• TABLE OF CONTENTS
HIDE
 Historic note
 Main














Group Title: Agronomy research report - University of Florida Institute of Food and Agricultural Sciences ; AY-85-2
Title: Weed populations in conventional and no-tillage peanuts
CITATION THUMBNAILS PAGE IMAGE ZOOMABLE
Full Citation
STANDARD VIEW MARC VIEW
Permanent Link: http://ufdc.ufl.edu/UF00056050/00001
 Material Information
Title: Weed populations in conventional and no-tillage peanuts
Physical Description: 9 leaves : ill. ; 28 cm.
Language: English
Creator: Costello, Shawn Randolph, 1960-
Gallaher, Raymond N
University of Florida -- Agronomy Dept
Publisher: Agronomy Department , Institute of Food and Agricultural Sciences, University of Florida
Place of Publication: Gainesville Fla
Publication Date: 1985?]
 Subjects
Subject: Peanuts -- Weed control -- Florida   ( lcsh )
Genre: non-fiction   ( marcgt )
 Notes
Statement of Responsibility: by Shawn R. Costello and R.N. Gallaher.
General Note: Caption title.
General Note: Agronomy research report - University of Florida Institute of Food and Agricultural Sciences ; AY-85-2
 Record Information
Bibliographic ID: UF00056050
Volume ID: VID00001
Source Institution: University of Florida
Rights Management: All rights reserved by the source institution and holding location.
Resource Identifier: oclc - 62558975

Table of Contents
    Historic note
        Historic note
    Main
        Page 1
        Page 2
        Page 3
        Page 4
        Page 5
        Page 6
        Page 7
        Page 8
        Page 9
Full Text





HISTORIC NOTE


The publications in this collection do
not reflect current scientific knowledge
or recommendations. These texts
represent the historic publishing
record of the Institute for Food and
Agricultural Sciences and should be
used only to trace the historic work of
the Institute and its staff. Current IFAS
research may be found on the
Electronic Data Information Source
(EDIS)

site maintained by the Florida
Cooperative Extension Service.






Copyright 2005, Board of Trustees, University
of Florida






f-.

Agronomy Research Report AY-85-2.



WEED POPULATIONS IN CONVENTIONAL
AND NO-TILLAGE PEANUTS

By
Shawn R. Costello and R. N. Gallaher, Former graduate student, presently
Agricultural Technician and Professor of Agronomy, Agronomy Department,
Institute of Food and Agricultural Sciences, University of Florida, Gainesville,
FL. 32611



Introduction

The Florida peanut (Arachis hypogaea L.) crop is often subjected to
intensive wind and water erosion. In an effort to conserve the soil along with
expensive chemical fertilizers and herbicides, no-tillage practices for peanut
production in Florida are under investigation. Weed control in no-tillage
systems, which do not allow for the frequent, intensive cultivation often
practiced in peanut production, might be difficult or ineffective, resulting in
crop losses. However, no-tillage does allow for the use of an organic surface
mulch which can have several beneficial effects on crop production, including
weed control (Gallaher, 1978; Reeves, 1971) Several growers and researchers
working with no-tillage peanuts have noted from informal observation a
reduction in the numbers of broadleaf weeds in no-tillage peanuts as compared
to conventional (1, 2, 3). The objective of this study was to evaluate the
influence of rye (Secale cereale L.) residue on yields of and weed populations in
no-tillage and conventional tillage peanuts.


Materials and Methods

The experiment was conducted on an Arredondo fine sand (loamy,
silicious, hyperthermic Grossarenic Paleudult) on the Green Acres Agronomy
Research Farm located west of painesville, Florida in 1981, 1982, and 1983. In
late fall (November), 100 kg ha of 'Wrens Abruzzi' rye was drilled into a
conventionally tilled seedbed4 Fertilizers and herbicides applied to the winter
rye crop are shown in Table 1.
The rye crop was harvested _1ith a combine in late May. Over all 3 years,
yields of rye averaged 1,547Tkg ha grain and 3,360 kg ha straw. Straw was
removed from some plots with a forage chopper and redistribteabt y hnd on
the plots designated to receive a mulch treFqi qe FEbuo tllg OI-ch
treatments were set up as a factorial expe mWitn 'i'a"randomized com lete
block design, and were replicated four time The four-treat6ents we 1)
no-tillage into rye straw mulch, 2) no-tillag into ry `stubble where th rye
straw was removed, 3) conventional tillage ith the rye straw ioor ted, and
4) conventional tillage following rye straw rmv JV, O ..

1. Cobb, Leonard. 1983. Personal communication. Marianna, FL.
2. Harden, Gerald. 1983. Personal communication. Banks, ALA.
3. Wright, David. 1983. Personal communication. Quincy, FL.










Plots were 4.6 m wide, and allowed for six, 0.76 m rows. In all 3 years
'Florunner' peanuts were planted in late June to insure good moisture for
germination as the peanuts were unirrigated. Fertilizers, herbicides, and other
pesticides applied to peanuts are shown in Table 1.
Approximately 3 weeks after emergence weeds were identified and
counted in a representative 3.05 m long inter-row sample area in each plot for
all 3 years. A second weed count was made half-way through the growing
season in 1981 and 1983, and a late season weed count was taken at about 100
days after emergence in 1981 and 1982. For exact weed sampling dates, see
Tables 2 through 8. Grassy weed populations were visually estimated as number
of individual plants per unit area.
Peanuts were dug by hand, and yields calculated from a 1.58, 0.76, and
4.65 m area in 1981, 1982, and 1983, respectively. Plants were dried in an
oven at 70 C for at least 48 hours and then separated into kernel, hull, and
plant residue, and weighed. Peanut yields were adjusted to 15% moisture.
Statistical analysis for yield data was done using the ANOVA procedure of SAS
(statistical analysis systems) at NERDC (Northeast Regional Data Center),
Gainesville, Fla. A randomized complete block statistical analysis was preformed
on weed count data using the Radio Shack TRS Model HI microcomputer and a
program written in BASIC.


Results and Discussion

Weed species identified and their populations in each tillage-mulch
treatment are shown for each sampling date in Tables 2 through 8. Broadleaf
weed populations were reduced in the no-tillage plots as compared to
conventional for all 3 years, especially early in the growing season (Figure 1).
There were no grasses in any of the plots following an application of a
post-emergence grass herbicide in 1983, therefore population levels of the major
broadleaf weed present (hairy indigo, Indigofera hirsuta) are shown for both an
early and late sampling date. Broadleaf weed populations increased by
approximately 20% over all plots between 1981 to 1983.
The major broadleaf weed species found in all plots were sicklepod
(Cassia obtusifolia), Florida beggarweed (Desmodium tortuosum), and hairy
indigo. Grassy weeds were a serious problem in all the plots in the second year
of the study and consisted mainly of perennial species such as Texas panicum
(Panicum texanum), and sedges including both purple (Cyperus rotundus) and
yellow (Cyperus esculentus) nutsedge.
For all 3 years the species of weeds found were similar under both
no-tillage and conventional tillage management, although the numbers of weeds
present differed significantly. In 1981 conventional tillage had almost 300%
more total weeds than no-tillage when measured soon after emergence. In 1983,
the no-tillage plus rye straw mulch treatment had significantly fewer broadleaf
weed than all other treatments. This reduction can probably be attributed to
the combined effects of the lack of soil disturbance under no-tillage practices
and the weed supressing characteristics of the rye straw mulch (Gallaher, 1978;
Reeves, 1971). A reduction in the number of broadleaf weeds present under
no-tillage plus mulch systems has been noted by other researchers and growers
working with no-tillage peanuts (4, 5, 6).

4. Brecke, B. 1983. Personal communication. Jay, FL.
5. Cobb, Leonard. 1983. Personal communication. Marianna, FL.
6. Harden, Gerald. 1983. Personal communication. Banks, ALA.










Yields under the four tillage-mulch systems did not differ in any one year
(Table 9), although yields declined significantly over the 3 years of the study. In
1983 a severe outbreak of Cercospora leaf spot prevented peanuts from
reaching full maturity.


Conclusions

An additional benefit from no-tillage management of peanuts in Florida
besides soil and water conservation considerations is suppression of broadleaf
weed populations. A reduction in the numbers of certain noxious weeds such as
sicklepod or Florida beggarweed, especially early in the season as the data
indicates, would give the young peanuts a definite advantage against weed
competition during the growing season. Perennial grassy weeds in peanut can be
effectively controlled with a timely application of the post-emergence grass
herbicide Poast (Table 1) Yields of no-tillage peanuts were comparable to
conventional tillage, and the presence of a rye straw mulch did not affect
peanut pegging or yields.


Literature Cited

1. Gallaher, R.N. 1978. Multiple cropping-value of mulch. In Proceedings of
the First Annual Southeastern No-till Systems Conference. Ed. by J.T. Touchton
and D.G. Cummins. University of Georgia, College of Agriculture, Experiment
Stations. Special Publication No. 5. pp. 9-16.

2. Reeves, Dale L. 1971. Do you have a rye future ahead? Crops and Soils.
23:15-17.












J












1981
--------weeds/100 m2 .-------


a
40 a -

20 -



total
broadleaf


total
grasses


a a a a


1982


total
broadleaf


1983


weeds/10 m-


total
grasses


a


hairy
indigo


total
broadleaf


- a a

"a


total total total total hairy total
broadleaf grasses broadleaf grasses indigo broadleaf

Sno-no-tillage no-tillage cnvenonventoal + conventional -
rye straw mulch / /rye straw mulch 1 rye straw incorp { rye straw


Fig. 1. Weed populations in Florunner peanuts under different tillage and mulching
treatments sampled early (E) and late (L) in the growing season over three
consecutive years. Bars topped by the same letter within weed groups are not
significantly different at the 0.05 level of probability.


a

- Z&


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


_____________________


a a
a a l









Table 1. Management inputs used in 'Wrens Abruzzi' rye and 'Florunner' peanuts
in 1981, 1982, and 1983.


Crop 1981 1982 1983


Rye


-1
336 kg NH4NO3 ha1

1 -1
336 kg 6-11-34 ha-
at planting
0.47 L 2,4-D2 h-1
0.47 L 2,4-D ha


Peanut


3 -1
0.47 L glyphosate ha
pre-plant (no-till only)

4 -1
2.84 L alachlor ha-

5 -1
1.42 L dinoseb ha




7 -1
6.63 L toxaphene ha
in 2 applications

8 -1
908 g bentazon ha

0.94 L chlorothalonil10

I1
0.24 L paraquat-
+ wetting agent
post-directed


-1
112 kgNH4NO 3ha-I

224 kg NH NO ha-
in a split application

0.47 L 2,4-D ha1


- pre-emergence

-1
0.47 L glyphosate ha
pre-plant (all plots)

-1
2.84 L alachlor ha-

1.42 L dinoseb ha-


- post-emergence
-1
6.63 L toxaphene ha1
in 3 applications

0.94 L Poast9 ha-
(too late to be effective)


24 kg K2S04 MgSO4
-1 at planting
ha at planting


-1
0.47 L glyphosate ha
pre-plant (all plots)

-1
2.84 L alachlor ha-

6 -1
1135 g dinitramine ha

-1
336 kg 6-11-34 ha-


-1
0.94 L dinoseb ha

-1
1.89 L Poast ha-1
(in 2 appl., effective)

-1
454 g bentazon ha

glyphosate
(wick application
prior to harvest)


1 N-P20-K20

2 2,4-(dichlorophenoxy) acetic acid

3 N-(phosphonomethyl) glycine-

42-chloro-2'6' diethyl-N-methoxy methyl
acetanilide

2-sec-butyl-4,6-dinitrophenol

N 4,N -diethyl-triflouro-3,5-
dinitrotoluene 2,4-diamine


Chlorinated camphene

8 3-isopropyl-l1H-2,1,3-
benthiadiazin


92-(1-(ethoxyamino) butyl)-5-
(2(ethylthio) propyl)-3-hydroxy-2-
cyclohexen-1-one
10
tetrachloroisophthal-
onitrile

1 ,1'-dimethyl-4,4'-
bipyridinium ion


--


,

ii;. ...
~










Table 2. Weeds in no-tillage (no-till) and conventional tillage (con. till)
'Florunner' peanuts both with and without a rye straw mulch (+ mulch and -
mulch, respectively) on two sampling dates in 1981.


Treatment Weed



Sickle- Beggar- Total Grasses Total B/G
7/23/81 pod (1) weed (2) broadleaf + sedge weeds ratio


# plants / 100 m2
no-till ** ** **
+ mulch 5.1 1.5 6.9 5.5 12.4 4.2
no-till
- mulch 7.8 2.6 10.6 5.4 16.2 3.3
con. till
+ mulch 16.8 12.7 35.0 18.5 53.5 7.0
con. till
- mulch 12.1 12.4 40.9 19.8 60.7 5.8

L.S.D.0.05 5.0 11.0 7.0 15.0 11.0 4.8


Beggar- Hairy Total Grasses Total B/G
9/21/81 weed (2) indigo(3) broadleaf + sedge weeds ratio


# plants / 100 m2
no-till U ** **,
+ mulch 5.1 4.0 9.0 10.1 19.1 1.1
no-till
mulch 9.9 7.5 17.4 11.0 28.4 2.5
con. till
+ mulch 11.9 16.T 28.6 11.0 39.6 4.1
con. till
mulch 7.5 1T.2 24.6 8.6 33.2 3.5

L.S.D.0.05 5.0 10.2 12.0 4.0 11.0' 1.5

*
*Broadleaf to Grasses ratio
Values within columns within sampling dates are signicantly different at the
0.05 level of probability.
(1) Sicklepod (Cassia obtusifolia)
(2) Florida beggarweed (Desmodium tortuosum)
(3) Hairy indigo (Indigofera hirsuta)









Table 3. Weeds in no-tillage (no-till) and conventional tillage
'Florunner' peanuts both with and without a rye straw mulch
mulch, respectively) on three sampling dates in 1982.


(con. till)
(+ mulch and -


Treatment Weed


Beggar- Hairy Sickle- Total Grasses B/G
weed (1) indigo(2) pod (3) broadleaf + sedge ratio


# plants / 10 m


6.8

6.4

23.4

9.5

8.0


**
11.3

12.9

37.9

18.3

12.7


78.1

73.8

54.6

17.4

70.0


12.8

13.6


1.8

1.0

5.6

1.4

6.0



3.4

2.1

10.9

4.9

10.0


8/17/82
no-till
+ mulch
no-till
mulch
con. till
+ mulch
con. till
- mulch

L.S.D.0.05

8/30/82
no-till
+ mulch
no-till
- mulch
con. till
+ mulch
con. till
- mulch

L.S.D.0.05


9/16/82
no-till
+ mulch
no-till
- mulch
con. till
+ mulch
con. till
- mulch

L.S.D.0.05


5.8

3.4

12.8

5.8

10.1


11.3

12.6

10.8

1.4

15.7


**Broadleaf


to Grasses ratio


Values within columns within sampling dates are significantly different at
the 0.05 level of probability.
(1) Florida Beggarweed (Desmodium tortuosum)
(2) Hairy indigo (Indigofera hirsuta) (3) Sicklepod (Cassia obtusifolia)


2.6

2.1

8.3

3.8

7.0


k**
2.8

3.9

9.8

6.0

4.5


0.6

2.5

4.9

2.8

5.5



1.6

4.1

8.3

15.0

20.0


15.0


Grasses + sedge
- % ground cover -


13.1

17.2











Table 4. Weeds in no-tillage (no-till) and conventional tillage (con. till)
'Florunner' peanuts both with and without a rye straw mulch (+ mulch and -
mulch, respectively) on two sampling dates in 1983.


Treatment Weed


Beggar- Hairy Sickle- Total
8/5/83 weed (1) indigo(2) pod (3) broadleaf

2
# plants / 10 m2
no-till
+ mulch 9.7 8.2 2.3 20.7
no-till
- mulch 3.7 16.0 6.7 27.3
con. till
+ mulch 7.2 20.2 9.7 36.3
con. till
- mulch 7.0 28.0 7.0 43.2

L.S.D.0.05 5.0 12.0 5.0 15.0


Beggar- Hairy Morning- Total
8/26/83 weed (1) indigo(2) glory (4) broadleaf


# plants / 10 m2
no-till
+ mulch 8.7 32.2 3.2 46.1
no-till
mulch 5.5 50.7 4.3 61.7
con. till
+ mulch 7.5 46.3 1.7 55.5
con. till
mulch 7.0 54.3 3.5 66.8

L.S.D.0.05 4.0 25.0 3.2 30.2


Values within columns within sampling dates are significantly
0.05 level of probability.
(1) Florida Beggarweed (Desmodium tortuosum)
(2) Hairy indigo (Indigofera hirsuta)
(3) Sicklepod (C assia obtusifolia)
(4) Morningglory (Ipomea sp.)


different at the










Table 5. Yields of kernels, hulls and plant residue of 'Florunner' peanuts
planted no-tillage (no-till) and conventionally (con. till) both with and without
a rye straw mulch (+ mulch and mulch, respectively) over 3 consecutive years.


Treatment Year


1981 1982 1983 X


kg ha-1
kg ha


910

630


560


420

400

470

490


430


1700

1650

1780

1650

L.S.D.0.05=400




560

480

530

530

L.S.D.0.05=200


Plant Residue


2520

2270

2400

2240

L.S.D.0.05=800


Values among
probability.


years are significantly different at the 0.05 level of


Kernels

vo-till
+ mulch
no-till
- mulch
con. till
+ mulch
con. till
- mulch


2880

3240

3230

3130

3120


1310

1080

1400

1390

1290


Hulls


no-till
+ mulch
no-till
- mulch
con. till
+ mulch
con. till
- mulch


710

700

690

720

710


no-till
+ mulch
no-till
- mulch
con. till
+ mulch
con. till
- mulch


4210

3840

4150

3760

3990


1300

1160

1340

1370

1290


2060

1810

1700

1600

1790




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