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Fluid Journal : Winter 2013
7 The Fluid Journal Winter 2013 (P=0 .0034). For the measurement made 24h after foliar application (Figure 3B), a significant treatment effect was also observed (P<0.0001). Compared to the control treatment a significant increase in leaf urea content was observed in the treatments Foliar Urea (P=0 .0013) and Foliar Urea+NBPT (P=0 .0006). In this case, the treatments Foliar Urea (3.15±0.18 mM g FW) and Foliar Urea +NBPT (3.57±0.18 mM g FW) and Foliar Urea+NBPT (3.57±0.44 mM g-1FW) had, respectively, a 48 percent and 68 percent increase in leaf urea content compared to the Control treatment (2.12±0.11 mM g-1FW). Significant differences were also observed when the Foliar NBPT treatments were compared with the treatments Foliar Urea (P=0.0003) and with Foliar Urea+NBPT (P=0.0002). On the other hand, comparative analysis of the Foliar Urea with Foliar Urea+NBPT (P=0 .4780) and of the Control with Foliar Urea (P=0.5887) was not significant. The data of GS (Table 1) and leaf protein (Table 1) content did not have any significant interaction or treatment effect. The treatment effect P values for GS and protein were, respectively, 0.4354 and 0.1193. Similarly, the measurement of photosynthesis (Table 2) and chlorophyll fluorescence (Table 2) had no statistical effect of interaction or treatment. In this case, the treatment effects P-values for photosynthesis and chlorophyll fluorescence were 0.1961 and 0.8531, respectively. Field Results A significant (P=0 .0012) interaction effect between treatment and year of the experiment was observed in the data of seed-cotton yield. There was a significant (P=0.0029) treatment effect (Figure 4A) with the treatments 100 percent N Soil-No Foliar and 75 percent N Soil-Urea+NBPT Foliar exhibiting the highest yields. Significant differences were observed between the treatments 100 percent N Soil-No Foliar and 75 percent N Soil-No Foliar (P=0.0013), between 100 percent N Soil-No Foliar and 75 percent N Soil-Urea Foliar (P=0 .00167), between 75 percent N Soil-No Foliar and 75 percent N Soil- Urea+NBPT Foliar (P=0.0017), and between 75 percent N Soil-Urea Foliar and 75 percent N Soil-Urea+NBPT Foliar (P=0 .0221). No differences were observed between the treatments Table 2: Effect of foliar treatments on leaf photosynthesis and chlorophyll fluorescence (Growth Room Study). Foliar Treatment Leaf Photosynthesis Chlorophyll Fluorescence μmol m-2 s-1 Yield (Fv/Fm) Control 12.46 ± 0.60 708.06 ± 14.98 Urea 13.00 ± 0.47 703.98 ± 9.17 Urea+NBPT 13.36 ± 0.50 698.98 ± 6.64 NBPT 13.58 ± 0.34 702.65 ± 7.00 P-Value 0.1961 0.8531 Figure 3: Effect of foliar treatments on leaf urea content measured at 2h (A) and 24 h (B) after application in cotton grown in growth room conditions.
Early Spring 2013