wdsci 301 second exam

8/18/2019 WDSCI 301 Second Exam

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WDSCI 305. Weed Ecology

2nd term exam

2nd sem 205!20"

Is it real? Is it real?

Write i# t$e statement is true and 0 i# t$e statement is #alse.

. %llelo&$at$y came #rom t$e 'atin (ord )allelos* ($ic$ means toget$er and

)&at$os* ($ic$ means su+er.2. 2,-!D is an e+ectie $erbicide to control t$e s&read o# Echinochloa colona

and Rottboellia cohinchinensis.3. 2,-!D, ($ic$ is manly based on salts are not olatile/ t$us, $as t$e tendency

to linger in t$e soil and a&&lied &lant &arts #or a long time.-. +!barring is &lo(ing or cultiating in a (ay t$at t$e soil is dra(n to(ards

t$e &lants, usually in bet(een t$e #urro(s #or t$e &ur&ose o# 1illing t$e

(eeds.5. ost $erbicides during t$e reen reolution came #rom t$e sur&lus c$emical

(ar#are agents em&loyed by t$e combatant nations.". Direct seeded rice #aces greater com&etition oer trans&lanted rice.4. %llelo&$atic substances can be &resent only in select and s&ecic &arts o# t$e

&lant.6. Cyperus rotundus can be classied as dryland &erennial (eed s&ecies.7. Eleusine indica can be use#ul in assessing 8otential 9ydrogen leels in t$e

soil. Its &resence can be a strong indicator o# soil &9 leels o# aboe ".0.0.Imperata cylindrica secretes allelo&$atic substancres on t$e soil. $us, it not

only $inders t$e cro& gro(t$ t$roug$ alleloc$emicals but also indicates a

$ard and t$ic1 to& soil &role ($ere &lant roots $ae di;culty to &enetrate..Cannabis sativa is a (eed s&ecies t$at is classied under t$e genera o#

Canabaceae ($ic$ is commonly 1no(n as Cannabis.2.Weed s&ecies gro(ing on disturbed enironments s$ould be called stress!

tolerators rat$er t$an ruderals.

3.%gric$emicals suc$ t$e DD $ae been banned in agricultural used due toenironmental and $uman $ealt$ issue. ne o# ($ic$ is t$e .-.Saccharum spontaneum also 1no(n as tala$ib can be an indicator o# toxic

concentrations o# organic substances in t$e soil.5.Contact $erbicides act #aster t$an systemic $erbicides.


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-. 5 met$ods o# (eed management

". Classication o# $erbicides based on mec$anism o# action

4. 9erbicides based on a&&lication

6. - Exam&les o# cultural control &ractices

Deeper stuf. Answer the questions with discernment, you may still ask

them many years rom now. (5pts. each

!. W$at is t$e di+erence bet(een selectie and non!selectie $erbicides W$en

do you use selectie Contact


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". W$at are t$e adantages and disadantages o# biological (eed control

Would you recommend its use W$y

#. %s (eed scientists o# t$e 2st century, s$ould you recommend t$e use

c$emical control W$en and W$y


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$. Is it &ractical #or t$e 8$ili&&ine agricultural system to mec$aniAe our

&lanting&est control o&erations considering t$e large &otential (or1#orce in

t$e &roinces

5. 9o( (ould you connect national issues suc$ as t$e ongoing armed con@icts,

Fida&a(an assacre, t$e $orrors o# &oerty and lac1 o# education in t$e


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ruralurban areas to our subGect o agriculture and your education as a

($ole

“We must win when we deserve it, by elevating reason and the dignity of the individual, loving justice and the

good and the great, even dying for it.”

― José Rizal, El Filibusterismo
https://www.goodreads.com/author/show/186192.Jos_Rizalhttps://www.goodreads.com/author/show/186192.Jos_Rizalhttps://www.goodreads.com/work/quotes/314683https://www.goodreads.com/work/quotes/314683https://www.goodreads.com/author/show/186192.Jos_Rizal

wdsci 301 second exam

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