Pima Cotton Regional Variety Trial,
Safford Agricultural Center, 1997
L.J. Clark, Safford Agricultural Center
E.W. Carpenter, Safford Agricultural Center
G.L. Hart, Maricopa Agricultural Center
J.M. Nelson, Maricopa Agricultural Center
Sixteen long staple varieties were tested in a replicated small plot trial
on the Safford Agricultural Center in Graham county at an elevation of 2950
feet. The highest yielding variety in 1997 was OA 325 with a yield of 746
pounds of lint per acre. It was followed by four other Olvey varieties yielding
over 700 pounds per acre. 1997 was not a good Pima cotton year in this valley,
weather problems early and insect problems late in the season both took their
toll. Yields were more than 300 pounds lower than the previous year and 100
pounds less than in 1995. Yield and other agronomic data as well as fiber
quality data are contained in this paper.
The burden of developing new long staple cotton varieties has changed from
the USDA program to the University and commercial seed companies. With this
change, newer and better long staple varieties are being developed and tested.
Our part in this process is to provide an unbiased testing program where new
strains and varieties can be evaluated in a high desert environment so varieties
can be selected that will be beneficial to the high desert cotton growers in
Arizona, New Mexico and Texas. This is part of an Arizona Regional variety trial
as well as a Beltwide Regional variety trial.
Materials and Methods
This trial was designed as a replicated small plot trial with four
replications. The plots were planted with a cone- type planter which
distributes a given weight of seed uniformly over the length of the plot.
This year the seeds were planted into moisture where they germinated and produced
reasonable stands. The following crop history provides the information on how
the crop was managed:
- Previous crop: Cotton
- Soil type: Pima clay loam variant
- Planting date: 17 April 1997
- Rate: 25 pound per acre
- Herbicide: 1 pt/ac Triflurilin pre-plant, Cotton Pro at lay-by
- Fertilizer: 100 lbs/ac of urea under green manure crop 2/10/97, side dressing of 100 lbs/ac of urea on 6/3 and 7/14
- Insecticide: 5 applications to control pinkie, aphids and whitefly
- Pix/Prep: None
- Defoliation: Ginstar
- Irrigation: Furrow, planted to moisture + 6 irrigations (ca. 24 inches + 6 inches of rain)
- Harvest dates: 1st pick: 17 October 2nd pick: not taken
- Heat units per growing season: 3730 (86/55)
The plots were picked using a modified 2-row cotton picker. The production
from each plot was caught in a sack and weighed on a hanging scale to
determine seed cotton yields. Sub-samples were taken to determine lint
quality. Fifty boll samples were collected prior to harvest to determine boll
weights, these samples were then ginned to determine percent lint turnout.
Results and Discussion
April and the first part of May had cold spells that affected the growth of
most field of Pima cotton grown in the Safford valley. The crop was short and
didn't produce well. In this test yields were down 336 pounds
(Table 1). Adequate plant populations were
achieved even though the seedling vigor index (higher is better) varied greatly.
The ranking of the varieties did not vary greatly over the past two years,
even with greatly varying climatic conditions. The Olvey varieties were in the
upper third of the test, Pima S-6 and S-7 were in the middle of the test and the
New Mexico and Chaney Ranch varieties were in the bottom third of the test.
OA 325, also known as HTO (high turn out), had the highest lint yield even
though it was listed 4th in seedcotton yield. The high lint turnout brought
it to the top of the list. The plant populations were quite consistent across
the varieties and all within the optimal range. The seedling vigor index was
determined by making stand counts 2 to 3 weeks after planting, then normalizing
the resulting stand counts. A value of 1.00 indicates that the stand count was
the average of all of the varieties. NM 1601 and OA 312 demonstrated the lowest
seedling vigor, whereas OA 337, S- 6 and CH 271 had the highest vigor.
Table 2 reports on more agronomic variables.
Plant heights and Height to Node Ratios (HNR) were down compared with 1996.
First fruiting branches were about the same and boll weights were slightly
heavier. NM 1601 was the tallest variety and OA 328 was the shortest variety.
The HNRs were closely related to the plant heights. First fruiting branches
should be studied together with the physiological characteristics of each
variety. This study will be left to the reader. The heaviest bolls were
produced ty UA 4 and the lightest by CH 972. All of the agronomic variables were
correlated with lint yield and the following was found:
HVI values of the lint are included
in Table 3. The NM 1331 variety, with Sea
Island parentage, had the longest fiber, OA 312 had the strongest fiber,
and OA 337 and OA 361 (White Pima) had the whitest fiber.
Individual fiber quality studies are left to the reader.
- Brown, P., B. Russell and J. Silvertooth.. 1998. 1997 Weather conditions. Cotton, A College of Agriculture Report, The University of Arizona, Tucson, AZ. In this publication.
- Clark, L.J., E.W. Carpenter, G.L. Hart and J.M. Nelson. 1997. Pima cotton regional variety trial, Safford Agricultural Center, 1996. Cotton, A College of Agriculture Report, The University of Arizona, Tucson, AZ. Series P-108, pp. 177-181.
- Hart, G.L., J.M. Nelson nd L.J. Clark. 1998. Pima regional variety test at the Maricopa Agricultural Center, 1997. Cotton, A College of Agriculture Report, The University of Arizona, Tucson, AZ. In this publication.
This is a part of publication AZ1006:
"Cotton: A College of Agriculture Report," 1998, College of Agriculture,
The University of Arizona, Tucson, Arizona,
85721. Any products, services, or organizations that are mentioned, shown, or indirectly
implied in this publication do not imply endorsement by The University of Arizona.
The University is an Equal Opportunity/Affirmative Action Employer.
This document located at http://ag.arizona.edu/pubs/crops/az1006/az10064c.html
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