330 MONTHLY WEATHER REVIEW. May. 1919
ALFALFA SEED GROWING AND THE WEATHER, IN UTAH.
By J. CECIL ALTER, Meteorologist.
[Dated: Weather Uurenu. Salt Lake City, Utah, June 16,1919.]
SYNoms.-The first crop of alfalfa is usually cut for hay in Utah, and the second ~p is alloWed.to go to seed. The seed crop.shorlld
have sufficient molsture during ita early growth to produce a vigorous, healthy plant, but the weather should be dry and not too warm while the plants are in bloom. The % spell must not be too extended, ,however, as t+e seed must have su cient moisture while setting to give it size and weight. Definite comparisons with geld in Utah show that the spring tem erature should average from 3 to 5 O F. a day above the normal, an3 from 3' to 4' F. a day below the normal during the summer months, for best results. It takes nearly twice as long to grow and mature a seed crop as it d o e ha crop. Seed is usudv ready for harvest in Ut& one to two weeks in dvance of the average'killing frost date. AE a tern erature of 86' to 2 8 O F. in the foliage will seriously dam- age partdy ripe and unripe seed burrs, the frost and minimum temperature forecasts at seed harvest time are of e8 ecial importance. The usual practice is to cut as ly an area aa passibre on the receipt of frost warnings, but as the first co d period is often followed by several weeke of fine ripening weather, and as the value of the seed is said to increase at the rate of nearly $5 an m e each 24 hours when ripening, efforts should be made to protect the planta from frost damage without cutting.-J. w. 5.
To every alfalfa grower comes the uestion, Shall the
eastern States grower it arises but rarely, while in the bterior western third of the United States, where the altitude, aridity, sunshine, and summer warmth are especially favorable for seed development in average years, the question is perennial. Owing to the great demand for seed, its production is imperahve whenever meteorological conditions will per- mit, the climate being the limitlng factor enerally, and
season's yield. When droughty conditions threaten the l i e of the alfalfa plant, nature aims to revent the de-
duction of seed; it is not produced 111 large quantities
crop be cut for hay or left for seed? % o the central and
the current weather being the major contro K affecting any
struction of the spedes apparently by t R e prolific. pro-
. under other conditions.
States. A crop when the corn
abundance of precipitation until near utting time of the
earl growth, or just sufficient to produce a vigorous, rains thereaftsr until the bloom has fallen. A very avorable noirnrrl distribution of precipitation occurs u1 Utah, where the
first hay cro ; the second growth, w L 'ch is usually the seed crop, s R ould have a moderate supply during its
hea 9 thy plant; there should be no hea
7
season is wet until the end of May and nite dry there-
moisture to produce unlimited development and of the root system, and provide the necessary p ysical vigor for bi-inging on the seed crop. More especially, however, does ths hea spring precipitation provide a
storage of moisture in "% t e soil for the early use of the seed crop. There must be a rapid and early rise of springtime temperatures, without setbacks, to get the first or ha
in good season. Such seasons have grozuced yields above the average usually, especially if t e ensuing sum-
mers were moderately cool and not too dry. Deficient ields have very frequently been associated with late, gachard spriags and much wet weather. The summer drought, along about seed setting and ripening time, must not be too severe, aa there must be ample moisture to fill the seeds out and ive them wei ht.
must rainy periods interfere greatly with the work of bees. If the \vieid is dependent on natural precipitation, studies made in Utah would indicate that 2 or 3 inches of pre- cipitation a month from March to May, inclusive, are desirable, with about one-half an inch per month, there after in light showers. The summer must not be too warm at blossom time, as
the wilting and blightin of the bloom are readily accom- plished by sustained hig wind and a deficienc of mois- ture occurring inopportune1 . Aver e mont ly maxi-
soming are unfavorable; and a short period of tern era-
tures about 100" F., when nioisture is deficient, Rave resulted in light yields. the month in which alfalfa stctrts its giowth in spring, s 7 iould have a mean temperature nor- mally of about 40" (F.); about 48" (F.) in the next month for best development; 56" (F.) in the nest month; and about 65" (F.) in the month during which the first hay crop is taken, these bein approximately the optimum fi ures prevailin in the Uta 5 seed regions. They are for $arch, A p l , day, and June. The crop matures in months o similar temperatures but of different name, in both cooler and warmer climates generally. The seed crop follows in months with mean tempera- tures, which are considered a proximately the optimum,
the blossomin and seeding months in 8tah. Statistica studies show k a t this period may be followed by either warmer or cooler periods, for the work of harvestin , though if the mean temperature of the following mont % , Se tember, be 60" (F.) or lower, there is a strong proba-
pleted. Definite comparisons with yields in several ears and localities show that mean spring temperatures Z-om 3" to 5" above normal in Utah are necessary for securin a yield of seed above the average, in regions
crop of hay and its subse uent seed crop, between the average dates of spring an 8 autumn killing frosts. Such spring seasons should be followed by summers from 2"
(F) to 4" (F.1 below norinal, to ive a slow and gradual
sive setting of the seed.
after, thus giving the first growt6 of a If alfa sufficient
rwth
crop out of the way and get the seed cro started o h
Also, heavy rains must not wash away t 5 e pollen, neit -5 er
t %
mum temperatures above 90 B (F.) in Y t e months of blos-
Broadly speahn
7
of 70" (F.) to 75" (F.1, in Ju F y and Au ust, these bein
bi P ity of frost damage before the average harvest is com-
where t a ere is normally but scant time to mature a good
plant growth, and a consequent 5 etter and more exten-
-
MAY, 1919. MONTHLY WEATHER REVIEW. 331
Studies of killing f r a t data show that the seasons are longer and safer on the gent1 slopin or foothill lands
length of the summer frosbfree season amounting to from two to three weeks. Also, that the actual altitude, within certain limits, exerts less influence on the average frost dates than the immediate surface configuration or topography. The most favorable altitudes in Utah for seed are from
4,300 to 5,500 feet above sea level, where the second crop is saved for seed. Above 5,000 feet on the broad open plains ,where frost formation is not retarded by air move ment regularly, the seed crop must be started off very promptly to escape the average dates of autumn frosts. At altitudes of 5,500 to 6,500 feet, where seed is usually
gown from the first cutting! the startin of the seed crop
of the second crop for seed nia be regulated by the time of cutting the first crop, and d development and cutting dates can be forced or delayed somewhat by withholding or applying irrigation water and also by proper cultiva- tion to conserve moistime while in stubble stage. The average cutting dates vary with the accumulations of excesses or deficiencies in temperature-that is, with the amount of the retardation or advancenient of the season in any year. This is determined b adding the
average maturing season for the principal seed producing regions in Utah is about 80 days, the first cutting coni- ing about June 15 to 20 in average years. Forty days are then required, as a rule, to reach the early blos- som sta e or cutting time for hay, about July 25 to 30.
the seed brings the harvest about September 4 to 9, a week or two before the average date of first killing frost in autumn. It takes a little longer to mature a t the higher altitudes and incooler seasons, but an excess of mois- ture is much more potent in prolonging the growin season.
during a droughty season, when feed elsewhere is scarce; and weevils are more predatory in late spring seasons, when it is cold and wet. The weevil may be very suc- cessfully combated by cutting the first crop as early as may be necessay and workmg the field energetically with brush and wire dra and other implements, if the
thus covered in the dust mulch the seed crop will prob- ably be retarded as much as several weeks, depending on the amount of moisture and the uantity of the
of hay would result in an early cuttin , heavy asturing
States Bureau of Entomology officials in Utah. To avoid or mitigate injury from the occasional early autumn frost, in case the seed is still in the field a t this time, as is often the case in Utah, the coninionest practice is to cut all the seed practicable upon the issuance of the frost warning and lrrigate such fields as may not be ready to cut and as have water available. The partially ri ened seed will mature after cutting, though since i t is
. a i ding many pounds per acre per day in weight and im- proving steadily in quality, only those portions of the non-irngable fields most subject to frost should be cut. In the ile, shock, or windrow there are fewer seed pods exposei to the frost; though those that are exposed will be injured about the same as if left standing. The prac- ticability of cutting seed prior to frost waa first stat,ed in Utah by Mr. George McCune, of Mills, Utah, now special
than in the broad open flat 9 h ands, t e increase in the
*
is regulated by close pasturing frequent 9 y. The starting
'
daily temperature departures from norma P daily. The
Forty a % ditional days in an average year for maturing
Grasshoppers are usually more nunierous in t a e fields
weather is dry, to bury t T e larva If the weevil is not
weevils. If the spring be greatly retarde 8 , and much loss
ma be substituted, or spraying with so 7 utions o P arsenate of 9 ead or zinc arsenite, as reconiniended by the United
meteorological observer, who, as spokesman for a number. of growers, requested the f h t alfalfa seed frost-warhing service, which was begun in 1913.
The use of irrigation water to ward off frost injury or formation has been fairly well demonstrated in many fields and seed regions, and is rapidly growing in favor,
wherever tphe water is available. Some growers con- serve water for this special use by withholding some that might be applied a short time earlier to make the seed fill out roperly. In all cases the ditches must
to provide a little water for use on the afternoh or evening prior to the expected frost in the fields which can best be irrigated or which are most retarded in growth. The wateiing will prolong the growing sea- son ancl retard the ripening of the seed somewhat, but it usually makes a greater number of pounds in the yield, and, by warding off a light frost, the quality is undoubtedly improved. Early autumn frosts are very often followed, in Utah, by several weeks of fine weather, at least enou h time in which to mature and harvest the seed crop, t h erefore every effort niust be made to protect the crop against this first frost. The probability is that the first frost will not be as severe nor as hard to combat as the later frosb. There has been some experimental smudging, that is, producing a sinal1 amount of heat and a great deal of a siiioke and steam or moisture blanket to prevent the loss
the windward side of largc seed areas; and in view Y o
of heat by racliation, by burningwet straw or manure do
the certain amount of success of this form of protection for the fruit orchards of California, Oregon, Idaho, Ohio, parts of Utah and other States, the practice warrants every possible consideration in the alfalfa seed growin regions, especially where it can be made a community a B air. Every effort has been made to Gorrelate the weather conditions in the Utah alfalfa seed general conditions shown on the from which the daily weather forecasts district and national forecastser, for the fying these forecasts for the several in and for estimating as accurately as ossible the probable nilliinium temperature that may !e espected on the following mornmg. Special meteorological stations are maintained in a few places, where the need has seemed to be greatest, from which weather re orts are received by telegra h daily
until the last has been harvested. The tate forecasts and the amplifications are made available a t government espense to every seed growing region where the growers wish to make use of them. Cooperative weather stations are located conveniently to ractically all the seed roducing regions of the State, an B thus the climates of t I? ese regions have become more or less familiar, through the Bureau's publications. The special alfalfa seed remion meteorological Station at Deseret, Utah, in charge 07 Mr. Samuel W. Western, for the past five years (see Qs. 1, 2, and 3), shows that tem- peratures in the alfalfa foliage, in which the special station is located, is about 3' cooler on the average than in the ordinary weather station es osure such as Mr.
years. On cloud mornings tlie temperature in the alfalfa foliage wily not differ greatly from that in the ordinary thernionieter shelter. In general, the colder it
is the greater has been the difierence between. these readinos; that is if the general tem eratures are 111 the
not be allowe c r to become useless and every effort made
at Salt Lake City rom the time the first ri e see i; appear P A)
Western has had on his farmstead P or the past twenty
lower Torties the difference will be s ess than if general
332 MONTHLY WEATHER REVIEW. M4r, 1919
values are in the lower thirties. slightly above freezing occurred in the tive station, temperatures 6" or 8"
in the special station shelter in the alfalfa foliage. A thermo raph has been exposed in this special alfalfa
the records of which the duration of t, e cod iaa been determined. marx!h of temperature and the duration of both tlie hig 1
and the low temperatures as shown on thermograph records at Salt Lake City, so far m the records have been obtained for study. The principal feature of this, how- ever, is that the cold occurs just prior to sunrise, and
K $P
station, as s % own in the accompanying hot0 a h, from
5;
This does not vary greatly from the hour1
that the damaging values are usually of rather short duration. Hence smudging as a frost prevention need not begin until toward morning, nor need it c.ontinue long, the tinie being dependent entirely on tlie tenipera- tures recorded in the region at the time. In general, on a clear night, when a minimum temperature of 25" (F.) is reached, the thermograph sh?ws that the temperature was
below 30" (F.) not to esceecl two hours. This value, 'however, vGries somewhat on different nights, depending principally on the amount of clouds and wind. Temper- atures of 33" (F.) in the foliage have resulted in some daniage; temperatures of 30" (F.) usually cause con- siderable damage.
BIBLIOGRAPHY.
RECENT ADDITIONS TO THE WEATHER BUREAU LIBRARY.
C. F'ITZHUQH TALMAN, Professor in Charge of Library.
The following have been selected from among the titles of books recently received as represen tsing those nios t likely to be useful to Weather Bureau officials in their meteorologicd work and studies:
Bigelow. Frank H[agar]. Four fundamental formulas for discussinq the observations made with the various types of pyrheliometers. New York. 1919. v, 34 p. charts. tables. 3i em. (Sup lement no. 1 to the treatises on the atniospheres of the sun anif the earth.)
Wettervorhemage. Vortrag gehalten auf Clem skandinavischen Geophysikerkongress in Goteborg. 2s .4UgUSt, 1918. Uppsala. 1919. 15 22+ cm. (Meddelanden f r h 6. Veknskapsnka- demiens dbelinstitut. Rand 5. No. 3.) [Published in Eng- lish in Mo. Wea. Rev., Feb., 1919, p. 90-95.1
Bjerknes, V[ilhelm Friman Koren].
Braak, C[ornelis]. Cyclonen in den Oost-Indisclien archipel. Weltevreclen. 1919. charts. tables. 24 cni. (Overgedrukt uit het Natuurkundig tijdschrift voor Ned.-Inrlie, Dee1 78. Dercle aflevering, p. 195-211.)
Eredia, Filippo, & Palazzo, Luw. Snl servizio meteorologico coloniale. Relaxioni . . . a1 Con- vegno nazionale coloniale per il dopoguerra delle colonie del 15-18 gennaio, 1919. Ronia. 1919. 11 p. 23 cni.
Solarkonstantens bestanining. Uppsala. 1919. 17 p. 22) cni. (Meridelanden frnn K. Vetenskapsakademiens Nobel institut. Band 5. No. 13.)
Bulletin hydrographiqrie. Variations de la kin erature de l'eau de surface dans certains C W ~S choisis de l'btfantique pendant les ann6es 1900-1913. publi6 par le Bureau c h i conwil. Copen- hague. [1919] 37 p. fold. charts. tables. 32+ cm.
Qranqvist, Gustaf.
International council for the study of the sea.
Levine, Joseph, Lea 220 ans d'observations de Paris. Parie. 1919. 2 p: 27 cni. (Reprinted from Cornptes rendus, t. 168, 1919. p. 5611.)
Oskamp, Joseph. Winter injury of fruit trees. 12 p. illus. 23 em. (Purtlue University. Agricultural experiment station. Circular no. S7.
LaFayette, Ind. Kov. 19lY.)
The Harvard station in Jamaica. 37 p. plate. charts. tables. 30 em. (Reprinted from Annals of Harvard college observatory. vol. 82. no. 1.) [Deals chiefly with the nietcorologicnl con- ditions at the station, especially as affecting telesc-opic olmer- vations.]
Seasonal deposition in aqiieo-glacial seilinients. C'anibrirlge. Mass. 1919. 67 [lG] p. plates. fold. diagr. 31 cin. (Meni- oirs of the Museum of comparative zoology at Harvard rollege. vd. 47. no. 1.) [Banding in .$irial clays is bplieved hy the author to be due to the alternation of the smaons and tlier+hrP to furnish a meteorologid record dating from tlie G1wi:il .Period .]
Results of meteorological, magnetical and seismolooicsl observa- tions, 1918. Toronto. 1919. 51 p. incl. tal&. 20+ cni. At head of title: Department of mnrine and fisheries. Doniinioii
of Canada.
' Pickering, William H[enry].
Sayles, Robert qilcox].
Toronto. Observatory.
Utah. Industrial commission. Hiillet.in no. 5. Period July 1, 1917-June 30. 191s. Salt Lakc. 1919 43 p. niym t.aliles (part. fold.). 23 mi. [The cliniate of Utah. 11y J. (... Alt.er. 1'. 35-13.]
Wegener. Alfred.
DM rlctonicrc.nde Meteor Toni 3. April. 1910. 3+ Uhr nachniit.t.ags, in Iiurhessen. Mnrbiirg A. L. 1817. 1 > 1 illns. taldes. Sy mi. bclded t,. p. : Schriftm der &s%%,ft ziir Befijrllerung der geeamten Nnturwissencli~ft,eii zu Marhurg. Band 14. Heft, 1. Likrat,iir. p. 81-53. Inclulles some inci- clent,al discussion of nict.eorologica1 features5
RECENT PAPERS BEARING ON METEOROLOGY AND
SEISMOLOGY.
C. FITZHUGH TALPAN, Protessor in charye of library.
The following titles have been selected from the contents of the periodicals and serials recent1 received in the Library of the Weather Bureau. 4 he titles selected are of apers and other communications bear- ing. on nieteoro F ogy and cognate branches of science. Thls is not a complete meteorological index of all the jour- nals form which it has been com iled. It shows only the articles that appear to tlie compi I; er like1 to be of partic- ular interest in connection with the worf of tlie weather Burcau.
deronaittien. Lo?tdm&. v. 16. 1919.
Weather and the At,lantic flight. Wireless niet,eorological infornia- tion to and from ships at. s a . p. 51S-519. Tucker, Frank T. minds and the trans-ADlantie flight.. p. 584.
I June 5 .)
American eorkty of Acat& and vaitilatiiig enginfc?rrr. Jbitnwl. Pilts-
Report of Weather bureau coinniit.t.ee of Eaat.ern Pennsylvania chapter. p. ?3-334. [Deals with efforts to senire midday observations of 1iumirlit.y at Weal.her bureau stations.] -
(May 15.)
bit.rgh, Pa. v. 2.5. d p r i l , 1919.
Astrophysical joit.rna1. Chicago. v. .f9. Maq, 1919.
and t,hc wave-length of the chiefmuora line. p. 2GC-273.
Gropphieal r c i k v . Neuj York. T. 7. May, 1919.
Slipher, V. M. On the general auroral illumination of the sky
Ward. Robert DeCrourcrl. Frost. in the United states. I). 339-
344. [Review 01 pait'of Atlas of Anierican agricultirt! C'f.
Ward, Robert DeC[ourcy]. d e cliniatology of the cotton plant. Mo. Uea. Rev., Nov.. 131s . 516-517.
p. 34s-349.
Geoqrnphical society of Philadelphia. Bidlrtiir. l'hzladelphia. v. 17.
Slope exposure and the distribution of
dionthly btillctin of agricuhral
Shaw, H. B. Climatic control of the morphologv and hysiology
-4pri1, 1919.
Harshberger, John W. plante in eastern Pennsylnnia. p. 53-61.
Intmiatioi&al institiitt! of agricdtitrf. intt.lliyr.nce ~i i d plant diseaaa. Romp. Fear 10. Jan., 1919.
of beets. p. 27-30. [Abstract from Sugar (C ' h h g o ).~
h h e e abstracts. ~o l i t ~o n . v. 22. April, 1919.
Burger. H. C. On evaporation from B rirciihr surface of a liquid. p. 171. [Abstract.]