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8 1920
Alabama
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DIRECTOR'S COMMENTS
P roblems f acing Alabama produce's ot
foo~d and tiber are mr o Cmplex today
( han CX er before. Ill lears pacst , XX Cwe rC
contcernled primari ly wXithI plod ucinge
procduicts to feed and clothe the population. Iio
day the same goal is present, but thle road toc
achieX e this coal is filled wsithi many speed bunips
that slowX us down I. T odaX 's business-orienited
agriCultutre is Cccetied w~ith giener at ing a ret urn
to sutpport 
a quality 
litfe stysle. 
At the 'same 
time, 
u ocr 
o osraino 
aua eore
and preserv ation Cot the etiXironnient requireCs LOWELL T. FROBISH
caretful integr ation of pr oduction pi actice "iIthI
existing regulat ions. Research in orte area sometimes plIciXides aniswXCrs that
cause problems in othiet areas, so Xwe at the E xperIimenit St ation luist CCIn-
sider all Iiplications ot outr research.
To help alleXiate agricultutral pr oblemis, t hetre is a reniewscd ittct ntoh~
a systemis appr oach in our researcli. Teanis of scientistsi ate worIIking togethlet
to solv e todaX' ptroduct ion pr obleiis whle pirotectitug and imiproi g lie
envir onment. Extension specialists are more IinvolvXed inii dentit'yitig pr oblems
and helping the basic and applied scietitists in deX elopiiig resear ch procgr aims
to solX e the problenis. Thc research teanis iticlude botanists, plant atid atitial
pathologists, soil and animal scientists, wieed scientists, social scientists ... atid
lhe list could go oii and on. It is thliroughi a teami approach that wie wXill be
able to conttinuci to assist ill the prouductiont ot focod atid fitbet in Alabamak.
You, the producet atid cotisutmer, are ati integral part of this tresetirch teamn.
Y~our cotmments help to establish our reseatrch litogrami, 'soul support anid
assistanice assist itn obtainitng research futtids, and 'sour genetrous enthicsiasti
tot Alabatna sustains us. The latter is ev idetit mn tinies itn the Ireseatrch
gifIts that are prov ided to the facutlty . Recenitly, cut pro~grarn in sport f ishetries
research wXas giveti a t remiendous boost wxit h the dedication ot thle Wiilliami
R. Ireland Fisheriles Research L aboratory . With thle aid Of MIr. I relatid's cift
anid some additional assistance, this labotratotry strtengt hetis ani existitig
Ifishieries and aqua.ultre ptrocramn that is recoctizied airountd the worlt d. WXe
thank Mr i. Itreland Ifor his cottributionti
Many ot her (irganizationis cotitribute to or research ptrogtratms thiioughl
check-off Ifutids, direct gratits, atid othet support. This claly exetmplif ies
the true teatm appr oach. On behalt ot all the scientist's associated wXith the
Alabatia Agr icuiltural Experitmetnt Station, XX e say '"Thank Yion.'
'. 'INt'I R 1989 OL. .36, NO. 4
A q9tiderl\ Iepti~ of r1eseaI cl publistiect
bXv the Xlabatma XAiriciltciial Expeimlenit
Station, Xubctrni Uiieiti.
IOWsELI T. FROBISH .. . Director
DAV ID H. TEEM. . Associate Diieicoi
R.E. STEVENSON ............ [citoi
ROY ROBERSON . ssociate Icditor
KAXIE SNII I H ..... Xssistdant Eitci
11 RI SX RODI)RtUtL .Xit Desigeuue
Editorial C omiilee: I oinset 1. 1 iohisli;
L.K . LtkeiC .lss5otilfc' I e s il/ii! ni/ i
an/d ChIi i/H X c'o/bin 1, 1 .55. Roceter, C
.4. sia I Pro's sor o/ I C/icu/!ii/0/ L i-
nreetion; S. P. Schidt, cl Issoimi Profe'ss 10(1
h u a acnd Dlairy ie'cn ces, I.. B ri ii h
1 ssoo)u111 Proeso 1/of 10 i/ ro/ioo v ind Soils,
N .R . Hiolltei, A 550110/c Profcessor of /1)1)!
ogr Iancd ii e s/icice; Ji.D.1. ii c'c'ic, Pro-
Ic 550/ o/ Bolti iaid MLicitology, P.AX
Dufiit I. kmvisior Prolc'ssor Io! t rc/itnt 11
Li nno/ii La/Id Rural Sot oloc I, R.I.
I iii lt, Pr/c'so of / i / ic I aInIL LI/ll /ic'd
i/LL nrr/tarecs T .P. Ma\ I a tss ((7c' /ti
Ic'i ~ 
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mloy 
anii/ii/ i d iR 
.EI. StevCs 
Cioi.
MAY WEi INTRODUCEF
Dr. IDas id liianss
Soits. A nati~e of
I i li ll/ uTg
South Alica
lBi di ,Is cam toC
Akuhulin il 1987
%iS r heC C ha Iis f0o(1Ccs]
his~ recrch effoils on lie tock ad forae
lIi la aClC i t.i
Hi aiihs earne~d his B.S. dcree C in
21 ,issladli sAcince1011I fo Itle 1l iritX of
Natal ini Soithi AXila heforeC colming 1o the
Illiti StdICs to1 Cdrn i \IXS. in dCIrl10ll1
loint he I iiieit ofS i \liksoiii- COIliihia.
1o Cadn i Ph.D~i. )in Cirassladi scinceiC andi
dlsoca)vCd ali post1 gIaduadie diplomai ill
nmaiketing~ resech a di adkerClisiliC 11011 the
t- liii Cist 01 Souih AXica.
Hi insli tdughi ,iind conducIe CiiI seaCd Clt
theC 1115Cislit of Natl 11rom1 1975 to 1987'
Mil hei earnellid the dialk o1 senior lectureI
simiilal to a professoiis rank in t hei .Lnited
States. He aldsc) spen~t a 1-SCar sahhatical at
lIcxds lCCh ini 1984.
IIis 51tudies at Auhuin ii v hiSCeilped idiel
tify o ptiml grad/ing managdCement miithoids
ithC imidli facets of rioniill ru Cion-
ltiiuius graingli. He rCport s oni the piossiblC
hcinelits d citllls cit a lcitllilil Cii!-
ing S~sc onil p011 3C 1 tii issuiC 01
Higlightsli
ON THE COVER. Wildflowers similar to these
growing near Mobile promise to beautify
Alabama's roadways. See story on page 4.
I tITOR'S NO IL. NleCioni 0f t1ade
namelis doe luol inicateI Clidoilsemienlt hi
Ilhe Aidhdiii Agicuit cil ExpelIiment
Stat iii 01 Auiburn Illi flu i ii of 0 ne blhriind
oxCI anlother. XiiX use cif pesticidlC IdtCs ini
ecCss cot IdhcIccl amiounllts ini ICscarc rc-iI
pore I dcoec)s noti consit5Iute re.ommienuda-
licin 01 sch Idle. Such usC is simiply pdarI
of theC sCiCltiii invig tionil nicCssaI toIc
CXlut dIdcardlis mateIrials. Nocihem~iical
shldc~c he used at I aIes abhoe Cthcose pCI-
lliflih ti IdC l it l. Informaion ConII
ined~c helinI is adiladhle Ico all withut IC-
gad co ra1.ce colol, sex, orI niationl 01igin.
- 0.I. BRANSBY, D.D. KEE, and W.H. GREGORY
INTENSIVE ROTATIONAL GRAZING NOT ALWAYS
BENEFICIAL
2 LA R G~RAZIN 
G
1 
e \peii-
Amenti on wxinter annual
pastuore shoxxed that intenvixe
(Il0-paddock) r otationial graz-
ig m ,piilog did viot prox ide higher
anim ral gain.,x thay traditiovial conitiuous
graingi. I his ix in stark covitrast to
mavix recenti claims that initeniyxe, con-i
toiled cia/inc inicreases carrxying capac-
itx avid aviimal gainsx wxhey compaired to
tr aditiovial methods oit grazing.
lIn .Sptembere o1 1987 avid 19S8b,
pastures xweire planted wxith a mixturie of
Nlar xhall i egi axs (25 lb. per acre),
lBoi~i irxc (45 lb. per acre), avid MIcNair
I10013 xxhcat (45 lb. per acie) at thc E.\V
.Smiit h Rcxcarch C enter of the Alabama
\gi cviiiiial Experiment Station ini
Sho(1tcir. N itrogeni wxas applied as am-
monium nitrate at a rate of 100 lb. per
acre at plant ing avid 60 lb. pci acre in
eail ixM\aich. Soil test results wxeire used
to witrect lx cls of phosphorus avid
potassiuim pr ior to plantinig. G ood
stands xx cie est ablished both xycal, avid
pastus vii xere liightlx grazed in late tall
avid xvitei prioi to the start of the
expei illmi.
iIn Febiruar ot both years, 625-lb.
steers xxere axxicvied either to continuous
gra/inc (nvo xobdix isioni) or irotat jiinal
cirazing xx hich ivi olx ed crazinc each of
101 subdix isiotn, for 2-3 dax s at a time.
Bo0th cont inuvoux avid rotational gra/ivig
xx crc cotnducted at tour xtockivic latex:
1.11, 2.0), 3.0, avid 3.7 steers per acre.
Gria/ingc conitinued for an ax ciace ot 84
dat s, avid axverage daily gain (A DG) xwas
computed from becinnving avid enidiiig
xx i chts of s tcers for all ti eat menit.
Steer ADG avid gaivi per acirex~ we
hicthci for vit tiuous craiic at li. it to
moderate stockivig ratex, but ,liehtlx
loxv.cr at moderate to hich xtockie
rates, see table. Hoxxexer, thix dif lerenc,
wxax small avid the data in the table shoxx
that choice of stockinic rate is more im-
poi tavit thavi the choice of1 rotatiovial or
conlt iuous cia/inc. A\ tockinie rate of
about 2.5 , teris per acre xx ovild pr obablx
haxe beitn optimal, pioxidingc a re.t
xoixbie comvpt omixe bet xxccvi ivaxvinuvm
gain pei animal avid maximum cain
per acie.
Result s o i this stutdy emphasi/e that
rotationial grainig, xxhich is a labor in-
tensix e sx steim, cannot be jostified for
all situoat iOns and is uinlikeix to piroxide
signifi cant lx higher i'ains than con-
tinulouis gra/ing except indhet specific
pasturc conidit iovis. Rotational gira/ing
may be mosit beneificial xxhen dealinic
xxith past ute sper iC, such as altfalfIa
xxhich do not xithstand coit inous
gra/ing 01 xwhen animal ,,,]cct ion in
multispecies pastutres needs to be eon-
trolled . It max' also be bentefIicial duinvi
Grarie mehod 
Cain, bystic 
kine rate
I race .Aeieiage dih te
Coninuus _ Ilb 1.9 1.1 .96 L69
Rttional ... 2.26 1.84 1.42 1.13 i.6
Gain per acret
Continuousi . .. 210) 324 343 299 294
Rtationtal.... 1911 3109 358t 35ii 30i2
per iods of IvIivid oi curtailed paxture
groxxth, such as drought or cold
xxeat her, xwhlen rotat ionial gra/ing couild
more ci Iicienit l rat ion accumulated
forace 01 xxhen pastures aire irrigated
xwith animal xwastewater xxhich makes
pastures tempoirarily unpalatable.
The sitidx suggest thai ioiaiional
gr a/invi is pr obablx uiidesi rable xx lin
manacemenit t imc ix limited or i etn
rainy conidit ions make pastuores x vl-
vierable to lix estock t ramplingc damae
under high stock concenitrations. Also,
rotational gra/invg max be unvixoit able
xxhen past ore xcedliead product ion ix
detrimental to animals because it ustiallx
alloxxs mu e seeding than continuiouis
g ra/inig. I or example, tfuncus-infected
tescue and dallisprass are usually mote
toxie doiring seeding.
Consequent ly, it is import ant to col-
sider all f aetors avid estimate potentiatl
benetfits befor e embarking on ,ophis-
ticated, labor-invt ensix e rotatitonal giraz-
ing schemes.
vitan~bs i,scuiae Protco and ~itKee i,
Reseaich \A~ociie of Aronit andt Sot il,;
Gtegori , sip uiiieiit otf the tBed tini a1 tihe
E .. Smiith ResechI (detr
vs
I/bnne A1 'nil/eral Lx pcrimnwnt Sfll[ir]
R. DICKENS, C. DIXON, and D. TURNER
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O VER IHE PASI L)LCAxUL
the Alabama Highway
Department has developed a
vegetative management pro-
gram utilizing selective herbicides to
reduce mowing and control noxious
weeds. It has eliminated many unde-
sirable plants and converted miles of
roadside to uniform stands of common
bermudagrass, providing the State's
motorists with safer roadsides and
saving taxpayers over $1.5 million
annually in maintenance costs. One
drawback to the program is a lack of
species diversity and color on roadsides.
Research in the Alabama Agricultural
Experiment Station is underway to
develop wildflower species that are both
compatible with Alabama's highway
maintenance program and add color to
the State's roadways. A survey con-
ducted in 1988 identified showy even-
ingprimrose, and 
roadside verbena,
shown above, as species most pro-
minently growing along roadways in the
State. Both are perennial species which
occur throughout Alabama, but they are
more prominent in the southern part of
the State.
Germination studies indicate seeds
from local populations of both species
WILDLOWERS WHI(H PROD)CED SAIIStA(IOuRY
SIANDS FROM COMMIRc(IAI SEED AI LOcAIIONS
THRIOULHOLL ALABAMA IN 1988-89
Common name Flower color Life cycle
Cornflower blue annual
Plains coreopsis yellow annual
Indian blanket red, yellow annual
Lemon mint pink perennial
Corn poppy red, pink annual
Drummond phlox red, pink annual
Blackeyed susan yellow perennial
germinate poorly. Varying light, tem-
perature, and storage conditions and
mechanical scarification of seed failed
to improve germination. Verbena
spreads from creeping rootstock and
there is no commercial source of seed.
Thus, studies are underway to propagate
this species by planting sections of
rootstock of varying lengths at pre-
determined depths. Application of her-
bicides during 1988 for selective control
of grasses had no effect on the amount
of lateral spread of either species in
1989.
Experimental plantings of 15 addi-
tional species were established using
commercially available seed at 40 loca-
etoit inroughout the State. Seeds were
planted in October and November with
a drill seeder especially designed for
uniformly planting seeds of varying
sizes. The seeds were planted in plots
sprayed in September with Roundup at
2.0 lb. active ingredient per acre and/or
flail mowed to eliminate standing
vegetation. Plots were examined in
spring and summer, and though results
varied throughout the State, the species
listed in the table produced the greatest
density of flowers. Over half of these
species planted are perennials, so evalua-
tions will need to be continued for at
least 3 years to fully assess the relative
potential of the individual species.
Once current investigations are com-
pleted, information should be available
for developing criteria for wildflower
management procedures compatible
with other practices in the State's
highway vegetation management pro-
gram. Implementation of the plan
should help bring about more colorful
and interesting vistas for motorists.
Dickens is Professor of Agronomy and Soils;
Dixon is Landscape Engineer, Alabama Highway
Department; Turner is Research Associate of
Agronomy and Soils.
Alabama Agricultural Experiment Station
I " """ ~ ~~ ~.
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h.r:r,
P ia)
C.C. MITCHELL and D.M. BALL
HIGH ALFALFA YIELDS POSSIBLE IN ALABAMA
A LFALFA is experiencing a
slow but steady comeback in
Alabama and the Southeast.
With newer varieties, better
insect control, and improved soil fertil-
ity practices being used, Alabama
farmers are producing around 5 tons per
acre per year. But much higher yields are
possible, and Alabama Agricultural Ex-
periment Station research is seeking
methods of producing up to 10 tons per
acre.
Maximum yield tests were begun in
1986 at the Tennessee Valley Substation
and in 1987 at the Gulf Coast Substa-
tion. The objective was to determine soil
fertility and other soil factors necessarx
for top yields. The highest recorded
alfalfa yield in past Experiment Station
research was 7.6 tons, but the target for
this test was 10 tons per acre.
Treatments listed in the table include
various rates of phosphorus (P) and
potassium (K), some based on soil test
recommendations and some based oni
anticipated removal in hay. A yield of
5 tons per acre is known to remove 70
lb. P
2
0, and 300 lb. K
2
0, and removal
by higher yields would be expected to be
in the same proportions. Soil fumigation
was included in one treatment to deter-
mine effects of nematodes and diseases
on yield. Other practices tested includ-
ed irrigation, deep lime incorporation
(to 36 in.), and high rates (5 tons per
acre) of agricultural gypsum.
Apollo was the variety used at the
Tennessee Valley Substation and Florida
77 at the Gulf Coast Substation. Forage
was harvested first when 10% of the
plants were blooming and every 30 days
thereafter. This resulted in 7 harvests the
first year, 6 harvests 
the second year,
and 5 harvests the third year at the Ten-
nessee Valley Substation and 8 harvests
and 7 harvests for the 2 years at the Gulf
Coast Substation.
First-year yields were 9.7 tons per acre
at the Gulf Coast Substation-a new
record-and 7.5 tons at the Tennessee
Valley Substation. These yields were
produced on plots receiving the high-
est P and K rate (0-240-600 lb. N-
P
2
O-K
2
0). Average yields for the 3- and
2-year periods were less than 1
year, but went as high as 7.4 tons, as
recorded in the table.
Soil fumigation actually reduced first-
year yields at the Tennessee Valley
Substation. The treatment resulted in
rapid, lush growth during establishment,
which was severely damaged by subse-
quent cold weather. This did not hap-
pen at the Gulf Coast Substation, so
yields were improved by fumigation.
Since growth on the soil fumigation
treatment recovered quickly, soil
fumigation resulted in the highest
average annual yields at both locations.
Nematode assay showed that root-
knot nematodes were extremely high in
nonfumigated plots at the Tennessee
Valley Substation. At the Gulf Coast
Substation, dagger and root-knot
nematodes were present in nonfumi-
gated plots.
The gypsum treatment had a highly
positive effect on yields, producing
yields as high as on the fumigated treat-
ment. In 2 years of production at the
Guif Coast Substation, irrigation did
not improve alfalfa yields or stands.
Soil fertility was a more important
factor in yields and stand longevity at
the Gulf Coast Substation than at the
Tennessee Valley location. Initial soil
ests indicated that P was 'low' and K
was 'high' at the Tennessee Valley
Substation, with an annual soil test
,A recommendation of 0-120-120. The Gulf
- Coast location tested 'high' in P and
. 'low' in K, with an annual recommen-
dation of 0-0-240. The Tennessee Valley
Substation yields indicated only a small
. esponse to P and K application. At the
Gulf Coast Substation, yields indicated
no response to P but large responses to
K fertilization. The no-K (0-240-0) and
ow-K (0-240-120) treatments resulted in
osses of stand and more weed problems
it the end of the first harvest season.
Soil testing apparently does a good
iob of predicting P fertilizer needs for
ilfalfa. With yields as high as those pro-
duced at the Gulf Coast Substation,
however, rates of K based on anticipated
crop removal may be a better approach.
Mitchell is Assistant Professor and Ball is Pro-
the first fessor of Aeronomv and Soils.
REsui s o. Ai Ai A MAxiMI i YIEL D TESTI A
Two Al IAAMA LO(AIIONS
Av. yield/acre
Treatment, lb. Tenn. Gulf
N-P,0,-K:0' Valley Coast
3 years 2 years
Tons Tons
0 0-600 (no P) ............ --- 6.3
0-60-600 (low P)........... 6.0
0-240-0 (no K) ............ --- 4.7
0-240-120 (low K) ......... 6.2 5.2
0-240-300 (intermediate K).. 6.6 5.9
0-120-1202 ................ 6.1
0-0-240 .................. --- 5.6
0-120-600 ................ 6.3 6.5
0-240-600 (high P)......... 6.4 6.3
0-24)0-600+ deep lime. ... --- 6.5
0-240-600 + soil fumigation 6.7 7.4
0-240-600 + 5 tons gypsum --- 7.4
0-240-600 without sulfur.... --- 6.3
Annual rate of N-P0,-K,0; other treatments
applied before planting. The same treatments
may not have been applied at both locations.
'Soil test recommendations for Tennessee
Valley soils.
'Soil test recommendations for Gulf Coast
soils.
'Rate based on crop removal.
Alabama Agricultural Experiment Station
I.R. HARDIN
METHODS SOUGHT TO MAKE COTTON FABRIC
NONFLAMMABLE
FAmnericans hasve been unable to
bus children's sleepwsear made
of cotton, even though cotton
ione of the more comfortable, durable
tabr ics as ailable. The reasons fot this
date hack to the early 1950's and ins olve
three related situations: (1) federal las
that requirc children's sleepwsear to be
flame-resistant, (2) cotton's natuoral
tlammahilit ss hich necessitates the ad-
dition of (,pensise flame retardant
finishes to ensure nonflammabilitx , and
(3) the tendency for metal ions found in
hard wsater to combine with compounds
in phosphate-free detergents and dilute
the ef fectis eness of flame retardants on
cotton.
Researchets explortng the reasons for
the third problem soon discosvered that
the chemical reactions insvolved wsere ex-
tremely complicated. Because of this
and cost factors, many sleepswear
manufacturers rejected cotton and turn-
ed to fabrics wxhich could be managed
mote easily and less expensisvely.
Research on the flammability of cot-
ion by the Alabama Agriculturial Experi-
meni Station has continued to explor e
this intricate process. T his research has
been directed at understanding and then
ox ercoming the problems associated
swith making cotton sleepwsear flame-
resistant.
Cotton fibers are composed almost
cntitrcly of cellulose, long-chain
mtolecules sshich torm the basis for most
plants, including all trees. Ptrcvious
research has shown i that sxhen celloulose
butrus and under goes thermal decom-
posit ion (psyroly sis), miany di ffetrcut
chemical products are f ormed. I he
relatix e amounts of these Ptroducts pro-
duced depend on the speed of py roly'sis.
Rapid burniug alloss the Cellulose chaitn
to break itnto small ftragmeut s and pro-
duce tarry substances (anlhx diosugat s)
ss iclh sustain the f lamie and proumote
buining. Flame retardlants ssoi k (is en-
cout acuth le fotmtion jol wat11etr and
Understanding the burning process of cotton helps in develop-
ment of new ways to make cotton sleepwear flame retardant.
inhibitinig ithe fragmtentationi of Cellulose
so thle f abric chars rat he thbait igites.
[lie key to utiderstaiiditig lie effect
of metal ions on the flammabilits of cot-
ton is to explain hoss thle ions iniflune
the cour se of' this thetrmal breakdossni.
Because the pirocess is exitremiels corn
plecated, the reactioii of pure cellulose
ssas first studied; thietn, s arious o gaii
salts and mietals ss cie added to the pro-
cess to test their iinflunice on the
py rolysis. C otton fabric wxas thotrougll
ceained, and then sodiumi, potassium,
iiiagntesi utm, and calciumi salts of
chilorinte anid carbonate swere applied to
or foirmed in the fabric. Thle coietria-
tions of positiv ely charged iotns, ot ea-
tis, oii thle f abrics svaried f romi 0.0111'0
fo 3ll'0. Pyrolysis of these saimples vvas
perform iied at s arious heatin r t es and
temiperatutres.
I olloss ieg psi olysis, the r esultin up li-
ducts wxere separated aiid ident if ied.
(atrboii tionioxide atid dioxide, ss atet,
and a satriet s of organiic eases s et e
lie litedominaiit produoct s f (it titd (is
pyrolsis. (Glscolaldehsde. a smtall
ot ganic mtateital foirmied. C ationis of
eqtual electrtical charge had simtilar ef-
f'eet ott thle tields of miost pyrolysis pro-
ducts, ss tile getuetals the amounts of all
ga seo us litoduoct s generat ed ftromi
soditit- anid poitassium-itreated saiiiples
s\ ete losse ethilan those ftrom calciuiii
anid magitesi n ii ated samples.
Ai nost all intoirantic salt additis es,
r egardless of liedis tpe, iticreased thle
amuout of carbhon dioxide, xx ater, anid
eatrlon muonuoxide. Rat her thiaii les eliite
of f, thle sields of mtost py rolx sis piro0
ducts inceteased or decreased as addi-
tonal salts ssetc added, dependitig oni
the is le of salt used.
ThIiis ireseatrcli, swhIich helps explaini
toss ions chaiige thle cemnistry of bun-
ing, is thle first step toswaid explaiinii
lie coitiplex litr(cess invsolsved iii cottonii
py roly sis. Ontce this lirocess is uiiider-
stood. ness flame tret ardaiit finiishies
couild he des elopied for cottoii ss hicht
c oiild lead to coiltot reclaimiing part of
a mtat ket nio5 closed to it, anid alloss
cotnsuitet s a ss idet choice.
[ it i . 5 it [t' 01 01 o C on~tl
sIt1I,
l lulhrun l' -11(.ltul a! P pei Itl Station
1
SK.F. BRONSON, J.T. TOUCHTON, and R.D. 
HAUCK
N LEACHING UNDER WINTER 
WHEAT MINIMAL
ON SANDY SOILS
C ONCERN OVER ground-
water contamination from
agricultural chemicals has in-
creased in recent years, and
nitrates from heavy nitrogen fertilizer
applications on small grain are a fre-
quently accused culprit. However, tests
by the Alabama Agricultural Experi-
ment Station indicate that leaching of
nitrogen (N) fertilizers is not a major
problem. Nitrates leached into the sub-
soil by N fertilizers are in the tenths of
a part per million range and nitrate from
organic matter is only a few parts per
million.
A field study was conducted from
1987 to 1988 at the E.V. Smith Research
Center on a Norfolk loamy sand to
determine the effects of timing of N ap-
plication. To keep track of the urea
nitrogen used in the study, it was 'tagg-
ed' with the stable isotope 15N.
Treatments consisted of fall applica-
tions of N at planting or split applica-
tions where 30 lb. N per acre was applied
at planting and the balance was top-
dressed in early spring. Rates of N fer-
tilizer were 60, 90, and 120 lb. per acre,
but nitrate leaching was monitored only
for the 120 lb. per acre rate.
FIG. 1 (left). Total nitrate leached at harvest from winter wheat as affected by time
of nitrogen application (120 lb. N per acre). FIG. 2 (right). Fertilizer nitrate 
leached
at harvet harvest from winter wheat as affected by time of nitrogen application (120 Ib.
N per acre).
prolTo Ntal nitae, ~
0. 31 . . 6.0
8 -
16 -
24 -OFall
.
.
f oi Split
..40..
48 -
:''' '':'':'':'' '3 :::O : ::::::::: :'
:;o}ace)
::::::::::::::::::::::....................... I................ *---.*''---*'*.-..".....*--::::---:::...:::,...''*..*...
::Tiij itttrtiijj tiiiii
~it 
~itiiii::: 
;"::S 
""".:: -fiiiocir:: : }i ::{ :: iiir :; :; : ::::::::::::: "}:.:i.r i:.i? ? :r;:>;}: ?: ' ::;;
Wheat yields averaged 68 bu. per acre
for split-applied N and 61 bu. per acre
for fall-applied N. Results of previous
research suggest that split-applied N
often gives higher wheat yields than fall-
applied N. Yields of more than 60 bu.
per acre from an average N rate of 90
lb. per acre indicate efficient crop use
of the N fertilizer applied.
Profiles of total residual inorganic N
and of fertilizer N (both mostly nitrate)
for the 120 lb. per acre N rate are shown
in figures 1 and 2. Inorganic N remain-
ing in the surface soil (0-8 in.) at harvest
averaged 3 p.p.m. (parts per million), or
9 lb. N per acre. This N originated most-
ly from organic matter decomposition
and only 0.3 p.p.m. was fertilizer N.
Split-applied and fall-applied N had
similar N profiles at harvest.
While nitrate at levels of 10 p.p.m. is
considered potentially dangerous in
groundwater, figure 1 shows less than
6 p.p.m. nitrate in soil depths below 8
in. in the Experiment Station tests. Ap-
proximately 90% of this came from
organic matter breakdown during the
growing season. The concentrations of
fall-applied fertilizer N that leached
were less than 0.5 p.p.m., figure 2, and
split-applied N resulted in less than 0.01
p.p.m. nitrogen leached. This equates to
about 0.1 and 0.4 lb. fertilizer N per acre
leached from split-applied N and fall-
applied N, respectively. The beginning
of a nitrate front (5.5 p.p.m.), apparent
in figure 1, is probably due to N leached
from previous cropping seasons.
Near normal rainfall combined with
efficient use of the recommended rate
of N by growing wheat apparently kept
leaching of nitrate to a minimum. Other
loss mechanisms of fertilizer N, such as
gaseous losses, were likely more impor-
tant than leaching.
Bronson is a former Graduate Student and
Touchton is Professor and Head of Agronomy and
Soils; Hauck is Senior Scientist, Tennessee Valley
Authority.
Alabama Agricultural Experiment Station
IFertilizer, pp.m i
S 00 
0 1 :02: 
0.3: 0.4
.24 
O 
pF' ce*Gall
= * o Spilt
7
R. RODRIGUEZ-KABANA, D.B. WEAVER, 
and E.L. CARDEN
SOYBEAN YIELDS 
IN NEMATODE-INFESTED 
FIELDS
BOOSTED BY CROP 
ROTATION, RESISTANT 
VARIETIES
OYBEANS are susceptible to
a variety of nematode species,
many of which can cause large
yield losses. Particularly
damaging are the root-knot and soy-
bean cyst nematodes. These two species
can cause almost complete yield loss
when they occur together. Fumigant W
nematicides, such as DBCP (dibromo- pr
chloropropene) and EDB (ethylene di- tr
bromide), effectively control nema-
todes, but these can no longer be used
because of EPA restrictions. Alterna-
tive nematicides are either ineffective
or not economical to use. Thus, effec-
tive alternative control methods are
needed.
Research on this problem begun in
1986 by the Alabama Agricultural Ex-
periment Station indicates that crop
rotations offer an effective alterna-
tive. In fact, such rotations more than
doubled the yield of soybeans in fields
heavily infested with root-knot and
cyst nematodes.
Three rotational crops-corn, grain
sorghum, and bahiagrass-were com-
pared to continuous soybeans in three
separate experiments on nematode-
infested fields in Baldwin County:
Experiment 1-soybeans in 
1987
following either corn or soybeans the
previous year.
Experiment 2-soybeans in 1988
following either grain sorghum or soy-
beans in 1987.
Experiment 3-soybeans in 1988
following either bahiagrass or soybeans
in 1986 and 1987.
Before the experiments were begun,
the experimental sites had been 
in con-
tinuous soybeans for several years.
The seven soybean varieties listed 
in
ith no nematode resistance, Ransom 
varie
oduced poor yields in the continuous 
soybe
eatment.
.1"'
,'"
~It
-:
'e
B "
-d
7t R43"
B>
the table were compared for 
their
response to crop rotation in each experi-
ment. Six varieties were common to 
all
experiments, with the seventh variety be-
ing Forrest in Experiment 1 and
Stonewall in experiments 2 and 
3. Each
variety was compared with and without
nematicidal treatment with aldicarb.
The aldicarb had little effect on yield,
so variety yields with and without
nematicide were averaged, as reported
in the table.
Although the experiments cannot 
be
compared directly because 
they were
conducted in different years and fields,
qty certain trends are 
evident. Previous
an crop had a large effect on yield in all
three experiments. Average yield 
in-
creases from rotation ranged 
from
31%7o for beans following corn to
106%o for beans following bahiagrass,
as compared to continuous soybeans.
Varieties differed widely in their
response to previous crop. Varieties
Xith resistance to both root-knot and
,oybean cyst nematodes (Centennial,
Forrest, Gordon, Kirby, and Leflore)
lad a smaller yield response to rota-
ion. These yielded more in the con-
.-" tinuous soybean treatment than varie-
S'ies with resistance to only one or no
nematode species, such as Braxton
N (resistant to root-knot nematode, sus-
, ceptible to soybean cyst), Stonewall
(susceptible to root-knot nematode,
resistant to soybean cyst), and Ran-
som (no nematode resistance). Leflore
yielded particularly well in the con-
tinuous soybean plots. When following
the rotational crops, however, variety
selection was less dependent upon
nematode resistance. In experiments 1
and 3, varieties that were less resistant
to the nematode complex made the
highest yields: Braxton in Experiment 1
and Stonewall in Experiment 3. In Ex-
periment 2, Leflore and Stonewall yield-
ed equally well, despite their difference
in nematode resistance.
As shown by results reported, proper
crop rotation can boost soybean 
yield in
fields that are infested with root-knot
and soybean cyst nematodes. When soy-
beans follow soybeans as a previous
crop, a resistant variety is especially
important.
Rodriguez-Kabana is Professor of Plant
Pathology; Weaver is Associate Professor 
of
Agronomy and Soils; Carden is Superintendent of
the Gulf Coast Substation.
Alabama Agricultural Experiment Station
YIE D OF SOYBEAN VARIETIES AS AIFECTED BY PREVIOUS C511 
"
Soybean yield/acre
Experiment 1 Experiment 2 Experiment 3
Variety Following Following 
Following Following Following 
Following
corn soybeans sorghum soybeans bahiagrass soybeans
Bu. Bu. Bu. Bu. Bu. Bu.
Braxton.................. 44 25 27 
10 36 11
Centennial ............... 41 32 34 
23 33 19
Forrest .................. 31 25
Gordon................... 36 29 32 
20 31 12
Kirby ................... 39 34 33 
25 28 17
Leflore .................. 39 34 
42 29 36 27
Ransom .................. 36 27 
34 12 36 14
Stonewall ................ -- -- 
42 12 42 16
Average.................. 38 29 
35 19 35 17
, f
., L:
"~;"~
J.L. DUSI
I
4*
S INCE THE 1960's, the cattleegret 
has been a common sight
in Coastal Plain pastures 
of
Alabama. However, the
droughts that occurred 
between 1985
and 1989 have changed this scene.
The cattle egret, a long-legged 
wading
bird that is a member of the heron 
fam-
ily, relies on frequent rainfall 
to sustain
feeding and nesting areas. It is 
common-
ly found feeding on insects 
in lush
pastures, particularly where 
cattle or
farm equipment have disturbed 
soil and
pastureland to allow the birds 
easy ac-
cess to insects. Frequent 
rains also
stimulate the cattle egrets' 
nesting
behavior and keep their swamp 
nesting
colony sites filled with water.
These birds are desirable because 
they
help control populations of undesirable
insects. Unfortunately, they 
can pose
sanitation problems if they nest 
too close
to urban areas.
Alabama Agricultural Experiment
Station studies had been 
monitoring
four swamp nesting colony 
sites along
the Chattahoochee River in 
Alabama
when the drought period began. 
This
monitoring was done by using airplanes
to sight and photograph egret 
nesting
areas. Prior to 1985 these 
colonies had
contained a total of 13,025 cattle 
egrets.
In 1986 the total dropped to 12,400 
and
by 1987 only three colonies 
remained.
These contained a total of 3,200 
birds.
In 1988, only one colony remained 
with
a total of 1,251 egrets.
A similar census of the Black Belt 
area
of Alabama identified colonies 
at Mont-
gomery, Uniontown, and 
Faunsdale.
The Montgomery colony site 
was
located in scrubby trees on an 
island in
Cooter's Pond. The Uniontown 
and
Faunsdale colony sites were 
in upland
stands of cedar trees. In 1985, the 
Mont-
gomery and Uniontown colonies 
had a
total of 22,000 egrets. The Uniontown
colony left that site in 1986 and 
moved
about 7 miles to a similar site northwest
of Faunsdale. This Faunsdale 
colony
combined with the Montgomery 
colony
totalled only 5,300 egrets but, by 1987,
both colonies totalled 20,000 
egrets. In
1988, the Montgomery colony 
was
deserted after a small number 
of egrets
started nesting, but the Faunsdale 
col-
ony became well established and reach-
ed a population of about 
57,000.
These results indicate that the 
popula-
tion of egrets in the swampy sites 
along
the Chattahoochee River, 
an area with
limited access to pastures, declined 
as
the drought progressed until only 
one
colony remained. A total net 
loss of
11,744 birds resulted. However, 
colonies
in upland sites of the Black Belt region,
where pastures are abundant, were 
not
as severly affected. Though the 
Cooter's
Pond colony was lost, the 
number of
birds in the Faunsdale colony 
showed a
net gain of 35,000 nesting cattle 
egrets.
Declines in bird numbers may be 
due to
death or dispersement of 
colonies,
though the loss of the Cooter's 
Pond
colony was likely caused 
by human
harassment early in the nesting 
season.
This study suggests that the availabil-
ity of pasture has a direct effect 
on the
cattle egret's ability to withstand
drought and that years of severe 
drought
can cause cattle egret colonies 
to decline
or vanish from dry areas.
Dusi is Professor of Zoology and Wildlife
Science.
Alabama Agricultural Experiment 
Station
\R1
J.E. UMPHREY, B.R. MOSS, K.A. 
CUMMINS, and D.A. COLEMAN
WHOLE COTTONSEED 
HELPS MAINTAIN
MILK PRODUCTION 
IN HOT WEATHER
HEAT STRESS is a major con-
cern of Alabama dairy pro-
ducers. When temperatures
exceed 86 ?F during the day
or do not fall below 66 ?F at 
night so
animals can dissipate heat, milk 
produc-
tion can drop as much as 15 
to 30%o.
Production losses are primarily 
because
cattle consume less feed during hot,
humid weather. Increasing nutrients,
especially energy sources, in the
feed can help sustain production
levels. However, this must be 
done
carefully to avoid extreme decreases
in fiber consumed, which can cause
digestive upsets and lower milk fat
content.
Whole cottonseed (WCS) is a
good option because it is high in
energy (about 200 fat) and protein
(23%), but not as apt to cause
digestive upsets because it is also
high in digestible fiber (34% ADF).
Feeding WCS is one alternative,
though it does not always increase
milk and fat production. The recent
development of commercial 
fats
which bypass rumen digestion 
but
are digested and absorbed in 
the
lower gastrointestinal tract provides
another option.
An Alabama Agricultural Experi-
S ment Station study conducted at 
the
E.V. Smith Research Center evalu-
ated the effectiveness and economics 
of
(1) WCS, (2) a commercial fat 
(Mega-
lacR), and (3) a combination 
of the
two. Megalac is a commercial inert 
fat
which increased milk and milk 
fat pro-
duction in early lactation studies.
During June through August of 1987,
32 Holstein cows averaging 130 days 
of
lactation were as-
signed to one of four
treatment groups: (1)
a control diet of
corn silage, corn,
and a protein/min-
eral/vitamin supple-
ment; (2) the control
diet plus 10.3%o
WCS; (3) the con-
trol diet plus 2.67o
Megalac; and (4)
the control diet plus
5.2%o WCS and 1.3%o
Megalac. These pro-
ducts, which were
introduced gradually
over a 2-week adjustment period, 
add-
ed about 3.4% fat to diets 2, 3, and 
4.
These diets had equal 
amounts of energy
and protein, but all were higher than 
the
control diet.
Cows received their feed as a total
mixed ration twice daily while confined
to tie stalls so individual feed 
intake
could be determined. Cows were 
milk-
ed twice daily and allowed to rest 
in a
closely clipped bermudagrass sod exer-
cise area when not tied. Milk was weigh-
ed at each milking 
and morning and
afternoon milkings were sampled 
at
least weekly for butterfat and protein
analyses.
Results in the table show that 
cows
receiving WCS, Megalac, 
or a combina-
tion of the two consumed 
more dry mat-
ter than cows on the control diet. 
This
higher intake resulted in increased 
milk
production. Milk fat percentage 
was
slightly lower among cows on the 
rations
containing WCS. Fat-corrected milk
was lower on the control diet 
than on
other rations and cows on the control
diets were more efficient at converting
feed to milk, as indicated by 
the higher
amount of FCM per pound of feed con-
sumed. Cows receiving 
fat-containing
diets produced milk 
with a lower pro-
tein content. Overall, income was higher
for cows receiving the WCS or control
diet.
Results from this study indicate 
that
milk production can be maintained 
dur-
ing periods of heat stress using 
fat pro-
ducts, however, economics should 
be
considered. Feeding dietary fat products
is a strategy that producers may 
consider
at any time, but it seems 
especially ap-
propriate during periods of heat stress.
Feeding these products, 
especially WCS,
is accomplished easier by using 
a total
mixed ration, but feeding in grain 
mixes
has also been done successfully.
Umphrey is a former Graduate Student, Moss
is Professor, Cummins 
is Associate Professor, 
and
Coleman is Assistant Professor of Animal 
and
Dairy Sciences.
Alabama Agricultural Experiment Station
EFFECT OF WHOLE COTTONSEED (WCS) AND 
MEGALAC IN DAIRY RATIONS ON
FEED CONSUMPTION, MILK PRODUCTION, AND 
ECONOMICS
Result, by treatment
Item Control WCS Megalac 
WSMegalac
Daily dry matter
consumption/ 
cow, 
lb.
Total......................... 35.4 
38.9 40.0 38.9
Per 100 lb. body wt............ 
2.86 3.13 3.19 3.16
Daily production/ cow
Milk, lb .................... 
54.3 59.8 57.0 57.9
Milk fat, pct .................. 3.37 
3.12 3.31 3.18
Protein, pct ................... 
3.09 2.99 3.01 2.84
3.5
0
o fat-corrected milk, lb..... 53.0 
55.2 55.9 54.3
Economic evaluation'
Feed cost/cow/day, dollars ..... 
2.54 2.79 3.61 3.13
Income over feed cost/cow/day 4.75 
4.80 4.07 4.34
'Based on 1987 feed prices of $130 
per ton of WCS and $0.38 per
lb. Megalac and $13.75 per hundredweight 
milk prices.
10
D.P. DAVIS, T.P. MACK, R. RODRIGUEZ-KABANA, and P.A. BACKMAN
AUNUTS-AAES DEVELOPED EXPERT SYSTEM
HELPS MANAGE PEANUT PESTS
NEW TERMS are appearing
with clock-like regularity as
agriculture becomes more
technology oriented. One of
the newest terms is 'expert systems,'
which refers to computer programs that
use the knowledge of human experts to
solve problems. One such system is be-
ing developed by the Alabama
Agricultural Experiment Station-called
AUNUTS-to aid Alabama peanut
growers.
The goal of expert systems is to ap-
ply expert-like reasoning for decision
making by computer when human ex-
perts are not available. Most expert
systems can even inform the persons us-
ing them how a conclusion was reach-
ed. Eventually, the user may learn how
the expert system arrives at decisions,
which has the added benefit of
educating the user.
Expert systems differ from traditional
computer programs by:
1. Engaging the user in a questioning
session that changes as problem condi-
tions vary.
2. Having an expert's knowledge
stored in a knowledge base in usable
form.
3. Having an expert system shell, a
supportive program that allows the user
and the knowledge base to interact. It
directs the question and answer sessions
and determines what information is
needed and whether a solution can be
generated. It may even inform the user
why a particular conclusion was
reached.
Over 200 expert systems have already
been developed, with applications rang-
ing from geology to medicine. A pro-
gram called ProspectorR helps geol-
ogists determine the likelihood that a site
contains ores or minerals and one
named MycineR helps doctors deter-
mine antibiotic therapy for patients. Of
course, the user of such programs must
have a working knowledge of the sub-
ject area to make use of the recommen-
dation presented by the system.
AUNUTS is an example of the many
expert systems being developed for use
in agriculture. This AAES-developed
system is for managing pests in peanuts,
and was designed to be a 'planting-to-
harvest' decision aid. Growers may
maximize profitability while reducing
pesticide use by using AUNUTS to (1)
determine yield loss from root-knot
nematodes and identify profitable alter-
natives for nematode control, (2) deter-
mine most profitable timing of
treatments for fungal diseases, and (3)
conduct cost/benefit analyses for con-
trol of foliar feeding insects and the
lesser cornstalk borer. Management of
these pests requires knowledge of pest
density, crop value, costs of control, and
weather conditions.
The flow chart gives an example of
the logic used by AUNUTS in evaluating
peanut production where root-knot
nematodes, which can seriously reduce
yields, are present in the soil. As noted,
the expert system would inquire what
the previous crop was. If the previous
crop was not peanuts (or another crop
on which these nematodes survive well),
then peanuts could be planted without
economic losses from nematodes. If the
previous crop was peanuts, then
AUNUTS would ask for the number of
nematodes extracted from a soil sample.
An equation has been developed that
allows prediction of yield loss based on
nematodes in soil samples. If this loss
is greater than 600 lb. per acre, then
AUNUTS would recommend planting
an alternate crop. If the loss estimate
was less than 600 lb. per acre, then it
would recommend planting peanuts.
AUNUTS would also ask for the cost of
nematicides to determine whether they
should be used, and what alternative
crops the farmer could plant, to estimate
the most profitable rotational schemes.
AUNUTS has several important ad-
vantages over other methods of decision
making for pest management. It recom-
mends pesticide applications only when
they are economically justified, so un-
necessary applications will be reduced.
Further, AUNUTS integrates the
management of insects, diseases, and
nematodes into a single unit, since deci-
sions made for one pest affect almost all
subsequent actions.
Davis is Postdoctoral Fellow and Mack is
Associate Professor of Entomology.
Alabama Agricultural Experiment Station
11
A.G APPEL and L.G. WOODY
RAPID KNOCKDOWN
PROVIDED BY WASP
AND HORNET SPRAYS
AEROSOL WASP and hornet
sprays are often used for im-
mediate control, or knock-
down, of wasps, 
hornets,
yellow jackets, and other stinging in-
sects. These products have four major
components-propellants, solvents, in-
secticides, and synergists-which are
critical to the performance of the sprays.
Homeowners are frequent users of
these sprays, however, various industries
also utilize these products. For example,
utility technicians often encounter wasps
and other stinging insects infesting out-
door equipment, particularly equipment
that is mounted on utility poles. Con-
trol of these insects must be immediate
to protect technicians who may be work-
ing 20 to 30 ft. off the ground when they
confront the insects. In addition, sprays
used by electric and telecommunications
utilities must not damage plastics which
are used to form telephones, splice
cases, and vitally important wire insula-
tion. These sprays must also be non-
conductive, nonflammable, and rela-
tively noncorrosive.
To analyze sprays 
for industrial use,
an Alabama Agricultural Experiment
Station study looked at two aspects of
available sprays: (1) knockdown effi-
ciency and (2) material compatibility.
Worker honey bees were collected
from hives maintained on the Auburn
University campus and taken to a
laboratory for testing. Honey bees were
used because they are a reliable
representative stinging insect model, are
available year round, and are frequent
pests in outdoor electrical equipment.
Bees were immobilized in a walk-in
refrigerator and gently transferred with
flexible forceps into 1-pt. cardboard
cans. Ten bees were placed in each can
and a single thickness of cheese cloth
was secured on the top. Bees were allow-
ed to recover for at least 1 hour before
testing began. Knockdown as reported
in the table was determined by spraying
2 milliliters (0.7 oz.) of each formula-
tion into the can and counting the
number of immobilized bees after 1
minute. Ten cans were treated with each
formulation, and mortality was assess-
ed 5 minutes after spraying.
In addition to determining effects on
bees, the sprays' effects on plastics were
studied. Injection molded 3-in. bars of
ABS, Noryl, and polycarbonate plastics,
types of plastics commonly used by elec-
trical and telecommunications in-
dustries, were tested for stress cracking
with each spray formulation. Bars were
conditioned for 24 hours at 298 ?F (ABS
and Noryl) or 249 F (polycarbonate)
prior to testing. The bars were bent to
duplicate outer fiber strain of molded
plastic and then six pieces of each were
treated with each spray for-
mulation. Treatment con-
sisted of thoroughly coating
each piece of plastic 
with the KNO( 
K
spray and allowing these to
stand at room 
temperature 
Forn
for 48 hours. Each piece was
then evaluated as intact or
damaged. Six pieces of each Adios ...
Blast...
plastic were also prepared as 
Do It Yo
above but left unsprayed as 
Hunter's
Marko.
control models. Wasp Kil
One-minute knockdown Zep Tox
ranged from 27 to 100%o 
and Malter N
Multicide
could be categorized 
in three Zep TFox
groups: more than 98%, 89- FAWH-I
98%o, and less than 897o. Ex- ARI-B..
Dead Ev
cept for Wasp Killer II, 
all CRC ...
formulations that had 100% Hi-Sting
knockdown also 
damaged 
A-15 ...
some type of plastic. All for- Utilitel #
mulations having 
1-minute Enforcer
Blackflag
knockdown between 98 and Blackfl....
81 % also damaged at least
one type of plastic. The two formula-
tions with the lowest knockdown abili-
ty (Blackflag and SCS) did not damage
plastics. All formulations gave 10007o kill
5 minutes after spraying.
Additional analysis indicated no cor-
relation between 1-minute knockdown
and any of the active ingredients in the
wasp and hornet sprays. Instead, swift
knockdown was found to result from
rapid body temperature depression. For-
mulations providing the best knock-
down lowered body temperature the
most. These formulations contained
Freons, methylene chloride, and other
volatile solvents.
The results further indicate that
sprays can be developed that do not
damage plastic material.
Appel is Assistant Professor of Entomology;
Woody is Staff Manager, Product Evaluation and
Selection, BellSouth Services.
DOWN Eclti NECY ANI) Pi ASIr( STRESS CRACKING OF
WAsP AND HORNET SPRAT FORMuLATIONS
Knock- 
Plastic damage
uation dowmin at ABS-T Noryl Polycarb
1 min.,
Pct. Pct. Pct. Pc.
.100 0 100 100
100 83 100 83
urself...... 100 17 100 33
ZF........ 100 0 100 100
100 0 67 67
ler 11 ...... 100 0 0 0
IV ........ 100 100 33 100
F ......... 98 0 67 100
.......... 96 50 100 0
III........ 96 100 100 83
5 ......... 95 0 33 0
........... 95 0 100 0
e.......... 94 33 100 0
........... 93 17 100 100
........... 91 0 50 0
.......... 91 0 67 0
5 ......... 90 100 100 100
6.......... 89 67 83 0
........... 81 0 17 33
50 0 0 0
........... 27 0 0 0
Alabama Agricultural Experiment Station
Aerosol
sprays
were
applied to
bees con-
fined in
these card-
board
cans.
J. C. JACOBI, P.A. BACKMAN,
and L.W. WELLS
DISEASE REDUCED BY MANAGEMENT
OF SOUTHERN RUNNER PEANUTS
e4-
4n" 4'-- .! l~ ~
Leatsput uariiaye to Florunner peanuts (left) compared to u..utrerr Hujirier
(right), when both were left unsprayed.
UNGICIDES provide good
control of leafspot on peanuts
and some control of other
peanut diseases. The downside
is that leafspot control alone may cost
$50-$60 per acre. Tests at the Alabama
Agricultural Experiment Station in-
dicate that alternative management
practices and a new peanut 
variety,
Southern Runner, may cut production
costs in fields with historically high
levels of peanut diseases.
Florunner is by far the most popular
peanut variety grown in the Southeast,
because of its high yield potential and
other beneficial qualities. However, it is
highly susceptible to leafspot, white
mold, and limb rot. Since the release of
Southern Runner by the University of
Florida, AAES research has been
developing a reduced input fungicide
program to take advantage of the new
variety's reported resistance.
Tests at the Wiregrass Substation in
Headland compared reduced rates of
Bravo, longer intervals between Bravo
applications, and the use of less expen-
sive and less effective fungicides on both
Southern Runner peanuts and Florun-
ner peanuts. Yields of Florunner
peanuts decreased more sharply than
Southern Runner when the rate of Bravo
was decreased from 1.1 lb. (l'/z pt.) to
0.55 lb. (3/4 pt.) and when harvest was
delayed 14 days beyond optimum
harvest date, table 1. The table also
shows the amount of defoliation to be
comparable in the two varieties;
however, Southern Runner apparently
tolerates leaf loss better, based on com-
parative yield loss.
Southern Runner has a more compact
growth habit than Florunner and pro-
duces more secondary branches. In the
figure, neither cultivar received any
fungicide, yet Southern Runner, due to
increased branching, has a relatively
healthy looking canopy compared to
Florunner, which looks nearly defoli-
ated. Delaying harvest produced greater
Ttirt. 1. F FECTSOF FULL SEASON SPRAY PROGRAI
ON YIE D AND LEAr 101 SI VIRITY Oi SoTHIERN
RUNNLR ANL FLORUNNER PLANUI-rs
3-YLAR AVLRALL
Yield/acre at
Optimum Harvest
harvest delayed
date 14 days
Lb. Lb.
Leafspot
defoli-
ation=
Pct.
Florunner
Bravo 0.55 lb.. 2,757 2,666 44.7
Bravo 1.1 lb. . 2,868 2,672 36.0
Manzate 1.5 lb.' 2,649 2,114 53.0
Southern Runner
Bravo 0.55 lb.. 3,124 3,344 46.1
Bravo 1.1 lb... 3,179 3,106 31.8
Manzate 1.5 lb. 3,143 2,837 51.2
All rates are in pounds active ingredient per
acre.
'Defoliation rated prior to harvest.
'Equals 2.0 lb. Manzate 200 BE.
TAHt 2. INE tDLENLE O WH(it MOi o ANU Lots
ROT IN PttNIIN6 of FIORt NER PEANUTS.
3-YE,1R AVERAGE
White mold
hits/80 row-ft.
Florunner
Bravo 0.55 lb............. 8.1
Bravo 1.1 lb ............ 11.1
Manzate 1.5 lb........... 9.9
Southert Rutner
Bravo 0.55 lb... ....... 3.1
Brato 1.1 lb.............. 3.3
Manzate 1.5 lb.............3.7
'All ratev are in pounds active tngredient per
acre.
yield loss in Florunner than in Southern
Runner, especially at high levels of
defoliation. The ability of Southern
Runner to maintain yield could become
important when harvest is delayed due
to adverse weather.
Over the past 3 years, Southern Run-
ner has averaged 650o less white mold
damage than Florunner in tests at Head-
land, table 2. Observations of the two
varieties indicate Southern Runner is less
susceptible to tomato spotted wilt virus,
but no differences were detected in limb
and pod rot.
These tests indicate Southern Runner
can be managed for peanut leafspot less
intensively without significant yield loss,
and it is less susceptible to white mold.
It can he a good varietal choice in fields
where serious leafspot or white mold
damage is expected. However, Southern
Runner is a later maturing variety, re-
quiring about 10 days longer than Flo-
runner to reach harvest maturity.
Jacobi is Research Associate and Backman is
Professor of Plant Pathology; Wells is Associate
Superintendent of the Wiregrass Substation.
Alabama Agricultural Experiment Station
J. L. NOVAK, C.C. MITCHELL, JR., and 
JERRY R. CREWS
AAES "OLD ROTATION" RESULTS IDENTIFY 
LEAST
RISKY ROTATIONS
F INDINGS FROM 92 years of
the Alabama Agricultural Ex-
periment Station's 'Old Rota-
tion' experiment indicate that
the 3-year rotation of cotton-winter
legumes-corn-small grains-soybeans of-
fered the greatest net return potential.
However, this rotation also had a high
level of economic risk. The analysis fur-
ther showed that this risk could be
reduced by a farm plan that put part of
the cotton acreage into a continuous
cotton-winter legume rotation.
In the AAES economic study, data
from 92 years of the Old Rotation were
used to analyze the effect of alternative
AVERAGE ANNUAL NET RETURNS ASSOCIATED
WITH THE OLD ROTATION
Rotations and Net returns
fertilization, over variable
1978-85' costs/acre
Continuous cotton with
winter legumes (0-80-60).... $ 55.09
Continuous cotton without
legumes (0-80-60)...........- 153.98
Continuous cotton without
legumes (120-80-60)-........ 21.42
2 years cotton (0-80-60)-
legumes-corn (0-80-60) ..... - .51
2 years cotton (120-80-60)-
legumes-corn (120-0-0)..... 9.89
3 years cotton (0-80-60)-
legumes-corn (0-0-0)-small
grain (60-0-0)-soybeans ..... 120.31
'Values in parenthesis are annual rates of N-
P
2
05-K
2
0 per acre.
Minimized Deviations from a $40,000 Target Inc
Cotton-Legumes-Corn-Rye-Soybeans, Acres
700
640
580
520
460
400
340
280
220
160
100 I I I 
I I I I I
0 20 40 60 80 100 120 140 160
Continuous Cotton-Legumes, Acres
rotations on sustainable cotton yields.
In particular, the analysis looked at the
effect of winter legumes following cot-
ton as a source of green manure and
nitrogen for crops included in the rota-
tions. Rotations included in the long-
running experiment, as described in the
Winter 1988 issue of Highlights, are as
follows:
1. Continuous cotton, with and
without winter legumes and nitrogen
fertilizer.
2. Two-year rotations of cotton,
winter legumes, and corn, with and
without nitrogen fertilizer.
3. Three-year rotations of cotton,
winter legumes, corn, and small grain-
soybeans double cropped, with nitrogen
fertilizer applied to the small grain.
All rotations received 80 lb. of
phosphorus (P
2
0
5
) and 60 lb. of
potassium (K
2
0) per acre per year ap-
plied to the summer crop or winter
legume, or split between the summer
crop and winter legume.
The net return potential of each of
these alternative rotations was calcu-
lated using the past 10 years' data.
Comparisons were also made of the
economic riskiness of the alternative
rotations on 570 acres of crop land.
The greatest net return was real-
ized from the continuous cotton with
winter legumes and the 3-year rota-
tion of cotton-win-
ome-570 Acres 
ter legumes-small
Risk, $ grains-soybeans.
-24,500 In contrast, the
-23,930 continuous cotton
23,360 without winter le-
-22,790 gumes and nitrogen
22,220 fertilizer 
and the
-21,650 2-year 
rotation of
- 21,080 
cotton-winter 
le-
- 20,510 gumes-corn 
(with-
out nitrogen fer-
19,940 tilizer) did not 
gen-
i 1,80 ecrate 
enough in-
180 200 come to cover out-
of-pocket (variable)
costs.
Results of the risk analysis indicate
that the most profitable farm plan in-
cluded the 3-year rotation of cotton,
winter legumes, corn, and small grains-
soybeans (1/3 of acreage to cotton, 1/3
to winter legumes-corn, and 1/3 to rye-
soybeans double-cropped). However,
this 3-year rotation also had 
a high
economic risk. To reduce this risk, more
and more of the continuous cotton with
winter legumes rotation had to enter the
farm plan. This shift also resulted in a
lowering of potential net return.
Despite a slightly lower net return
margin, the best overall management
strategy to minimize risk while achiev-
ing an expected return of $52,581 in-
volved planting 3100 of the cotton
acreage in continuous cotton with winter
legumes and the remainder to the 3-year
rotation of cotton-winter legumes-corn-
small grain-soybeans.
A curve of the production possibilities
(illustrated by the graph) shows the
highest net return alternative acreages
for the 3-year and the continuous
cotton-winter legumes rotations. Ac-
cording to this graph, a minimum of
a $40,000 net return from 570 acres at
a minimum risk to the producer can be
attained by planting approximately 392
acres (69%) in the 3-year rotation of
cotton-winter legumes-corn-small grain-
soybeans and 178 acres (31%) in the
continuous cotton-winter legumes rota-
tion. A farmer who is willing to take
greater risks may use a higher propor-
tion of his acreage in the 3-year rotation
acreage and less in the continuous
cotton-winter legume rotation acreage.
The analysis reported would be ap-
plicable only to areas with soils and crop
adaptation similar to the Old Rotation
location. In areas where peanuts was a
viable crop, for example, results could
be different.
Novak is Associate Professor of Agricultural
Economics and Rural Sociology; Mitchell is Assis-
tant Professor of Agronomy and Soils; Crews is
and Rural Sociology.
Alabama Agricultural Experiment Station14
- R.T. LOVELL and G. EL NAGGAR
- - r
.0~. ~
4
4
1~.
~
- - - - ~ -
* ,
.4 , ~ .. ~..* A'
4 - , , ~ 44~
~ ?,~ ~ - *4
~44~ /
C .3', ~.- .,
44' 4 4.' A .' '4
,,t. 
.4 *.~ '4 .444
0 ~
4 -~ * I,. -
F - 4. S ,,~ 
4
p
4 .4 ~ 9
NEW SOURCE OF VITAMIN C FOR FISH FEEDS
P RED IO S RESIARH at
lie Alabama Agt icult ural [x-
perimtent Station sltossed that
channel cattish, unlike tat ii
animals, require a dietars soure ot
vitamin C. W\ithtout it they shose e-
duced gr owsth, scut 5 (crooked backs,
depientetitation), and reduced resistance
to iutfect ion and at her stresses.I-
ascorbic acid is the v itamin C source
normally used in commercial tfish teed.
Because this matetrial is sensitiv e to ox-
dat ion, iresultiiig in 4(0-600'o being lost
itn processing, and its halt-litte (time re-
quired f or 50?o to be lost) is less t hait
90t day s, a bettet source ot s itamin C is
needed by catttsh producets.
Ascotrbic acid phosphates and suit ates
are relat iscls stablc agaitist osxidatiot,
howses er their pottetntial as sources ot
5 itamin ( wsas pres touslr unknown i.
Ascotrbic acid phosphate, sx Iich is used
in w'~ometn's facial cosmetics, had not
been es aluated as a source ot 5 itamin C.
A\scorbic acid suitfate is somiet imes used
in salmon feeds, but its sVttamtin C ac
isits also wxas riot k nowsn. I }he Ex~peri-
ment Statiton test com pared these comt-
po~unds ss ith I -ascotrbic acid tot vitamini
C actisvity tor channel cattish. Each
soutrce of s itamitn C ss as ted at f ise dlose
les cls: 01, 11, 22,44, and 132 pp.mi.
(patis pci tiillioni) in purtfied diets nuclet
cotrol(tled enitsiionmitett conditions tot
14 ssecks.
IFisli ted rio ascot bic acid (control) or
he loss et les ets oft ascotrbic acid sultfate
gresw poorly. Although groswthI impros ed
as the dietars lesvel of ascorbic acid
sulfate inctreased, it nes er treached itle
gtoosih tate ot the fish ted 1 -ascotrbic
acid. By coimparisoit, growsthi rate of f ish
fed ascotrbic acid phosphate, esven at a
les el neat t he lossc etimit (of the s itain
C t equitremiett of catfish, was equial to
that of the tish ted I -ascorbic acid.
[lhetc \sere ino stins ot scutsv itt ant
ot the tfish ted I_-ascorbic acid at ascot-
bic acid phosphate. IHowsesetr, 500,% ot
tmore of the tislh ted the contirol diet at
diets containing 44 p. p.mi. or less ascot-
bic acid sulfate had deformed backs
sy mptomtic 0 t scilts y. Only thle highest
dose ot ascorbic acid siulfate (132
ppm.) pt .-,enited deformiities in cattish.
Cothct.I~tiotts ot ascothic acid ini
I isci aind kicities tissue inrcreased as
dietari ascotrbic acid incireased swith tfish
ted I-ascotrbic acid and ascorbic acid
phosphfat c. but onits trtaces ss ere tfound
itt ttssuie ot tishi ted ascotrbic acid sulfate.
I-Iighet cotncentrtat ions ot ascorbic acid
ssete tounid itt tissue at fish ted ascot-
bic acid phosphate than itt fish ted L-
ascot bic acid. Ii his itndicates ascotrbic
acid phosphate is more as ailable to cat-
fish thatn [--ascotrbic acid.
Din bg heat pr ocessing at catftishi
teed, only 0I to 200% itt ascorbic acid
phiospha~t e swas lost, coimpared to 50 to
60(o of at-ascotrbic acid. Because of
intctrcased stabilits during processing and
iie s iiamin C actisvity', ascorbic acid
phtosphtate wsill pirobably be a major
souicc at' sitatnin C in fish feeds in thte
iuttite. I his wsill reduce the lesvel of'
vit amnt C siipplementat iotn necessars in
tish teeds, sshicht should mean a cost
sas ings arid incirease the assurance that
the feed is suitfticienit in sitamini C sshen
fed to fish.
Cira r,,i t'eseaci h S .ila )I I i hcic, and
1 'talu I .'rri ii/ural F spernmenr S tutiot
D.L. KUHLERS 
and S.B. JUNGST
GENETIC SELECTION 
a
FOR GROWTH
GETS FEEDER 
PIGS
TO MARKET
QUICKER 
,A
~luir~uiur a
d:
i, w;7
i 8* n:2i
G ETTING feeder 
pigs to
market early could 
save pro-
ducers money by shortening
the return time on 
invest-
ments in the animals and 
reducing labor
time. Research in the Alabama 
Agri-
cultural Experiment 
Station indicates
that genetic selection for pigs 
that grow
more rapidly between 
weaning and 70
days can shorten production 
time and
save producers money.
In the 6-year Auburn test, 
a line of
Landrace pigs was selected 
specifically
for 70-day weights. These 
pigs weighed
10.1 lb. per pig more 
at that age than
Landrace pigs not selected 
for 70-day
growth. There was little 
difference in
birth weight or weaning 
weight of the
select line of pigs versus 
the control pigs,
indicating that all the increased 
growth
came between weaning and 
70 days, see
table.
The experiment was initiated 
in 1982
using a single population 
of Landrace
pigs, which were weighed 
at 70 days of
age. One line was selected 
for heavier
70-day weight (select 
line). The second
line was randomly bred, 
with each sire
leaving a son and each 
sow leaving a
daughter to go back 
into the herd as
replacement animals (control 
line). All
other production characteristics, 
except
70-day weight, were ignored 
in selection
decisions throughout the 
6-year test.
Management of the 
pigs from the
select and control lines was 
as similar as
possible, with both groups 
of animals
reared in the same building 
and fed the
same diets. Weights 
of the pigs were
recorded at birth, 
21 days, 35 days
(weaning), and 70 days of age. 
Because
no outside breeding stock 
was intro-
duced into either breeding line, 
the in-
breeding of pigs increased to about 
2170o
in both lines at the end of the sixth 
year.
After 6 years of selection, 
the select-line
pigs averaged 10.1 lb. more 
weight than
the control line at 70 days 
of age, which
corresponds to a 13% heritability. 
How-
ever, the select-line pigs 
were only 0.3
and 0.4 lb. heavier than 
control line pigs
at birth and 
at weaning, respectively,
and they did not 
differ in their pre-
weaning average daily gains. 
In the 35-
day postweaning period, 
the select pigs
grew 0.27 lb. per day faster 
than con-
trol pigs.
This study indicates that 
genetic selec-
tion for heavier 
70-day weights in 
pigs
would not be an effective means 
to in-
crease preweaning pig weights 
or growth
ALABAMA AGRICULTURAL EXPERIMENT 
S
AUBURN UNIVERSITY
AUBURN UNIVERSITY, ALABAMA 36849-54
Lowell T Frobish, Director
POSTMASTER-Address Correction 
Request
WEIGHTS ANI GAINS OI SELECI V 
( CONROI
P;s AFIER SIX YEARS O SELECION
Item Select Control
Trait
Birth, lb............. 3.7 
3.4
Weaning, lb.......... 18.0 17.6
70-day wt., lb........ 48.7 
38.6
Average daily 
gains
Preweaning, lb./day... .40 
.40
Postweaning, lb./day.. .87 
.60
rates. However, it appears 
that purebred
swine producers 
can help feeder 
pig pro-
ducers get their feeder pigs 
to market
more rapidly 
or at heavier 
weights by
selecting for 
heavier 70-day 
weights.
Furthermore, feeder pig producers 
can
improve their profitability by 
more
carefully considering 
postweaning 
per-
formance information 
supplied by
breeding stock suppliers.
Kuhlers is Professor and Jungst is Research
Associate of Animal and Dairy Sciences.
TATION
NON-PROFIT ORG.
03 POSTAGE & FEES PAID
PERMIT No. 9
AUBURN, ALA.
ed