New version page

400258B

Upgrade to remove ads

This preview shows page 1 out of 2 pages.

Save
View Full Document
Premium Document
Do you want full access? Go Premium and unlock all 2 pages.
Access to all documents
Download any document
Ad free experience

Upgrade to remove ads
Unformatted text preview:

58Turf cut toa.height of1'l4incheswas greener and more vigorous thanthat cut at three-fourths of an inch,~nd there was slightly more cloverin the longer turf.'CAN GRASSES BE HYBRIDIZED?Plant improvement generally isachieved by one of several methods,perhaps the two most common beingby selection and perpetuation of themost desirable individuals and byhybridization. The improvement ofturf grasses so far has been accom-plished largely by the process of se-lection, but the possibility of hy-bridizing has not been overlooked.In1937and1938Walter Hertzschin Germany made 57 crosses betweenvarious species of fescue, ryegrass,brome, wheatgrass and others. Theresults of these crosses, as publishedin Der Ziichter, are not encouraging.He emasculated and cross-pollinatednearly16,000flowers in making thesecrosses, and a total of only333seedswere set. In 42 of the 57 crosses noseeds were set, and in5there wasjust one seed set.Most of the grasses used were pas-ture grasses, but numerous crosseswere tried with Festuca ntbra.When it was used as the male parentcrossed on Festllca pra/emis, only8TURF CULTUREseeds were developed out of 765crosses. However, when used as themale parent crossed onLo/im11 pe-ren1le,41 seeds were produced out of303crosses. No seeds were producedwhen Fes/llca rllbra was used as thefemale plant.LOSS OF VIABILITY IN NEW ZEALANDCHEWINGS FESCUEDecline in the germination capac-ity of Chewings fescue seed duringshipment from New Zealand to thenorthern hemisphere has for manyyears been a constantly recurringtrouble. In spite of this fact, ourannual import totals have remainedreasonably steady. American buyersappear to have accepted Chewingsfescue seed as being delicate andshort-lived, and, although periodiccomplaints have followed unsatisfac-tory deliveries, particularly in un-favorable seed production seasons,the demand has been well sustained.Many theories have been advanced,both in the United States and abroad,as to the causes of deterioration ofgrass seed during shipment, but re-sults from experimental work ha,veshown that it is largely due to un-favorable conditions of shipment.These unfavorable shipping condi-tions, to which seed of Chewings fes-cue was found to b:: particularlyFebruary, 1940susceptible, were high temperatureand humidity in the ship's hold. Al-though no reliable data concerningtemperature and humidity in ships'holds are available, it is known fromobservation that both are invariablyhigh.Foy carried on experiments on theeffect of temperature and moisturecontent of seed on viability and pre-sented his results in the New ZealandJournal of Agriculture. Reference tothis article is made on page4of thisissue. Foy's results showed that hightemperature, together with highmoisture content of the seed, effecteda rapid decline in germination ca-pacity. He found that when one ofthese conditions was at normal leveland the other unfavorable, a slow59loss in viability followed, and thatwhen one condition was extremelyfavorable the other might be veryunfavorable without causing harmfulresults.A tempera ture of1040F. was con-sidered the average for a ship's holdin the tropics and 13 percent as thenormal moisture content of Chew-ings fescue seed.The results of Foy's experimentsare shown in the table below. It willbe noted that the moisture contentof the seed was the more importantfactor. At a moisture content of5percent there was practically no lossof viability at any temperature; atmoisture contents of 13 and 20 per-cent there was sooner or later a lossof viability at each temperature.RESULTS OF STORAGE OF CHEWINGS FESCUE SEED WITH INITIAL GERMINA-TION CAPACITY OF98PERCENT. THE NUMBER OF DAYS OF STORAGEARE GIVEN IN PARENTHESES AT THE HEAD OF THE COLUMNS SHOWINGPERCENTAGE OF GERMINATION CAPACITY.Storage.Moisture contenttemperatureof seed,.------Percentage of germination capacityof.Percent(1)(7)(14)(21)(35)(42)12259797989798 971221396 91222094104598 979898 969810413967338211510104209466122186598989898 9796861397858285~9758620957957 3910


Download 400258B
Our administrator received your request to download this document. We will send you the file to your email shortly.
Loading Unlocking...
Login

Join to view 400258B and access 3M+ class-specific study document.

or
We will never post anything without your permission.
Don't have an account?
Sign Up

Join to view 400258B 2 2 and access 3M+ class-specific study document.

or

By creating an account you agree to our Privacy Policy and Terms Of Use

Already a member?