INETOCUCTION SssceccccsdcovenssdocccsdecaccovscsecnccococsccceoccscccsseeSereccocscccuccecece oars sCCC Ces Cee eee N STE OTe eae 
Light and seed germination © 0000000098000 OF O08 0G00 008098099099 900 000 008 09009090000 0099099008 090 009 0008000000000 00008000009 000000000000 
Light and plant DTOWU Ss coccoceccsocceccocccosecccseeocececcsscoccoscoccececconereccoreOneCoesec Cc eee Ce OS ONCE CTO NUIT TEES TTT 
Light and plant PISITICNES ies ccccsccacocesccoectcecssaccconcccescceccnceconccocenccoceces poccascenccCece Cocca she CST Tee EET 
Effect of duration of light on DIANUS .cccocecsscccecocessces sccescccadecscsccasscscccecesescedescceccscoccdee coceswenscrsosroneieenne 
General cultural hints ©0008 00 0000000000980 0 0000000008 099 9090008000 08080090000 90008 90090080089 0098 099000000 800000 000000 005900000000000000 
General REICFENCES .2cscccdvonvagdeccsdeosecedsas cceceeconcacesesconcecbocesscoceaccsencccosesatncoeeesoeaeeeeSCceeT ESET eee 
Demonstrations 
A. Light 
B. Light 
and seed germination 
Effect of light on.germination of seeds’ planted! in) SOilcicccccceccecscseecesssccvcceccconesecseescserecescsess 
How to test various kinds of seeds to determine their light requirement for germination .....oce. 
Effect of duration of imbibition period (soaking) on effectiveness of a given light exposure in 
promoting germination of light=SEMSitive’ SCEdS|... cccconscoscocccescescocccasosccscccccessccaccceccoceceseccess 
How a light requirement for germination can be induced in seeds that normally do not require 
light for germination © 0000 090080080000 000000000008 00000 98008900008 0000900 08900980009 09800009000 0000 9890000000008 00000000 
Photoreversible control of seed germination by red and far-red light,.....cccocccccocccccoccccccccccece 
and plant growth 
Gontroliby lightiofithe growth of an intennoden-cccossscecsetoce cocecorcescesecesccsacseteccsscocecescosaccacesce 
Controlyby, lightof:;growthtand| chlorophyllformati ombesscecsesccscceesccconccccvoceeceroncecoonncoceneanecten 
Why; plants) bend toward’ light (DhototropISm)\ co. <..ccsccccosscesscccscoccecsccessocscosscessorsocasscssessceeses 
Effect of red and far-red light on elongation of stems of light-growNn PlaNtS....cccccocceccccscccccccce 
and plant pigments 
Effect of light on formation of anthocyanin in S€Ed1INGS....cccccccccccccccccccccovecesccceccososccececocceecs 
Effectioflightomtomato Skintandi trulticolome sccccocaccscesctececececcccccrecseocecesercccsacceccsececcescseses 
Localization of response to light by the pigment im tomato SKIN ...cccoscccosccccscecesseecesceeccecsccoees 
Effectiof lightonicolorationlOfiapplesicscccescccccssceccecaccancconcessucesscscaccesccaacecssascsusscacasesersccses 
D. Duration of light 
ue 
2. 
3. 
4, 
Washington, D.C. 
Photoperiodic control of flowering of short-day Plants......ccccccccccccccccssccscsccceccccccecececcesooeesee 
Photoperiodic control of flowering of long-day Plants ......ccccecccccccccccsccecccccceccccccccccccesceccccece 
Photoperiodic control of growth and dormancy of Woody PlAaNts...ccccccceccsccccscrecesececccescccescsoescs 
Photoperiodic) control of: bulb! formation! Of ONIONS ccccccocooscososcscccccocoescesccccanscocsccocseccessescsccss 
This publication replaces a temporary 
bulletin ARS 34-19, of the same title. 
For sale by the Superintendent of Documents, U. S. Government Printing Office 
Washington 25, D. C, Price 20 cents 
Issued July 1961 
