TX-53F Haby 07 Annual Rpt.pdf

TX-53
third harvest, the ACT 62D+KCl treatment significantly increased Mg uptake compared to the KMag
treatment.
Table 8. Tifton 85 bermudagrass Mg conc. response to N and K rates and K, Cl, and S sources, 2007.
N rate Plant Mg concentration †
lb/ac/harv. Harvest 1 Harvest 2 Harvest 3 Harvest 4 Harvest 5 Season avg.
---------------------------------------------------%--------------------------------------------------
60 0.30 0.32 0.29 0.27 0.30 0.30
120 0.32 0.33 0.28 0.28 0.31 0.30
K rate
lb K 2 O/ac
0 0.37 a 0.40 a 0.34 a 0.32 a 0.37 a 0.36 a
134 0.35 b 0.39 a 0.32 a 0.31 a 0.36 a 0.35 a
268 0.28 c 0.30 b 0.27 b 0.26 b 0.28 b 0.28 b
402 0.27 c 0.27 b 0.25 b 0.24 c 0.26 c 0.26 c
K Source
KCl 0.29 b 0.31 0.27 0.26 b 0.28 b 0.28 b
KMag+KCl 0.32 a 0.34 0.28 0.28 a 0.32 a 0.31 a
ACT 62D+KCl 0.29 b 0.31 0.28 0.27 a 0.30 b 0.29 b
R 2 0.84 0.61 0.80 0.87 0.82 0.85
c.v. 9.9 24.0 10.9 8.8 11.4 9.6
† Values in a column/group followed by a dissimilar letter are significantly different statistically (α = 0.05).
Table 9. Tifton 85 bermudagrass Mg uptake response to N and K rates and K, Cl, and S sources, 2007.
N rate Plant Mg uptake †
lb/ac/harv. Harvest 1 Harvest 2 Harvest 3 Harvest 4 Harvest 5 Season total
-------------------------------------------------lbs/ac------------------------------------------------
60 4.1 10.3 8.6 8.2 4.0 35.1
120 4.5 11.1 8.6 9.1 3.6 36.9
K rate
lb K 2 O/ac
0 2.3 b 6.4 c 5.0 b 5.3 b 2.2 b 21.3 b
134 4.8 a 12.5 a 9.3 a 9.6 a 3.8 a 40.0 a
268 4.5 a 11.0 ab 8.7 a 8.6 a 4.0 a 36.8 a
402 4.2 a 10.0 b 9.1 a 8.7 a 4.1 a 36.1 a
K Source
KCl 4.3 9.8 b 8.3 b 8.6 3.5 b 34.5 b
KMag+KCl 4.6 12.2 a 8.6 b 9.3 4.4 a 39.0 a
ACT 62D+KCl 4.7 11.4 ab 10.2 a 9.2 4.0 ab 39.5 a
R 2 0.67 0.62 0.70 0.74 0.57 0.71
c.v. 19.9 26.9 21.3 16.0 28.2 17.1
† Values in a column/group followed by a dissimilar letter are significantly different statistically (α = 0.05).
The Zn concentration and uptake in and by Tifton 85 bermudagrass was increased at the higher N rate in
the first harvest and in the season average. Increasing the main effect K rate had no effect on Zn
concentration in the bermudagrass but the increased yields resulting from increasing K rates significantly
increased Zn uptake. In most harvests and in the season average, the experimental ACT 62D+KCl
treatment significantly increased the Zn content in, and uptake by Tifton 85 bermudagrass.
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