that growers

first try applying N to a few fields to evaluate the use of this practice in

their operation, and then proceed accordingly.


-1-










SILICON SLAG

For several years significant yield increases have been obtained by

applying calcium silicate slag at rates of approximately 10 to 20 metric tons/ha

(4.5 to 9 english tons/acre) to soils in the eastern Everglades prior to

planting rice. Ratoon yields also have been increased consistently. In 1983,

slag applications of 5 and 20 tons/ha prior to planting Lebonnet rice increased

plant crop yields by 43 and 58%, respectively. Ratoon crop yields were increased

by 33.6 and 53.2% for the 5 and 20 tons/ha rates, respectively. Total yield for

the two crops at the higher slag rate was 11,295 kg/ha (10,052 lb/ha).

Nevertheless, there is some question as to whether even these yield increases

can be justified in view of the delivered cost of slag. For those growers

following rice with sugarcane, slag applied for rice may also benefit sugarcane

production, thereby allowing the cost of slag application to be spread over

several crops. This point is being investigated in one test initiated in 1983

and two trials begun in 1984.

An evaluation of the responsiveness of various soils in the Everglades

Agricultural Area (EAA) to calcium silicate slag was conducted in a pot

experiment in 1983, using Lebonnet rice. Of the seven soils collected, in only

two did application of calcium silicate slag appear not to increase rice

production (grain yield and total plant biomass). These were soils collected

from a field near the lake west of Pahokee, and a soil collected west of the

Gulf and Western sugar mill. Calcium silicate slag significantly increased grain

yield and/or total plant biomass when added to soils collected from the

following locations: Seminole sugar southeast of Sem-Chi rice mill, Seminole

Sugar Brida Ranch, Seminole Sugar M&M Ranch, Gulf and Western east of Route 27,

Shelton Land and Cattle in the southern EAA east of Route 27. Field studies

conducted on the first two Seminole Sugar locations listed above produced









significant increases in rice production as a result of calcium slag

applications, which is in agreement with the results of this pot study. It

appears that slag may produce rice yield increases in a number of EAA locations.

SEEDLING CHLOROSIS

When rice is planted on certain low-iron soils of the EAA a problem

termed seedling chlorosis develops. One to 3 weeks after emergence the seedlings

become chlorotic and nearly cease growth. This condition generally persists

until several weeks after flooding. Although flooding appears to correct the

condition, many seedlings are to small or weak to survive the drastic changes

imposed by flooding. Applying iron sulfate with the seed has been shown to

alleviate this condition.

Three factors related to the use of iron sulfate (FeSO4) for

reducing seedling chlorosis were studied in 1983. Factors investigated were a)

iron sulfate sources, b) iron sulfate rates, and c) varieties.

Iron sulfate sources and rates Three iron sulfate sources were compared for

their effectiveness in alleviating seedling chlorosis of Lebonnet rice:

a)"heptahydrate" iron sulfate (FeSO .7H20), b) a granular "monohydrate"

iron sulfate (FeSO4.H20), and Iron-Sul, a product that contains

FeSO4 and some free sulfuric acid. As a separate treatment, zinc was applied

at 10 kg/ha. All products were drilled with the rice seed at equivalent iron

rates. Visual ratings were made approximately one month later, using a scale of

1 to 10, where 10 indicated the best possible green color and 1 indicated

extremely chlorotic plants. Grain yields were measured at harvest. The results

of these evaluations are presented in Table 1.












Table 1. Seedling color ratings and
sources and rates.


grain yields as affected by iron sulfate


Heptahydrate

Rating Yield

kg/ha

5.1 4849

5.8 5064

6.0 5327

6.9 5258

7.4 5747


Iron Source

Monohydrate

Rating Yield

kg/ha

5.1 4849

5.9 5398

6.1 5121

6.3 5177

6.6 5566


Iron-Sul

Rating Yield

kg/ha

5.1 4849

6.1 5196

6.4 5323

6.6 5680

6.9 5231


All sources appeared to improve seedling color and yield. Highest

color ratings were obtained with the highest rate of each source, whereas

highest yields were obtained at either the 20 or 30 kg Fe/ha rate. Highest

yield for the heptahydrate source was obtained at 30 kg Fe/ha. Since this

source contained 20% Fe, the product rate was 150 kg/ha (134 Ib/A). For

Iron-Sul, the highest yield was obtained at 20 kg Fe/ha. This source

contained 16% Fe, so the product rate was 125 kg/ha (111 Ib/A). The small

differences observed among sources probably are not significant. Factors

such as cost, availability, and ease of application may be as important or

more important than efficacy differences among sources in deciding which

source to use for reducing seedling chlorosis. The zinc treatment resulted

in a color rating of 5.3 and a yield of 4912 kg/ha, which were not

substantially different from the check treatment.

Varieties .

Differences among varieties in susceptability to seedling

-4-


Iron rate

kg/ha

0

5

10

20

30


- - -- - - -- - - - -- - - - - - - -- - - - -


-----------------


- - -- - - - -


"""


""'


""'


--- --- ---










chlorosis have been noticed in past years. These differences were

quantified for the first time in 1983. Iron sulfate from the heptahydrate

source was drilled with the seed at the rate of 20 kg Fe/ha. Color ratings

and yields were taken as described above. The results are presented in

Table 2.


Table 2. Response of various rice varieties to iron sulfate on a low-iron soil
in the EAA.
----------------------------------------- ----- ------- -
Rating Yield

Variety 0 20 0 20
--------- ------- --- ------ ------------ ----- -------------
- kg/ha - -

Labelle 5.3 ** 7.1 4123 NS 3751

Lebonnet 4.8 ** 6.4 4851 NS 5238

L-201 6.8 ** 7.8 4467 NS 4499

Mars 5.6 ** 8.1 4672 ** 5144

Leah 2.4 ** 7.2 2733 ** 4706
------------------------------------------------------------
** between two values indicate the values are significantly different at
P < 0.01. NS indicates no statistical difference at P < 0.10.




Although the color rating of all varieties was imporved by

application of iron sulfate, L-201 clearly was least affected by seedling

chlorosis and Leah was most affected by it. The grain yield of Leah was

increased 72% when iron sulfate was drilled with the seed.










Rice Diseases in the Everglades: 1984 Update

D. F. Myers & D. B. Jones

Disease Incidence:

Rice diseases have occurred sporadically in the Everglades Agricultural Area

(EAA) from 1982 1984. Brown leaf spot ("HO"), caused by Helminthosporium

oryzae, has been a persistent problem, yet there is no evidence that this

disease has caused economic losses. Some plant pathologists believe that HO is

mainly a disease of a physiologically stressed rice plant and can be corrected

with proper nutrition. We have observed this phenomenon in the EAA. When basic

nutritional problems in Florida rice fields have been corrected, the incidence

of HO should decrease.

Rice blast, caused by Pyricularia oryzae, occurred extensively in 1982.

Frequent rains, which keep relative humidity high and prolong periods of leaf

wetness, are important in the epidemiology of blast and increase the rate and

amount of disease development. While rainfall totals for 1983 were record -

setting, the rain was not as frequent as it had been 1982 particularly during

the rice growing season.

In contrast, sheath blight, caused by the soil-borne fungus Rhizoctonia

solani, has been an increasingly important problem. Once a field has a history

of the disease, it is likely that it will be of increasing importance in

subsequent years. We have observed what appears to be an increasing incidence

of the disease in one field at EREC, Belle Glade in three successive crops.

Two species of Rhizoctonia, R. solani and R. oryzae-sativae, cause disease

in rice. We have not determined which species is present in south Florida. R.

solani is prevalent throughout the south. While this species is thought to

occur in the EAA, its presence has not been confirmed here. Currently, we are

comparing isolates from Florida rice to descriptions of R. solani and to R.









oryzae-sativae, the cause of aggregate sheath spot of rice in California.

Generally, these pathogens can be distinguished by symptomatology by a trained

observer and genetic make-up. We have a preliminary indication that R. solani

is the pathogen in the EAA. We are planning to type our isolates for

anastamosis group for a more complete identification.

Crop Rotation Studies: The possibility that Rhizoctonia sheath blight could

become a major rice disease in the EAA has alarmed some vegetable growers.

Rhizoctonia is involved in many major root and stalk rots of vegetables in the

EAA. Any rotation that would result in an increase in the population of R.

solani in soils where vegetables are grown could theoretically hurt vegetable

production. Nonetheless, there is no evidence that this has actually happened.

We are currently involved in a long-term rotation study with rice and lettuce on

the EAA. Thus far, the incidence of Rhizoctonia in the field has been low and

no conclusions can be made. Our objective in the 1984 rice crop is to increase

the incidence of sheath blight in the field to build populations of Rhizoctonia

solani, to study the epidemiology of the disease in the field, and to map sites

of severe disease closely. This would allow us to compare disease development

in the subsequent lettuce crop next fall with the occurrence of the disease in

future rice crops.

Disease Control: A high level resistance to the sheath blight organism has not

been found. Screening new varieties for disease resistance, however, should

continue under Florida conditions. Crop rotation has not provided much help in

other rice-growing regions of the south, because many of the crops grown in

rotation with rice are also susceptible to Rhizoctonia solani. Fungicides have

been evaluated in other southern rice-growing areas of the U. S. Currently

Benlate and Merfect 340-F are the only registered materials in Florida for

foliar application on rice. Other materials including Tilt & Duter have proven









more effective than Benlate, the current fungicide of choice, in chemical tests

in production states outside of Florida.

Chemical control for HO is not thought to be necessary and we have no

experience yet with blast control .

Duter has been withdrawn from testing because of residue problems. Tilt

could be considered for an exemption under Section 18 of FIFRA, but the chemical

is costly. Further evaluation of fungicides under Florida conditions is needed.

The choice of chemical, doseage, and timing are particularly crucial for good

sheath blight control. Apparently, striking losses can occur after only a

single application of a generally effective fungicide, or at lower application

rates, or because of poorly timed spray applications.









Weed Management Systems for Rice in Florida

J. A. Dusky



The organic soils in the Everglades Agricultural Area is presently devoted

to sugarcane and vegetable production. Rice is an economically feasible

rotational crop during the summer months when these lands are fallow. Sugarcane

land that is followed has a somewhat different weed spectrum than fallow

vegetable land. A rotation of rice following sugarcane has as its major weed

problems, spiny amaranth (Amaranthus spinosus), the panicums, particularly fall

panicum (Panicum dichotomiflorum,) and bloadleaf panium (Panicum adspersum),

sedges (Cyperus sp.) and crabgrass (Digitaria sp.). The major weed infestations

in fallow vegetable land are goosegrass (Eleusine indica), pigweeds (Amaranthus

sp.) and barnyard grass (Echinochloa sp.).

An effort has been made during the past four years to evaluate potential

herbicides that may be utilized in rice production. These herbicides have been

evaluated for their crop safety and weed control efficacy. Earlier testing has

been discussed in previous field day publications. Results from 1983 trials

will be discussed in this paper.


-9-








Materials and Methods


Rice, variety LeBonnet, was planted on May 27, 1983 at the rate of 100 lbs

per acre. Plots were 4 ft by 13 ft. Applications were made at two different

times. Preemergence herbicide applications were made on June 4, 1983 and early

postemergence treatments were made on June 21, 1983 when weeds were 2 to 4

inches tall. The major weed infestations in this trial were dayflower

(Commelina diffusa) and an annual sedge (Cyperus sp.).

Herbicide applications were made using a tractor mounted sprayer operated

at 30 psi and 3 mph to deliver 30 gpa. Flat fan nozzles (1104) were used.

Compressed air was used as the propellant. Herbicides evaluated were propanil,

thiobencarb, pendimenthalin, bifenox, butachlor, and molinate alone and in

combination at various rates. Weed ratings and crop vigor ratings were made 2,

4 and 6 weeks after treatment.

Another experiment was conducted to determine the effects of gallonage of

the water carrier used in the application of propanil and the time of treatment

upon rice crop vigor. Rice was planted in the same manner as above. Propanil

was applied at the 2-, 4- or 6-leaf stage, at 1.5 or 3.0 lb ai/A, using 10, 20,

30 or 40 gallons of water per acre. The tractor mounted sprayer was used and

pressure, speed and nozzles were altered to deliver the appropriate gallonage.

Crop vigor evaluations were made 1 week after application.

Results and Discussion

Results of the preemergence herbicide applications are presented in Table

1. Thiobencarb (3.0 6.0 lb ai/A), bifenox (3.0 Ib ai/A), butachlor (4.0 lb

ai/A) and molinate (3.0 6.0 Ib ai/A) provided acceptable control (>70%) of

dayflower for 4 weeks. This percent control did not continue for the season and

by six weeks after treatment control for the most part was no longer acceptable.


-10-









Bifenox, butachlor and molinate provided greater than 80% control of the annual

sedge. This control did last during the entire season. None of the treatments

resulted in a loss of crop vigor.

Early postemergence treatments of thiobencarb (4.0 Ib ai/A) and bifenox

(3.0 lb ai/A) did provide adequate control of dayflower and annual sedge four

weeks after treatment (Table 2). This other herbicide treatments did not result

in adequate control. Little or no loss in crop vigor resulted.

When these same compounds were combined with propanil as an early

postemergence treatment, weed control efficacy was enhanced. All the treatments

resulted in excellent control of annual sedge four weeks after treatment (Table

3). Thiobencarb, pendimethalin, bifenox, molinate or butachlor when combined

with propanil provided excellent control of dayflower as well four weeks after

treatment. Residual herbicide control was also greater in that regrowth of the

dayflower did not start until 8 weeks after treatment. There was little or no

loss in crop vigor.

The plots were not harvested in 1983 due to a serious sheath blight

infestation.

Results for experiments to determine the effects of gallonage, rate, and

time of application of propanil on rice injury are presented in Table 4.

Propanil injury was iost severe when it was applied in 10 gallons of water to

the acre. Injury was significantly reduced when the amount of water used in

application was increased from 10 to 20 GPA at the 2-leaf stage. Increasing the

gallonage at the 4- and 6-leaf stage in the application of propanil did not

significantly reduce injury although the trend for increased tolerance was

indicated.


-11-









Conclusions



Considerable research is still needed, however, it appears that the use of

compounds that provide residual control such as thiobencarb, pendimethalin,

butachlor and molinate in combination with propanil as in an early postemergence

treatment would provide adequate initial weed control and residual in rice

culture. It also appears that increasing the amount of water used in the

application of propanil will reduce the severity of rice injury.


-12-









Table 1. Influence of preemergence herbicides upon weed control and crop
vigor 6 weeks after treatment during the 1983 season. Average
of 4 replications.


Treatment

Check

Thiobencarb

Thiobencarb

Thiobencarb

Pendimethalin

Pendimethalin

Bifenox

Butachlor

Molinate

Molinate

*Propanil

*Propanil


Rate (lb ai/A)



3.0

4.0

6.0

1.5

3.0

3.0

4.0

3.0

6.0

1.5

3.0


Weed Control
DF AS

0.0 0.0

7.4 6.9

7.4 7.2

7.1 8.1

5.8 3.5

4.9 4.0

7.1 9.0

8.5 9.0

8.0 8.0

8.4 9.5

7.6 8.8

7.8 9.2


* postemergence


-13-


Vigor

9.5

9.5

9.4

9.2

9.2

9.2

9.2

9.1

9.4

9.2

9.1

8.9








Table 2. Influence of early postemergence herbicides upon weed control
and crop vigor 4 weeks after treatment during the 1983 season.
Average of 4 replications.


Treatment

Check

Thiobencarb

Thiobencarb

Pendimethalin

Pendimethalin

Bifenox

Molinate


Rate (Ib ai/A)



3.0

4.0

1.5

3.0

3.0

3.0


Weed Control
DF AS

0.0 0.0

7.0 3.4

7.9 8.0

5.2 0.0

6.2 2.5

8.8 8.9

6.2 3.5


-14-


Vigor

9.5

9.1

9.2

9.1

9.1

9.1

9.2








Table 3. Influence of combination postemergence herbicides treatment
upon weed control and crop vigor 4 weeks after treatment
during the 1983 season. Average of 4 replications.


Treatment


Rate (lb ai/A)


Check


Thiobencarb +
Propanil

Thiobencarb +
Propanil

Pendimethalin +
Propanil

Pendimethalin +
Propanil

Pendimethalin +
Propanil

Bifenox +
Propanil

Bifenox +
Propanil

Molinate +
Propanil

Butachlor +
Propanil

Propanil

Propanil


3.0
3.0

3.0
1.5

1.5
3.0

1.5
1.5

3.0
1.5

3.0
3.0

3.0
1.5

3.0
1.5

4.0
1.5

1.5

3.0


Weed Control
DF AS


0.0 0.0

9.2 9.6


8.8 9.2


7.2 9.4


7.0 9.4


8.5 9.2


8.4 9.4


8.8 9.5


9.6 9.2


9.3 9.5


7.6 8.8

7.8 9.2


-15-


Vigor


9.1


9.5


8.9


9.5


9.5


9.2


9.2


9.4


9.0


9.1

8.9










Table 4. Influence of gallonage, rate and time of application on
propanil rice injury. Average of 4 replications.


Rate (lb ai/A)


1.5




3.0


GPA


10
20
30
40

10
20
30
40


Check


2 leaf

7.9
8.8
9.0


6.7
8.6
8.6


10.0


Time of Application
4 leaf

8.2
8.6
9.0
-

6.9
7.6
8.0
8.4

10.0


-16-


6 leaf









1983 Stink Bug Studies

D. B. Jones and R. H. Cherry



Since rice is a relatively new crop to the Everglades Agricultural Area

(EAA) of south Florida, little is known about insect pests attacking the crop.

Although many different insect pests can be found in rice fields in the EAA,

stink bugs are currently the most important pest. Therefore, the objectives of

this study were to: 1) determine the relative abundance of various species of

stink bugs in rice fields, 2) determine the abundance of stink bugs with respect

to plant phenology and calendar date, and 3) develop insecticidal control

recommendations.

Eight rice fields, approximately forty acres per field in size, were

sampled with fifteen inch diameter sweep nets throughout the growing season.

Planting dates for fields sampled ranged from March 1 through May 12, 1983.

Each field was sampled weekly, each sample consisting of 100 sweeps (1800).

Growers sprayed fields for stink bugs when they felt it was appropriate.

Monitoring began three weeks after planting and continued through harvest. Four

fields were monitored through harvest of the ratoon crop.

Samples showed that 88% of the adult stink bugs captured were rice stink

bugs, Oebalus pugnax (Fabricus). Stink bugs began appearing in the fields as

the rice began to head, regardless of the calendar date of heading. Data

indicate that chemical control recommendations developed in other southern rice

growing areas should be applicable to the EAA.

The individual farms (2 fields/farm) will be discussed on the following

pages. This discussion is not meant to be critical of the management programs,

rather it is intended to illustrate how research information can be utilized to

improve stink bug management in the future.


-17-









U 120 -
a-
LU
LU
S100 /


8 t \ TOTAI
I

I
C) /
z 60-

SNYMPH
m 40

/ / ADULT
S20 /
SPRAY /
0
-20 -10 0 10 20 30

DATS FROM HERDING
planted: April 26
headed: July 1
sprayed: July 11
harvested: August 7
variety: Labelle


Stink bugs began appearing in the rice shortly after heading (approximately

July 1). The insecticide was applied on July 11 since the last application of

fungicide was scheduled at that time. Stink bug numbers were well below the

suggested treatment level (5 stink bugs/10 sweeps from heading to soft dough

stage) at that time. But, shortly after the spray was applied, stink bug nymphs

began to rapidly appear. Since the nymphs cannot fly it can be assumed they

arose from the hatching of eggs already present in fields. Approximately two

weeks after the insecticide was applied, the stink bug population reached

treatable levels (at this stage, soft dough to harvest, treatment is recommended

when 10 stink bugs/10 sweeps are found). This situation illustrates the fact

that incorrectly timed spraying will not necessarily control stink bugs until

harvest, and fields should be monitored throughout the grain filling period.


-18-






100
f) SPRAY
a_
UJ -
s 80
U,
08

60
*
z
c 40_

03 TOTAL

20
U,
Ur) SPRAY



-50 -40 -30 -20 -10 0 10 20 30

DRTS FROM HERDING

planted: May 12
headed: August 1
sprayed: August 9, August 24
harvested: September 2
variety: Lebonnet


Stink bugs began appearing in the rice field in significant numbers at

heading. This rapid buildup and the fact that the majority of the population

consisted of adults indicates there was a large population of stink bugs nearby.

This was in fact the case. A nearby rice field was being harvested the same

time this field was heading and the adult stink bugs probably were immigrating

into the newly headed field. In this case, the grower observed the stinkbugs

and sprayed at the appropriate time effectively eliminating the stink bugs.

However, he sprayed again, unnecessarily, two weeks later when very few stink

bugs were present. Again, fields should be monitored throughout grain filling

to determine whether spraying is justified.


-19-




120


U,
a- 100
IJ
uJ

U 80-

W--4
S60-
0 HARVEST


L-7 40
SPRAY HEADED
SPRAY Y

20


0 6 1 S I 1 1 I -
-60 -40 -20 0 20 40 60 80 10I
DO TS FROM HEADING

planted: March 30
headed:
plant crop: July 16
ratoon crop: September 16
sprayed: July 6, July 19
harvested:
plant crop: August 3
ratoon crop: November 3
variety: Lebonnet


Stink bugs began appearing in small numbers prior to heading. Insecticide

was applied with both applications of fungicide when stink bug populations were

well below recommended treatment levels. Stink bugs began to build up after the

last spraying, but the crop was harvested before they reached treatment levels.

Stink bugs reappeared when the ratoon crop began heading and did reach treatable

levels in the ratoon crop. Even though grain filling of the ratoon crop

occurred during September and October, stink bugs were present. This indicates

ratoon crops, as well as plant crops, should be monitored for stink bugs.


-20-








a-
Uw 70

v,0
( 60


- 50

C 4 0 SPRAY HEADED
z

L3 30-
0 HARVEST
20-
'-
n 10_



-40 -20 0 20 40 60 80 100 120 140

DRTS FROM HERDING

planted: March 1
headed:
plant crop: June 15
ratoon crop: September 19
sprayed: August 2
harvested:
plant crop: August 6
ratoon crop: October 21


Stink bugs did not appear in this field until late grain filling and never

quite reached treatment level although the grower did apply an insecticide

shortly before harvest. In the ratoon crop this field had a fairly high

population of grassy weeds which probably supported stink bugs before the ratoon

crop headed. Stink bugs were present throughout grain filling of the ratoon

crop and remained just below recommended treatment levels.


-21-









Pesticides Approved for Use on Rice in Florida
1/
K. D. Shuler -



Most of the pesticides listed below have federal labels which do not

restrict their application to any specific area of rice production and are

therefore approved for use on rice grown in Florida. Several pesticides still

only have registrations for the traditional production areas of California and

the Mississippi Delta states. Some of the herbicides listed below which may be

used in Florida are approved for use on weeds and/or soil types which are not

common to Florida. Therefore, this is a list of pesticides which may be used in

Florida, but are not necessarily recommended for Florida conditions. Mention of

trademarks does not constitute a recommendation or endorsement of the product.


Read all labels carefully.


Follow label instructions for proper use of product.


Follow safety guidelines when using chemicals.

Material Company Use


A. FUNGICIDES

Benlate

Mertect 340-F

Dithane M-45

Vitavax R

thiram 50%

captain 50%

Difolatan-4F

Terra-Coat
L-205

Nusan 30-A


DuPont

Merck

Rohm and Haas

Uniroyal Chemical

BASF, Mobay, DuPont



Chevron


Olin


blast, stem rot

blast, stem rot

seed treatment

seed treatment

seed treatment

seed treatment

seed treatment


seed

seed


treatment

treatment


1-2 Ibs/A

6-12 oz/A

2-4 oz/100 lbs

3-4 oz/100 Ibs

1.5 oz/bu

2.25 oz/100 lbs

4 oz/100 lbs


4-8 oz/100 lbs

1.5 oz/100 lbs


SPalm Beach County Extension Agent, Florida Cooperative Extension
Service, located in Belle Glade, FL

/ Preharvest Interval
-22-


Rate


PHI 2









Material Company Rate PHI 2 /


B. INSECTICIDES


Malathion 57%




Methyl
parathion



Di-Syston 15G

Dibrom

Methoxychlor
50 WP

Malathion 57%


American Cyanamid stink bug,
Helena grasshoppers,
chinch bug, fall
armyworm


Helena


Mobay


Chevron


stink bug,
grasshoppers,
chinch bug, fall
armyworm


leafhoppers

grasshoppers

storage bin
treatment

storage bin


1.5-2.5 pts/A




0.5-1 pt/A




13.3 Ibs/A


7 days


100 days


0.5-0.75 pt/A

1 lb/1,000 sq ft


1 pt/1,000 bu


NOTE: Several fumigants are available for use in gas tight storage bins.

C. HERBICIDES


Stam M-4


Bolero 8 EC


Rohm and Haas


Chevron


annual grass &
broadleaf weeds

junglerice,
barnyard grass
& goosegrass


1-3 qts/A


4 pts/A


American Cyanamid


grass


1.5-2.0 pts/A


Basagran


Modown


MCPA Ester


BASF


Rhone Poulenc


Union Carbide


2,4-D 4EC
D. Harvest Aid
Sodium chlorate Helena


selected aquatics
& broadleaf

selected aquatics
& grasses

broadleaf,
bulrush, & sedge


broadleaf

defoliant
desiccant


1.5 pts/A


2-3 qts/A


1.5-2.5 pts/A


1.5-3 pts/A

3-4 qts/A


The label reads 3-6 qts/A, but on organic soils we recommend 1-3 qts/A
to prevent the excessive phytotoxicity to rice that occurs when higher
rates are used.


-23-


Prowl


Rate PHI 11


Material Company




University of Florida Home Page
© 2004 - 2010 University of Florida George A. Smathers Libraries.
All rights reserved.

Acceptable Use, Copyright, and Disclaimer Statement
Last updated October 10, 2010 - - mvs