Effects
of Foliar Fertilization of Texas Southern High Plains Cotton:
C. W.
Bednarz, N. W. Hopper, and M. G. Hickey
Foliar fertilizers have
become one of the many inputs used in cotton (Gossypium hirsutumL.) production systems across the U.S. Cotton
Belt. Their usefulness, however, in
producing high yielding, high quality cotton remains to be resolved. This study was conducted to determine the
effects of foliar fertilizers on cotton:
(i) lint and seed yields, (ii) plant dry weight, (iii) plant leaf area,
and (iv) leaf nitrogen concentration.
During the 1990 growing season, this study was conducted at the Texas
Tech University Research Farm east of New Deal, TX, on a Pullman clay loam
(fine, mixed, thermix, Torrertic Paleustoll.
Six foliar treatments were incorporated into a randomized complete block
design with six blocks. Treatments
2(15-2-0 with Ca), 3 (8-32-5 with micronutritnets), and 4(8-8-8 with
micronutrients) were commercial products and were applied in compliance with
their manufacturers’ recommendations.
Treatments 5 and 6 (46-0-0) were applied at various rates. During the 1991 growing season, this study
was conducted at an on-farm location northeast of Petersburg, TX. The soil at this location was also a Pullman
clay loam. The same six foliar
treatments were incorporated into a randomized complete block design with four
blocks. Foliar treatments were applied
during both growing seasons at 0, 2, 4, 6 and 8 wk after matchead square. One week after each treatment
application. 10 plants were removed
from each plot and divided into three nodal horizons: (i) from node 6 to node 9, (ii) from node 10 to node 13, and
(iii) node 14 and above. Leaf total and
nitrate N concentrations were determined by these nodal horizons. Also, at 1, 5, and 9 wk after matchead
square, plant leaf areas and dry weights were determined. Lint yields were determined after a killing
freeze in 1990 and after crop termination in 1991. Feed grade urea increased leaf total N concentrations during
1990, but these results were not repeated in 1991. Urea also increased leaf nitrate N during both growing
seasons. However, plant leaf are and
dry weight, and lint and seed yields were not significantly affected by foliar
fertilizers. Cost-benefit analyses were
not conducted due to the lack of a significant yield response from foliar
fertilizers. We conclude none of the
costs associated with foliar fertilization will be recovered in net returns.
Published in J. Prod.
Agric. 11:80-84 (1998).