Watermelon Varieties for Florida


 G. W. Elmstrom

 University of Florida

 Agricultural Research Center, Leesburg.


I'.ld trials of watermelon varieties have been conducted on Apopka
sand at the ARC, Leesburg since 1953. Direct-seeded plants were
spaced at 4-5 feet in rows ten feet apart. The land on which the
melons were planted could not be considered 'new' since watermelons
had been grown on the land within the past 6 to 8 years.

Several fertilizer programs have been followed during the eight-year
period. bver the years 120 to 140 pounds of N and K20 and 100 to 160
pounds of O205 were applied per acre. Fritted micronutrients were
applied at a rate of 25 to 35 pounds per acre each year. In 1976 a
4-.12-4 fertilizer mix was applied at a rate of 1000 lb/acre in a
3-ft-wide swath centered in the row. This was incorporated with a
disc prior to bedding. The nitrogen in this bed fertilizer was 50%
organic and about 38% nitrate. The source of phosphorus was triple
superphosphate.. In addition, an emergence fertilizer (100 lb
15-0-1itacre), a sidedress (200 -lbt.14-..Q-14/acre), and a layby (350 lb
14-0-14/acre) were applied. The 15-0-14 Was a natural nitrate of
soda-potash material and the 14-0-14 was an ammonium nitrate-sulfate
cf potash mix.

 'Charleston Gray', 'Jubilee', and 'Crimson Sweet' continue to be the
 three most important commercial varieties grown in Florida. Acreage
 of 'Crimson Sweet' and 'Jubilee' has increased in recent years and
 often a premium of one-half to one-cent-per--pound is paid for these
,-tvarieties.

Recently, Fusarium wilt has caused serious losses in many fields of
 'Charleston Gray' and 'Jubilee'. In 1971 and 1972, tests for wilt
 resistance in 'Jubilee' from commercial seed stocks indicated a lower
 level of resistance than that in the original 'breeder" seed. Loss
 of wilt resistance in 'Jubilee' was most likely the result of seed
 being increased in areas with low or no selection pressure for-cFusarium
 wilt. Increases of 'Jubilee' seed from breeder stocks were made
 available to commercial seedsmen in 1972 and registered seed (one
 generation removed from foundation seed) is available to growers. In
 most cases better wilt resistance will be found in plants from this
 "registered" seed than from standard commercial seed.

 Old standard watermelon varieties and many new inbred and Fl varieties
 have been evaluated since 1969. With the exceptiono-of-''Yello 1 Baby'
 all F1 hybrids tested were highly susceptible t -"Fusarium Wilt and



 Leesburg ARC Research Report-WG77-l ..
 250 copies W
 January 14, 1977