Sign up for email alerts of new Fluid Journal issues!
Fluid Journal : Winter 2013
6 The Fluid Journal Winter 2013 18 percent (P=0.0070) in MDA content. The treatment Foliar Urea+NBPT (58.59±7.41 percent injury) had only a numerical decrease (P=0.827) in membrane leakage (Figure 1A) compared to the Foliar Urea treatment (61.65±6.38 percent injury). Similarly, data of MDA (Figure 1B) also indicated only a numerical (P=0 .1761) decrease in the values of the Foliar Urea+NBPT (20.38±1.17 mmol g-1 FW) compared to the Foliar Urea (22.44±1.24 mmol g-1 FW) treatment. Glutahione reductase data (Figure 1C) did not have any significant interaction or treatment effect (P=0 .1191). The Foliar Urea+NBPT treatment had a numerical increase in GR values compared to the rest of the treatments; however, due to the high variability in the measurements, the data were not significantly different. Data of urease activity (Figure 2) had a significant (P=0.0349) interaction effect between the parameters treatment and time of measurement. The analysis indicated that no significant treatment effect (P=0.7913) was observed in the measurements made at 2 h after foliar application (Figure 2A). However, measurements collected 24 h after foliar application (Figure 2B) showed a significant (P=0.0114) treatment effect, in which the foliar urea treatment exhibited significantly higher urease activity values than the rest of the treatments. In comparison to the Foliar Urea+NBPT (0.007±0.0001 units g-1 FW) treatment, the Foliar urea (0.011±0.0001 units g-1 FW) treatment had a 42 percent increase in urease activity (P=0.02335) when measurements were made 24 h after foliar application. Furthermore, the Foliar Urea+NBPT treatment did not exhibit increased urease activity; its values were not significantly different from the control treatment (P=0.4909). Leaf urea content (Figure 3) measurement also indicated a significant (P=0.0382) interaction effect between the parameters treatment and time of measurement. In the measurement made 2 h after foliar application (Figure 3A) a significant treatment effect was observed (P=0.0200); however, the only statistical differences observed were when the Foliar NBPT treatment was compared with the treatments Foliar Urea (P0.0129) and Foliar Urea+NBPT Table 1: Effect of foliar treatments on glutamine synthetase and leaf protein content (Growth Room Study). Foliar Treatment Glutamine Synthetase Leaf Protein (mM glutamyl hydroxamate g-1FW hr-1) mg g-1 FW Control 0.070 ± 0.005 11.48 ± 0.21 Urea 0.064 ± 0.003 11.81 ± 0.18 Urea+NBPT 0.066 ± 0.004 11.37 ± 0.19 NBPT 0.063 ± 0.002 11.33 ± 0.21 P-Value 0.4354 0.1193 Figure 2: Effect of foliar treatments on leaf urease activity measured at 2h (A) and 24 h (B) after application in cotton grown in growth room conditions. N.S . = not significant (P≤0.05).
Early Spring 2013