tO, E. Wagner, Wagner ResearchLaboratory,2645 SykesCreek Boad, RogueR ver Oregon 97537
W-Waves and Plant Communication
Abstract
Plantshave been found to communicatedirecrly with each other. An ar chop to one tree has been d€lected in a neighboing tree for example.The basis of this communication has be€n hypothesizedto be W-wave sisnals.
lntroductlon
There is much recent research that suggests plants are able to communicate.Under stress, such as from insect attack, plants are hypothepheromones, sized emit chemical to substances, that, it is hypothesized, stimulate the surrounding plants to prepare to resisl a similar attack (Rhoades1985). Earlier ve reported the discovery W-waves of in plants (Wagner l988a,b). Evidence for their existence consistedof measuredelectrical patterns,recordedoscillations,excitationbehavior, phenomena. and reflection Measured electrical patterns appeared indicatethat standingwaves to are alwayspresentin plants and have something to do with their physiology. Recorded oscillations demonstrated anotherfeaturethat oue would expectto find if waves werepresent, Other evidence indicatedthat the observedwayeswere not electromagnetic but they interacted weakly with chargeso it waspossible observe to someof their effects with ordinary electrical measurement equipment, We found that one could disturb the apparentstanding wavepattern in a tree at different locationsand detect oscillatory behavior coming from two probes elsewherein the tree. This would be typical behavior for disturbing a standing wave pattern anywhere.Using pulse reflectionswe found the velocity of the wavesin the tree.The evidence pointedto the existence all of wavesin plants. We hypothesized that if insect damage caused treesto communicate maybedamage with an ax or nail wouldcause tree to sendan imthe mediate message the surrounding to trees.The givenhere seems indicatethat this evidence to is the case. alreadyknewthat suchmechanWe ical trauma producedchanges the standing in wave pattern in the damagedtree itself. We theorized that the W-wavesinvolved could also
propagatethrough spaceor ground to adjacent trees(Wagner 1988a,1989fl.The purposeofthis paper is to further discuss evidence the that suggests thatW-haves involredin thiscommuniare plants. cation between
Materialsand Methods LiveTreeSamples
Much of the rnethodology described is elsewhere (Wagner 1988b, 1989h). To determine a live tree responded stress if to damageto a neighboring tree we placed probes in a "transmitting tree" and in one or more "receiving trees," Every lead was groundedcoaxial cable.Pairs of probesin receivingtrees werespacedat varying distances optimize the to signalstrengrhof the received signals. Treeswith relativelyfew and smallerlowerbranches seemed to work best. Since we are dealing with wave phenomena that setup differently in each tree it is difficult to determine ahead of time rhe appropriateplacement contactsor exactlywhere of one shouldchop to producean optimumpulse. It was often effective to place the lower of the two probeson receiving treesjust a few centi metersabovethe ground.Probeson transmitting trees usually used the standardtwo probe spacing (Wagner1988b). Next the transmitting tree was chopped, struck with the sharp edge of a woodcutlei's nearits base ax, oneto threetimes and the resultantsignalsimultaneously recorded from both the transmitting and receiving trees. Where two receiving tiees were used,only the signals from the receiving trees were recorded becausea two channel strip chart recorder was available the time. Eachchannelwaselecticalat ly isolated ftom the other one.A dry cell operated offset adjustablepreamplifier was used in each w c h a n n e lA t t e m p t s e r em a d et o m i n i m i z e n . u necessarydisturbancesto all plants near and NorthwestScience, Vol. 63, No. 3, l9B9 ll9
involved in the experimentssince any kind of damageseemedto increasethe electrical noise output levels of the trees involved in the experiments. To obtain velocitiesof disturbances traveling between treeswe usedthree trees.Table I shows resultsfor both two-lreeand three-tree experiments.SinceW-wavedisturbances seemto travel at appioximately I m/sec in plant material (Wagnerl988a,b;1989h), processing the time (rhe time the wavetakesto spreadwithin the sending and receiving treesbeforepassing probes) sensory may vary with tree height and positionof probes. To reducethe possible variationto effectsof processing time, we reasoned that the use of two receiving trees of near equal heighrswith equally probesand using the differencein arrival spaced times of the transmittedsignalswould eliminate (assuming receivthe possible delayvariables the ing tree delays equal). are When usingthreetrees, olre was chose[ as a transmitting tree and the others as receiving trees.Following a chop into the transmitting tree a sharp rise (heretermed a "pulse" for descriptive convenience) appeared in the output voltage first in the transmitting tree then in the receiving trees.The pulsearrival times were used, together with the difference in distances from the transmittingtree,to calculate the velocityof W-ryaves travelingbetveentrees.Communicationdata were taken spanningmore than a year in time, with variations in methods, to assurethat the observedphenomenaare real. Measurements weretaken in treesat about,160 m abovesea level.
capacitors were madeof Celotex,a foam type insulating material comprisedof foam separating foil layers 3.81cm (1.5in).Oneof rhe sensors by was 96,5 cm x 50.8 cm (#l), and the other was 243.8 cm x 25.4 cm (#2). The capacrtorswere placed flat on level platforms, 1.52m abovethe ground,madeof two inch PVC pipe attached(by ropes)to treesin clumpsof predominantlywhite fir (Abiesconcolorl(fi1) and in madrone(lrbatzs (a2\.Many precautions, minimize menziesii\ to noise,were followedwhen using the spectum analyzer(seeWagner 1989h). Salt SolutionSaturatedTree Sections To demonstrate that W-waves arisefrom external sources and that thesewavesare not peculiar to living organisms used sectionsof trees filled we rith saltsolution communicalion for experiments. Salt solution filled sampleswere prepared by placing 2.4 meter (or less) sectionsof freshly debarked live treesinto l0 cm (4.0inch) diameter PVC pipe filled with saturated solution.Then salt the end wascapped.The containerwasthen laid on its side for at leasta month to allow the wood to absorb the salt solution. Salt solution filled sampleswere removedfrom the PVC pipe and tested on a wooden table in the laboratorv.
Results LiveTreeTransmissions
Figure I showsthe responseof two ponderosa pines to three ax chops in quick succession (within 5 seconds) the baseof the transmitting to tree.The two treeswereabout13.?m apait and both were approximately28 cm in diameter at the base,and 9 m high. To assurea large amplitude transmitted pulse three ax chopswere delivered. Further, not every chop gives a good response because cannotbe knownaheadof it timewhere exactly strikethetreefor maximum lo response because the differencesin the wave of within differenttrces. struclure Delivering more ax chopsinsteadof one often makesthe leading edge and other portionsof the damage.curve more complex than that for just one chop. For example,there are extra bumps after the start of the sharp rise in Figure l. In Table I are shown someolher results I experiments. of One chop or more wasfollowedby a response a in neaiby tree. In the earliest two cases(Table l) we testedpairs of madrones. The damagecunes
Capacitor Sensors
To directlyrecordW-waves, capacitors wereused (Wagner l989a,c,j). preliminaryresults,caIn pacitorsconnected high impedance to voltmeters have been observed producecomparatively to large fluctuating voltages. We attribute these fluctuationsto W-waves space(e.g.a 2 microin farad capacitorhas beenobserved produceas to (unpublished largeas t 50 mv fluctuations observation)). We reasonedthen that large volume capacitors would presenta large crosssectionto W-waves. Thus we usedthem to monitor W-waves travelingin air between trees.Signalsfrom these were analyzed a Schlumberger on rnodell20l FFT low frequency spectrumanalyzer. differenA tial input setting waE used on the analyzer to minimize common mode signals.Two sensor 120 Wasner
\ '16 o
Transmittinq Tree
o
J
F J
J
=
Tree Receiving
20
40 SECONDS
60
80
Figxre I. Transmitting and receivine lree responses ax chops to the baseof the trsnsmitring tree. The higher curre is what to has been previously designateda damage curve from chopping into the base of a tree The lover curv€ repres€nts the output of a receiving tre€ 13.7 m aray. Note the rather small but sharp rise at abour 20 secondswhich is the the curv€sjust b€fore the b€sinnins of th€ receiving tree response. The firsr chop occurred where the line crosses sharp nse.
are smallin amplitudeand the receiverresponses close 0.1 mv with receiverprobespacings to of 1.5 m. Thesefirst resultswere enoughto encourage further testing but we used larger receiver probe spacings (up to 7 m) with apparentlysomewhat larger amplitudes resulting. Due to the delaysmentioned previouslywe did n o l u s el h e s e n i t i a le x p e r i m e n t o d e l e r m i n a i s e velocityfor W-rraves betweentreesbut they still demonstratethat there is communication.The first 4 entries of Table I are typified by Figure l. In Figure I the first chop occurredapproximately at the time the small line crosses two the cuNes just before the sharp rise of the damage curve. The two curvesare synchronizedin time because datafrom the strip chart recording the (where pensare displaced the alongthe recording paper to prevent collision) uas transferred point by point to a computerprogramwhich then replotted At the curves. about20 seconds there
is a sharp rise (in some casesa dip, apparently depending the wavepaltern)in the receiving on t r e er e s p o n sie d i c a t i n gh a t t h e r e c e i v i n t r e e n t g has received data from the tra[smitting tree. From there the receiving tree responseusually flattens (or begins oscillationsor pulsations).In the meantimethe damagecurve from the transmitting tree is decaying rapidly. It is difficult to obtain a secondset of good data from treesin the vicinity immediatelyafter finishingan experiment, nhere r"hopping inis volved due to the noise (oscillationsand changgenerated ing voltages comingfrom probes) in rhe chopped and nearby tiees. We usually attemptedto obtain immediatesecondsetsof data The noisy condition but often without success, persistsfor a few hours and then tests can be resumed. Figure 2 showsthe responseof two receiving trees taken from a strip chart recording. W - W a v e s n d P l a n tC o m m u n i c a t i o n l 2 l a
TABLE l
Thes€ are results fron some of the eaperimentsdone here relarive ro elant comnunication. Trans/Rec. Separation Anpl. Trans. (m,) Anpl. Rec. (-,)
Date Tenp.
Delay G"cs)
3/lB/BB. l90c 3/17/BB. 23ac 3/B/BB' l70c 3/9/88. 7"C 0.1 14.0 34.4 17.6 35.4 7.3 33.2 5.2 3t.7 0.3 0.2 0.3 0.1 0.1 0.1 0.2 0.1 13.7
l3
N/A N/A
P. p'ne
Figure I
First (nadrone)
N/A
3/3r/88.. l6.c
4/l /88. r 24"C
Figure 2
4/r/BB'.
250C 4/5/88..
5.0
pine remp. nor r€c.
' The r€suhs from chopping at the base of a transrnitting tree and one .eceiving tree. Data fron sets of thre€ tre€s wh€re only th€ receiving trees w€.e rnonitoredrhile the transnitting lre€ was chopped. In the last four sers the delay is the time betve€n th€ puls€s receivedfrom th€ Lworeocrvrs rre€s. The velociryofW.waves betwe€ntre€sis calcularedby dividing rhe diff€rencein disbnces fron rhe rransmitting tree by ihis delay.The speci€s treesus€din theseexperim€nts of were pon dercsapi^e (Pinusponderoid), Oregon ash\Ft&inus latifolia), and nzdtone (4rbutus metrziestt.The rine for rheseexperimenrs wasbetween0900 ard 1700 hours. See the rext. "
Thesecurvesare illustratiye of the secondset of four entriesof Table l. Using 20.4 m for the difference in distance of the receiving trees from the transmittingtree and dividing by 4,2 seconds (the time betweenthe sharp rises of Figure 2) gives4.9 m/secfor the W-wavevelocity between trees in this case.SeeTable I for other results. The averagevelocity obtained from the values in the rable is 4,9 cm/secfor W-wavestraveling beh{eentrees.The sameprocedurewasusedfor the three last eotriesfor determining the velocity of W-wavesbetweentrees. Much additional data \,vere taken to be sure of the communicationresult. Someof the additional data had relatively large receiving tree amplitudessomeof which are: 0.6, 0.6, 0.3, 0.2, 0.8,and 0.4 mv. The corresponding distances of separationbetweenreceiying and transmitting t r e e s e r en e a r 1 5 . 2 , 3 . 1 , 2 0 . 4 , 2 1 . 1 3 . 0 a n d w 1 6, , 122 Wagner
13,7 m respectively. These data were from pooderosa pine pairs.
Capacitor Signals
The very existence apparent plant spectra of from the large area capacitorsensors the vicinity of in treesseemlo indicatethat W-waves travel in air rather than through the earth alone since these sensorsare in air with no direct connectionto trees.Thesesensors when connected the l20l to usuallyshowed 1.6 Hz seriesof harmonicsplus a some other peaks(Figure 3) that apparentlyare plant relatedsincethey seemto showonly in the vicinity of a relativelyhigh concentration live of plantsand may indicate constant a communication betweenplants.They are found with much more detailwhenthe spectrum analyzer conis necteddhectlyro plants(Wagner1988a; l989b,d, e,g,h,ij). The data here may indicate somekind phenomena plants. of W-waveresonance in
t-
6.4
o
F
4.8
o
= J =
3.2
Receiving Tree-
l o ,\y*_I_ T .lo
[
1.6
f,""1 l""",frn
, At14.0m I
0 18
22.8
27.6
37.2 32.4 SECONDS
42.4
of Figure2. Cuwesof a strip chart recording of the response two r€ceiyinguees to a {oodcutters ax chop to a transmittingtr€e. The tine on the abscissais the approximate time from the ax chop. All three trees were ponderosa pine (Pinu pond.ercso) near l0 rn in h€isht. S€e th€ texr for mor€ discuasion and Table I for more data.
Salt SolutionFilled Tree Sections Attempts have been made to demonstratecommunicationbetweensalt solution filled tree secdue tions.So far the resultshavebeenambiguous sincewavepatto noise.This might be expected ternsobserved salt solution filled tree sections in havesmalleramplitudes(compareFigure 4 with pattern data of Wagner l9BBb).Also signalsthar are transmittedalong salt solutionfilled tree sectionsappearto be weaker than comparable signals in trees (compare,for example,Figure 5 with Figure I the top curve).Thus probably transmitted sisnalswould also be weaker.
Discussion Characteristics W-waves of fromelectromagnetic W-waves to bedistinct seem waves. Some theapparent of characte stics Wof
wavesare as follows: (l) W-wavesappear to travel very slowly;at about 96 cm/secin live plants (Wagner 1988a; l989h,c)and herewe find that they seemto travel at about 4.9 m/secin air (the range was 4,6-5.0 m/sec). This is not characteristic of electromagneticwaveswhich travel at about 3.0 x 103 m/sec. W.Waves and Plant Communication 123
AVG
-5 dB AVG 4.8 -1 0
't1.2
16
19.2
PowER(dB)i FREa(Hz)
20
Figure 3. Tpical spectrafron the tv/o different capacitorsensors that wereused.Th€ upper spectrum1{asfrom #l and the lower from H2 Geerhe text). Som€of the najor peals sre narLed {ith frequencr(Hz). Othe. peakscan b€ id€ntifi€d b} the facr |hat major peals are spacedby 1.6Hz. Thesespectraare presentmost ofthe tin€ whenrhe s€nEors near plants, are appar€ntlyindicating a W.wave field in the spacenear plant.
(2) A W-wavedisturbancetypically seemsto producea semipermanent displacement charge of (e.g.damagecurve (Wagner l9BBb)and Figures l, 2, and 5 as indicated by the voltage changes) with a relativelyslow decayof this displacement back to equilibrium. A typical electromagnetic pulse,however, a quick changein voltagewith is a quick return to the original value.The W-wave behaviormay be analogous a light pulse fallto ing on a semiconductor which producesercess minodty cardersand then theseslowlyrecombine with majodty carriem in an exponentialmanner. (3) W-wavesappear to interact weakly with chargeso that it takesappreciable time to build up charge(Wagner 1988b). (4) A spectrumanalyzer shows that characteristic W-wave frequencies often appearto combine (heterodyne; e.g.Halliday et al. 1970pp. 332see 334)to form sum and differencefrequencies with (f) the frequency of a smallac voltageappliedwith two probesalong a plant stem(Figure 6). For exampleif f1 is a proper(asyet we don't knowwhat 124 Wagner
determineswhich W-wavefrequencies will combine with the ac signal) W-wavefiequency then f+ f1 will appearin the specrum as well as f- f1. The analyzed signalis monitoredfrom additional probesplacedbetween probesfurnishing the the ac voltage.The observed sum and differencefrequencies appearto providedramaticevidence for the existence W-waves of because their amplitudes are so large (can be millivolts) and the frequencies obtained(fJ match those obtainedfrom or" dinary spectraas well asthose obtainedfrom plant spacings(Wagner l9BBa; l989b,g,h). (5) W-waves seemto be a factor in the spacing of plant structuresas the spacings whenconverted to frequencyappearto match fiequencies measured on the spectrum analzyer (Wagner l989b,c,g,h). This appears demonstrate to standing wave action within a conducting niedium whereelectromagnetic waves wouldquicklydecay. (6) W-waves seemto come from an external source sincethe setoffrequencies obtainedseems to be the samefrom every source.Concernthat
o
o
J
F J
0
J
=
-20
-40
-60 10 20 30 UP CENTIMETERS SAMPLE
Figure 4. Wave pa ern talen froln a portion of a salt solution filled section from *illow (Salr.rsp.).Ii was 3.5 cn in diamer€r at the base and 94 cn long. Probeswere spacedat 1.25cn. The amplitudesof peaks are considerablysnaller rhan a m o l i t u d e s s u a l h o b t a i n e df r o m l i v e t r e . s . u
the spectramight be induced by external noise are areaddressed noting that the spectra nearly by on identicalfrom experiments conducted treesin different locations.Tests also indicate that they don't comefrom the equipment(Wagner 1989h). Thus W-waves(or whateverproducestheir fiequencies W-wavesensors in such as plants, salt filled tree sections, capacitor and sensors) solution For they appear be matterpenetrating. example to appearto travel in plants and highly conducting and their spectraappearcomsalt filled samples, ing from either plants or salt solution filled samples located in metal shields (Figure 7; Wagner l989d,e,ij). Also we obtainedcharacteristic spectra from a potted lemon tree located moie than 100 m undergroundin a mine shaft (Figure 8). Such matter penetrating behavior is waves. The not characteristic electromagnetic of qualitycoEelates with the fact matterpenetrating that other plant phenomena appearto work anywhere on and in the earth (e.g. Salisburyet al. 1969pp. 550-552).
and others Most of the abovecharacteristics (see Wagner 1988b) not tlpical of electromagare netic behaviorand thus we believethat W-waves are a real and separate entity but they do seem wares to interact withcharge eleclromagnetic and in a mannerwhich is not completelyunderstood at this time. The curvesin Figures I and 2 look typical of W-wavebehavior with, for example, and the their buildup and decaycharactedstics the obtainedand thus we associate smallvelocities behaviorwith W-waves. observed communication
LiveTreeTransmissions
time delay between Figure I showsconsiderable from the transmittingtree and the initial response the overt response the receivingtree (at about of This time lag is apparentlylarger 20 seconds). than just the transmissiontime perhapsdue to of in the low velocity(approx.I m/sec) W-waves the transmitting and receivingtrees.Ambiguiry is presentdue to the time it took to make three W-Wavesand Plant Communication 125
o
F
1.6
J
=
1.4
E
1.2
SECONDS
Figure 5. Resultsfron a nail pushed quickly into the base of a salt solution filled tr€e section(Dou e]Gs (keudotsuca nenft :;esii)). This sample was 7.5 cm in dian€ter at the base.A pair oI probes spacedar 2.5 cm were placed along the sampl€ al 30 cm fron the base.Another pair of probes Gpacedat 2.5 cn) were placed along rhe sectionar 3.75 cm fron th€ top. The distancebetweenthe centersof the pairs of probeswas 263.?5gn which when divided by 3.5 sec s l r h Ft i m eb e r w e e n i s n s la r r i v a l sF v e . a b o u r7 5 . m s e cf o r r h e v F I o . i g i n r h i s" a . e . ( l ) i " r h eb e g n n i n go f r h er € b p o n s e ) from the botrom contact pair and(2) r t}e beginning of rhe responsefrom thi-iop contact pair.
dB AVG
N d)
I
t F
@ ,
|
1ll
- l
N . I -
w,i ttr,",,^nlr fl rli,rt
-100 0
I . r t' i l /
pOwER(dB)/ FREA(Hz) 20o
t r it/ i'/
I
I
Fisure 6. A sum and difference ftequ€ncy specrrum(seethe texo .esulting fron applyins a 6mall ac signal (96 Hz) along the stalk of a begonia plant (Begontdsp). Th€ current source electrodeswere 45 cm apart with 65 mv applied through a 50,000ohn.esislor. The electrodeswith leads goiDg to the spectrun analyzerw€re 3.5 cm apa.r along the sralk bebveenthe source electrodes.The first two peaks that are syrnmetricalabour the 96 Hz peal were ar 92 Hz and 100 Hz or at :t4 Hz away from the 96 Hz peal. The next easily readablepeaksare ar i 12, a 16.8, rt9.2, !2t.6, + 2d, a 28.8, i 30.8, ,i 36, t 40.8, and i 60 Hz ud so on away ftom &€ 96 Hz peak. Three of rhe frequ€nciesr€pre6enr€d herc (19.2,24, and 28.8 Hz) a.e integral nultiples (ha.nonics) of 1.6 Hz while rhe others appear to be ha.monics of a subharmonic of 1.6 Hz which here is 0.16 Hz (ercept for 30.8 Hz wher€ it is 0.08 Hz). To the far riehr one sees the second harmonic of Hz ot t92 Hz.
t26
Wagner
t-
-30
dB AVG
19.2
-130
o
( PowER dB) FREa Hz) ( /
20
Figrre 7. A spectrun from probesin a sali solution filled tr€e section(hazelnut,CorlLr sp.)in an aluminun box. The specr.um is tlpical of specha obtained from plants and soludon filled tree sectionsoutside rhe box. The 0.32 spacedpeaks (for a 20 Hz baseband)are still p.e6ent wi& rhe generallylarger anplitude 1.6 Hz harmonicsson€ o{ 1rhichare labelled.
-10
dB AVG
1.6
8
9 . 6 11 ' 2
*nil,,,,,n'
- 11 0
jil,'t'\r,,,ll,l.
(Hz) (dB) FREo PowER / 20
o
Figrre 8. A spectrum taken from probes on a potted lemon (Citrus Linon sp.) tree 100 m underground in a mine shaft. The spectrun is sinilar to that obtained above ground from other plants and salt solution filled tree seciions.Ir appears so far thar W-wave phenomenaare unaff€cted by shielding.
W-Wavesand Plant Communication
t2?
chops (less than 5 seconds). The received (lowercurve at about20 seconds) conis response s i d e r a b l y m a l l e rt h a n t h e t r a n s m i t t i n g r e e s t response it is still quite appreciable but whenit is consideredthat W'wave effects are basically hard to detectdue to the lack of good sensors and a lack of complete knowledgeof the wave characteristics a particular tree. The rises of resultingfiom the receptionof chop information usuallyhad amplitudesof from 0.1 mv to 0.8 mv. The rise in the receiving tree curve preceding the received signal is a normal positive drift whichoften occurson initial placement ofprobes. The top curve is the damagecurve of Wagner l988b, We see no apparent reflection blip becausethe results of severalchops often obscure later curve structure but there are some roughnessin the region wherethe reflectionblip would be expected. A processing time is likely requiredby receiving and tiansmitting trees.We attempted to reduce this effect by testing pairs of trees with presumablysimilar processingtimes to obtain velocitiesfor signalstraveling betweentrees.Of procourse,this may or may not be true because timesmay dependon signalstrength, tree cessing structuredifferences, etc. However,generallyrte obtaineda velocityfor signaltravel between trees which rrasbetween m/secand 5.0 m/secasthe 4.6 air (or gound) velocity(Table l). The magnitude excludetree root of the velocitywould seemingly sincethe velocityin rootswouldprobcoturections ably be similar to that in the body of the plant. ree speedmeasured here is approxThe between imarelyfive times the in siru velocity(96 crn/sec) (Wagner 1989h). The radical differencebetween the in silz velocityand this velocitysuggests that
an air velocitywasmeasured rather than a velociry through earth since salt filled sample tests give an even lower velocity for more densematerials.For example foundvelocities near we of 70 cm/sec pushingin a nail at the baseof fresh by salt solution filled tree sectionsusing time of (Figure5). The flight measurement techniques velocity for W-wavesobtained from Figure 5 is 75 cm/sec but an earlier test on the samesample (24 hoursearlier)gavea velocityof 66 cm/sec and whenthe samplewaspulled from solutionthe apparent velocity was 62 cm/sec.The loss of salt and water as the sample dried appearedto rncreasethe W-wavevelocity.
Conclusions Observations and
T h e d a t ah e r es u g g e sl t a tp l a n l s o m m u n i c a l e h c in a much more fundamentalway than just by (Rhoades meansof aerosols 1985). The data also suggest that this communication involves W-waves. Still there is the challengeof developing a better transducerfor thesewaves.Thesewaves don't interact with anythingvery much and thus a really superiorsensor might be difficult to construct. Trees and other plants with salt solution filled samples and capacitors seemto providethe best detectors far. so
Acknowledgments
The author vishes to thank Dr. Alan Streaterof physics Southern 0regon StateCollege department for his commentsand suggestions. am I grateful to John Salinas of Rogue Community Collegefor his assistance analyzingdata.I apin preciate wife Claudia's my help in taking data.
l989c. Standing vaves in plant tissue. Bull. A m e r . P h y s .S o c . 3 4 : 1 1 0 l,l l . . 1988b.Wave behaviorin plant tissue.Northw. Science.62:263-270. 1989d.V-wales and biologicalclocks.No(hw. Science63:70. l9B9e. W-vaves and cosmology.Bull. Amer. Phys. Soc. 34:506. 198ff.W.Waves and plant comnunication.Buli. Amer. Phys. Soc. 34:110. 19899. V'waves and plant spacings. Bull. Amer. P h y s .S o c . 3 4 : 1 2 2 ? . 1989h.W-lllavesand plant spacings.Northw. Science.In pres. 1989i. W-waves, cosnology, and biolosical clocks. Bull. Amer. Phys. Soc. 34:1227. 1989j.W-waves space. in Bull. Amer. Phys.Soc. 34:506.
Literature Cited
Halliday,D., and R. Resnick.1970.Fundanentalsof Physics. John Wiley and Sons, Inc. New Yor} Rhoades,D. F. 1985. Pherononal communication betwe€n plants and other organisms.ln ChemicallyMediated Interactions Bet*een Plants and 0ther Organiams. Plenun Publishing Corp. New York. Pp. 195-218. SalisburJ, F. B. and C. Ross. 1969. Plant Physiology. Vadsworth Pubiishing Company, Belnont. Vagner, 0. E. 1989a.Plant connunication and W-waves. Norrhw. Science63:69. 1989b. Plant spacing and W-waves.Northrr. Science63:70. 1988a.Standing waves in plant tissue. Bull. Aner. Phys. Soc. 33:2203. Receioed, 3 Norember 1988
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-.
-.
Accepted. publication 26 April 1989 for \28 Wagner