rice objective yield feasibility study

7/26/2019 Rice Objective Yield Feasibility Study

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RI CE OBJ ECTI VE YI ELDFEASI BI LI TY STUDY

I NTRODUCTI ON

Th e de vel opmen t of an obj ec t i ve yi el d pr o gr a m f o r r i c e i s on e of t he s ubt as ksi dent i f i ed i n t he Yi el d Model Devel opment I mpl ement at i on Pl an f or AgRI STARS. 11A f easi bi l i t y st udy was conduct ed dur i ng 1980 i n Ar kansas by t he Economi csand St at i st i cs Ser vi ce ( ESS) . The pr ocedur es used i n t he st udy wer e s i mi l art o t he obj ect i ve yi e l d pr ocedur es used i n t he oper at i ng pr ogr am f or wheat .Some changes wer e made i n t he pr ocedur es t o acc ommodat e r esear ch dat a r equi r e-ment s and speci a l pr obl ems i n r i ce f i e l ds, such as t he f l ooded condi t i ons.

Devel opment of a r i ce obj ect i ve yi e l d pr ogr am pr esent ed sever a l known ande nvi s i o ne d pr o bl e ms n ot n ec e ssa r i l y e nc o un t e r e d i n o t h er c r o ps. T he f e as i -b i l i t y s t u dy wa s c o nduc t e d t o e val u at e t h e se ver i t y o f a nd so l u t i o ns t o t h esepr obl ems. Most of t he pr obl ems wer e due t o t he f l oodi ng of t he r i ce f i e l ds.Li st ed bel ow ar e some of t he concer ns associ at ed wi t h t hi s st udy:

1. di f f i cul t y i n handl i ng sur vey equi pment i n t he f i e l d,

2 . e xc ess i ve dama ge t o f i e l ds a nd o bse r va t i o n u ni t s ,

3. enumer at or saf et y due t o snakes, mosqui t oes, and hi gh humi di t y,

4. di f f i cul t i es wi t h post har vest measur ement s, and,

5. f ar mer r esi st ance.

I n addi t i on, i t was necess ar y t o det er mi ne opt i mum pl ot s i ze, and l abor at or y

pr ocedur es .

Th i s pa pe r r epo r t s on t he f i ndi ngs of t he s t ud y wi t h i mpl i c at i on s f o r f u r t h er

dev el opment .

11 AgRI STARS i s an acr onym f or " Agr i cul t ur al & Resour ces I nvent or y Sur veys

Th r ough Aer os pa c e Remot e Se ns i ng" .

SAMPL E DESI GN

Si n c e t h e pur pose o f a f e as i bi l i t y s t u dy i s t o deve l o p pr o c edur e s a nd i den t i f y

pr o bl e ms, i t wa s n ot n ec e ssa r y t o o bse r ve a l a r ge n umber o f f i e l ds o r t o r a n-doml y se l e c t t h ose f i e l ds . Ni n e f i e l ds we r e c h ose n f o r t h e st u dy by t h eenumer at or s. Cr i t er i a f or sel ect i on wer e f ar mer cooper at i on, di st r i but i onacr oss t he gr a i n l engt h t ypes, r epr esent at i on of bot h aer i a l and dr i l 1~d

s owi ng met hods, and pr oxi mi t y t o t he enumer at or .- - -

Th er e wer e t wo s t age s of pl an t de vel opmen t t hat wer e of pa r t i c ul ar i nt e r es ti n t he st udy- - shor t l Yaf t er headi ng and at mat ur i t y. Si nce mat ur i t y var i esgr eat l y t hr oughout Ar kansas, enumer at or s wer e i nst r uct ed t o col l ect dat a dur i ng



2

t h ese st a ge s r a t he r t h an o n a spec i f i e d dat e . T he a dvan t a ge s, ma ny o f wh i c har e i nt er t wi ned, of compl et i ng measur ement s at t he headi ng st age wer e:

1. a n i n di c a t i o n o f t h e t o t a l s t a l k popul a t i o n wh i c h mi ght beencount er ed dur i ng ear l y season vi s i t s coul d be obt a i ned,

2. so me i mpr e ss i o n o f f r u i t su r v i val c o ul d be dr a wn , a nd,

3. f i e l d pr ocedur es coul d be eval uat ed wi t h t he f l ooded condi t i ons.

The mea s ur e ment s at mat ur i t y pr o vi des t he needed mea s ur e ment of f i nal yi el dc ompone nt s .

Thr ee uni t s wer e r an doml y l oc at ed i n ea c h f i el d at headi ng. Each uni t was3- r o ws by 21. 6 i n c he s i n s i ze . St a l k s , l a t e boo t h ea ds, a nd e me r ged h ea dswer e count ed. Emer ged heads and heads i n l at e boot wer e c l i pped i n r ow 1o f e ac h u ni t a nd se nt t o t h e St a t e La bo r a t o r y . At ma t u r i t y 10 u ni t s we r er andoml y l ocat ed i n each f i e l d. These uni t s measur ed 6- r ows by 21. 6 i nches.Each r ow was br oken i nt o 7. 2 i nch sect i ons i n or der t o eval uat e var i abi l i t y.Post har vest gl eani ns wer e col l ect ed f r om 3 uni t s per f i e l d, each 3- r ows by21. 6 i n c he s. Be c au se o f dee p t i r e t r a c ks i n ma ny f i e l ds , i t wa s n ec e ssa r y t or e l o c at e ma ny post h ar vest u ni t s . T hi s pr o bl e m wi l l be di sc u sse d i n det a i l i na l a t e r se c t i o n o f t h e paper .

RI CE CROP CHARACTERI STI CS

The di s c us s i on i n t hi s s ec t i on i s bas ed pr i mar i l y upon i nf or mat i on gat he r edf r om t he 9 f i e l ds used i n t hi s st udy. The 9 f i e l ds wer e di st r i but ed amongt he 3 east er n Cr op Repor t i ng Di st r i ct s i n Ar kansas. Due t o t he ext r eme hi gh

t emper at ur es and l ean r ai nf al l exper i enced dur i ng 1980 i n Ar kansas, some of t he r esul t s may var y f r om what woul d be obser ved i n a mor e nor mal year .

Ri c e f i e l ds i n Ar k an sas a r e e i t h er se eded wi t h a gr a i n dr i l l o r a er i a l l y . Atso me poi n t a f t e r se edi n g, t h e f i e l ds a r e f l o oded t o a dept h a ve r a gi n g 2 t o 4i nches. Gener a l l y, t he f i e l ds r emai n f l ooded unt i l shor t l y bef or e har vest .

The maj or advant age of f l oo di ng i s wee d cont r o l . The hi gh t emper at ur e s t hi sseason caused hi gh evapor at i on and made mai nt ai ni ng t he wat er l evel di f f i cul ta nd e xpen si ve. Ri c e t i l l e r s i n a s i mi l a r ma nn er a s wh ea t . Ha r vest o c c ur sa bo ut 2 we ek s bef o r e t h e r i c e i s f u l l y ma t u r e . T hi s i s bec a use t h e sp i k el e t so f t h e r i c e h ea d h an g l o ose l y , i n a ma nn er s i mi l a r t o o at s , a nd sh at t e r e as i l y

once f ul l y mat ur e.

The f i el ds obs er v ed i n t he Nor t hea s t er n Di s t r i c t of Ar kans as wer e s ee ded dur i ngl a t e Ma y a nd e ar l y J u ne . F i e l ds we r e f l o oded wi t h i n 3 we ek s o f se edi n g. T hef i e l ds wer e har vest ed dur i ng l at e Sept ember . The East Cent r a l f i e l ds wer ese eded i n l a t e Apr i l . T he se f i e l ds we r e f l o oded 4 t o 6 we ek s a f t e r se edi n gand wer e har vest ed l at e i n Sept ember t o ear l y Oct ober . The Sout heast er n f i e l dswe r e se eded i n e ar l y J u ne a nd f l o oded a bo ut 3 we ek s l a t e r . Ha r vest o c c ur r e di n mi d Oct ober . Al l f ar mer s r epor t ed consi der abl e yi e l d l osses due t o t hedr y , h ot we at h er a nd, i n so me c a ses, l o dgi n g c a use d by l a t e se aso n st o r ms.



3

OPERATI ONAL FEASI BI LI TY

Due t o st andi ng wat er i n t he f i e l ds t he r i ce pr esent ed sever a l oper at i onalc o nc e r n s n ot e xpe r i e nc e d i n o t h er o bj e c t i ve y i e l d c r o ps. E xper i e nc e gai n ed

i n t hi s st udy, and enumer at or comment s, have shown t hat most of t he con-c e r n s c a n be r e so l ve d.

One of t he maj or concer ns was enumer at or heal t h due t o snake and mosqui t oi nf est at i on and hi gh humi di t y. The enumer at or s i ndi cat ed t hat heal t h r i sksma y be e ven l o we r t h an f o r so ybe an s a nd c o t t o n. T hi s i s bec a use t h at despi t et he hi gh humi di t y i n r i ce f i e l ds, t he enumer at or can get mor e f r esh ai r t hanwhen wor k i ng under t he soybean and cot t on veget at i on. Sever a l enumer at or si ndi cat ed t hat t he j ob woul d be f ar mor e di f f i cul t i f an enumer at or wor kedal one because of t he di f f i cul t y i n handl i ng equi pment i n t he f l ooded f i e l ds.However , wi t h pr oper equi pment and i mpr oved pr ocedur es one enumer at or shoul d

be a bl e t o o pe r a t e a s e f f i c i e nt l y a s i n a ny o t h er c r o p.

Excessi ve damage t o t he cr op and t he obser ved uni t s was anot her concer n.Damage t o t he cr op when ent er i ng t he f i el d appear s t o be a l egi t i mat e con-cer n. Al t hough any l ~ss t o t he f ar mer i s pr obabl y mi nor , t he enumer at or sf e l t t he appear ance ot t he f i e l d woul d hur t f ut ur e f ar mer cooper at i on. Thi si s a pr o bl e m wh i c h mu st be r e c ogni ze d, but c a n pr o ba bl y be r e du c ed by u s i n gsampl i ng t echni ques whi ch wi l l l i mi t t he number of paces i nt o t he f i el d.Damage t o t he uni t s was not anal yzed i n t hi s st udy, but f ut ur e st udi es wi l ll ook at t hi s pr obl em si nce i t coul d s i gni f i cant l y ef f ect f or ecast i ng pr ocedur es Th e pr o bl em may be wor s e t han f o r ot he r c r ops be c au s e r oot da mage, f r o m s i nk i ngi nt o t he mud, may gr eat l y a l t er f ut ur e pr oduct i vi t y of t he r i ce i n t he uni t .

Some equi pment changes ar e necess ar y f or r i ce. I n t hi s st udy t he f r ame usedf o r wh ea t wa s u se d t o del i n ea t e t h e r i c e u ni t s . S i n c e t h i s f r a me s i n ks , i t

was cumber some f or t wo enumer at or s t o use and woul d be near l y i mpossi bl e f oro ne e nu me r a t o r t o u se c o r r e c t l y . I n 1981, sp i k e s wi l l be a dded t o t h e f r a mewhi ch wi l l hol d t he f r ame above t he wat er l evel . Equi pment bags used f orot her cr ops ar e unsat i sf act or y i n r i ce f i e l ds. Most enumer at or s used l ar ge

buc k e t s i n 1980. T he buc k e t s wo r k e d r a t h er we l l .

Th e l ar ge s t unr es ol ved pr o bl em i s wi t h t he ha r ves t l os s mea s ur e ment . F i el dsar e usual l y qui t e sof t when har vest ed. The har vest i ng equi pment l eave r at herde ep t r a c ks . No t a l l o f t he gr a i n c an b e f o und i n a p os t h ar v es t u ni t wh i c hf a l l s o n a t i r e t r a c k . T hi s r e qu i r e s p l a c i n g t h e u ni t bet we en t h e t i r et r acks. However , t he ar ea bet ween t he t i r e t r acks may cont a i n a di spr o-por t i o na t e l y h i gh a mo un t o f h ar ve st l o ss . T hi s s t u dy h el ped i den t i f y t h e

sever i t y of t hi s pr obl em, but not t he sol ut i on.

MTAR~I ~

As di scuss ed pr evi ousl y, t he pur pose of t hi s st udy was t o eval uat e oper at i onalf e as i b i l i t y , n ot t o c o l l e c t dat a f o r bui l d i n g mo de l s . Ho we ver , so me o f t h e

dat a ar e wor t h r evi ewi ng.



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Ta bl e 1, c on t a i ns f i el d l ev el yi el d s t at i s t i c s . Th e es t i mat ed yi el ds ar ebase d u po n 10 u ni t s per f i e l d f o r t h e b i o l o gi c a l y i e l d a nd 3 u n i t s per f i e l df o r h ar ve st l o ss . T he l i mi t e d sa mpl e s i ze pr e ven t s t h e ma k i n g o f a ny def i -

nat e s t at ement .a - aUsi n g a mu l t i p l e t - t e st ( c - / 2x9) , t o a dj u st f o r ma ki n g 9 c o nc u r r e nt t e st s ,

t he har vest ed yi e l d est i mat es of onl y 2 f i e l ds wer e s i gni f i cant l y di f f er entf r om t he f ar mer r epor t ed yi el d at a = . 05. The f ar mer r epor t ed yi e l ds andt he est i mat ed yi e l ds wer e adj ust ed t o a 12 per cent moi st ur e l evel . The useof f ar mer r epor t ed yi e l ds has i t s obvi ous pr obl ems. However , as i n manyst udi es, f ar mer s have t he best check dat a avai l abl e.

Th e es t i mat es appe ar t o t end t owar d unde r es t i mat i ng l ow yi el dse st i ma t i n g h i gh y i e l ds . F i e l d 7 doe s n ot f o l l o w t h i s pat t e r n .y i e l d i n f i e l d 7 mu st be que st i o ne d s i n c e t h e b i o l o gi c a l y i e l dt he 10 uni t s was l ess t han t he f ar mer r epor t ed yi e l d.

and over - Th e f a r mer

of onl y 3 o f

As st at ed ear l i er , har vest l oss measur ement i s a ser i ous pr obl em. The har vestl o ss dat a do n ot pr o vi de a ny r e al c l u es t o a nswe r i n g t h e pr o bl e m. I t i s t h ou gh tt h at i n mo st f i e l ds i t wi l l be n ec e ssa r y t o l o c at e t h e g l e an i n g u ni t s bet we ent h e c o mbi n e t i r e ma r k s . I t i s e xpec t e d t h at t h i s a r e a wi l l c o nt a i n a d i spr o -por t i onat el y hi gh amount of l oss, par t i cul ar l y i f t he combi ne i s not equi ppedwi t h a s t r a w s pr e ader . T he dat a do n ot n ec e ssa r i l y su ppor t t h i s c o nc e pt .Ha r v es t l o s s i n f i e l d s 4, 5 a nd 6 wa s l e s s t h an 10 0 p ou nd s . Ho we ve r , t h es ewer e t he onl y f i el ds t hat r epor t edl y wer e har vest ed wi t h combi nes l acki ngst r aw spr eader s. Si nce t hese t hr ee f i e l ds wer e enumer at ed by t he same setof enumer at or s, t he qual i t y of t he dat a must be quest i oned.

Anal ysi s t o det er mi ne t he opt i mum s i ze of a pr ehar vest uni t i ndi cat ed t hat a

3- r o w by 7 . 2 i n c h u ni t i s best u nder a r e st r i c t i o n o f a mi n i mu m o f 3 r o ws.However , t her e i s some r e l uct ance t o r educe t he uni t bel ow t he si ze usedf or wheat ( 3- r ows by 21. 6- i nches) f or f ear t oo many bl ank count uni t s wi l lbe obt a i ned. I n addi t i on, t he l ar ger uni t may pr ovi de mor e st abl e par amet er s

f or t he f or ecast i ng model s.

Ta bl e 2 c on t a i ns f i el d l ev el s t at i s t i c s of t he bi ol og i c al yi el d c ompo ne nt s .

Th e C. V. val ue s appe ar t o be qui t e r eas on abl e.

CONCLUSI ONS AND RECOMMENDATI ONS

Except f or t he di f f i cul t i es wi t h post har vest measur ement , a l l ot her dat a col -l ect i on concer ns wer e f ound t o be mi nor or no pr obl em at a l l . Some r evi s i onsof sur vey equi pment and pr ocedur es wi l l enabl e one enumer at or t o compl et e t her i c e da t a c o l l e ct i o n wi t h n ea r t h e e f f i c i e nc y o f o t he r c r o ps . T he l a c k o f concer n expr essed by enumer at or s over saf et y f act or s f ur t her suppor t s t he

use of onl y one enumer at or .



.

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Th e c on c er n t hat en umer at or s Dl i ght ex c es s i vel y da mage l ev i es , r es ul t i ng i nst r ong f ar mer r esi st ance, appear s unf ounded. However , i f t he f i e l d i sf l o oded, pac i n g i n t o t h e f i e l d r e su l t s i n a ve r y o bvi o us t r a i l t h r o ugh t h er i c e . T he c o nc e r n s wi t h f a r me r r e l a t i o ns due t o t h i s i s ve r y r e al . Da ma ge

t o t h e o bse r va t i o n u ni t s a ppea r e d t o be a pr o bl e m. T he st u dy wa s n ot de-si gned t o eval uat e t he ef f ect of t he damage. Fut ur e st udi es wi l l eval uat e

t hi s pr obl em.

Th e r ec ommen da t i on t o ex pa nd t he s t udy i n 1981 ha s be en appr o ved. Appr oxi -ma t e l y 100 sa mpl e f i e l ds wi l l be o bse r ve d. Ha l f o f t h e sa mpl e wi l l bevi s i t ed mont hl y begi nni ng i n ear l y August . The r emai nder wi l l r ecei ve af i n al pr e ha r ve st v i s i t . I n f i e l ds r e c ei v i n g mo nt h l y v i s i t s , o ne u ni t wi l lbe v i s i t e d e ac h mo nt h a nd t h e o t h er u ni t wi l l be r e l o c at e d e ac h mo nt h . T hi swi l l per mi t a na l ys i s o f t h e dama ge t o u ni t s . post h ar ve st u ni t s wi l l bel o c at e d i n a l l f i e l d s . At t hi s t i me , n o s p ec i a l p r o c ed ur e s ha ve b ee n

devel oped t o sol ve t he har vest l oss pr obl ems.



1: F i e l d l e ve l y i e l d s t a t i s t i c s

4

Es t i mat ed F. s t i mat ed Es t i mat ed :Fanner

Bi o l ogi cal Y i el d Har vest ! . Dss Har vest ed Yi el d : Repor t ed DI FF

Le n t h Var i et Mean St d. Er r . Mean St d. Er r . Mean St d. Er r . : Yi e1d

Pounds Pe r Acr e

I J : mg Label l e 5435 362 117 16 5318 362 4780 538

Medi um Lebonnet 5756 218 379 163 5377 272 4319 1058*

Med i um Mar s 4557 378 319 155 4238 408 4349 - 111

Long Label l e 1853 286 35 10 1818 286 3436 : - 1618*

Shor t Nat o 3806 372 87 30 3719 393 3820 · - 10

Long St ar bonnet 4884 246 12 5 4872 246 4226 646

Long Label l e 3142 474 274 31 2868 475 1677 1191

Long St ar bonnet 2853 172 497 462 2356 493 2935 - 579

Long Label l e 4776 372 476 271 4300 460 3355 945

FF - Est i mat ed Har vest ed Yi el d - Far mer Repor t ed Yi el d

The di f f er ence i s si gni f i cant l y d i f f e r e nt f r o m z er o a t a 95 per cent pr obl ' l bi l Uy l evel usi ng a mul t i p l e t - t est .



•

Ta bl e 2: Fi el d l ev el yi el d c ompo nent s t at i s t i c s

Wei ght Per F i n al He ads Per

Head Acr e

Fi el d Mean C.V. Mean C.v.

( gr ams ) (000)

1 1. 33 38 2040 31

2 1. 87 33 1486 23

3 1. 86 22 1114 21

4 . 66 56 1336 28

5 2. 88 15 590 22

6 2. 41 12 919 9

7 1. 39 38 1042 32

8 1. 09 24 1238 27

9 1. 73 19 1280 32

rice objective yield feasibility study

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