ROW SPACING AND IRRIGATION
EFFECTS ON PEANUT YIELDS
D.L. Wright, and I.D.Teare
UfMt'R ]3 0 1993
University of Florida
Optimal plant population and irrigation are two methods of
increasing yields of row-crops. This study was to evaluate the
peanut (Arachis hypogaea L.) yield advantage of no-till and
conventional tillage methods at differing row spacings and under
irrigated and nonirrigated conditions. Research was conducted at
the North Fla. Res. and Educ. Ctr. at Quincy FL on a Norfolk sandy
loam soil. Row spacings studied were 15 and 30 inches and
irrigation regimes were no-irrigation and irrigation at three
tensiometer levels (20, 60, and 100 cb) during 1981, 1982, and
1983. The 15 inch row spacing significantly outyielded the 30 inch
row spacing in 1981. In general, no advantage was found between
no-till and conventional tillage. The best signal for scheduling
irrigation on peanut seems to be 60 and 100 cb depending on the
North Fla. Res. and Educ. Ctr.,
Stn. Res. Rep. NF 93-10.
Univ. of Fla., Fla. Agric. Exp.
One method of increasing yield of row-crops is to use optimal
plant population that can be achieved by modification of farming
equipment. Optimal in-row spacing in peanut has been reported as
114.6 plant/ft by Chin Choy et al. (1982) for maximum yield and
Knauft et al. (1981) found 16 inch the best row spacing of 8
inch or 32 inch spacings that were in his experiment. Chin Choy et
al. (1982) found that the 10 inch row spacing gave the highest
yield, which was the narrowest row spacing in his study. Hauser
and Buchanan (1981) found that the narrower row spacings (8 and 16
inch) yielded 14% higher than the 32 inch row spacing. They showed
that the 8 and 16 inch row spacings reduced sicklepod DM yields 53
and 28%, respectively.
A second method for increasing peanut yields is by irrigation.
Yield enhancement is most evident in arid and semi-arid regions,
but irrigation may or may'not be valuable in the more humid areas
of the Southeast. Coffelt et al. (1985) found irrigation increased
peanut in Virginia and Wilson and Stansell (1983) found that water
stress during the last 40 to 75 days of the peanut season
contributed to aflatoxin contamination of peanut kernels.
The objectives of this study was to evaluate the yield
advantage of no-till and conventional tillage methods at differing
row spacings and under irrigated and nonirrigated conditions.
MATERIALS AND METHODS
All peanut studies reported herein were conducted at the North
Fla. Res. and Educ. Ctr. on a Norfolk sandy loam soil (fine-loamy,
siliceous, thermic, Typic Kandiudult).
Cultural practices used on Florunner peanut for 1981, 1982,
and 1983 are shown in table 1. Peanut irrigation dates and amounts
of irrigation water applied are shown in Table 2. Rainfall
distribution in relation to irrigations for the growing seasons are
shown in Fig. 1, 2, and 3.
The experimental design of the row spacing experiment was
randomized complete block with 4 replications and the three
irrigation experiments were split plot arrangements with four
replications per treatment. The main plots were tillage methods
and the subplots were irrigation treatments assigned at random.
Table 1. Cultural practices used on Florunner peanut in 1981,
1982, and 1983 at Quincy, FL.
1981 1982 1983
5 June 19 May 3 June Planted inoculated Florunner seed
at 45,000 seed/A-with Temik at 15
lbs/A, Paraquat at 1 1/2 pt/A and
Prowl at 1 lb-AI/A.
9 June 26 May 9 June Cracking
30 days after planting Bravo was
sprayed on a 2 week schedule
until 2 weeks before harvest.
Fertilizer was applied according
to soil test results.
Herbicides (i.e., Poast,
Butoxone, Lasso and Basagran were
applied as needed during the
12 Oct 1 Oct 19 Oct Peanuts inverted
14 Oct 4 Oct 26 Oct Peanuts harvested
I I 8 I
o I -
.-l 3l 3
(O CO 0
CO i- C
v-l4 n o ;
l r-IH t tP 0'4
LO co o a% cRT oT
14 C H N N)
S1 4J 4)
III l l
I ll Il
r- Un co --
r-I CM NMt r-lT-
10 1 10
1 0 l 0
V V 4J 4J
S)0) 0) 0
4rCU a M tCo
r-4 H NM to %0
NM rl CM NM CM4
00n tn t
r -l -
0 U C
1 I I t If tI It tt tt
o 0 I I .I 1 ,, ,11
135 155 175 195 215 235 255 275 295
3 -i= IIIl !
,,1 tI ti __ ,tttt t
155 175 195 215
235 255 275 295
Si, I i, Ii.
155 175 195 215 235 255
Day of Year
Figure 1. Rainfall during the 1981, 1982, and 1983 peanut growing
season in relation to rainfall and irrigation amounts and
dates of events. Arrows identify irrigations.
RESULTS AND DISCUSSION
The peanut results cannot be discussed without first
describing the weather for the years of 1981, 1982, and 1983 (Fig.
1, 2, and 3). The 1981 peanut growing season was very dry. Only
10 inches of rainfall occurred. Thirteen irrigations were
scheduled on the 20 cb irrigation treatment (12.8 inch irrigation
for the season) (Table 2). The 1982 peanut growing season was wet,
but contained two dry periods from day 145 to day 176 and day 238
to 259. Ten irrigations were applied (4.5 inch irrigation for the
season) to the wettest treatment (20 cb) during two dry periods.
Nine irrigations were scheduled on the 20 cb irrigation treatment
or 5.0 inch of irrigation for the 1983 season. A dry period did
occur from day 260 to day 275 where irrigation was needed.
Table 3. Influence of row spacing with near constant population
densities of 45,000 pl/A on peanut yields under no-till and
conventional conditions (Quincy, FL), 1981.
Row Yield (Ibs/A)
Spacing No-till Conv. Avg.
15" 3462 3940 3701 a
30" 3049 3348 3199 b
Avg. lb/A 3256 3644
In 1981, and experiment was conducted to measure the yield
advantage of narrow rows on peanuts. Population densities were
maintained at approximately 45,000 plants per acre in the narrow
and wide row treatments. The 15 inch row spacing yield
significantly more peanuts than the 30 inch row spacing (Table 3).
Peanut yields between conventional and no-till planting methods
were not significantly different.
Table 4. Influence of four water regimes on peanut yields at'30
inch row spacing and a population density of 45,000 pl/A under no-
till and conventional conditions (Quincy, FL), 1981.
Water1 Yield (lbs/A)
Regime No-till Conv. Avg.
0 irrig 2882 3257 3070 b
100 cb 3624 3960 3792 a
60 cb 3648 3832 3824 a
20 cb 2868 3359 3114 b
Avg. lb/A 3256 ns 3602 ns
Rainfall during growing season = 10.0 inch.
The irrigation study with four water regimes was conducted in
1981, 1982, 1983 with a row spacing of 30 inches and a population
density of approximately 45,000 plants per acre. The dry 1981
season resulted in two significant groupings (Table 4). The 0
irrigation and 20 cb regime were not significantly different
indicating that the 20 cb irrigation signal overwatered the
peanuts. The 60 cb and 100 cb regimes were not significantly
different, but both yielded significantly more peanuts than the 0
irrigation and 20 cb regimes.
Table 5. Influence of four water regimes on peanut yields under
no-till and conventional conditions (Quincy, FL), 1982.
Water1 Yield (Ibs/A)
Regime No-till Conv. Avg.
0 irrig 4233 4123 4178 a
100 cb 3675 3284 3470 b
60 cb 3633 3201 3417 b
20 cb 3738 3361 3350 b
Avg. lbs/A 3820 a 3492 b
'Rainfall during growing season = 29 inch.
The 1982 peanut growing season was wet (29 inches rainfall),
except for the two short periods mentioned above. Peanuts
irrigated at the two higher water regimes resulted in overwatering
and a reduction in peanut yield (Table 5). The 100 cb, 60 cb, and
0 irrigation regimes were not significantly different.
Table 6. Influence of four water regimes on peanut yields under
no-till and conventional conditions, (Quincy, FL), 1983.
Regime Conv. No-Till Avg.
0 irrig 3340 3289 3314 a
.100 cb .3384 3356 3370 a
60 cb 3105 2563 2834 b
20 cb 2468 2893 2680 b
Avg. lb/A 3074 ns 3025 ns
'Rainfall during growing season 22 inch.
The 1983 peanut growing season 22 inches of rainfall occurring
primarily during the first part of the growing season followed by
a dry period from day 255 to harvest is more difficult to
interpret. The greatest peanut yields were at the 100 cb water
regime and the 0 irrigation. The peanut yields were not
significantly different (Table 6), but both were significantly
different from the 20 cb and 60 cb water regimes, indicating that
20 cb and 60 cb irrigation signals overwatered the peanut crop.
The peanut yield between no-till and conventional tillage
methods were not significantly different in 1981 or 1983. The
peanut yields for no-tillage was significantly greater than
conventional tillage during the wet year of 1982 which may indicate
no-tillage allowed more runoff.
Our thanks to B.T. Kidd, Biological Scientist II; and E. Brown,
Senior Technician; North Fla Res. and Educ. Ctr., Univ. of Fla.,
Quincy FL; for plot preparation and management, data collection,
computer processing, and data illustration.
Chin Choy, E.W., J.F. Stone, R.S. Matlock, and G.N. McCouley.
1982. Plant population and irrigation effects on spanish
peanuts (Arachis hypogeaea L.). Peanut Sci. 9:73-76.
Coffelt, T.A., F.S. Wright, and D.L. Hallock. 1985. Performance of
three chinese peanut cultivars under irrigated and
nonirrigated conditions in Viriginia. Peanut Sci. 12:62-64.
Hauser, E.W., and G.A. Buchanan. 1981. Influence of row spacing,
seeding rates and herbicide systems on the competitiveness and
yield of peanuts. Peanut Sci. 8:74-81.
Knauft, D.A., and D.W. Gorbet. 1989. Peanut breeding for leafspot
resistance in wide and narrow intrarow spacings. Peanut Sci.
Knauft, D.A., A.J. Norden, and N.F. Norden, and Beninati. 1981.
Effects of intrarow spacing on yield and market quality of
peanut (Arachis hypogaea L.) genotypes. Peanut Sci. 8:110-
Kvien, C. S. and C.L. Bergmark. 1987. Growth and development of
the florunner peanut cultivar as influenced by population,
planting date, and water availability. Peanut Sci. 14:11-16.
Mozingo, R.W., and J.L. Steele. 1989. Intrarow seed spacing
effects on morphological characteristics, yield, grade and net
value of five peanut cultivars. Peanut Sci. 16:95-99.
Roy, R.C., D.P. Stonehouse, B. Francois, and D.M. Brown. 1988.
Peanut responses to imposed-drought conditions in southern
Ontario. Peanut Sci. 15:85-89.
Wilson, D.M., and J.R. Stansell. 1983 Effect of irrigation
regimes on aflatoxin contamination of peanut pods. Peanut