Temperatures from a local weather station near the experiments
were used to calculate the growing degree days (GDD) ac-
cumulated from emergence to heading. Rain data as well as total
radiation and photosynthetically active radiation data were used
from the weather station also.
 To ascertain whether there is any correlation between the
number of days required from plant emergence and the heading
date of the test entries, and possible yields, correlation coeffi-
cients were calculated for each of the tests during the three years.
Regression equations were also calculated for each of the tests to
show the relationships. Such data were not calculated for the time
between flowering and maturity, since the available hybrids all
physiologically mature in 29 to 33 days, regardless of the flower-
ingdate no matter what date or month of planting.
 In the experiment planted on 16 August 1979, at the Green
Acre Farm, disease ratings were made for each plot from just
before flowering almost to physiological maturity. They were
made at weekly intervals on 1, 8, 15, 22, and 29 October. These
data were averaged and graphed with a smooth curve of the data.
A regression equation was calculated from the data giving: R =
2.05 + 3.43D 0.415D2, where R is the numerical rating and
D is the weekly rating date in October.

RESULTS AND DISCUSSION
 All the agronomic and meteorological data gathered and
calculated are shown in Tables 1 through 11 and in Figure 1. The
individual figures in the tables and graph represent the average
derived from summing the data for each plot in each replication
for an individual entry or cultivar and dividing by the number of
plots of that entry in the test.


 Table 1. Days from emergence to flower. Over the 11 plant-
ings, days from emergence to flowering varied from 44 to 69.
August plantings, made when days were shortening as to total
hours of sunlight, were earlier than when planted during other
months when the days were getting longer. Time from
emergence to flowering was longest for the 2 February 1979, and
the 6 March 1980, plantings which were made during the coldest
seasons. Number of days required for those plantings averaged
68. Correlation coefficients and regression equations from these
data showed that there was no significant relation between the
number of days from emergence to flowering and the yields that
were obtained in these tests.




 Table 2. Plant heights. The shortest plants grew in plots and
in an area where continuous tobacco had been grown for years.
The sunflower plants grew only to 109 cm. The tallest plants grew
from February plantings, growing into long days, averaging
about 174 cm. April plantings were slightly taller than August
plantings and were about equal in height to March plantings,
other than those after tobacco.




 Table 3. Seedhead diameter. The smallest head diameters ac-
companied plants grown on the nematode-infested soil following
continuous tobacco from the 6 March 1980, planting. The largest
seedheads grown from 14 March 1978, planting gave the highest
yield of clean seed. See Table 4.


Table 1. Confection and Birdseed Sunflower Hybrid Characteristics, Gainesville, FL. 1978 1980. DAYS: EMERGENCE TO FLOWER


Brand Hybrid 1978 1978 1978 1978 197
 -- -----------------------------Dateof P
 Mar 14 Apr 13 Aug 17(W) Aug 17(E) Feb


Dahlgren
Dahlgren
Dahlgren
Dahlgren
Dahlgren
Dahlgren
Sheyenne
Sheyenne
Sheyenne
Sigco
Sigco
Sigco
Dahlgren
Dahigren
Dahlgren
Dahlgren
Dahlgren
Gurney

Gurney
Interstate
Sigco


D-715
D-717
D-818
D-719
D-821
D-823
853
883
923
852
923
924
D-820
D-933
D-716
D-722
0-135
Black
stripe
Mammoth Rus
Sundak
934


1979 1979 1980 1980 1980
---a--c--n g -- ---


l2anting--------------------------------
S2 Feb 28 Apr 2 Aug 16 Mar 6 Mar 12 Aug 14


44










44
45

44

45


VOL. XX-PROCEEDINGS of the CARIBBEAN FOOD CROPS SOCIETY


Acc.
No.


C-1
C-2
C-3
C-4
C-5
C-6
C-7
C-8
C-9
C-10
C-11
C-12
C-13
C-14
C-15
C-16
C-17
C-18

C-19
C-20
C-21


---------------------------------------------------Days-----------------------------------------------------


52 52 -- -- -- -- -- --
53 52 -- -- -- -- -- -- -- --
52 51 ---- ---- ---- ---- ---- ---- 64 57
48 48 -- -- -- -- -- -- -- --
53 52 -- -- -- -- -- -- -- --
54 47 -- -- -- -- -- -- -- --
52 45 ---- ---- 76 55 58 44 --
50 45 48 -- -- ---- -- -- -- --
56 53 51 ---- 64 63 61 50 --
50 51 49 52 -- -- -- -- -- --
50 58 49 49 -- ---- -- -- -- --
49 52 51 52 67 57 58 51 67 58
 -- -- -- -- 63 57 58 50 71 58
 -- -- -- -- 68 57 57 40 66 59
 -- -- -- 65 58 58 40 65 56
---- ---- ---- ---- ---- ---- ---- ----
---- ---- ---- ---- ---- ---- ---- ---- 67 59

---- ---- ---- ---- ---- ---- ---- ---- 71 ----
---- ---- ---- ---- ---- ---- ---- ---- 72 --
---- ---- ---- ---- ---- ---- ---- ---- 70 58
 -- -- ---- ---- ---- ---- ---- ---- ---- 55
---- ---- ---- ---- ---- ---- ---- --- --- 59


Test Average 52 51 50 51 67 58 58 46 69 58 44


121


45


2 2 Int stat IS 4


Days