Glade EREC Research Report EV-1985-7
EIGHTH ANNUAL RICE FIELD DAY
UNIVERSITY OF FLORIDA
EVERGLADES RESEARCH AND EDUCATION CENTER
INSTITUTE OF FOOD AND AGRICULTURAL SCIENCES
COOPERATIVE EXTENSION SERVICE
BELLE GLADE, FLORIDA
JULY 10, 1985
EIGHTH ANNUAL RICE FIELD DAY
EVERGLADES RESEARCH AND EDUCATION CENTER
BELLE GLADE, FLORIDA
JULY 10, 1985
Kenneth D. Shuler, Presiding
Palm Beach County Extension Agent
9:30 AM Discussion Session
Welcome Remarks/Opening Comments
The Rice Effect Further Evidence
Rice Straw Feeding Studies
Leafhoppers and Planthoppers in Southern
Florida Rice Fields
Review of Herbicide Recommendation
Rice Fertility Studies 1984
Rice Varieties and Cultural Practices
Pesticides Approved for Use on Rice
K. D. Shuler
J. D. Phillips
R. H. Cherry
K. D. Shuler
11:00 AM Tour Rice Plots EREC Rice Fields
Lunch Dutch Treat
1:15 PM Field Tour Visits to commercial rice fields (to introduce
Everglades rice production to field day visitors).
The Rice Effect Further Evidence
J. Alvarez, R.H. Caruthers, G.H. Snyder and D.B. Jonesl
Everglades sugarcane growers often have the option of producing rice
during the summer on land fallowed between sugarcane crops. A study was
conducted on an organic soil at three locations on the Big B Farms in the
southern Everglades Agricultural Area using sugarcane varieties CP-1210 and
CP-1153 to determine whether rice culture affects sugarcane production in the
plant crop following rice. Sugarcane production from a total of 15 commercial
fields averaging about 35 acres each in which rice was produced during the
summer prior to sugarcane (termed rice fields) was compared with that from 16
near-by fields in which there was no rice production (termed check fields).
Comparable fields generally were planted within 2-week periods and were
harvested within the same time span. Summer fallowed fields were not flooded,
whereas those used for rice were flooded as part of the normal rice culture.
Averaged across the three locations, gross cane yield in fields
following rice was 46.5 tons/acre, compared to 42.7 tons/acre in fields not
cropped to rice. However there was no significant difference at one location.
The biggest differences were observed in juice quality, and these differences
were statistically significant (P<0.05) at all locations. Fields following rice
averaged 81.4% purity, compared to 77.2% in check fields. Sucrose averaged 14.4
and 12.6% in rice and check fields, respectively. Net standard tons averaged
52.9 and 41.4 tons/acre, in rice and check fields, respectively. Recoverable
sugar per acre (RSPA) was 4.8 and 3.8 in rice and check fields, respectively.
Using a sugarcane price of $ 23.85 per net standard ton, fields following rice
produced $ 234.27/acre more income than summer fallowed fields, after accounting
for harvesting costs.
Prior to the sugarcane planting, both rice and check fields were
fertilized approximately in accordance with the Everglades Research and
Education Center Soil Test Laboratory recommendations. As a result of the
prolonged period of flooding associated with rice production, soil pH in rice
fields was greater than that in check fields, whereas soil test P and K were
lower. Therefore, more fertilizer was recommended for sugarcane in rice than in
check fields, at a cost of approximately $40.00/acre. An examination of the data
indicated that RSPA was increased by K fertilization, although this analysis was
somewhat confounded by the location variable. Since rice fields in general
received more K fertilization prior to sugarcane planting than did check fields,
part of the rice effect may be attributable to K fertilization. But statistical
analysis performed on the data set indicated that differences in K fertilization
accounded for only a portion of the rice effect. For example, at a K 0
fertilization rate of 180 Ibs/acre on both rice and check fields, RSPA averaged
0.67 tons/acre higher in the rice fields.
1. Associate Professor, University of Florida (IFAS) Everglades Research and
Education Center (EREC); General Manager, Big B Farms; Professor and Assistant
Professors, EREC, respectively.
The finding that plant crop sugarcane production increased following
rice is in agreement with a previous study that utilized multiple linear
regression analysis of data from grower records (see Field Crops Research
9(1984):315-321). For example, in the present study rice culture increased RSPA
by an average of 1.0 tons/acre. In the previous study plant crop RSPA was found
to average 0.93 tons/acre higher in rice fields. The data in the present study
were not included in the previous study and, therefore, represent further
evidence of the rice effect.
Preliminary Report on Ammonia Treated Rice Straw
Fed to Beef Cattle
J. D. Phillips, W. F. Brown and D. B. Jones
Typical low quality forages such as tropical grass hays and small grain
straws are often so low in protein and energy that cattle cannot consume enough
of the forage to meet maintenance requirements. Anhydrous ammonia treatment of
a low quality forage can improve animal performance by increasing intake,
protein content and digestibility of the consumed forage.
Rice production creates a crop residue, the rice straw, which is a typical
low quality forage. This straw needs to be removed from the field after grain
harvesting, especially in the plant crop, to facilitate regrowth of the
following rice crop. One way in which this straw could be utilized would be as
a cattle feed, and any process which would improve the nutritive value of the
straw would be beneficial to both rice and cattle producer.
A two-phase study was conducted to evaluate the use of rice straw as a
cattle feed and the effect of ammonia treatment on the nutritive value of the
straw. Phase I of the study consisted of a 90 day feeding trial in which intake
and weight gain were measured. Phase II utilized a 4-period metabolism trial to
determine % digestibility of the rice straw.
The information presented in this report is only preliminary, as laboratory
analysis of samples from the trials is not yet complete and data has not been
subjected to statistical analysis.
Ammonia Treatment The rice straw was put into large round bales approximately
48 hrs. after combining. The bales averaged 650 lbs. and produced 3.25
bales/acre or just over 1 ton of straw/acre. Fifty bales were set aside for
ammonia treatment and the rest stored under an open shed.
The bales to be ammonia treated were stacked in 10 rows of 3 bales on the
bottom and 2 on top. The stack was covered with a 40' x 100' x 6mm polyethylene
sheet and sealed around the edge with dirt to prevent ammonia leakage. An
anhydrous ammonia tank was parked beside the hay stack and a hose from the tank
inserted under the plastic. Ammonia was injected under the plastic at the rate
of 4% of straw weight. After the proper amount of ammonia had been released
into the stack, the hose was disconnected and sealed and the straw was allowed
to set for 30 days.
Approximately 1 week before feeding, the plastic was removed so the straw
could air out. Prior to feeding, both the ammonia treated and the untreated
straws were ground in a tub grinder.
Feeding Trial Fifty-four cross bred yearling steers averaging 610 lbs. were
randomly divided into 9 groups of 6 head each. Three groups of steers were
assigned to 1 of 3 treatments (Table 1).
In formulating the treatment diets, the protein and energy content of the
ammonia treated straw (treatment I) was first determined. Treatment II was
untreated straw supplemented with urea to equal the protein content of ammonia
treated straw. Treatment III was untreated straw supplemented with urea and
molasses to equal the protein and energy content of the ammonia treated straw.
The steers were offered ad libitum feed for 90 days. Initial, final and 28
day interval weights were taken.
Table 1. Composition of Feeding Trial Diets.
---------.---- a------ -------
NH treated Straw Straw plus
Ingredient straw plus urea urea & molasses
Rice straw 89.97 73.21
NH3 treated straw 90.61
Molasses -- 16.18
Urea -- 1.50 1.59
Supplement 9.39 8.53 9.02
All values expressed on dry matter basis.
Salt, minerals, vitamins and by-pass protein.
Metabolism Trial Four Braford steer calves averaging 520 Ibs. were used in a
series of 4 metabolism trials to determine the digestibility of the rice straw
treatments. The treatment diets used were basically the same as those used in
the feeding trial, except that a fourth diet of unsupplemented untreated rice
straw was also used (Table 2). Water and minerals were available to the steers
on a free choice basis.
Each trial was 20 days in length, consisting of a 13 day adjustment period
and a 7 day collection period. During the collection period, feed intake and
fecal output were measured. Daily samples of feed offered, feed refused and
feces were collected for laboratory analysis.
The 4 steers were used in a latin square design such that each steer was on
each treatment during the course of the 4 trials, giving a total of 4
observations per treatment.
Table 2. Composition of Metabolism Trial Diets.
- ------------------------%a ------_
NH3 treated Straw Straw plus
Ingredient straw plus urea urea & molasses straw
Rice straw -- 98.24 84.80 100.00
NH3 treated straw 100.00 -- -- --
molasses -- -- 13.58
urea -- 1.76 1.62
aAll values expressed on dry matter basis.
Feeding Trial Daily dry matter intake of ammonia treated straw (14.62 lb/h)
was higher than untreated straw plus urea (11.48 lb/h), but was not different
from untreated straw plus urea and molasses (14.23 lb/h). Average daily gain ws
similar for the ammonia treated straw and the untreated straw plus urea and
molasses (.88 and .91 lbs., respectively), but was lower (.51 Ibs) for the
untreated straw plus urea treatment. Feed to gain ratios were similar for the
ammonia treated straw and untreated straw plus urea and molasses (16.61 and
15.64 Ibs feed DM/lb gain respectively), but was higher (22.51 lbs. feed DM/lb
gain) for the untreated straw plus urea (Table 3).
Table 3. Feeding Trial Data.
ND3 treated straw straw plus
straw plus urea urea & molasses
Initial wt. (Ibs) 612 610 607
ADGa (Ibs) .88 .51 .91
DMIb (Ibs/h/d) 14.62 11.48 14.23
Feed/Gainc 16.61 22.51 15.64
a Average daily gain.
b Dry matter intake; lbs. feed dry mater/head/day.
C lbs. feed dry matter eaten/lb. liveweight gain.
Metabolism Trial At this stage in our analysis of the metabolism trial data,
very little can be conc:.;ded about the digestibilities of the various rice straw
treatments. An increase. in organic matter digestibility was observed, however,
in the ammonia treated scCaw over the untreated straw (58.88 and 50.27 %
Anhydrous ammonia treatment of rice straw resulted in an improvement in the
nutritive value of the straw. The chemical response in the rice straw due to
the ammonia treatment was evidenced by an increase in the crude protein content
and by a reduction in the % NDF, indicating a partial breakdown of the
hemicellulose fraction. The response in animal performance was seen as an
increase in forage intake and an increase in organic matter digestibility,
resulting in improved weight gains.
Ammonia treatment of rice straw increased the nutritive value of a low
quality crop residue to a level equal to rice straw supplemented with urea and
molasses. This treated straw could provide a maintenance type ration for
cattle, and be used in a number of ways, such as in a winter pasture
Chemical Composition of Rice Straw
NAS Glades NH treated
Component rice straw rice straw rice straw
Dry Matter 90.50 90.40 89.98
Organic Matter 83.00 91.20 91.03
Ash 17.00 8.80 8.97
Crude Protein 4.50 6.89 11.56
NDFc 79.83 75.45
ADFd 49.54 49.61
Lignin 7.64 6.55
Cellulose 41.25 41.52
IVOMDe 43.39 59.00
aDry matter expressed as a percentage of as fed rice straw; all other
values expressed on a dry matter basis.
bAtlas of Nutritional Data on U.S. and Canadian Feeds. National Academy
of Sciences. 1971.
C Neutral Detergent Fiber.
Acid Detergent Fiber.
e In vitro organic matter digestibility.
LEAFHOPPERS (HOMOPTERA: CICADELLIDAE) AND PLANTHOPPERS
(HOMOPTERA: DELPHACIDAE) IN SOUTHERN FLORIDA RICE FIELDS
R. H. CHERRY, D. B. JONES AND F. W. MEAD
Several species of leafhoppers and planthoppers are serious pests of rice
in different areas of the world and frequently occur in numbers large enough to
cause complete drying of the crops. In addition to the damage resulting from
direct feeding, leafhoppers and planthoppers are vectors of most presently known
rice virus diseases (Pathak 1968). Other than a brief description of
leafhoppers and planthoppers in Everglades rice fields by Genung et al. (1979),
little is known of the species composition or seasonal population dynamics of
leafhopper and planthoppers occurring in Florida rice. In this study, we
describe the relative abundance of leafhoppers (Cicadellidae) and planthoppers
(Delphacidae) occurring in southern Florida rice fields. In addition, the
seasonal population dynamics of the most abundant species of leafhoppers in
southern Florida rice fields are examined.
MATERIALS AND METHODS
Eight commercial rice fields in the Everglades agricultural area of
southern Florida were sampled with 15 inch diameter sweep nets during the 1983
and 1984 growing seasons. Each field was ca. 40 acres in size and fields were
located throughout the Everglades agricultural area to obtain a representative
sample of insect populations. All fields were subject to normal rice production
practices. Planting dates for the fields ranged from March 1 through May 12
which covered the range of normal planting times for the rice. Each field was
sampled weekly and each sample consisted of 100 consecutive sweeps (1800)
taken at least ca. 50 yards into the field to avoid possible edge effects.
Sweeping began 6 weeks after planting and continued through harvest. Eight
fields were removed from production after one harvest during August September
and eight crops were removed from production after one ratoon crop during
October November. After collection, insects were frozen for later counting.
Only adults of the leafhoppers and planthoppers were counted because of the
large number of insects collected and to facilitate taxonomic identification.
An overall survey of the relative abundance of the leafhopper and planthopper
species was determined from 42 random samples containing 6060 leafhoppers and
planthoppers identified by F. W. Mead. Thereafter, the seasonal abundance of
the total number of leafhoppers and 3 most abundant leafhopper species was
determined. These latter 3 species were ca. 97% of all leafhoppers collected.
Delphacid seasonal abundance was not determined because of the low numbers of
these insects collected.
RESULTS AND DISCUSSION
The relative abundance of leafhoppers and planthoppers in Florida rice
fields is shown in Table 1. Leafhoppers outnumbered planthoppers ca. 41 to 1.
Genung et al. (1979) also reported that leafhoppers were more abundant on
Everglades rice than planthoppers. However, generally leafhoppers feed on the
leaves and upper parts of rice plants, whereas planthoppers confine themselves
to the basal parts (Pathek 1968). Thus, our sweep net samples probably
overestimated leafhoppers relative to planthoppers present in the rice. The
most abundant leafhopper was the blackfaced leafhopper, Graminella nigrifrons
(Forbes). This species has a wide distribution on grasses in the eastern United
States and has been shown to breed on rice (Stoner and Gustin 1967). This
species is also a vector of several corn stunting pathogens (Nault and Bradfute
1979). The second most abundant leafhopper was Draeculacephala portola Ball.
D. portola is the most common Draculacephala in eastern and central United
States and has been reported in Cuban rice fields (Young and Davidson 1959).
Since this insect is common on sugarcane in the southern United States
(Pemberton and Charpentier 1969), it is probable some D. portola immigrated into
the rice fields from the numerous sugarcane fields in the Everglades area. D.
portola has been reported to be a sugarcane pest in Florida (Strayer 1975).
Abbott and Ingram (1942) reported the transmission of chlorotic streak of
sugarcane by D. portola. However, after reviewing several more recent studies,
Pemberton and Charpentier (1969) opined that the insect transmission of
chlorotic streak had not been adequately demonstrated. The most abundant
planthopper was Delphacodes propinqua (Fieber) which is also a vector of maize
rough dwarf virus (Break 1979). The second most abundant planthopper was the
sugarcane delphacid, Perkinsiella saccharicida Kirkaldy. This species is a
serious sugarcane pest of Australian origin. Besides direct damage to sugarcane
by feeding and ovipositional activities, the insect is also a vector of the
virus that causes Fiji disease in sugarcane. The first North American record of
this insect was reported in 1982 in.Palm Beach County, Florida. Subsequent
surveys revealed that the delphacid ranged throughout southern Florida (Sosa
1983). Another delphacid species of interest detected in this study is
Sogatodes oryzicola (Muir). This insect is a vector of hoja blanca which is one
of the most destructive rice diseases in the Western Hemisphere (Harris 1979).
Fortunately, hoja blanca currently is not known to exist in the United States.
Detection of S. orvzicola in this study is the first report of the insect in the
United States in more than a decade.
The seasonal population trends of total leafhopper number and the 3 most
abundant leafhopper species are shown in Fig. 1. Total numbers of leafhoppers
rose quickly in April and remained relatively constant (Range = 44 to 78
adults/100 sweeps) from May until October, decreasing to 26 adults/100 sweeps in
November. In contrast to the total leafhopper numbers, the 3 most abundant
leafhopper species showed more variable seasonal trends. The early increase of
leafhoppers in rice fields during April and May was almost wholly (> 97%) due to
G. nigrifrons. During June to August, G. nigrifrons remained > 75% of all
leafhoppers, and then declined to lower levels during September to November.
Genung and Mead (1969) also found a decline in G. nigrifrons populations after
August in pasture grasses in southern Florida. D. portola populations increased
slowly during April to June and remained somewhat constant (Range = 8 to 23
adults/100 sweeps) thereafter. In contrast to G. nigrifrons or D. portola,
Balclutha incisa (Matsumara) increased rapidly during the late summer fall
period and during October was the most abundant leafhopper species. Reasons for
this October increase in B. incisa are not known, but may be related to the
weedy condition of a few of the ratooned rice fields.
In conclusion, Genung et al. (1979) have noted that leafhoppers are often
very abundant in the aggregate on southern Florida rice and may contribute to
the unthrifty appearance and discoloration often observed in the rice.
Currently, southern Florida rice growers have expressed no concern for
leafhopper or planthopper populations in their rice fields and S. orizicola was
the only rice disease vector detected in our survey. However, as also shown in
this study, several economically important leafhopper and planthopper species
are present in the fields and may increase rapidly in numbers. Presently, we
have little understanding of the impact of leafhoppers and planthoppers on
southern Florida rice production or how these insects are interacting with other
local crops such as corn and sugarcane. These above subjects warrant future
research, especially if rice acreage continues to increase in southern Florida.
Abbott, E. V., and J. W. Ingram. 1942. Transmission of chlorotic streak of
sugar cane by the leaf hopper Draeculacephala portola. Phytopathology
Break, J. 1979. Leafhopper and planthopper vectors of plant disease agents in
central and southern Europe, pp. 97-155. In Maramorosch, K., and K. Harris
(eds.), Leafhopper vectors and plant disease agents. Academic Press, New York.
Genung, W. G., and F. W. Mead. 1969. Leafhopper populations (Homoptera:
Cicadellidae) on five pasture grasses in the Florida Everglades. Florida Ent.
Genung, W. G., G. H. Snyder, and V. E. Green, Jr. 1979. Rice-field insects in
the Everglades. Belle Glade AREC Research Rept. EV-1979-7.
Harris, K. F. 1979. Leafhoppers and aphids as biological vectors: vector-virus
relationships, pp. 217-309. In Maramorosch, K., and K. Harris (eds.),
Leafhopper vectors and plant disease agents. Academic Press, New York.
Nault, L. R., and 0. E. Bradfute. 1979. Corn stunt: involvement of a complex of
leafhopper-borne pathogens, pp. 561-587. I bid.
Pathak, M. D. 1968. Ecology of common insect pests of rice. Ann. Rev. Ent.
Pemberton, C. E., and L. E. Charpentier. 1969. Insect vectors of sugar cane
virus diseases, pp. 411-427. In J. R. Williams, J. R. Metcalfe, R. W.
Mungomery, and R. Mathes (eds.), Pests of sugar cane. Elsevier, New York.
Sosa, 0., Jr. 1983. Sugarcane delphacid discovered in Florida. Sugar J. 45:16.
Stoner, W. N., and R. D. Gustin. 1967. Biology of Graminella nigrifrons
(Homoptera: Cicadeilidae), a vector of corn (maize) stunt virus. Ann. Entomol.
Soc. Am. 60:496-505.
Strayer, J. 1975. Sugarcane insect control. Florida Coop. Ext. Serv. Entomol.
Young, D. A., Jr., and R. H. Davidson. 1959. A review of leafhoppers of the
genus Draeculacephala. USDA Tech. Bull. 1198.
Table 1. Relative abundance of leafhoppers and planthoppers in
Florida rice fields.
Graminella nigrifrons (Forbes)
Draeculacephala portola Ball
Balclutha incisa (Matsumara)
Draeculacephala product (Walker)
Balclutha hebe Kirkaldy
Delphacodes propinqua (Fieber)
Perkinsiella saccharicida Kirkaldy
Saccharosydne saccharivora (Westwood)
Sogatella kolophon (Bmr.)
Sogatodes molinus Fennah
Based on random samples identified by F. W. Mead (see text).
B. guajanae (DeLong), Exitianus exitiosus (Uhler), Hortensia similis
(Walker), Macrosteles fascifrons (Stal), Planicephalus flavicosta (Stal).
Delphacodes puella (Van Duzee), Pissonotus piceus Van Duzee, Sogatodes
% of Total
% of Total
Fig. 1. Mean adult leafhoppers per 100 sweeps in Florida rice rixi,. -,,,ing
1983 and 1984.
G. nigrifrons-- -
80 D. portola--------
i60' / \
20- / -\ '--'.--
June July Aug
oe 40"- %% %% 1.. *14. *-%
Weed Control in Rice Update on Propanil Use
J. A. Dusky
Studies were conducted during 1984 to determine the effect of propanil rate
and gallonage used for application on rice crop vigor and yield. Studies were
conducted at 2 locations. Propanil rates used were 1.5 lb ai/A and 3.0 Ib ai/A.
Gallons of water per acre utilized in application were 10, 20, 30 and 40. Crop
vigor ratings were made at 2, 4 and 6 weeks after treatment. Yields were
recorded at the time of harvest.
From previous studies it was found that using higher rates of water used in
the application of propanil reduced crop injury (Figures 1 and 2). It was also
noted that there was reduced crop injury when propanil was applied at the 2-leaf
and 6-leaf stage of rice rather than at the 4-leaf stage. Propanil is most
commonly applied when the rice is at the 3-4 leaf stage in that the flush of
weeds is most predominant then. At the 2-leaf stage there is not enough surface
area for the droplets of propanil to congregate on the rice because of its
upright growth pattern at that point. This upright growth would explain the
reduced crop injury when propanil was applied. At the 3-4 leaf stage the leaves
are beginning to fully expand and provide some leaf area where the droplets can
congregate thus causing injury. At'the 5-6 leaf stage much more surface area is
present. The leaves have drooped or bent over. Even though there appears to be
more leaf area to intercept the herbicide spray droplets it may be that because
of its "lush" growth and the way the leaves are arranged that there is reduced
injury to propanil. It also appears that as the rates of water used in propanil
application is increased at any stage of rice growth crop injury is reduced.
With increased gallonage the concentration of propanil in the spray droplets is
less concentrated thus reduced crop injury.
Because of these previous findings the 1984 studies were conducted. Even
though there is less crop injury at the two leaf stage with propanil application
this may be an inappropriate time for growers to apply propanil for there may
not be weeds present. Consequently, the only thing that a grower may vary is
the amount of water used in the application of propanil. At one location in
1984, the time of application of propanil was at the 3-4 leaf stage of rice
growth and there were no weeds present. In the second study, the rice was at
the same growth stage but there was a flush of weeds in the 2-4 leaf stage.
This coincided with the rice being at the 3-4 leaf stage of growth. Rates of
water used in the propanil application were varied by changing tips, pressure
and speed at which the sprayer was operated.
The yield results from this study are given in figures 3 and 4. The crop
vigor ratings made 2 weeks after application were similar to those of previous
studies, in that, as rate of water used in the propanil application increased
crop injury was decreased. At 4 weeks after application the rice was starting
to recover from the initial burn and at 6 weeks the rice was almost fully
recovered from the propanil application. However, as the rice recovered
differences in growth were observed in that the rice that suffered the most
severe injury was smaller and less vigorous than that which had not received
such serious injury.
The yield data for the first experiment (Fig. 3) indicates that as the
amount of water used in the application of propanil was increased yields
increased. Yields in this study were not affected by weed competition in that
no weeds were present in the study. In the second study (Figure 4) the same
general trend was observed as in the first study.
Other observations made during these trials were time of maturity and
incidence of disease. At lower rates of water used in the application of
propanil where there was more severe injury to the rice, there was delayed
maturity and an increase of Helminthosporium oryzae (H.O.)
From these studies it was concluded that if possible, dependent upon the
time of the weed flushes, it is more feasible to apply propanil at the two-leaf
stage of rice growth. It is also more judicious to use increased amounts of
water in the application of propanil in order to reduce the amount of crop
injury from propanil. Studies will be continued to determine what physiological
processes are being affected by propanil application and what might be done in
order to reduce rice injury.
Percent rice injury 2 weeks after application of 1.5 lb ai/A
propanil at 3 stages of rice growth using varying amounts of
water (gal/A) in the application.
Percent rice injury 2 weeks after application of 3.0 lb ai/A
propanil at 3 stages of rice growth using varying amounts of
water (gal/A) in the application.
The effects of propanil rate and the amount of water used in
its application on rice yields at location 1.
I I I I I I I
The effects of propanil rate and the amount of water used in
its application in rice yields at location 2.
301 1 1 I 1 I 1
RICE FERTILITY RESEARCH
PHOSPHORUS AND POTASSIUM : In cooperation with Mr. Ken Shuler, a phosphorus (P)
and potassium (K) fertility study was conducted at Okeelanta Sugar Corporation
during the summer of 1984. Prior to planting Labelle rice, P (triple
superphosphate) and K (muriate of potash) were soil incorporated in factorial
combination at the following rates, expressed in kg/ha (multiply by 0.89 to
convert to lbs/A. Multiply K by 1.2 to convert to K20. Multiply P by 2.29 to
convert to P205):
P 0, 25, 50, 75
K 0, 75, 150, 225
Manganese (Mn), zinc (Zn), and boron (B) were applied at 5, 5, and 1 lb/A, in
accordance with the Everglades Research and Education Center (EREC) soil test
recommendation for rice, except that micronutrients were committed on one of the
five replications. The rice was planted on 3 March and harvested on 5 July.
The soil pH was approximately 6.2. Soil samples taken 19 March tested as
follows using EREC soil test methods:
Applied Soil Test Applied Soil Test
P P205 P K K20 K
(kg/ha) (Ib/A) (lb/A) (kg/ha) (Ib/A) (Ib/A)
0 0 2.4 0 0 60
25 51 5.8 75 80 82
50 102 8.4 150 161 121
75 153 15.8 225 241 178
Phosphorus and K fertilization of rice is recommended by the EREC soil
test laboratory when soil test P and K are below 5 and 100, respectively, as in
the case of the unfertilized treatments, above.
There were no significant differences in rough rice yield (12% moisture)
attributable to P, K, or the interaction between P and K. Main effect means
Effect of P and K fertilization on rough rice yield
Applied Rice yield Applied Rice yield
( --------- kg/ha -----------------)
( - - - - - kg/ha - - - - - -)
0 3938 0 3906
25 4019 75 3967
50 3884 150 3911
75 3981 225 4037
There were significant differences among replications, but yield was not
lowest in the replication on which micronutrients were committed. The results of
this study suggest that rice fertilization at rates greater than recommended by
the EREC soil test lab is not justified, and that lower rates may be acceptable.
MINERAL COMPOSITION OF Y-LEAVES : Several growers cooperated in a survey of the
mineral composition of Y-leaves (defined here as the most recent fully developed
leaf) at panicle initiation. Samples were received from A. Duda & Sons, Double-D
Corporation, Okeelanta Sugar Corporation, and Seminole Sugar Corporation.
Through the cooperation of these organizations, a high percentage of the rice
fields of the Everglades Agricultural Area (EAA) were sampled in 1984.
Additional sampling in 1985 is anticipated. The data base thus generated will be
used to develop DRIS (Diagnosis and Recommendation Integrated System) criteria
which may be useful for assessing rice fertilization needs. The mean values
(based on leaf dry weight) for various nutrients obtained in this survey were:
Nitrogen (N) 2.79 %
Phosphorus (P) 0.28 %
Potassium (K) 1.86 %
Calcium (Ca) 0.24 %
Magnesium (Mg) 0.17 %
Iron (Fe) 71 ppm
Manganese (Mn) 115 ppm
Zinc (Zn) 41 ppm
Copper (Cu) 15 ppm
Additional interpretation of the data is provided by the distribution diagrams
presented in Figs. 1-5. Looking at the diagram for N, for example, reveals that
although the mean N content was 2.79% (as presented above), 55% of the samples
contained slightly less N (about 2.5%), 25% contained about 3.00% N, and 10%
contained about 3.5% N. However less than 3% of the samples contained 2% or less
CALCIUM SILICATE SLAG STUDIES : In 1981, 1982, and 1983, rice production was
significantly increased by pre-plant incorporation of calcium silicate slag (see
Rice Field Day Reports for 1982, 1983, and 1984). Most rice in the Everglades is
grown in rotation with sugarcane. While at the EREC, Dr. Gascho showed that
sugarcane production can be significantly increased by slag application. A study
was initiated in 1984 in cooperation with Drs. Anderson and Jones to determine
whether slag applied prior to rice planting will affect sugarcane production
following rice. Calcium silicate slag was applied at rates of 0, 2.5, 5.0, 10.0,
and 20.0 metric tons/ha (multiply by 0.47 to convert to english tons/A) prior
planting Lebonnet rice at Brida Ranch and in Section 10 at Seminole Sugar. Four
additional plots in each of the four replications at each site were established
for the purpose of receiving slag just prior to sugarcane planting. Due to a
very poor stand at the latter site, rice yield was not significantly affected by
slag applications. However at Brida yields were significantly increased by slag
application, as is shown below.
E 6000 *
k 5000 *
I ( I I
0 5 10 15 20
Prior to replanting the fields to sugarcane, calcium silicate slag was
applied to the unused plots cited above, to provide a comparison between slag
application 1) prior to rice that proceeds sugarcane and 2) immediately prior to
sugarcane planting. The sugarcane will be harvested during the 1985-1986 season.
NTROGEN STUDIES : A study utilizing the non-radioactive isotope of nitrogen,
N, was initiated to better understand N fertilizer utilization by ric 4in
orga c soils. Nitrogen occurs naturally as a mixture of two isotopes, N
and N. Although N by far predominates, m ern analytical equipment
canldetect very small "mole percentages" of N. Ammonium sulfate depleted
in N, i.e., containing much less N than occurs naturally, was
obtained gratis from Dr. R.D. Hauck of the Tennessee Valley Authority (TVA). It
was applied between the center two rows of six-row plots of Lebonnet rice at the
EREC. The rice, which was at the panicle initiation stage, was flooded and there
was a strong east wind at the time of N application. The N rates were 0, 60 and
120 kg/ha. In previous studies a N rate of approximately 60 kg/ha has produced
maximum rice yield. A much higer rate was used in this study because of
uncertainty as to how whether N-depleted N could be detected in rice grown
in a N-rich organic soil. Flag leaves from the center two rows were sampled
shortly after head emergence, and again at harvest. Whole plant straw samples
were taken at harvest. Dr. Hauck determined the mole percentage of N in
the tissue samples. A Ipwer than normal percentage indicates that N from the
fertilizer (which was N depleted) was present in the tissue.
Although there were no significant differences in overall N content
(expressed as a weight percentage) of the flag leaves or of the straw, N from
the fertilizer nevertheless was detected in the plant tissue in approximately
direct proportion to the rate of application (see table, below).
Nitrogen and N mol percent in rice plant tissue following N
application from a N depleted source at the panicle initiation stage.
At Harvest In Straw
At Harvest In Straw
%N Mole %
1. **, *, and NS refer to statistical significance
and P> 0.05, respectively.
at P< 0.01, 0.05,
These data indicate that 5N-depleted N can be used to trace
fertilizer N applied to flooded rice at panicle initiation in organic soil.
Because the overall N content of the tissue did not increase with N
fertilization, it migt have been concluded that the N fertilizer did not enter
the rice plant. The N data prove that this was not the case. Perhaps
increased plant growth resulting from N fertilization was responsible for
diluting the fertilizer N in the plant.
To determine how much lateral movement there is of N applied
rice at the panicle initiation stage, tissue samples5were taken from
side of the center two rows of the plots receiving N-depleted N at
kg/ha. The rows immediately outside of the center two rows were termed "guard"
rows, and those outside of the guard rows were called "outer" rows. Since the
plot rows were aligned North-South, both east and west "guard" and "outer" rows
were sampled. The results of this sampling are presented below.
N mole percent in rice plant tissue following N application at 120
kg/ha between the center two rows of flooded 6-row rice plots at the
panicle initiation stage.
----------------- ------- -------------
Location N rate At Heading In Straw Straw
East Guard Row
East Outer Row
West Guard Row
West Outer Row
Center Rows Check 0
1. Means within a column followed by
different by Duncan's multiple range
0.308 b 0.314 c
0.372 a 0.368 ab
0.371 a 0.367 ab
0.357 a 0.358 b
0.372 a 0.370 ab
0.371 a 0.373 a
the same letter are not
15 The data indicate that there was little uptake of N from the
N-depleted N fertilizer by plants outside of the center two rows, i.e.,
away from the point of N fertilizer placement. Some fertilizer N was detected at
harvest in plants from the west guard row, i.e., the first row downwind from the
center two rows. Since this N was not detected at heading, and the N rate used
in this study was twice that that has been found to produce maximum yields in
Everglades rice, it probably can be concluded that under normal circumstances
most of the fertilizer N utilized by rice under Everglades conditions is used by
plants growing very close to the point of application. This conclusion points
out the importance of uniform N application.
RICE ISSUE N
CE ISSUE P
RICE IISSUIE F
l. l4 l.5illl .6 .lllll ,li ll
.3 .4 .5 .6 .7
Fig. 1. Percentage of rice Y-leaf
Agricultural Area in 1984
samples collected from the Everglades
containing various percentages of N
RICE TISSUE K
RICE TISSUE CH
Fig. 2. Percentage of rice Y-Leaves samples collected from the Everglades
Agricultural Area in 1984 containing various percentages of K and
RICE TI-'rtH M'
RICE 1 IS-: IE FE
4I F 6 100I
Fig. 3. Percentages of rice Y-Leaves samples collected from the Everglades
Agricultural Area in 1984 containing various percentages of Mg and
PPM of Fe.
RICE ITI~ '! MN
18e 15 2500
RICE TI3J"'E ZN
t II u lpl gmLi
Fig. 4. Percentage of rice Y-Leaf samples collected from the Everglades
Agricultural Area in 1984 containing various PPM of Mn and Zn.
RICE ISISE '.I
_ 1 11 ~ 4 I11
Fig. 5. Percentage of rice Y-Leaf samples collected from the Everglades
Agricultural Area in 1984 containing various PPM of Cu.
The Effect of Plant Crop Cutting Height on Ratoon
Crop Agronomic Performance and Yield
D. B. Jones, Rice Agronomist
Three rice cultivars, Lemont (LMNT), Lebonnet (LBNT) and Skybonnet (SKBT)
were harvested at maturity at five cutting heights (10, 20, 30, 40, 50 cm) above
the soil surface to study the effects of cutting height (i.e. stubble height) on
ratoon crop agronomic performance and yield. The three cultivars were chosen
because of their different agronomic traits. LMNT has a short stature plant
type (also called a semi-dwarf) with proven high yield potential in the plant
crop. LBNT is the most widely grown cultivar in Florida. It is a tall cultivar
(120 cm) with good yielding ability in both the plant and ratoon crops. SKBT is
very similar to LBNT in most agronomic characters, except it is about one week
earlier in maturity.
Cutting height had a significant effect on ratoon crop maturity, Table 1.
Shorter cutting heights delayed ratdon regrowth thus delaying days to 50%
heading for all cultivars. There also appears to be an interaction between
cutting height and cultivar with respect to days to 50% heading.. SKBT was
least effected by cutting height (only a range of about 3 days difference) while
LBNT was most effected (7 days difference) and LMNT was intermediate of the two.
The magnitude of this difference (4 days) is probably of little significance to
growers. The ratoon crop only required approximately one third of the number of
days to reach 50% heading as did the plant crop. Short duration cultivars seem
to have short duration ratoon crops.
Mature ratoon plant height was also effected by plant crop cutting height,
Table 2. Shorter plant crop cutting heights resulting in shorter ratoon crops.
Both LMNT and LBNT mean ratoon crop heights reached approximately 80% of the
plant crop height. SKBT was somewhat less (73%). This might be attributed to
the fact that SKBT reached 50% heading only 26 days after harvest and thus had
very little time for vegetative growth.
The plant crop yields ranged from 5560 kg/ha for LBNT (SKBT was only 10
kg/ha more) to 5900 for LMNT, Table 3. Ratoon crop yields ranged from 1900
kg/ha for SKBT to 3840 for LMNT. LMNT's ratoon crop yielded 65% that of it's
plant crop while SKBT's was only 34%. On the other hand, the ratoon crop yield
range over cutting heights was somewhat less; from 3030 kg/ha at 20 cm to 2110
kg/ha @ 50 cm representing a range of 37 53% RC/PC yield. These figures
represent a 30% difference in ratoon crop yield attributable to plant crop
cutting height, yet there was a 100% difference in ratoon crop yields between
varieties. Therefore, it appears that varietal selection is more important than
cutting height with respect to ratoon crop yields, although cutting height does
have a significant effect.
Table 1. The effect of cultivar and plant crop cutting height on days to 50%
heading in the ratoon crop.
Days to 50% Heading
PC RC RC/PC,%
LMNT 89 34 38
SKBT 80 26 33
LBNT 86 29 34
10 33 39
20 -- 31 36
30 -- 29 34
40 -- 28 33
50 -- 28 33
Mean 85 30 35
Table 2. The effect of cultivar and plant
mature plant height.
crop cutting height on ratoon crop
Plant Height, cm
Table 3. The effect of cultivar and plant crop cutting height on ratoon
PC RC PC&RC RC/PC%
LMNT 5900 3840 9740 65
SKBT 5570 1900 7470 34
LBNT 5560 2330 7890 42
10 -- 2900 51
20 -- 3030 53
30 -- 2830 50
40 -- 2570 45
50 -- 2110 37
MEAN 5680 2690 47
Pesticides Approved for Use on Rice in Florida
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.
-Palm Beach County Extension Agent, Florida Cooperative Extension
Service, located in Belle Glade, FL.
Material Company Use Rate/Application PHI 2.., Comments
Rohm and Haas
BASF, Mobay, DuPont
blast, stem rot
reduce severity of
blast, stem rot,
sheath blight, and
narrow brown leaf
21 Apply at mid-boot (14
days before full
by second application
at heading. Do not
apply to stubble rice.
Apply at boot initiatioi
followed by second
application 14-21 days
later. When mixed in
water, suspension must
be constantly agitated.
2-4 oz/100 Ibs
3-4 oz/100 Ibs
3.3 oz/100 Ibs
2.25 oz/100 Ibs
4 oz/100 lbs
4-8 oz/100 Ibs
Material Company Use Rate/Application PHI 2 / Comments
shortly after first
rice blades appear
on the surface of
the water. Repeat
Rice stink bugs
Rice stink bug
Methoxychlor 50 WP
1 lb/1000 sq ft
7 Apply in 2 gal.
water/A during early
milk and dough stage.
Repeat as necessary.
Do not apply within
14 days of propanil.
15 Crabs, crayfish and
shrimp may be killed.
Do not apply within
15 14 days of propanil.
Restrict spill from rice
fields for 3 days.
100 Broadcast at planting
or prior to flooding.
Do not apply more
than twice per season.
2 Apply at first
sign of insects. Do
not make more than 3
Preventative spray for
empty bins. Use on
Note: Fumigants available for gas tight bins include carbon tetrachloride + carbon disulfide + sulfur
dioxide, carbon tetrachlorida + ethylene dichloride, and aluminum phosphide (Phostoxin).
Material Company Use Rate/Application PHI Co~ent s
grain for storage
1 pt/1000 sq ft
1 pt/1000 bu
Apply to run-off
2-4 weeks before filling
bin. Use on wooden or
Apply as grain is
being loaded or moved
into final storage.
Rohm and Hass
post emergence control
of annual grasses and
1-3 qt/A* Flushing fields prior
to treatment should
produce uniform grass
emergence. Apply to
drained fields when
grass in 1-3 leaf stage
and before rice reaches
4 leaf stage. Flood
fields within 24-hours
grass, and goosegrass
Apply 1-5 days prior
to rice emergence and
after soils have been
sealed by rainfall or
flushing. Soil should
be wet at time of appli-
cation and flushed to
Apply to junglerice
before 3 leaf stage
and after rice has
reached 2 leaf stage.
May be tank mixed with
control of grass
control of certain
aquatic and broad
leaf weeds and
early post emergence
control of barnyard
grass and certain
post emergent control
of broadleaf weeds and
. . 4
Apply as tank mix
with Stam M-4.
Residual activity of
Prowl allows flooding
to be delayed if
Apply when no water
is on the field and
24 hours or more
For continuous flood
culture, treat when
weeds are above water
surface. Retreat if
necessary. May be tank
mixed with propanil.
before early spike
stage. Post emergence
apply after 2 leaf
stage. Post emergence
may be tank mixed with
propanil. Only one
application per season.
Apply 7-10 weeks after
planting and before
rice is in the boot
stage. Do not spray
when temperatures are
. & r
of broadleaf weeds
Apply after rice is
well tillered but before
boot stage (apply 7-9
weeks after planting).
Rice plants are sensi-
tive to 2,4-D in the
early seedling, boot,
and early headingstages.
pre-harvest desiccant 3-4 qt/A
By air, use a
minimum of 5 gallons
water/A. Apply 7-10
days before harvest.
I C ,
0 * V