The relative ripening rate of the grain and straw of ten varieties of oats by Frank C Petr A THESIS Submitted to the Graduate Faculty in partial fulfillment of the requirements for the degree of Master of Science in Agronomy Montana State University © Copyright by Frank C Petr (1952) Abstract: Ten varieties of oats were compared for rapidity of dessication of the straw following maturity of the grain at Bozeman in 1951. Moisture content of the grain and straw was determined at nine consecutive 3-day intervals commencing 30 days after the heading date of each variety. The oat varieties were assigned maturity ratings of early, midearly, midseason, midlate, and late on the basis of heading date. The moisture content of the straw decreased slowly at successive stages and remained relatively high for all varieties throughout the experiment. No significantr differences in straw moisture at the final harvest were evident between varieties. The moisture content of the grain receded rapidly in all the varieties during the first four 3-day intervals. During the 24 days between the first and final harvest of each variety the grain moisture decreased from an average of 43.2 percent to 17.0 percent. The developmental period of the kernel apparently was shorter in Maganski 044 than in the other varieties in the test as indicated by the tendency of the grain to start dessicating in a shorter time after heading. Differential shattering resulting from hail was observed. Mission and Aberystwyth S84 were most resistant. Mission apparently derived its shatter resistance from its Markton parent, which was. observed to have such resistance by another investigator, Late tiller counts were made days after heading. Early Varieties produced significantly more tillers than the late varieties. However, varieties with a tendency to produce late tillers did not differ in straw moisture content. Significant differences in height of the varieties were also noted, but had no apparent effect on the ripening characteristics of the straw. THE RELATIVE RIPENING RATE OF THE GRAIN AND STRAW OF TEN VARIETIES OF OATS
b y
FRANK C0 PETR ■
A THESIS
Submitted to the Graduate Faculty
i n
partial fulfillm ent of the requirements
for the. degree of
Master of Science in Agronomy •
a t
Montana State College
A pproveds
Headp Major Department
C hairm an5 Examining.Committee
Bozeman5 M ontana September^ 195’2 — 2 —
ACKNOWLEDGEMENTS
The w riter wishes to acknowledge the assistance given hjjn by-
Mr* R. F. Eslick. His advice and encouragement throughout the course
of the study are gratefully appreciated. The w riter also wishes to
thank Dr. A. H. Post, Dr. E. R. Hehn, and other persons who contributed
time and advice.
1 0 3 3 2 9 3
TABLE OF CONTENTS
Page
LISTING OF TABLES . ' . eeeeoeeeeeeeooeee e eeooeoe k
LISTING OF FIGURES© eoooeoeeeeooeoceeeeeoeeeee
APPENDIX TABLES ©©@#©©©©@©0 « ©©©©©©©©©©© © © © © © 5'
ABSTRACT *meoo©o**©©c©©©@ *©a*o*o©*e©©a©©© 6
INTRODUCTION© •■©©©©© • • ©«©.•© ©» ©©©©©© © ©©©© ©©© rJ
LITERATURE REVIEW ©©*©@*©*©e*o©*©©»9 o#©©© ©©©© ^
MATERIALS AMD METHODS ©©©©©©d***©©©©©©©©©©*©©©©
EXPERIMENTAL RESULTS© © ©o««o©©© ©©e©©©©*©©©©©© © @ 20
DISCUSSION© *© *4©«©,© * © 09 0 e © © 0 0 0 0 e 90 0 0 0 0 oe 00 0 0 3G
SUMMARY AND CONCLUSIONS © © © * . © © © , » © © © © . © * © © ...... 33
LITERATURE CITED© **00*00*0©*© © © * ©o©*©****©** 3^ *=» ii »
LIST OF TABLES
Page
T ab le I . Source, maturity, rating and principle area of production or development of the varieties and selections included in th e o a t r ip e n in g e x p e rim e n t a t Bozeman3 195>1...... 16
T ab le I I . Moisture content of the grain of ten varieties of oats at nine successive 3~day intervals at Bdzeman3 1951-...... 21 ■ f . • . • ' T ab le I I L Moisture content of the straw of ten, varieties of oats at nine successive 3-day intervals at Bozeman3' 1951 ...... 21
T ab le IV. Analysis of variance of straw moisture percentages at the ninth harvest Of the ripening experiment ...... 22
T ab le V. Reductions in oat yields resulting from hail on August 23, 1951 a t Bo zemhn...... * . . . . 25
T ab le V I. Number of late tillers in four feet dt row in 10 varieties of oats 5-1 days after heading...... 26
T ab le VIL Analysis of variance of number of late tillers in four feet of row in 10 varieties of.oats 5l days aftet heading . . . . 27 i ( ' ' Table VIII. Test weights of ten varieties of oats at nine consecutive 3-day intervals commencing 30 days after heading ...... 27
.Table IX. Heights of the ten varieties of oats included in the oat ripening experiment at Bozeman3 1951 ...... = 2 8 '
T ab le X. Analysis of variance of heights of ten varieties of oats included in the ripening experiment...... 29 LIST OF FIGURES
Pafee
Figure 1«, Moisture content of the grain and straw, of Reselect Glmton and Gopher Oats 0 00 0 * 0 0 0 0000 0 @ » » » ® . 23
Figure 2«, Moisture content of the grain and straw of the three late varieties of oats C 0 0 0 0 0 0 00 0 00 0 0 0 00 0© 23
F ig u re 3= Moisture content of the grain and straw in two midlate varieties of oats 0 0 0000 0000 # 0 » « c 000 0 0 0© 2U
F ig u re Ue Moisture content of the grain and straw in three midseason varieties of oats 0 0 OO0 o0 000 0, 0 * 0 0 0 0 00 0 00 2U
APPENDIX TABLES
T ab le „I» Summary of monthly temperature and precipitation5 May to September inclusive, Bozeman5 1951 • 0 *..0 00 0 0 0 0 -0 » ©37
T ab le I I 0. Harvest dates for successive stages of ripening of the varieties used in the oat ripening experiments at Bozeman5 1 9 5 1 c c c c e e -ei»T0 -0"0 "0'0 -0~0 -*0 0 o * * ® * * * © © © © 37 = 6
ABSTRACT
■Ten. .v.ar.ietiea...oi,...o.ats_wera....cQmpared„i,.Qr ..rap.idi± 3n-of- dessieation of the straw follpwtng..maturity...of....the.,grain,at—B o z e m a n .- . Moisture content o f .th^a..grain...and.-stEaw...was..-de±.erniined._at..nina...consac.u.tive 3-day in terv als commencing.3Q...4ays_.affen...the....heading.-dat.e..Qf...each, varnety. The oat v arie- t lea ._wene._aaslgned_.matnrity._natings- of. ..early^..Jnidearly5. midseason s m id la te 3 and, lata..on_th.e_.basis..of. heading., date.
Ihe_.mis±ure...-content...of.....the.-S.traw...de.creaae.d_.slowly. .at. successive stagaa..and.remained. _relatively..high_for_.all_varietie.s. throughout., the ex perim ents. Mo. S-ignificant_dif f erenc.asL-in..atraM. jnolsiure,,at ...the-f.inal..tarve st were evidenh-he.tween, variettea...... The...mois.tur.e..contentepf the. grain... receded. rapidly-.tn..all....the..varte.tie.s..during.._the._£ir.st„.fo.ur..3^day in te rv a ls,'1 During the . 2i;...days...between...the..firsthand..final..har.ve.at...of..-each'' v ariety the grain ' m o is tu re , .d ecreased...fro m ...an._average..o£: ^ 3*2 p e r c e n t to 17«0 p e r c e n t s .The de.velo.pmental.-.period...Qf-the...icemel. apparently..waa.aho..rter in. Maganski OiiU than in the. .other..varieties..dn...the....tea t .as vindicated..by the tendency of the grain to• start dessicating- in a shorter i' ' / * time after heading, . — — . 1 i""'' ~ ’ ‘~r D ifferential shattering, re suiting. fLrom...hai.l .was..nbs.e.rved,. M ission and Aberystwyth S8U were most resistant. Mission’.apparently derived its shatter, resistance from its Marktdn ..parent_5i.whlch .was. pliseryed to have such resistance by another investigator,
• Late' tille r, counts Were made ^l days after heading,- Early Varieties produced significantly more tillers, than..the_.late..varieties. Hpwever5 -varieties with a tendency. to .pr.oduce_.late-.tiller.s....did. no t d iffer in straw m oisture content,. . ,Sigpif.ic.ant....diC.fe.rence.s..,in..height.3f the v arieties "were also, noted,,. .but.Jiad;no".apparent.-effec.t-..on_ th.e...ripenin|:,.characteristics of th e s tr a w . ca 7 ra
INTRODUCTION
In the production of oats9 as compared to wheat and barleys con siderably greater losses result when the grain is left standing until it reaches a stage suitable for combine harvest» To a large extent3 these losses can be attributed to shattering after the grain is mature and low enough in moisture content for satisfactory storage but with the straw too green for successful combining,,
It has been observed that drying of the culms and leaves of wheat and barley generally proceeds simultaneously with the ripening of the grain while.in oats9 the grain and straw tend to react independently in this respect or9 at least9 the rate of dessication is much slower for the vege tative portions than for the grain,,
Various environmental factors have been cited as affecting ripening of oats and other crops (9)1/ Therefore9 it would appear desirable to develop varieties of oats that ripen due to some internal stim ulus' inherent in the plant and operating with little or no regard to external Conditions0
This property appears to be present to some extent in common wheat and certain other crops in which definite ripening, occurs even during periods when clim atic conditions are not considered favorable for ripening to take p l a c e , '
The object of this investigation was to determine the relationship of ■ grain and straw moisture as the grain approaches maturity,, and to invest!- = 8 =
gate possible varietal differences in straw dissipation which could be
utilized in the development of oats with the qualities necessary to over=
come this harvest problem. Since resistance to shattering is also an
important factor in combine harvesting,, observations were made to determine
varietal differences in this respect.
Late- varieties as well as tall varieties of oats with a large amount
■of vegetative growth are sometimes thought to have a slower ripening process
than varieties which head earlier in the season or short varieties that
produce little foliage, A correlation between rapidity of straw dessiqation
and such readily observable characteristics as height of straw or heading
dates could likewise be of value to the plant breedsr^
To avoid possible confusion, some of the terminology used in this
paper w ill be explained at this point, "Maturity" w ill denote the time at i i ■ ' which the maximum amount of dry m atter has been accumulated in the plant or
in a plant organ such as the caryopsis, nRipenihjgn w ill be used in refer=
epee to the dessication process commencing a t'maturity and possibly before maturity of either the seed or the foliage, Tiie grain is considered ripe
when its natural moisture content recedes to 16 percent, which is the maximum
moisture percentage, allowed in the four numerical market grades of culti
vated oats. (19)» Since no general standard is. available, 2$ p e r c e n t
moisture,, other than that absorbed from the atmosphere, is considered the
upper limit for ripe straw, . . C=I ^ CD
LITERATURE REVIEW
To date there are but few papers published on harvesting problems encountered in the production of oats 0 An intensive search of the liter-= ature has disclosed none in which the moisture relationships of oat. straw and grain have been studied® Much of the literature dealt with effects of varying degrees of m aturity on such factors as germination, yield, frost resistance, and chemical composition with reference to feed value of the grain and straw® However, some of the'findings are pertinent to this problem and w ill, be reviewed accordingly®
Burnett and Bakke (7.) studied the effects of delayed harvest on yield of grain in Iowa in 1930® Their results show that pats and barley are more susceptible to shattering losses resulting from delayed harvest than is wheat®
Rather (17) reported on studies of the effects of delayed harvest which were started by W ilsie and Brown at the Michigan A gricultural Experi ment Station in 1931®. Using the same crops, they obtained results sim ilar to those of Burnett and Bakke® One phase of the Michigan experiment involved the comparison of Markton, W orthy,. W olverine, and Iogold oats®
The results are best expressed in the summary by Rather in which he states,
"Of the varieties tested, none appeared, to have any special advantage for combine harvest as standing grain® Markton oats was the least susceptible to shattering but had the weakest straw ®11 - Bushel weights of oats' decreased rapidly when harvest was delayed and such losses were greater in oats than in barley® The moisture content of the straw was not reported for this " XO —
experiment or for the one by Barnett and Bakke cited previousIy 0
Kedzie (13) compared the chemical composition with reference to feeding value of wheat straw and grain harvested on h 6 consecutive days* Moisture
contents however, was not .determined for either the grain or the Straw0
He found that wheat straw deteriorated much more rapidly in nutritive value and composition than did the grain*
The moisture content of wheat foliage at flowering was studied by
Hurd=Karrer and Taylor (12) to test the contention that the moisture con tent of the vegetative, portions of the wheat plant drops suddenly after flowering* They found no evidence of a maximum water content at flowering nor of a sudden water loss after fertilization of the florets had occurred*
In general, their results indicated that the water content of the leaves was decreasing from the time the experiment commenced* This was nine days prior to anthesis in Kanred winter wheat and four days before, anthesis 'In
Purplestraw No* I wheat* A decrease'in moisture content of the foliage was usually' more closely associated with hot dry days than with any particular stage of maturity* '
Bakhuzen (I) measured the moisture content in various parts of wheat plants when grown under constant conditions* He found there was a definite increase in dry matter immediately after flowering* This was not in agree ment with the findings of Hurd-Karrer and Taylor (12)* However, the conditions of BakhuzeneS experiment apparently were not natural as each plant produced only one culm, and flowering commenced about th irty days, after the plants emerged* “ 11 "
Percival (16) at Rea.ding5 England# observed that in wheat# the
ripening process of the grain and straw' proceeded at about the same rate o'
He found the time between "earing and ripening" to be usually from 55 to
63 days 0
Numerous studies (2#3#lt#5s6#10#11#20) on the development of the oat
kernel as well as sim ilar studies on wheat and barley have been published®
There is quite general agreement on the ripening processes occurring from
flowering to maturity of the grain 9
B ooth (I4.) made a detailed study of the daily growth of Gopher oat kernels from pollination to maturity«, Flowering lasted for about eight
days starting with the term inal florets and progressing downward^ The kernels in the spikelets originating from the lowest whorl were in the late,
dough s tage when the apical spikelets were Idpe 0 The green weight increased rapidly £or 13 days and after 15 days there was a marked decline in green w e ig h t0 -Dry weight increased more rapidly than green weight during this period indicating a decrease in moisture percentagea
According, to Booth (it)# the developmental period of the kernels continued for 15 days after pollination and was concluded when the glumes of the apical spikelet became straw colored* General ripening was completed in it days* During this time# the lemma and palea became a uniform straw color and moisture decreased from itldt? to 21*00 percent* No observa tions. on straw moisture were made, as the primary interest was in the effect o f immaturity and frost on the germination of the grains = 12 =
Wilson and Raleigh (22) studied the changes occurring in Victory oats
as it approaches maturity* They found that dry matter percentages of all
parts of the oat plant increased with approaching maturity. This, is
sim ilar to their results with wheat, although the moisture content of the
oat plant averaged considerably higher from milk stage to m aturity than
was true for wheat. Twelve days prior to maturity, the kernels and glumes
contained about 39o$ percent dry matter. This increased to 81,3 percent
dry matter when the oats was considered mature. The vegetative parts at
the same stages of m aturity averaged 2£.9 percent and 66*9 percent dry
matter respectively. The experiment was carried on in a severe rust
season. Therefore, the dessication of the leaves may have been more pro= npunced than under normal conditions.
Harland and Pope (H ) studied the moisture level of the barley kernel from flowering to maturity. They report that no further increase in dry matter occurs when tjie moisture content of the kernel falls below U2 p e r=
cent. They likewise ■ considered this the end of the developmental period
and noted that dessication proceeded rapidly after that moisture level
occurred. Volume of the kernel began tp decrease at the end of the developmental period and continued to decrease throughout the ripening p r o c e s s .
The effect of certain mineral nutrients was studied by Noll (15>) and
McClelland (ill), Several nutrients apparently induced earlier ripening of oats when applied to area's deficient in those nutrients. Noll Reported phosphorus was outstanding in this respect. However, earliness pould not «=> 13 «=
be forced by applications greater than the amount needed to obtain maTimnm
yields# At the Ohio Experiment Station (Ui)9 acid phosphate |iad more
effect on promoting earliness than rock phosphate or basic slag even where
yield response was the same. Further investigations showed that the.
influence on earliness varied with yield response when low and moderate
applications were used. -The effect of phosphorus on the moisture content
of the straw was not investigated in any of several papers dealing with the
effect of phosphorus on m aturity.
Describing the difficulties in determining maturity of cereal crops,
Gapom (8) states, "The ripening of cereal crops is a characteristic which
is very difficult to study from either a physiological standpoint or from
a genetic point of view. Observations are usually made by 1Oye1 and are usually not based on any type cereal crops are the influence of climate and soil." • According to Graber and Ahlgren (?), cool weather encourages the development of basal buds, whereas hot and dry weather reduces and some= ' times eliminates all tillering. Delayed harvest due to uneven ripening is usually attributed to the development of additional tillers shortly before or after the emergence of floral heads. Burnett and Bakke (?) states that physiological properties have an important role in ripening and that sugars and proteins determine the water ■ i • relations of cells. Amino acids and glutenin found in wheat have great moisture retention properties which extend the ripening period of the grain© In 1917s Gaporn (8) studied, the heredity of early and late riperiing in a cross of Mesdag and Hopet6vm» The two varieties' differed in ripening time by: approximately 18 days* The progeny of the cross'ranged in ripening time from that of the earlier variety to the later. His analysis of the data indicated that inheritance was based on1 three factors. Color of the palea was used, as a criteria of ripening. Moisture, content of the kernels was not determined and the condition of the straw at the time the kernels were considered ripe was not ^mentioned. MATERIALS AtfD METHODS Six varieties and four unnamed selections of oats were used in this experiment. These were divided arbitrarily into groups according to heading dates. Table I gives the heading date, source, and other pertinent in formation. on. each- of the oats -included in this experiment, In this paper future references to varieties w ill be by name angl unnamed selections w ill be ,referred to by number As indicated ,by an asterisk in Table I, . The oat varieties usdd in this, experiment were grown on the- Aghbnomy and..Soi^s Department farm .located near ,Bozeman, The soil, classified as Huffine silt loam, was of good fertility, anh received no fertilizer treat ment, ,The plots received tinly one light irrigation during the season - applied,,on July l6 after all,,-the varieties were headed out, Although,pre cipitation was below ndtihil for- June- and July, the plants did not a t any time.show symptoms of moIhture deficiency. Climatic data is shown ,in Appendix Table I, The oats were grown in^fpUr-noW.plots ten feet long with one-fbpt spacing,,hetween rows to perm it. hand cultivation for weed control. The seeding rate used for all varieties was, 80 pounds per acre., A single-row push-type belt d rill was used for ,.seeding the plots. The experimental design was a randomized complete ..block replicated six tim es. This provided sufficient m aterial for harvesting samples at nine stages of ripening. Duplicate samples each consisting of plant m aterial from two feet of row were harvested from each blot at three-day intervals. Table 1» Source5 m aturity rating and principle' area of production-or' development of" the varieties and selections included in the oat ripening, experiment at Bozeman5 195)1» * 'f; V • <• - ^ - Name o f '"CVliT^oF” Principle"Area. V arieties "Involved, M h tu rlb y Date" V a r ie ty S e l e c t io n oi. Eroloctibh' in Parentage R a tin g H eaded Number ■ or; -Development. Reselect Clinton# CoIo 1)9-69 Iowa Bohd5 ~ R ichland5 E a r ly 7 -3 Green Russian Gopher# C0I 0 202? M in n eso ta S ix ty Day M id e a rly 7 -6 Mission# C.Io 2288 Montana Markton5 Victory Midseason 7 -9 (U nnam ed). . CoIo U283* Id ah o V ictbria5 Richland5 M idseason 7 -9 Markton5 V ictory (Unnamed.) 2 7 9 5 -1 1 -5 * Canada Alaska5 Golden Rain5 M id se a so n . 7 -9 .Naj I r a 5JB a n n e r (Unnamed). _. C6I 0 .6611# M ontana Bohd5"" Gfcepn R u s s ia n 5 M id la te 7 -12 V ictoria, Richldrid5 Markton5 Victory (Unnamed).... AB5989# Id ah o 8» M id la te 7 -1 2 B rid g e r* C o I4 2 6 1 1 M ontana Markton5.. Victory Late 7 -1 5 Magans’ki. Oi4t# C » I. 1)511 R u s s i a . Unknown. L a te 7-31) Aberystwyth 881).# C0I0 3519 .E n g lan d Unknown L a te 7-16 ^Denotes name or. number, used in th is paper ndien referring to the Variety0 \J wCereal. investigations” number assigned by UoS0D0Ao - 17 “ The first harvest was made thirty days after the heading date of each variety with subsequent harvest at three-intervals as shown in Appendix Table 11» Previous observations on Gopher, and Bridger oats indicated that at this stage the apical florets had turned from a green to a yellow color and the glumes subtending the apical florets showed only faint traces of g re e n . Samples were harvested at 9 AeMe- except on two dates when showers made it necessary to postpone sampling until mid-afternoon to permit drying of the foliage. According to Willard (19) rain or dew have little immediate effect on the moisture content of foliage prpvidihg that the surface moisture adhering to the leaves had been allowed tb evaporate,. . A hand sickle was used to harvest the oats leaving less "than one inch of stubble. This wad done in preference to using the normal height of harvest to avoid possible error. Otherwise it would have been necessary to leave stubble of a height proportional to the height of the variety in order to obtain a comparable estimate of straw moisture. Harvesting at a 1 ' height of twelve inches would have resulted in a lower moisture content for the short varieties as the oats appeared to be greenest near the base. Three of the six replications were harvested at one time and processed immediately to prevent excessive dessication between harvest and weighing. The m aterial was tied in bundles and marked with the plot number and stage of harvest for future reference.- A Fairbanks-Morris spring scale was. used for all weight determinations. One sample9 which had been marked with nAn C£» * = ' ' ■ : , I at harvest, was weighed green and again after oven-drying. The duplicate sample, maiiced WBM, was weighed green and threshed with a Vogel head thresher Even at the earliest harvest date no difficulty was encountered in threshing the oats. The rachis and pedicels generally remained intact and the1 giuines were easily separated from the kernels by the air blast. The threshed seed was weighed immediately and put in the drying oven until a constant weight was attained. Drying was accomplished with an electric oven equipped with a f a n . The total moisture and the grain moisture percentages were determined ■ ' 1 ■ . , •• from the decrease in weight of the respective samples. From this data the straw moisture was readily calculated. A random check on several samples indicated that the calculated straw moisture percentage varied only slightly from the figure obtained when actual green - and oven dry straw weights were used to determine the percentage of moisture in the straw. Late tille r counts were made at the eighth stage of harvest for each variety. At this stage the panicles on the main;culms and early tillers were completely lacking in chlorophyll while the late tillers were entirely green-and the kernels were still in the early stages of formation. Late tillers occurring in sections of row four feet long were counted in each of the six replications. Test weights of each variety were determined for each stage of maturity. These were originally intended to serve as a criteria of maturity of the grain. In order to have sufficient material for test weight determinations. — 19 «■ it was necessary to bulk the grain obtained from the six replications harvested at a given stage. A standard test weight apparatus' was used in determining the bushel weights®- «=> 20 *= EXPERBjEZTAL RESULTS The moisture content of the grain and straw at nine successive stages ' of ripening is given in Tables II and III respectively,. Grain moisture propped rapidly to a low level by the fourth stage of harvest and then !■ remained relatively stable during the remainder of the experiment, At the first stage of ripening (30 days after heading)5 the average moisture ; • ■ I : , content ranged from 36.1: percent for Maganski vOlUi. to U8el percent for ! : I : Reselect Clinton oats* The straw moisture receded more slowly and somewhat more uniformly than the moisture content of the grain. The lowest straw moisture at,the first stage Of ripening was 68,8 percent for AB5989 while ' Aberystwyth S81|. had a Mfgh moisture percentage of 75.7. At the fourth stage of ripening (39 days after heading)s Aberystwyth S81: s till showed the highest straw moisture content of 73.I percent while Maganski Ojhii was lowest in this respect with a moisture percentage of 6^.2» Maganski Oltli likewise had the lowest grain moisture .content of 16,8 percent while Reselect Clinton was highest with a moisture percentage of 28,6 per c e n t , ‘ At the ninth- and final harvest, occurring days after heading, the percentage of moisture in the straw varied from 6lalt percent for C,I, 1:283 to 66,0 percent for AB5989* At the final harvest the grain showed a con siderably wider variation between varieties, perhaps due to the clim atic' conditions on September I3 the last harvest date for the three varieties in the midseason group. An upward trend in grain moisture was noted, for a ll varieties' harvested 21 = on August 29 and September 1© It is interesting to note that a sim ilar ' increase in moisture content of the straw was not evident for the same dates» The last stage of harvest for Reselect Clinton occurred on August 26| consequently^ this variety does -not show the upward trend in ' grain moisture noted for the varieties harvested after that date© Table. II0 Moisture content of the grain of ten varieties of oats at nine successive .3-day intervals at Bozeman5 195>le Number of Days after Heading V a r ie ty ■ 30 .33 36. 39 42 45. 58 5i 5 ^ B rid g e r 44,8 40.2 34.0 24.3 19.7 ■ 22*2 21*4 17.1 13.0 Aberystwyth S8I4. 45.1 40 eO. 32.8 26.8 23.6 22.9 23.2 16*9 12.8 M agahski Oldt 39,4 28.9 19.7 16*8 14.5 19.8 20.8 15.0 10.7 Cole 6611 44.3 39.1 31.1 24.2 19.5 17.9 22*1 22.3 18*1 AB5989 43,5 37.9 29.6 22*3 19.7 17.6 23.3 22.4 16.2 M issio n 44.2 42.6 37.8 27,8 19.5 17.6 16.2 20*3 21*6 2795-11-5 42.6 40*9 36.3 22*7 17.3 17.6 16.3 19.3 21.2 Cole ij.283 40,8, 40.2 33.7 23.8 18.9 17.4 16.7 19.6 22*2 Goipher I 39.6 36.0 33.4 24.2 18*2 12.1 17.1 14*6 19.7 Reselect Clinton 48*1 40*9 . 30*8. 28.6 21.1 13.3 12*8 16.2 1 3.1 A verage 43.2 38.7 31.9 24.1 19.2 18.4 19.0 18*4 17.0 Table III0 Moisture content of the straw of ten varieties of o a ts a t nine successive 3-day intervals at Bozeman5 1921. Number of 'Days after Heading V a r ie t y . 30 33 36 39 -42 42 n r 5l 54 B r ih g e r 73.1 ■ 71.8 68*6 68.9 69.0 66.1 6 2.2 64*8 63.3 Aberystwyth S8ij. 75.7 69.4 68*6 73.1 69.5 67.6 62.9 66.1 63.8 . Maganski OlUt 71.4 &9.1 62.6 65.2 62.2 610 9 60 * 8 63.8 62*9 C0Ie 6611 70,7 72.9 71.0 67.8 68*6 65,6 67.7 63*0 64*6 AB5989 68.8 73.1 69.7 66.5 68*1 66*8. 68.0 .64.1 66*0 M issio n 72.6 70*8 71.2 68.7 68*0 68*9 64.6 64.8 61.8 2795-11-5 70.0 72.8 72.5 68.8 69.2 68.3 66.2 66*2 63.1 . Colo 4283 71.9 71.1 71.4 67.8 62.8 67.3 '6 5 .2 65»3 61.4 G opher 71.8 71.4 71.7 70*0 68*0 62.8 67.0 63.5 64.6 Reselect Clinton 70.5 6 8.1 71.4 67.9 67.2 67.3 66.8 62.8 64.2 A verage 71.7 71.1 69.9 68*2 67.9 66.6 6 5 .5 6 t4 63.6 « 2 2 = An analysis of variance of the straw moisture percentage at the final harvest is given in Table IVe No significant difference was indicated between varieties or replications when the "F" test was appliede S tatisti cal analysis of the grain moisture data for the final harvest was not attempted because of the apparent effect of environmental conditions on a. portion of the data* Table IVe' Analysis pf variance of straw moisture percentages at the ninth harvest of the ripening experimente Variation due to: dafo . ■ M0Se nFtl r a t i o Replications S 81*6? • 1*076 NeS* , V a r i e t i e s 9 113*76 1.1*99 N.S. E r r o r hS 75.88 T o ta l & Graphs in Figures l-li show the, trend of the moisture content of the grain and straw at successive stages of harvest for each maturity group# It is evident that the moisture content of the grain receded at a much faster rate than the decline of moisture in the culms and leaves„ Except for Oe99 of an inch of rain occurring on August Ii (two days • after the experiment was started)9 environmental conditions during the first 20 days of the experiment were ideal for ripening* No high winds occurred during this period and the temperature was moderately warm, but hot sufficiently hot to cause premature dessication of the grain or the foliage* Howevers.prior to the fifth harvest for the three late varieties and before the final harvest for the earliest variety (Reselect Clinton)* Percent Moisture Percent Moisture gur st e cont of t n ad r ect c le e s e D f o w tra s and in a r g e th f o t n te n o c re tu is o M . I re u ig F gur . st e cont of t n ad r he t e e r th e th f o w tra s and in a r g e th f o t n te n o c re tu is o M 2. re u ig F i on ad pe oats. s t a o opher G and n to lin C . s t a o f o s e i t e i r a v e t a l 33 ubr as er Heading H r te f A Days f o Number ubr as er Heading H r te f A Days f o Number 39 dger e g id r B aasi Ol*i|Maganski brswt S8ii Aberystwyth ______GRAIN STRAW STRAW GRAIN opher G ect c le e s e R i on to lin C Percent Moisture Percent Moisture gur Moi ur ent he grain ad r n to dl e te la id m two in w tra s and n i a r g e th f o t n te n o c re tu is o M . 3 re u ig F gur t Moi ur ent he grai n staw i hr e re th in w tra s and in a r g e th f o t n te n o c re tu is o M It. re u ig F dsaon varieties of oats. s t a o f o s e i t e i r a v n seaso id m . s t a o f o s e i t e i r a v t I ^ $ T I^ 5T" IT^ IT? 3$ 3^ ubr as er Heading H r te f A Days f o Number ubr as er Heading H r te f A Days f o Number 9 2 5 1:6 U5 H2 39 •n 2l± — ssi n io s is M STRAW GRAIN STRAW =D 2£ — rain and hail occurred causing considerable shattering of the grain* Mission and Aberystwyth S82j. showed the.highest degree of resistance to shattering while Reselect Clinton and Maganski OltU were most severely damaged* Reductions in yield attributed to the hail are shown in Table V* Actually the hail was rather mild because' damage to wheat and barley in neighboring plots was slight* At the time the hail occurred, the moisture content of the grain of all the oat varieties was down to 20 percept, dr less except for Bridger and Aberystwyth SSU5 which may account for the severity of the damage* s ’ ' Table V0 Reductions in oat yields resulting from hail on August 23, 1-951 a t Bozeman* Number of Days Grain Moisture at P e rc e n t V a r ie ty After Heading Harvest Prior to Hail ; Reduction i n Y ie ld B r id g e r 39 2U.3 Ul.3 Aberystwyth S8U . 39 26*8 32*1 M aganski OUU 39 16*8 50*1 C e l.o 6611 U2 19.5 Uo*5 AB5989 k2. 19 o.7 . U5.8 . M is s io n U5 17.6 33.9 2 7 9 5 -1 1 -5 U5 17.6 UU.8 C o I0 U283 . U5 17.U U l.2 G opher U8 1 5 .1 UU*5 Reselect Clinton 5 l 12.8. . 5i»U Late tille r counts made at the eighth stage of ripening (51 days after heading) for all varieties are given in Table VI* The analysis of variance in Table VII indicates that Reselect Clinton produced significantly more late tillers than other varieties in the test except Gopher, C,I* U283, and 2795-11=5* The late group of oats produced significantly less tillers than I «= 26 =3 R e s e le c t C lin to n 9 G opher9 an d C6I 0 R283«, As a lr e a d y m e n tio n e d i n th e experimental procedure5 the late tillers were readily distinguished from the early tillers by their overfall green color* Visual observation about three weeks after the original tille r counts revealed that ho change in the tendency to produce late tillers had occurred in any of the ten varieties in the test* Second growth or aftermath was much more prevalent on the plots occupied by the varieties which produced the greatest number of late tillersa Intervarietal variation in tendency to produce late tillers is evident from the tille r counts for different replications as shown in Table VI, This' wad probably due to soil heterogeneity. Table VI® Number of late tillers in four feet of row in 10 varieties of oats 31 days after heading, — < Uum^er pf' Late Tillers in Replication V a r ie t y . I . I I IIIIV . v VI A verage B rid g e r . 0 O . O O 0 O 0 .0 Aberystwyth S8J4. O O 3 O 0 O 0.2. M aganski OI4I4. 2 it ■ 2 3 0 1 ,8 CeIo 6611 ■ 7 3 2 11 -it 5 2.7 AB|? 98 9 8 3 8 it 2 8 6 eO. M issio n 10 2 it , 2 2 2 2 .2 2 7 9 2 -1 1 -2 6 It 7 9 9 9 7.3 C«Ta 1283 2 8 . 6 12 . 7 7 8 .0 G opher 2 9 19 16 8 O 9.2 Reselect Clinton 8 22 lit 12 18 • O 13.3 2 ,7 LaSaD0 (1%) 60 2- «== 27 Table VII, Analysis of variance of number of late tillers in ,four feet of row in 10 varieties of oats £1 days after heading. Variation due tog d®f 9 M«S , liFlt r a p ip .; .. Replications 5 . 2 3 ,5 1 , 1.5Q ■ V a r ie t ie s 9 1 0 3 .6 7 6 ,6 2 w E r r o r . 1 5 ,6 7 T o ta l 59 ■^Significant at 1% l e v e l . Bushel weightss reported in Table VIII5 increased until the fourth or fifth harvest) then levelled off9 and in most instances* decreased at th e• later stages. Seven of the ten varieties attained their maximum test weight at the fourth stage of harvest, At the fourth harvest* Maganski OliI).* Mis= sion* and Aberystwyth S8ii had test weights of 39 pounds per bushel* the highest attained during the experiment, 0,1, li283 attained a test weight o f 39 pounds at the fifth harvest, Bridger and Gopher also showed an in crease in test we I ght' through the fifth harvest with 38,Ii and 37o8 pounds per bushel respectively. Table V III,_ Test weights of ten varieties of oats at nine consecutive 3-day intervals commencing 30 days after Heading, Number o f Days after Heading V a r ie ty 30 33 36 39 42 Ii5 US 51 "IT B r id g e r " " " n r r c T 3 6 .0 3ooU 3 8 .0 30.2 3 8 .0 38.0 37.8 Aberystwyth S8ii 35.0 3 7.0 38.0 39.0 3 9.0 38.1 3 8.0 38.5 38.0 Maganski OlUi 35.5 38.0 3 8 .7 3 9.0 37.0 37.0 3 7 .1 36.7 37.2 C . I . 6611 3 5 .0 3 5 ,5 37.0 3 8 .0 38.0 37.9 37.3 37.9 37.9 AB5989 ' 35.0 36.5 38.0 38.5 38.1 37.3 37.2 37.2 37.2 M is s io n - 31.2 3 5 .5 36.0 3 9 .0 3 8 .5 3 8 .0 37.3 38.0 3 8.1 2 7 9 5 -1 1 -5 . 3 5 .5 3 6.0 3 6 .0 38.3 3 8 .0 37.8 3 7.0 37.3 3 7 .0 C . I . ii283 35.5 3 5 ,5 37.0 3 8.0 39.0 37.2 36^8 36.5 36.5 Gopher 3 1 ,8 3 6.0 3 6 .0 3 7 ,2 37.8 37.6 37.8 36.0 36.8 Reselect Clinton 3li.O 3 6 .0 37.5 3 8.0 3 8 .0 37.5 3 7.5 36.9 37.2 A verage 3 W 3 6 .2 37.2 3 8 ,3 ' 38.2 37.7 3.7.11 37.3 37.U < / ■=* 28 ”= Measurements of the heights of each variety made prior to the eigth . harvest are given in Table IX» The analysis of variance of the heights expressed in inches is given in Table X0. Using Gopher as a check, Bridgers Mission, Maganski Oljij., and Aberystwyth S82; were significantly talle r than Gopher at the I percent level and 2795-11=5 was significantly'taller than Gopher at the 5 percent level, At the I percent level of significance, Beselect Clinton and 0,1* U283 were shorter than Gopher* There was no difference in the heights of G=I0 66ll, AB5989, and Gopher, No further attempt was made to correlate plant height with rapidity of straw dessica- tion as varietal differences in the latter apparently did not exist under the conditions of this experiment* Table IX* Heights of the ten varieties of oats included in the oat ripening experiment at Bozeman, 1951® Replication V a r ie ty IIIIII IVVVI A verage B r id g e r HS- a 50 U8 U8 U9 U8»2 A b e ry stw y th S8U h2 a UU UU U5 U3 U3»5 M aganski Olth hi hi U8 U8 U6 U9 U7*5 C el* .6611 39 a Uo UI Uo Uo Uo *o AB5989 39 a Uo 39 Ui • Uo. 3 9 .3 M is s io n a U6 U5 ' U6 . U5 U5 U5.2 2795=11-5 . U3 U2 UU h3 . Ui U2 U2*5 C*'Io U283 37 38 37 38 38 39 3 7 .8 G opher h6 Ul 37 Uo Uo Ul Uo *8 Reselect Clinton 39 37 39 38 37 37 • 3 7 .8 a 2 p no Table X0 -Analysis of variance of heights of ten varieties of oats included in the ripening experiment0 Variation due tos dof, MeSe “F" ratio Replications ■ S .3 0 V a r ie t ie s 9 83<»06 U5 E r r o r 1 .8 2 T o ta l 59 **Signif4cant at 1% l e v e l . LeSeDe (%%) 1 .6 LdSeDe (1%) " 2 .1 “* 30 *=* DISCUSSION The moisture content of the grain at the various stages of harvest was in' agreement with data obtained by other investigators0 In this experiment5 the developmental period continued about th irty days' or approximately twice the length of time required for the developmental period of Gopher oats in Minnesota as reported by Booth (U)e iMaganski Oltlt appeared to have a shorter developmental period than the other varieties in the testo This is evident from the low moisture content of the grain and the comparatively high test weight of Maganski OlUt at the first stage of harvest. This shprter developmental period apparently had no adverse \ effect on test weight and the yield was' likewise satisfactory* Dessication or ripening of the kernel proceeded quite rapidly, decreasing from an average of lt3«2 percent at the end of the developmental period (beginning of test) to. an average of 2lt.2 percent nine days later and 17 percent at the close of the experiment 0 The sim ilarity in the rate of dessication of the grain of the varieties tested indicated that none would be of particular value in' this respect to the plant breeder. A slow rate of dessication of the grain could be useful in alleviating shattering while harvest is being delayed until the straw ripens. Loss of moisture from the straw was slow, decreasing from an average of 71« 7 percent at the beginning of the experiment to 68 of* percent at the fourth harvest and 63.6 when the experiment was concluded. The slow rate of dessication of the straw in this test was typical of the situation observed by the w riter under average irrigated conditions in CO 31 “* Ifontana0 The data indicated that the ten varieties were sim ilar in the ripening characteristics of the straw, Jf inherent differences exist in the varieties studied, they were probably .masked by environmental condi tions , This data does hot preclude the possibility that inherent differ ences', if present in the varieties tested, would be noted under different conditions. The inconsistent grain moisture percentages obtained for the stages of harvest occurring on August 29 and September I may be attributed to the showers occurring on these dates. Apparently, the dry grain absorbed moisture quite readily while the green leaves and stems absorbed little moisture. Consequently, harvesting the oats as soon as the rain.drops had evaporated from the foliage did not give the grain sufficient time to regain its normal moisture content. Since these variations were evident in the data, it was impractical to analyze the data statistically. The differential shattering observed in the experiment cannot be considered conclusive as the varieties were at different stages of ripening when the hail occurred. However, comparisons within m aturity groups are valid. Mission apparently derived its resistance to shattering from its Markton parent which was reported by Rather (I?) to possess resistance to shattering, Aberystwyth S8U likewise may be of .value as a source of shatter resistance. Bushel weights increased until the average moisture content of the grain was approximately 23 percent. This may appear to disagree with results obtained by other investigators (It9Il) who report that the 32 _ ■ accumulation of dry matter in the kernel ceases when the moisture content ■ ■ reaches 1*2 percent® Two explanations may be offered for this, continued increase in test weights (a) Shrinkage and compacting of the kernel brought about by normal dessication after it has attained the- maximum amount of dry matter® (b) Continued development of the less mature kernels on the panicle until they attain a moisture content of about 1+2 ' percent® The average moisture content of the entire panicles would pro bably be about 2j? percent at that time® Decreased bushel weights at the later harvests were in agreement with the results obtained by Burnett and Bakke (7 )e The presence of late tillers did not appear to affect the moisture content of the foliage under the conditions of this experiment® Thte reason for this may be that the main culms and early tille rss contributing a large proportion of the total f o ra g e a ls o contained a high percentage cf moisture® The grain produced on the late tille rs may have contributed to the grain moisture® This could not be verified because of the variability of the grain moisture data due to other factors® TJie apparent association of late tillering and aftermath growth indicates thkt this characteristic could be useful in a breeding program as a means of eliminating lines having a tendency to produce late tillers® From the standpoint of the rapidity of the ripening process of the- Straws short varieties have no advantage over ta ll varieties for combine harvest® Howevers a.short variety is less likely to lodge and usually it is necessary for the combine to handle more straw when a ta ll variety is grown® = 33 “ SUMMARY AMD CONCLUSIONS Ie Ten varieties of oats were compared for rapidity of ripening of the grain and the straw at Bozeman in 19$le There was no significant difference between varieties in straw moisture content at the con clusion of the experiment* a>h days after the. heading date for each variety* The average straw moisture at the beginning of the experi ment was 71»7 percent* During the 2k day interval between the first and last harvest for each variety* the straw moisture dropped to an average of 63„6 percent for the ten varietiese 20 Grain moisture receded rapidly from an average of i;3®2 percent to an average of 17*0 percent during the interval between the first and last harvests» Due to environmental- factors* grain moisture percentages were somewhat high and erratic at two of the later harvests* rendering statistical analysis impractical* The rapid ripening of,the grain and the relatively slow.dessication of the straw indicates that there is not a close relationship between grain and straw moisture in the varieties tested* 3« Dessication of the kernel commenced earlier in Maganski 0U4. than in the other varieties* Its grain moisture content receded to less than. 20 percent 36 days after heading* The ether" varieties required about U2 days to reach that level* ko M aturity of the grain* based on attainment of maximum test weight* was completed-, between 39 and lj.2 days after heading for a ll the varieties ■ te s te d * ■” 3U " 5o D ifferential shattering was observed following a hailstorm which occurred when the grain moisture level was. 2£ percent or Iesse Mission and Aberystwyth. S81j. appeared to be most resistanta 6« Significantly more late tillers were produced by the early varieties* Howeverg varieties with late tille rs were no higher in straw moisture than varieties with few or no tillers. 7o Average heights of the varieties ranged from 37»8, inches for Reselect Clinton and C0Io lj.283 to !4.802 inches for Bridger0 There was no appar** ent difference in rapidity of straw ripening due to height. 8® Eive m aturity groups were set up arbitrarily based on heading date0 No difference in straw ripening due to earliness fas noted® LITERATURE CITED 1 . BAKHU ZEN5 H. L» VAM DE SANDE„ S tu d ie s o n 1Hheat grown u n d e r c o n s ta n t conditions. Plant Physiology 3sl-30. 19280 2. BONNETTj O'. T. The development of the barley spike. Journ of Agrice Research ^lsli^l =U^7« 193$. 3. » The development of the oat panicle. Jour, of Agric. Research $Us927-931. 1937. U. BOOTH, E. 0. Daily growth of the oat kernel and effect on germination of immaturity and controlled low temperatures. Minn. Agr. Exp. S ta .Tech* Bulletin 62. 1929. $. BremCHLEY3. W. E. and HALL, a . D. The development of the grain of wheat. Jour, of Agr. Science 3sl97. 1909. 6 . ______. The developm ent o f th e g r a in o f b a r le y . Annals of Botany 26s903=928. 1912. ' 7. BURNETT, L. C. and BAKKE, A. L. The effect of delayed harvest on the yields of grain. Iowa Agr.■Exp. Sta. Research Bulletin 130. 1930. 8. CAPORN, A. ST. CLAIR. An account of an' e^perimept to determine the heredity of early and late ripening in an pat cross. Jour, of Genetics 7:2U7-2$7. 1918. 9. GRABER, L. F. and AHLGREN, 'H. L. . Agronomy Principles, and Practices. W. C. Brown Co., Dubuque, Iowa. 19U8. ' .. IO0 HARLAN, H. V. Daily development of kernels, of Hannchen barley from flowering to maturity at Aberdeen, , Idatio0 , Jour. ,Agr. Research 19:393-130. 1920. I l 0 . ■■_____ ,and POPE, M. N. Water content of barley kernels during growth and maturation. Jour, of Agric» Research 23:333=360. 1933.. 12. HURDi=KARRER, A. M. and TAYLOR, J. W. The water content of wheat leaves at flowering time. Plant Physiology U:393-397. 1929. 13. KEDZIE, R. C. Composition of wheat at different periods of ripening5 of the straw at the same periods. Mich. Agr. Exp. Sta. B ulletin.101. 1 8 9 3 . =». 36 ill.. MCCLELLAND, C. ■ K. Effect of various plant foods on growth activities and development of oats. Jour. Am. Soc. Agronpmy 23:30^-311, 1931. •13« NOLL, C. F. The. effects of phosphate;on early growth and maturity. Jour. Am. Soc. Agronomy 13:87-99. 1923. 16. PERCITAL, J.- The Wheat Plant. A Monograph. E. P, Dutton & Co. New Y o rk , N. I . 1921. 17. RATHER, H. C. The influence of delayed harvest on certain varieties of oats, and barley in Michigan. Mich. Agr. Exp. Sta. Quart. Bulletin. ■ Vol. 19. 1937. 18. STANTON, T. R., STEPHENS, D. E. and BAYLES, B. B. Relative resistance of oat varieties to shattering at Moro, Oregon. Jour. Am. Soc. Agronomy. 20:30^-303. 1928. 1 9 . UNITED STATES DEPARTMENT OF AGRICULTUiRE, G ra in I n s p e c t o r s ' M anual. . Agricultural Marketing Administration. Washington, D. C. . 19^2. 2 0 . UNITED STATES DEPARTMENT OF COMMERCE. C lim a to lo g ic a l D a ta (M ontana)„ Vol. LIT. Nos. 3^9. Weather Bureau. San Francisco, 1931. 21. WILLARD, C. J. The moisture content of forage at different times of the day. Jour. Am. Soc. Agronomy 23:833-839° 1931. 2 2 . WILSON, H. K. and RALEIGH,, S. M. E f f e c t o f h a r v e s tin g w heat and o a ts , at different stages of m aturity. Jour. Am. Soc. Agronomy 29:1037-1078. 1 9 2 9 . J 37 - APPENDIX Appendix Table I0 Summary of monthly temperature and precipitation^ May to September inclusives Bozemani, 195,1* Temperature Pre cip itation A ve0 Highest lowest No* c)f Total Greatest Date No,J o f Days Inches for. Ope • Diys 0.50 0V ' M onth . F. Above 90°: Day o r More May 5 1 .7 81 28 0 1.52 .55 18 I Ju n e 52*1 82 26 0 1*61 *37 7 0 J u ly 66*0 96 38 9 *87 0liii 2 0 • A ugust 61*7 9P 35 3 2.36 *99 k 3 S ep tem b er 52.U 83 .25 0 2*23 *83 20 2 T o ta l ; 12 1 8.59 6 A verage 56.8 Appendix Table 13I* Harvest dates for successive stages of ripening of the varieties used in the oat ripening experiments at Bozeman5 1951. Ripening Stage V a r ie ty I I l I I I IV V VI. VII VIII IX Harvest Date Reselect Clinton 8-2 8 -5 .. 8=8 8 -1 1 8—ll| 8—17 8—20 8-23 8 -2 6 G opher 8—5 8—8 . '8 -1 1 8—lli 8-17 ■ 8-20 8-23 8-26 8=29 M issio n 8-8 8 -1 1 8-H1 8-1 7 8-20 8-23 8-26 8 -2 9 9 -1 2795-11-2 8-8 8 -1 1 8—lli 8-17 8=20 8-23 8-26 8-29 9-1 C o l. U283 8-8 8 -1 1 8= iii 8 -1 7 8-20 8-23 8-26 8-2 9 9-1 C0I 0 6611 8 -1 1 8—lli 8-1 7 8 -2 0 8—23 8—26 8—29 9=1 9 -4 AB5989 8 -1 1 8—Ili 8-17 8-20 8«23 QaaZS 8=2^ 9—1 9 -4 B r id g e r 8 -lU 8 -1 7 8-20 8—23 8=26 8-29 9^1 9 -4 9—7 Maganski OhU 8 -1 4 8-1 7 8—20 8 -2 3 8—26 8—29 9—1 9 -4 ■ 9-7 A b e ry stw y th S8U 8 -lb 8 -1 7 8-20 8-2 3 8—26 8—29 9—1 9=4 9-7 V ' - t i ('y, 103329 ''!■IT MONTANA STATE UNIVERSITY LIBRARIES III IN I I ill CO 7<52 1001 51 85 9 N378 P456r 103329 AUTHOR Petr. Frank C T I T L E The relative ripening rate of daVeiMSslies of » "A"E /V 37< 9 J> 4S& > r c o p . Z - 7 103329