J

l

/

CIRCULAR 127 JANUARY 1959

MECHANIZED COTTON PRODUCTION
,o4eaeama

- 4 rictu~ira/ Experiment Stfation of the
ALABAMA POLYTECHNIC INSTITUTE
E, V. Smith, Director Auburn, Alabama

CONTENTS
Page
SELECTION OF

LAND ___

SEEDBED PREPARATION_ VARIETY PLANTINGWEED CONTROL

9 10 13 14 16 19 21 23 26 28

Rotary Hoe___ Chemicals ____
INSECT CONTROL DEFOLIATION H ARVESTING _----------INFLUENCE OF

WEATHER-

SUMMARY --------------

In order that the text content be readily understood, it is necessary at times to illustrate or use trade names of products or

equipment rather than
chemical identifications.

involved

descriptions

or complicated

In some cases it is unavoidable that

similar products on the market under other trade names are not. cited. No endorsement of named products is intended, nor is criticism implied of similar products that are not mentioned.

FIRST PRINTING

5M, -JANUARY 1959

MECI-CAN IZED COTTON PRODUCTION
i4 A4abama
T. E. CORLEY, Associate Agricultural Engineer* C. M. STOKES, Associate Agricultural Engineer F. A. KUMMER, Head, Dept. of Agricultural Engineering

MORE PROFIT is the aim of every cotton farmer. To do this, ways must be found to produce the crop as cheaply as possible. Of course there are problems other than high production costs. For example, acreage reduction and lowered prices are serious. But, there is little that individual farmers can do about such matters. Government programs determine acreage and, to a large extent, price. This leaves one important factor-production costs-that is controlled by individual farmers. High labor requirements are the main reason for high production costs. About 100 man-hours are required with present production and hand-harvesting practices for an acre of cotton yielding 1 bale. With labor scarce and becoming costlier, reduction in labor requirements offers the greatest opportunity for cutting production costs. Test results show that labor requirements for cotton production and harvesting can be greatly reduced by use of machinery. However, a reduction in labor will not necessarily mean a reduction in production costs unless the machinery is used efficiently and yields are high enough to justify the investment. Machinery is costly and its use must justify the investment. Many individu*Cooperative Agricultural Experiment Station of the Alabama Polytechnic Institute and Agricultural Engineering Research Division, ARS, USDA. The authors acknowledge the assistance of C. A. Brogden, superintendent, Wiregrass Substation; John Boseck, superintendent, Tennessee Valley Substation; S. E. Gissendanner, superintendent, Sand Mountain Substation; and J. O. Helms, superintendent, Agricultural Engineering Farm Unit.

MAKING

ally operated small farms cannot be completely and economically mechanized with machines now available. This is especially true of mechanical cotton harvesters. Most production equipment can be used for producing other crops usually included in a diversified farming program, but the cotton harvester can be used for cotton only. A farmer planning to buy a picker needs adequate cotton acreage (at least 50 acres for the smaller pickers) or arrange to do custom work. A farming program that permits -multiple use of machines can justify purchase of equipment in some cases. For example, a farmer with 10 acres of cotton might find it economical to purchase a sprayer for applying chemicals for weed control in cotton if the sprayer were also used for applying cotton insecticides and for spraying livestock and orchards or for custom spraying. This publication reports results from tests over a period of years and from field experience in mechanized production and harvest. It deals only with machines, methods, and practices for reducing labor and increasing machine efficiency. The latest recommended agronomic and insect control practices for producing high yields are essential in a mechanized cotton program. Good yields of sound bolls contribute to high mechanical harvesting efficiency and economical machinery use. Proper planning is essential for successful production and harvest of cotton with mechanical equipment. Every phase of mechanized cotton production from land selection to harvesting has a direct effect on the successful performance of each succeeding operation. Consequently, it is important to make a good start by carefully selecting land and properly preparing the seedbed. SELECTION of LAND In addition to choosing good soil capable of producing high yields, it is important to select land that is suitable for efficient operation of machinery. Since adjustment and operation of planting, cultivating, and harvesting equipment are more critical for cotton than for most other crops, cotton rates the best available land. Large fields with long rows are desirable. Fields can often be made larger by eliminating hedge rows and ditches and by changing fencing and road systems. Rocks and stumps that cause machinery breakdowns and interfere with planting, cultivating, and harvesting must be removed. Savings from fewer machine repairs and increased efficiency of the machinery will soon pay for removing rocks and stumps.
[4]

-

.4-

r-

2k'

f,,-

-s

I -4
~, ,-~

~

4 ~j

psi

.!

~!,

.

planting on well-drained land is essential for mechanized spot in this field prevented tim~ely use of rotary hoe.

cotton production.

Wet

D)rainiage- is ali imiportant fat-tor inimechtlan iz/d cottoii 1)10(11ictioii. A lcxv sxet sp~ots xxill ofteni dela> tiiniel\ produc ition opcra-iii tioiis for all cintire fieldl and linicl iflwCcaii(al han- (c5tiiii lbecaiise l of no0-uif iorii nliatilrit Flat fields arc- desirab~le for i at-hinerx op)eration s, lhiit tli I\ of ten pr(-s(-it dif ficiult d1rain~age prol em s. \Lausi tiimas it is nccetssars to p~ro itde dIrainiage tdittches, thent adlapt tillag- ope-ratioins to tht sxsteim. Tinirinig the soil towxaird the oiutei ed(ges of a field fom Onie(levxat(-t field b ordlers th at prexvet p~roper field drain age. After sex eral y ears of such practice, nmai areas caii iot dIrain ai (d wet spots dex elop. A\lso, tinin terracet l aud wxith toii xei tioi aI ig p)lowXs ofteii foriis high ridges just ab~oxe the teirate chIanciel anid~ dead furro~ws betweein themi that prex ent prope-r laiud driainiage. Two-wax turinig plows cai th1e used to great adx aintage iii ('I iai tati igelexvatedL field borders and dtetad fitroxxs b etxweei itrrac-es. The absence of elex ated fieldi borde(rs miakes it possible for the- rows to drain iiito tdraintage ditchies aiid terrace outlets. Sloping or c-ontoi red lanit Cait he uised fori imechaizied tottoin p~roduiction prox ided suitable dlrainI age aind terracin g sx steims are ii sed. \Iaji i presei t-tlax terraciniig s\ steims hindi~er effitieint operation) of tractor cdip)iiint, especijally muilltip~le roxw c(fifloi et. Shiarp ti ius in ter-aces make it difficult to Inai ei mx tractors cx cn (r at slow,\ speeds. Uneten ily spatced terratces resiult i ni tnelroi s poinit rowxs that are iiiidesi-al e for imechan iized( operations Te5 ir-

Contoured land with suitable terrace and drainage system con be used for complete mechanization. Conventional terrace system at left is contrasted with system at right that is designed for mechanized production.

itli narrow bases bare( sides too stee1 ) to aeeoi ii flo(Iate tractors andl c(liplflelt. In recent N ears, terracin(U 5\stco ls that lendR tliei seix (s to met 1 aiizatiolo andl tO] Serxatio1i hax e b een dev~\elop~edl. '1b sc s\ stemls are dlesignied to inc(II de xx ater dlisposal ou tlets in the0 major dlraws, whxinch permit straig;hter and Iulore ce eoi spaced terraces. In roaoox fieldls it is often p)ossible to lax ou~t all or m~ost of the terraces parallel. WVherc parallel terraces ar e lot poss ib le,
races \

v, t y¢{

-

J

Aerial view of terrace system designed for mechanization.

Terraces ore etched in.

[6]

This tour-ru cuot, rtor is being used on a broad terrace built for mechanization. Line in foreground shows cross section of broad terrace channel.

rowxs are t ade( pairalle~l to 01ic terrace atnd( areas x1 e p)oinI t rowxs occutr max lie sodded anid used for titring tihe ilfttipint wxithott (latagitig erops. Thiese areas taken ouit of roxw erops cam h e umsed for produmetionm of seed and hay\ crops. Thme imost desirahle txpe of terrace for mechan icjal piroducttion is time Jim mel pe terrace wxith sitdiejem t wxidth to permiit four rows bietween chlianc tel and1( ridlge. Flat atl si low water disposal hal ou tlets are essential to permit erossin g the(m wxithmtiachim erx. ields hieaxilx itnfestedi with j obmsom grass, lBernm dagrass, perenmiial vitnes, and other bard-to-conmtrol wxeeds are mitfit for inechat iecd cotton produc tioni unmtil wxeedls are cotntrolledi. Suct elweeds cm]i he controlled umsually h falloxxinlg amid or treatitng w~itlh lhemicial hmerb~icides, by pastming atd or mjiin or1b lan1 ting mm, <tcrop that wvill not lie cdamaged bx chemicial herlieidles.
-

SEEDBED PREPARATION ilain objectix es of seedbled p~reparatiotn are to tilit untdcer plant residuie, pulxvemrlze amid firim the soil, amnd sniooth the soil sutrface. Restul ts fronm seedbhed preparatiotn stuides ini :Uab am shoxw thmat ia aras xxhere the soil sumrfaee xxas nios otm iplete]" tin edl had fe(xxest xxeed(s at hiarxvest. liesults front these same stu dlies omi txxo soils, Greeixille fine saidx loai and )lecatmmrelax, shoxw thmat dleep till-

,,.y

ii

_1

*s

.

.

Shown above are four steps in good seedbed preparation-shredeing stalks, turning under residue, disking to firm soil anid eliminate clods, and smoothing.

e'ff(ect oil eottoni ' ields. Resul1ts tliroilg hoiit lt (10 not agree on e'fleet of tillage dlepth 00l \ id and1 plant groxvth. Tlh' greatest 1 ( efits of dleep tillfage hiax IbeenI obtained oil some soils of the D~elta, wh Iereas there wxere no app~arenlt eff ects o1 heax icr soils of oth er areas. Although it is possible to incerease cottoii , ieldls onl somze laud~ by\ suhlsoiling or d1eep tillage, site]) lbenefits are lim~itedf to soils with a comlpaced zonie (hard pan or ploxw sole) that initerf('res wxithi patroot dex (loptiletit. Power reduIietinetits and( cost foir snbag('
Inoticeall ]t

had

the

Cotton

soiling are higher than for normtal preparation mnethods. Tfherefore, subhsoilinug is not wXarranted unlless there is a (definlite nieedi for this t\ pe of tillage. Use of echisel plows or stilsoilcrs. hoxx ('x cr, wxill often result ini better pencetration of tulrninlg plowsx 5oil sonlie of the hard-to-turni elax soils. Results of tests h)ax c shoxni that miolboardI and (fisk p~lowxs are ahouit eq{ually effeetix e for turinitg land. Soil tx pe will determoine to a large extenit whichl tvp)( to uise. Turinit g to aitiniformi dlepthl of at Least (5 inehes is nieedfed to ittiprox (' penletrationl of platin g and( etiltixatitig ((uipoetit and~ anlix drouts 8111i1010 ap~plicators. Proper disposal of crop residlu wxill re'(fice' clogginlg oft nleluim'rx wxhen plowxinlg, planting, etiltix atitig. and( larx (stitig. As
[8]

soon as the crop is harvested, stalks should be cut close to the ground and into small pieces. Power-driven rotary cutters have proved very effective in shredding stalks. Such machines also can be used for clipping pastures. One phase of seedbed preparation that greatly improves planting and weed control is smoothing the soil surface. This eliminates unevenness of the soil surface caused by tillage tools, making it easier to plant at a uniform depth throughout the field for more uniform emergence. A smooth seedbed improves the performance of rotary hoes, mechanical cotton choppers, sweep cultivators, and equipment for applying chemicals for weed control. Homemade drags pulled behind harrows will eliminate many soil irregularities and are the most widely used smoothing tools. Although any kind of drag will help, land levelers are excellent tools for smoothing the seedbed. While the use of land levelers in other areas is usually confined to land leveling operations, their use in Alabama is intended primarily for smoothing land and improving drainage. VARIETY For machine harvesting, the same varieties are recommended as for hand harvesting. Storm resistance appears to be one of
TABLE 1. RESULTS OF COTTON VARIETY SPINDLE PICKER TESTS

Location and dates
Sand Mountain 1955 and 1956 One picking 1955 Two pickings 1956 Tennessee Valley 1955 and 1956 One picking when all open Wiregrass 1954 One picking when

Variety
Empire Coker 100 W. Plains Stone. 3202 Empire Coker 100 W. Plains Hale 33 Auburn 56 Coker 100 W. Plains

pre-harvest loss1 Per cent 2.3 4.8 4.1 2.2 0.8 1.7 1.5 0.7 4.1 16.9 16.5

Weather or

Spindle picker
efficiency Per cent 97.0 96.5 95.4 95.8 91.0 90.2 88.0 84.8 91.0 91.3 88.7

efficiency Per cent 94.8 92.8 91.5 98.8 90.3 88.6 86.7 84.2 87.2 75.8 74.1

Overall

all open
Wiregrass 1955 Two pickingsfirst when 55 per cent open
2 Percentage

All-in-One
Auburn 56 Coker 100 W. Plains All-in-one

12.0
3.5 5.1 5.9 4.0

90.9
95.8 96.3 95.0 95.8

80.0
92.4 91.4 89.4 92.0

1 Percentage of total yield on the ground at harvest time.

of cotton on the plant harvested by the machine. SPercentage of total yield harvested by the machine.

[9]

the most important characteristics to consider in choosing one of the recommended varieties for machine harvesting. Cotton intended for machine harvest is often left in the field until most or all of the bolls are fully open. Thus it is exposed to wind and rain longer than hand picked cotton. Varieties showing storm resistance have less weather or pre-harvest loss and still give high machine efficiency. Given in Table 1 are the results from 3 locations in Alabama of the cotton variety spindle picker test. There were no great differences among varieties in the overall harvesting efficiency, but the most storm resistant varieties, Empire and Auburn 56, were slightly better than the other varieties tested. PLANTING The common practice in Alabama is to plant cotton thick and hand chop to the desired stand. However, cotton can be planted .to a stand just like corn, peanuts, soybeans, grain sorghum, and most other crops to eliminate hand thinning. Tests in Alabama and throughout the Cotton Belt show that plant spacing in the drill can vary considerably without materially affecting yield, provided the plants are uniformly distributed. In Table 2 are results of spacing tests conducted at three locations in Alabama. These data show that a stand can vary from 20,000 to 60,000 plants per acre. Based on these results, it is recommended to plant for a stand of about 3 plants per foot or 40,000 plants per acre. If good weather prevails during emergence, a stand of
TABLE

2.

RESULTS

OF COTTON

SPACING SPINDLE

PICKER TESTS

Location and dates

Spacing Plants Plants per foot per acre

Per acre yield

Boils per
poundr

Spindle picker efficiency

No.
Sand Mountain Substation 1954, 1955, 1956 Tennessee Valley Substation 1954, 1955, 1956 Wiregrass Substation 1954, 1955 14,700 21,700 40,100 56,600 14,000 20,300 41,200 59,700 15,300 18,800 35,100 56,700

No.
1.1 1.7 8.1 4.3 1.1 1.6 8.2 4.6 1.2 1.4 2.7 4.8

Lb.
1,574 1,611 1,697 1,705 1,025 1,080 1,104 1,045 2,178 2,196 2,112 2,130

No.
56* 58 60 62 72 72 79 81 76 76 78 79

Per cent
94.9 94.6 95.1 94.7 90.7 91.3 90.5 90.3 91.8 92.5 92.9 92.5

* Average for 1955 and 1956 at Sand Mountain Substation. [10]

Cotton can be planted and pre-emergenice weed control chemical applied in same operation with sprayer mounted as shown above. Note the well-prepared seedbed and use of row marker and wide press wheel.

I towercr,1 if 1bad lesutt 60,000i( plants jher acre or imIore mayl wxeathter occutrs, a stai d of at least 20,000) plaits per acre can he exp)ectedl. lIn either case, \ ields wxill ntot be affectedI iaterialix. Althtoig fl0,(000 plants per acre may he juist as good as thi cke stan ds, it is inot ads isab~le to plaint to a stai d( of 20,000) plaitts isatisfactorx staid. because poor emnergeitce could result ill an un 'heit plantiing to a stand, it is imnportantt to reieitler thtat too itait plantts aic b etter than too f('«'.

Skips like the one shown reduce yield ond promote growth of grass and weeds that interfere with harvesting.

[ 1II]

n .ru, ,tuna attccts growth and fruuiny of cotton. t in photos at left is stand of 1 plant every 12 inches. Nate long limbs and low fruiting. Plants at right are spaced 1 every 2.7 inches and hove short limbs and high fruiting.

(Close spacing in the dIrill tends to produice iiniform plants wxith short and high fruiting limbs. Although thicker- spacings hlad but little effect on spindcle picker efficieiiex , higher fruiting in the thicker- stands miade it possible to operate the [picker hiigher above the groin d. This made it easier to keep the picking drum from goui tng into tihe dirt. There are 110 serious objection s to thick stands for hand picking, except that smaller hl)ls result from the thicker stands, Table 2. Hlowev er, the slight dlifferencee in bo011 size is less than v ariation among the recomummended v arieties. Determi nng how mny seed to plant to get at desiralble stand without thinning is a prob~lemn. It is difficult to predict aceuurateix the p)ercentage of emergence of cottonseed. Gem Iination percentage is nmot alway s a good measure of emetrgence. A good rule of thumb is to plant ab~out twice as I)IaII good seed (80 per cent germination or lbetter) as y ou wish to emerge. When planting to at stand and plani ing to uisc chemicals for weed control, about 7 seed per foot are needed. This seeding rate is approxim~ately .3 pecks of machine delinted seed fper acre. When using a rotary hoe for we ed control, the planting rate is ab~out 10 seed [pcr foot or at bushel per acre. LIn most cases, sev eral rotary hoe cultiv ations will eliminate enough plants for a [ 12]

Weeds and grass collected with cotton are difficult to remove in ginning and result in lower grades. Clean culture year after year is important in good weed control. The use of hand labor to remove late growing weeds before they go to seed will pay dividends. In a rotation, it is best that the crop preceding cotton be a clean culture crop. From the standpoint of weed control, cotton should not be in a rotation with corn. Where cotton is rotated with corn, weed control is more difficult because weeds are usually allowed to go to seed in the corn. Clean culture of cotton in fields infested with hard-to-kill perennials requires much hand labor the first year or two. However, it should result in relatively clean fields after several years of operation. Seedbed preparation influences weed control practices. A smooth, firm seedbed free of clods and debris is needed for most effective use of the rotary hoe and sweeps and chemical weed control equipment.
Rotary Hoe

Use of the rotary hoe and chemicals will eliminate much of the hoe labor for cotton production. Table 3 gives results of five tests comparing mechanical and chemical weed control with conventional hand chopping and hoeing at the Sand Mountain Substation. In these tests, the conventional or check plots were seeded in a continuous drill at the rate of 1 bushel of seed per acre, barred-off, and hand-chopped to a stand. The rotary hoe
TABLE

3.

RESULTS

OF 5 TESTS COMPARING 3 CULTURAL MOUNTAIN SUBSTATION, 1954-56

TREATMENTS,

SAND

Item Seeding rate, seed per foot Stand at harvest time, plants per foot..... Grass and weeds 30 days after planting, number per 100 row-foot...... Hoe labor, man hours per acre Yield, pounds per acre Spindle picker efficiency, per cent
2

Results from three cultural treatments Check' Rotary hoe 2 Chemicals' 11 1.8 525 17.1 1,540 94.6 11 4.1 163 9.5 1,480 95.1 7 3.0 2 1.8 1,517 94.4

Hand chopped and hoed. Broadcast-type rotary hoe used and hand hoed but not chopped. ' Pre-emergence chemical (C.I.P.C.), 1 to 2 post-emergence treatings, and hand hoed but not chopped. Note: All treatments received sweep cultivation. [14]

desirable stand. (Note: Test results of planting to a stand are discussed under Weed Control.) When planting to a stand, the seed may be hill-dropped or drilled. Hill-dropped cotton is easier than drilled to hand-hoe when weeds are numerous. Fuzzy seed and machine delinted or acid delinted seed can be used to get a stand. However, delinted seed can be planted with greater accuracy than fuzzy seed. Flat planting is desirable in mechanized cotton production. It leaves the row more accessible for effective rotary hoe cultivation, especially with a broadcast type rotary hoe. Flat or low bed planting is best where chemicals are used for weed control, because water will not collect and leach the chemicals into the soil and damage the cotton seed. Flat planting provides a desirable row profile for efficient application of post-emergence chemicals. Flat planting reduces the hazard of soil silting in from beating rains and sand storms. Furrow planting offers some protection from cold wind and sand storms as experienced in southeastern Alabama. However, sand will often fill the furrow and kill the emerged cotton or cover the seed too deeply for emergence. Fertilizer can be applied at planting time if put in narrow bands about 21/2 inches to either or both sides of the seed and 2 to 21/2 inches below the seed. Placement of fertilizer should be accomplished with minimum disturbance of the seedbed. For best machine use, uniformly spaced long rows are needed. Rows of uniform width are needed in obtaining good coverage when poisoning and defoliating with multiple-row sprayers and dusters. They also reduce damage by tractor wheels during cultivating, poisoning, defoliating, and harvesting. A row marker aids in planting rows of uniform width. For most efficient harvesting, mechanical harvesters must enter the row straight and continue past the end before beginning the turn, maintaining a normal speed. For this reason, it is important to have about 20 feet of turning area at ends of rows. WEED CONTROL Fields free of grass and weeds at 'harvest time are important for efficient use of mechanical harvesters and for obtaining high grades of cotton. Weeds, vines, and grass in the row sometimes clog mechanical harvesters, causing stops and high harvest losses.
[13]

Here, young cotton is being cultivated with a broadcast rotary hoe.

plots xwere also dilile d at the rate of 1 b)ushell per acre ( alout I I seed per foot) b)u t reccix d no hai d thionning. Tihe rotarx hoe wxas uisedi 1 to 4 times deitpeniniig u11on1 wxeed growxtlh and stand~ and h and h( oeing was cl one as needled. The cheic al plots wer drilled at tihe rate of :3 pecks per acre (about 7 seed per foot) but we n ot lhaiid-thinntied. Thev receix ed at pre-eterglence cheumical tre 1C. J.P.C.) applicatlion at planting time, I to 2 post-emergene appliciatins of oil, aild wXere han d-holedi as n eededi. The seed ill thlis test xwere p~lanted inI a continuious (trill, lhit tests in other state's liax shown that the seed1 mlay be hill-dropped. TIhese results show that uisiung the rotarv hoe eliinlatetd abou1 t 4(0 per cent ot the hoe lab~or. N\ here tilidl andtt frequent use of the rotary hoe xwere possile, hoe labor wxas redui ced ab o t 50) per cent. B~ecause of at thin standt Cauised by poorix treated s(eed inl one test, thle rotary hoe was used onlx once. Ini this test, hoe labor was only 20 per cent less than thlat for thet chfeck plots. Thlese tests are good examples (of tihe im portai ce of gettini ta good stand. The rotarx hloc should1( be used ju st ats weeds 1 egin to emerge. If weeds are allowedcc to estab~lishit deep root s\ stein, tile rotary hloe will nlot h~e effectixve. The greatest limitatidon of tile rotarx hoe is the illalbilitx to use it wdhen the ground is wet. A long xxet p)eriod wxill ailow wxeetds
[ 15]1

to establish a good root system and become too large for control with a rotary hoe. The destructive power of the rotary hoe on weeds increases as speed increases. In most cases it is desirable to run the hoe at speeds of 4 to 6 miles per hour. The rotary hoe also aids greatly in obtaining a stand by breaking hard crusts caused by rains.
Chemicals

Results in Table 3 show that the use of chemicals reduced hoe labor about 90 per cent. The chemicals were applied as recommended in API Agricultural Experiment Station Progress Report No. 51. A 12-inch flat steel roller was used to press the row, leaving a smooth clod-free band on which to apply the pre-emergence chemical. Recommended depth of planting is the same as for
planting without chemicals (3/4 to 11/4 inches).

Post-emergence oils were applied with fan-type nozzles mounted on parallel-action spray shields. Nozzles mounted on these shields are relatively easy to adjust for effective spraying of small weeds without spraying the cotton leaves provided cotton is planted flat or on a low bed and a flat roller is used at planting time. Success of this operation depends to a large extent upon a well-prepared and smooth seedbed. If cotton plants are large enough, the post-emergence oil is applied just as soon as the weeds begin to emerge. This is important because large weeds cannot be sprayed without spraying the cotton. For more information concerning spray equipment for weed control see API Agricultural Experiment Station Circular No. 126. The reduction in hoe labor by using a rotary hoe and chemicals was not only the result of reduction in weeds but also the elimination of chopping or thinning. To realize the greatest benefit from mechanical and chemical weed control, cotton must be planted to a stand. Not only does thinning require considerable time but disturbance of the soil by thinning reduces the effectiveness of the chemicals. However, there is no advantage to planting to a stand to eliminate hand thinning unless mechanical or chemical means are used to control weeds. If weeds are numerous, it takes as much or more labor to get the weeds without thinning as it does to get the weeds and thin the cotton. Sweep cultivation is the best method for controlling weeds in middles. When properly used it controls many weeds in the row. Sweeps must be set properly for effective, fast, and precise work. When set to run flat and shallow, sweep cultivation does not
[16]

*41

K :.rb.7:

*

P

.,

'A'

-.

'

At

I

Ax
I-' I~

K
.4

Ni.
,m -

*

4
I;

t

-

xx V\
N. F -1I
1.

I.

a-'

'a'

CL

t>

.

ir.
.a

9 1

4

.

4

T "re
j
N,'~

{S".Y
.

&

.4,; p. Above are results from chemicol weed control for 3 years at the Sand Mountain Substation. Top photo shows treated field in 1954. Center (1955) ond bottom (1956) photos sh~w ch~mical treated plots, right, ond nontreated, left. [K;]

ridlge the row it leav es the midd(le slightlx low er than tile r whiche is desirable for mechaniceal harvestin1g. Cotton to be h arv estedl mechaicjalix- is cuiltiv atedl late inl the season to redIie weeds at lharx (st timle.

Spraying post-emergence oils for weed top shows nozzles (arrows) mounted on weeds in row without spraying cotton sweeps cultivating middles and shields

control is shown obove. Overhead view at parallel action shields ond set for spraying leaves. At bottom is a front view showing keeping dirt off treated row.

[ 181

INSECT CONTROL
(:ottol inlsecticidles ma" h~e app)lijed as a Illust or a sjera.. Jests 1)X the Ag~ricu ltu ral lI.Xperimel t Statin I [aX sh ownI th at dullsts controlling cotton ins~ects. andt spray s arc ejnualx (ffectiX e inl Spray ilvg insect icides has seX oral adX antages ox cr dust application. Sprays lsnllhI call he appl)ied throulg1hout tile (lX, xxIlreas S restrictedi to carly mlorlnig, late (X n(IIil,or (lust apiaonis areas there hours XwhIen there is little or no0 wind1(.11n sof)( nlighlt are (laXs (luirillg the growilig seasonl wxellh diist calniot he appl)iedl pcx uits at anyI tille lecaulse of XX iil or air curren~ts. 'This oftenlj~ ichl is so) implorI ai-mrs fromi followinjg a poisolig sced~ulle wh tant f or effectiX e insect con~trol. Using s1 )ra\-s illcreases chlances
of

beilng

ab~le

to p)oisonl

ofl

sch~edulle.
Xxhell

Spay call be applied XXhue clIltiX atillg. Ill season~s
seulsolI

ilsect co) t]o

is 5impllortan t, eflectiX c con~trol call

carl Le oh-

Insect-damaged boll like one at top reduces yield and picker efficiency. ground or air spraying or dusting with insecticides can prevent damage.

Either

[ 19]

tained with sprayers mounted on regular cultivating equipment. Such application is economical from the standpoint of application costs. The same spray rig can be used throughout the 'growing season. Spray application is less objectionable to the operator than dust application. Dust applied during calm weather may stay suspended in the air to bother the tractor driver throughout the dusting operation, whereas spray will settle quickly on the plants. Spraying equipment has much wider use than dusting equipment. In addition to applying insecticides to growing crops, sprayers can be used for spraying livestock, chicken houses, and other insect-infested areas. They can also be used for applying herbicides. Warning-do not use 2,4-D in the same equipment that is to be used for spraying cotton or other broadleaf plants. While spray application has several advantages, it also has some disadvantages. One is that the farmer must mix his own spray solution in correct proportions. The amount of diluted spray for effective control may vary considerably (from 1 to 10 gallons per acre for cotton) so long as the correct amount of technical (active) material is applied. If the strength of the concentrate and the amount of solution the sprayer is applying are known, it is relatively simple to mix concentrate with water in correct proportions. Concentration of the solution is marked on the container and is usually expressed in pounds of technical material per gallon of concentrate. The amount of solution the sprayer is applying must be determined by calibrating the sprayer. (See API Agricultural Experiment Station Circular No. 126 for information on calibrating sprayer.) Another disadvantage of sprayers when compared to dusters is that sprayers have more parts, such as nozzles, strainers, hoses, and a pump, to cause trouble in clogging, corroding, and rusting. In Alabama, tractor-mounted dusters are used most widely for insecticide application. Dusters are relatively simple and are easy to operate and maintain. With introduction of the new organic insecticides, improvements were made in the metering and blowing systems to give more uniform distribution of insecticides. Multiple-row dusters have been designed for operating efficiently at high tractor speeds. Plane sprayers and dusters are now being used for applying cotton insecticides and defoliants. They have advantages over ground equipment in that they (1) do not damage the crop, (2)
[201

can be used when the ground is too wet for ground equipment, and (3) can apply the insecticides much faster. Considerable progress has been made in reducing mechanical damage to crops caused by ground applicators of insecticides. This damage may be quite serious, especially from late season applications in tall crops. Because of this mechanical damage, many farmers stop poisoning before the crop is mature. Test results show that late applications are often the most important. Progress in reducing this mechanical damage has included development of tractor wheel shields, design of sprayers and dusters with high-clearance mounting frames without low braces, and use of multiple row units. Several companies make tractor wheel shields and some farmers have improvised shields that work satisfactorily. Other progress in reducing mechanical damage to crops includes the development of high-clearance sprayers and the use of "stilts" (high clearance kits) for elevating row crop tractors. The special-purpose, high-clearance sprayers are relatively costly and have been used mostly on large farms and by custom operators. Stilts for tractors have proved to be quite satisfactory. Since the tractor can be removed from the stilts and used for regular tractor work, these rigs are relatively economical for insect control work. DEFOLIATION The benefits derived from applying a chemical to defoliate cotton will vary with plant condition and method of harvesting. Tests have shown that defoliation is not always economical or necessary for harvesting by hand or by spindle picker. However, the same tests show that defoliation either by nature or with chemicals is a must for harvesting with a mechanical stripper. Results from defoliation harvesting tests at two locations are given in Table 4. These results show that defoliation had no effect on harvesting efficiency of the spindle picker and trash content of the harvested cotton. However, defoliation gave a slight increase in lint grades. The cotton plants in this test were less than 3 feet tall and some natural defoliation occurred each year. Defoliation should prove more beneficial in rank cotton, especially during wet conditions. Although defoliation did not increase picker efficiency, removal of leaves made it easier for the operator to see and keep the picker on the row. Defoliation
[21]

N 11. F 011 LI)

COTTiON,

1954-563

itc'i ]Mld pouds
Spindl pice
per acre-

Dlefoliated
-

Ondelfoliatt(I 1,:300O 91.9 2-M -I4-SLMI 4 L\I
1-\ILt. Sp.

efficiency, pc r cLlt

1,395 92. 1

(h oh,

2M

I-SM

(3SlSI
2-1-M
1i

Sp.

1-SLNIIt. Sp.

also allowed the cotton to drv qu(icker for earlier harvesting; each
moi()i iiI'

Ini three tests in 1954, ui (efoliated

cottont harv estedl with a

mnechaniical stripper conttainied a high percentage of green leave and( wxas dliffilt to ginl. It requ~ired "2,500) poundtls of seed cotton mid( trash to make a 500-pound bale. These results show that cot-

ton nmtst be diefoliated for harv esting with a mechanical stripper. D~efoliantts can be ap~plied wxith equipment uisedi for applviig in secticides. Larger v olumes of dust and sprav are niceded for defoliation than for insect control. For insect control, good coverage of the terminal growth is uisually ade tt ate. HIow ever, for

Defoliated (left) and undefoliated rows of cotton applied show results from using the chemical.

1 week

after defoliant

was

[ 22 II

defoliation each leaf must receive an application of the defoliant. About 20 to 40 pounds of dust defoliant per acre or 15 to 25 gallons of spray solution per acre must be used. See API Agricultural Experiment Station Circular No. 126 for more information about equipment for applying defoliants. In droughty cotton and when there is no dew, tests results show that it is best to use a spray defoliant. For normal cotton and when dew is present, dusts and sprays are about equally effective. It normally takes about a week after applying the defoliant for the leaves to fall. Thus the chemical is applied about 7 to 10 days before machine picking. Staggered applications can be timed so that harvesting can be done soon after the leaves fall. HARVESTING Based on the principle of operation, there are two types of mechanical cotton harvesters-pickers and strippers. Pickers pick the cotton from the bur, whereas strippers strip the cotton, bur and all, from the plants. Pickers have rotating fingers or spindles that pick the open cotton and leave the green bolls for a later picking. Most strippers have stripping rolls somewhat similar to a corn picker, while others have stripping fingers or tines. It is necessary to wait until all bolls are open before harvesting with a mechanical stripper. Strippers are considerably lower in cost than pickers. Pickers and strippers were tested for several years in Alabama. Although many problems were encountered with both types of machines, there were more problems associated with the stripper. Results of these tests show that conditions for stripper harvesting are much more exacting than for picker harvesting. Poor defoliation, new growth, vine infestation, uneven plant size, and nonuniform maturity often made it impossible to use mechanical strippers. These same conditions, although unfavorable, did not necessarily prevent picking with spindle pickers. While waiting for all bolls to open as required for stripper harvesting, much cotton fell to the ground, especially during rainy and windy weather. This high weather loss occurred every year at the Wiregrass Substation, whereas only small losses were experienced in northern Alabama. The stripped cotton contained 30 to 40 per cent foreign matter (burs, limbs, and leaves), which usually caused trouble in ginning. Considerable clogging was often encountered
[283]

Harvesting cotton with machines like the stripper (top) and spindle picker (bottom) requires only 2 to 3 man-hours per acre.

(luring ginning. G;reen limlbs seemedl to cause the most trouble. The cotton gradled Low MIiddling in most tests. Results from some of the mechanical stripper tests are giver(i in Table 5. These show that the stripper is an efficient harvester, av eraging slightly aboxve the p)icker. The stripper used ini these tests wxas a 2-row machine with a single steel strip)ping roll and iastripping b~ar for each row (John Deere No. 15). In fields with moist sandy soil, the stripp er uprooted many plants and ome 1 times clogged sexveral times before adv ancing 100) feet..\orniu" glory and other xvines wrapped around the heaters of the convxeyxing1 sy stem andI clogged the machine. Cotton stripped in fields wxith poor defoliation or with ab~undant new~ growth contained [ 24]

TABLE

5.

SP:NDLE
VARIETY

PICKER

AND STRIPPER
AT

PERFORMANCE
THREE

IN

AND SPACING PLOTS

LOCATIONS,

HARVESTING 1954-56

ALL

Location and year

Picker Stripper Machine Overall Trash Machine Overall Trash efficiency efficiency content efficiency efficiency content Pct. Pct. Pct. Pct. Pct. Pct. 91.7
96.0

Sand
Mountain

1954*
1955

86.6
93.8

9.6
7.8

92.1
97.8

87.4
95.4

33.8
33.6

Substation Tennessee Valley Substation Wiregrass Substation

1956 1954* 1955 1956* 1954 1955

96.6 88.2 95.8 84.2 90.6 95.0 92.3

93.4 76.2 95.0 83.4 77.8 91.4 87.2

6.3 6.1 7.6 7.6 8.1 7.2 7.5

97.6 88.6 97.6 97.8 93.2 94.7 94.9

95.8 76.6 96.6 97.0 80.8 83.2 89.1

31.5 88.6 81.9 33.7 35.0 33.6 84.0

Average of 256 trials

* Cotton in these tests was severely drought stressed.

many green leaves; about 2,500 pounds of harvested cotton and trash were required for each 500-pound bale. There were some years when conditions were good for mechanical stripping and good results were obtained. While stripping is not ruled out for Alabama, these test results point up problems that can be expected with this method of harvesting. The picker used in these tests was a one-row, low drum machine with barbed spindles (IHC H-14 and C-14). As shown in Table 5; the efficiency of the spindle picker was greatly affected by plant or boll conditions that were determined by weather. Small and knotty bolls resulting from dry weather contributed to low efficiency. Where ample rainfall occurred during the growing season to produce good yields of sound bolls, picker efficiency was usually high. However, long period of wet weather, such as occurred in 1957, caused hard locks that contributed to low picker efficiency. Many of the hard locks that the picker failed to get would have been poor quality cotton even if they had been harvested. Unlike strippers, pickers can be used to harvest before all bolls are open. A test was conducted comparing twice-over picking (starting when the cotton was 60 to 85 per cent open and picking again when the remaining bolls were open) with once-over picking when all bolls were open. In this test, twice-over picking reduced weather loss and increased overall harvesting efficiency 2 out of 3 years of the tests. No measure was made of quality, but twice-over picking should result in higher quality cotton
[ 25 ]

because of less weathering. However, when yields are low, it might pay to take a chance on weather losses and make one picking when all cotton is open. The additional amount and quality of cotton obtained from two pickings might not offset the cost of the second picking. The plant compressor sheets of the picker used in this study can be equipped with a rib plate attachment that forces the cotton around the spindles and increases their effectiveness. Data from five tests show that machine efficiency was 89.5 per cent without the plates and 93.0 per cent with the plates. However, the attachment increased the foreign matter content of the harvested cotton from 6.3 to 8.1 per cent. This attachment causes the spindles to puncture green bolls; hence, it should not be used until the last picking. The grade of machine-picked cotton varies with weather and plant conditions and the ginning equipment used. Table 4 shows the grades obtained in the defoliant test. In comparing machinepicked and hand-picked cotton, field conditions and quality of hand pickers must be known. In early season harvesting, handpicked cotton will usually average about one grade better than machine-picked cotton. As the season progresses and cotton becomes weathered, the difference in grade between hand-picked and machine-picked cotton becomes less. INFLUENCE of WEATHER Weather conditions determine to a large extent the success of cotton production. Results of several years of testing have shown that efficiency of the spindle picker is affected more by plant and boll conditions that are determined by weather than by any other factor. Cold weather delays planting, hinders emergence, weakens the plants, and makes the plants more susceptible to diseases. Wet weather prevents timely field operations, makes mechanical grass and weed control more difficult, prevents emergence of deep planted seed, increases insect control problems, promotes rank growth, and causes boll rot. Dry weather prevents shallow planted seed from emerging, reduces the effectiveness of pre-emergence chemicals for weed control, reduces yield, and causes small and hardlock bolls. Weather is especially important in a mechanized cotton program where timely machinery operations, good yields, and high machine efficiency are essential for economical machinery use.
[26 ]

Effect of weather on picker efficiency at the Tennessee Valley Substation is shown above. In 1955 (top photos) there was ample moisture for good yields and sound boils, resulting in 96 per cent picker efficiency. Severe drought in 1956 caused low yields and the hard-lock cotton shown at bottom. Picker efficiency for this cotton was 86 per cent.

There are miane things that can he cdone to reduce weather hazards. The most important thing in a mechanized operation is to hax e equipment andI land prepared for efficient and conttinumous operation wxhen soil and weather conditions arc faxvorahle. Contim ionis

operation when the time is right

conitribuItes

greatix to

econonmical mach inerx uise. MIachine performan ce depends almost entirelx oiu skill of the operator. Good operators will help ini rediucing revpair costs and result in more efficientt an d com tiiois o[perationi.

[ 27]

SUMMARY

Cutting production costs by use of machinery can help solve problems facing cotton farmers. To do this, machines must be used efficiently. Results from experiments reported show that the following steps will permit efficient and profitable use of mechanized farming practices: (1) Select and prepare cotton land early. (2) Use best land for cotton and prepare it for using all types of machines. (3) Remove rocks and stumps that cause machinery breakdowns. (4) Keep terrace outlets open and drain low spots to permit earlier seedbed preparation following winter rains. (5) Prepare smooth, clod-free seedbed well in advance of planting time to reduce chances of late planting on poorly prepared seedbed. (6) Have tractor and planting equipment in good operating condition. (7) Adjust all units of multiple row equipment to plant alike. A difference of one-half inch in planting depth may mean the difference between a good and poor stand, especially in bad weather. (8) Plant to a uniform stand to eliminate hand thinning and reduce hoe labor. (9) Use chemical or mechanical means to control weeds instead of hoe labor. (10) Have dusting and spraying equipment adjusted to obtain good plant coverage. (11) Defoliate rank and leafy cotton. (12) Begin picking before all cotton is open. With mechanical picker, begin when 60 to 75 per cent is open. (13) Keep picker drum clean and serviced. (14) Adjust picker properly for efficient and clean picking. (15) Do not pick wet cotton. (16) Gin cotton soon after harvesting or make sure that only dry cotton is stored overnight in trailers. (17) Don't give up new machines or methods because of poor results during one year of unusually bad weather.