SUMMARY: A small plot variety trial was
conducted in a commercial onion field near La Grulla, Texas to evaluate
yield, bulb size and quality parameters. The top four yielding yellow
onion varieties were SR0 1200 (Nunhems), Safari (Nunhems), XP 93001
(Seminis), and XP 91001 (Seminis). These four varieties statistically
yielded more onions than the commercially planted variety of Mercedes
(Seminis). These new experimental varieties show promise for production
and quality parameters.
Onion varieties need to be regularly evaluated for yields as well
as for quality parameters. New onion varieties continue to enter the
market with little information in regards to these parameters. Therefore,
it is important for producers to be aware of new potential varieties
to improve onion production. This trial will include five new experimental
varieties as well as some commercially available varieties that have
had little testing.
Experimental units measuring 4 lines per bed (40 inch bed spacing)
by 25 feet were planted on October 24, 2003. The experimental plots
were replicated three times in a randomized complete block design.
The onions were direct-seeded using a hollow cone planter calibrated
to dispense approximately two grams of seed per 25 foot plot (field
rate of about 2.3 pounds per acre) of each variety. The field was
under drip irrigation and irrigated the next day. All further irrigations
and production practices for this small plot study were carried out
in conjunction with the commercial field which was planted to the
onion variety Mercedes. Different germination rates were experienced
and many plots had excessive plant populations while others had few.
Nevertheless, they were hand thinned by a field crew to help match
the plant population to the field plant population (Mercedes variety)
on March 4, 2004. They were approximately thinned to a four inch in-line
plant to plant spacing. The field was harvested on April 20, 2004.
Onions were weighed and sized at the field. Samples of ten onions
from each variety were randomly selected and kept for the quality
evaluations. Quality parameters included pungency, sugar content and
growing point criteria (single centers). These quality parameters
were evaluated at the Weslaco TAES facility on May 11, 2004 three
weeks after harvesting to allow dry ambient temperature curing.
The overall results can be found in table 1. The top four yielding
yellow onion varieties were SR0 1200 (Nunhems), Safari (Nunhems),
XP 93001 (Seminis), and XP 91001 (Seminis). These four varieties statistically
yielded more onions than the commercially planted variety Mercedes.
The next group yielding similar to Mercedes were SR0 1202 (Nunhems),
Prowler (Nunhems), SR0 1201 (Nunhems) and Don Victor (Nunhems). White
onion varieties, Cirrus (Seminis) and Kristal (Nunhems), easily out-yielded
Texas Early White. The white onion varieties had generally lower plant
stands than the yellow varieties due to poorer germination rates.
Cirrus, however, out-yielded several yellow onion varieties with similar
plant stands. The red variety, Mata Hari, performed poorly due to
plant stand and more importantly to pink root which severely affected
this variety.
Plant stand is very critical to onion yields. The plant stands within
the yellow onions were very similar statistically (64 to 96 plants
per 13 linear feet or 1/1000 of an acre) except for the plant stand
in the Cougar variety (36 plants per 13 linear feet). The plant stand
for the Cougar variety (Seminis) was very low due to poor germination
of the seed lot. It is likely that if the plant stand had been better
the Cougar plots would have yielded much better. The extensive rains
experienced in March and April did cause blighting by Alternaria sp.,
Botrytis sp. and bacteria but good control of these diseases were
achieved with the spray program. No downy mildew was observed in the
plots as well as very few seed stems. The overall plant stands for
the white and red onion varieties were much reduced when comparing
them to the yellow onion varieties as expected.
ACKNOWLEDGEMENTS: We would like to thank
Cliff Chambers and Meliton Alvardo of Duda of Texas (Valley Onions)
for supporting and providing all the field work that was necessary
to make this study possible. Also, we would like to thank Norman Linkenhoger,
Robert Arriaga, and Jim Gledhill for providing the seed. We would
like to also acknowledge the training and supervision of Robert Saldana
(TAES) for performing the quality tests based on established protocol.
| Table1: Yield and Quality Results -
2004 Onion Trial - Lower Rio Grande Valley |
| Variety |
Total Yield
(bags/A) |
> 4inch
colossal |
3-4inch
jumbos |
2-3 inch
mediums |
<2 inch
culls |
Plant Stand
(plants/acre) |
Pyruvic acid
(umole/ml) |
Brix
(%) |
Single
Centers |
Shape |
| SR0 1200 |
1,144 a |
(11.7%) |
(66.3%) |
(20.5%) |
(1.5%) |
89,700 |
4.3 |
8.8 |
100% |
round |
| Safari |
1,061 ab |
(10.6%) |
(49.6%) |
(36.7%) |
(3.1%) |
91,000 |
4.9 |
9.2 |
70% |
round |
| XP 93001 |
1,029 abc |
(22.5%) |
(56.2%) |
(16%) |
(5.3%) |
76,300 |
4.8 |
9.4 |
50% |
flatter round |
| XP 91001 |
1,001 abc |
(11.4%) |
(56.6%) |
(29.4%) |
(2.6%) |
85,000 |
5.1 |
8.6 |
60% |
round |
| SR0 1202 |
944 bcd |
(12.6%) |
(63.2%) |
(22.3%) |
(1.9%) |
72,000 |
4.2 |
7.8 |
90% |
round |
| Mercedes (field) |
933 bcd |
(9.3%) |
(40.6%) |
(43.2%) |
(6.9%) |
96,000 |
5.1 |
10.2 |
90% |
teardrop round |
| Prowler |
926 bcd |
(0.9%) |
(51.7%) |
(43.6%) |
(3.8%) |
91,700 |
4.7 |
8.8 |
90% |
round |
| SR0 1201 |
911 bcd |
(4.2%) |
(63.3%) |
(29.9%) |
(2.6%) |
79,300 |
4.9 |
8.4 |
100% |
round |
| Don Victor |
901 bcd |
(9.7%) |
(55.3%) |
(31%) |
(4%) |
76,000 |
4.6 |
5.6 |
70% |
round |
| Sweet Sunrise |
800 de |
(11.2%) |
(60%) |
(23.5%) |
(5.3%) |
69,300 |
4.8 |
9.4 |
100% |
round |
| Nikita |
712 e |
(11.2%) |
(53.4%) |
(28%) |
(7.4%) |
68,000 |
4.9 |
9.0 |
70% |
long round |
| 1015Y |
507 f |
(2.8%) |
(37.7%) |
(49.9%) |
(9.6%) |
64,000 |
5.0 |
6.2 |
50% |
round |
| Cougar |
473 f |
(26%) |
(53.9%) |
(15.5%) |
(4.6%) |
36,000 |
5.2 |
9.2 |
40% |
round |
| Cirrus (white) |
875 cd |
(14.9%) |
(53%) |
(28.5%) |
(3.6%) |
68,700 |
5.3 |
11.4 |
40% |
round |
| Kristal (white) |
707 e |
(33.3%) |
(44.8%) |
(21.4%) |
(0.5%) |
47,300 |
4.3 |
9.2 |
100% |
flatter round |
| Texas Early (white) |
543 f |
(1.5%) |
(47.2%) |
(43.4%) |
(7.9%) |
57,700 |
6.3 |
10.8 |
80% |
long round |
| Mata Hari (red) |
180 g |
(0%) |
(18.5%) |
(46.3%) |
(35.2%) |
51,300 |
5.1 |
10.6 |
100% |
round |
|
