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The production of crops in Pakistan is severely affected by the widely prevalent problem of salinity in the soil with salts including fluoride. The aim of the present study was to examine, in a pot experiment, the effects of sodium fluoride (NaF), applied as a foliar spray and as a soil drench, on the growth and other attributes of turnip (Brassica rapa L.). The percentage reduction in root length after treatment with a soil drench and a foliar spray was found to be at a maximum in plants treated with 300 ppm NaF, 62.6% and 51.02%, respectively, at 50 days after sowing (DAS) and 66.4% and 54.59%, respectively, at 70 DAS. The percentage reductions in the number of leaves, at 50 and 70 DAS, was 50.03% and 65.23%, respectively, for plants having an application of 300 ppm sodium fluoride by soil drench, while the corresponding reductions for the application of the 300 ppm NaF by foliar spray were 50.03% and 58.7%, respectively. At 50 DAS, the least percentage reduction in leaf area, 2.18%, occurred when the plants were given 50 ppm NaF by foliar spray and the highest value, 59.87%, was for the plants given 300 ppm NaF by soil drench. After 50 DAS, the percentage decrease in shoot fresh weight was found to be highest, 78.84%, when 300 ppm NaF was used as a soil drench, with the corresponding figure for the foliar spray application being 76.65%. Similarly, at 70 DAS, the percentage reduction in fresh shoot weight increased gradually with higher concentrations of NaF and was a maximum at 300 ppm NaF with both methods of application. We concluded that the application of NaF as a soil drench caused a greater reduction in the various parameters of turnip plant growth than did application as a foliar spray. [ABSTRACT FROM AUTHOR]

Teratological capacities of fluoride ions (F), from NaF, and bifenthrin (BN) in ovo exposure were compared in the golden black variety of domestic chicken. Three groups (n=55) were studied: (i) vehicle control group (VC) with 0.1 mL 5% dimethyl sulfoxide (DMSO) in demineralized water; (ii) F group with 0.01 µg F/g egg weight (EW) and (iii) BN group with 0.01µg BN/g EW. The relevant doses were injected in freshly laid fertilized eggs. The embryos were removed from the egg shells after 14 days of incubation. The embryos were weighed and fixed in Bouin's solution for further studies. Morphological studies indicated general growth retardation in the embryos in the F and BN groups compared to the VC group. Reduced beak length, microphthalmia, exocardia, and meromelia were observed in the F group embryos whereas, different appendicular deformities such as fore-limb meromelia, contorted and polydactyl hindlimbs, un-clawed digits, and elongated digits corresponding to the index fingers were seen in the BN group embryos. Statistical analysis revealed a significant increase in dead and growth-retarded embryos in both the F and BN groups compared to the VC group. The morphometric data also showed a significant (p=0.05) decrease in mean embryonic weight (F: 5.36±0.17 g, BN: 5.27±0.16 g; VC: 6.82±0.13 g), crown-rump length (F: 45.78±0.25 mm, BN: 44.30±1.15, VC: 51.67±0.81), and occipito-frontal length (FE: 13.92±0.18mm, BN: 12.65±0.14, VC: 16.05±0.13), in the FE and BN groups compared to the VC group. The findings indicate that fluoride is a potent disruptor of avian development both in ionic and organic forms. [ABSTRACT FROM AUTHOR]

Although there are thousands of small-scale, poorly regulated brick kilns in rural areas of South Asia their impact on local agricultural crops is largely unknown. The impact of fluoride on crops in a brick kiln area in the Northern Punjab Region of Pakistan was investigated. Fluoride accumulation, leaf necrosis, and reduced corm diameter and weight were found in the brick kiln area in two cultivars of Gladiolus that have been widely used as biomonitors in Europe. The rate of increase in leaf injury of the sensitive Gladiolus cultivar was greatest at all sites when the temperature was lower and there was a high relative humidity of 60–75%. The necrotic leaf tip lengths of the indicator plants correlated very well with their fluoride concentrations. The fluoride accumulation was directly proportional to the Fluoride Injury Index, although a higher injury index was observed with the fluoride-sensitive cultivar Lavendell Puff compared to the fluoride-tolerant cultivar Flower Song. These results suggest that injury to sensitive crops from fluoride may occur in other brick kiln areas in South Asia, and that Gladiolus plants could be used as a cost-effective biomonitor for further investigation in this region. [ABSTRACT FROM AUTHOR]

Fluoride (F) is an emerging pollutant that originates from multiple sources and adversely affects plant growth and nutrient bioavailability in soil. This greenhouse study investigated the effects of soil F (0, 10, 20, 50, 100, 200 mg kg−1) on morpho-physiological growth characteristics of wheat, soil F contents, and bioavailability and uptake of F, phosphorus (P), sulphur (S), potassium (K), calcium (Ca), magnesium (Mg), aluminium (Al), iron (Fe), manganese (Mn), silicon (Si) and zinc (Zn) by wheat. Higher F significantly reduced plant height and number of leaves particularly at early growth stages and increased visible leaf injury index. Powdery mildew infestation coincided with leafy injury and was higher in elevated soil F treatments. Fluoride treatments (>50 mg kg−1) significantly increased water (H 2 O)- and calcium chloride (CaCl 2)-extractable F contents in soil. Water-extractable soil F contents from soil in all concentration were higher than CaCl 2 -extractable F. This increased F bioavailability resulted in significantly higher F uptake and accumulation in live leaves, dead leaves and grains of wheat which followed order: live leaves > dead leaves > grains. Leaf injury index and number of dead leaves correlated significantly positively with soil H 2 O- and CaCl 2 -extractable F contents. Patterns of nutrient (P, K, S) and trace metals (Al, Ca, Mg, Fe, Mn, Si, Zn) varied significantly with F concentrations and between live and dead leaves, and grains except for Zn. Dead leaves generally had higher nutrients and trace metals than live leaves and grains. Fluoride contents in live leaves, dead leaves and grains showed positive correlations with nutrient elements but negative with trace metals. Number of dead leaves correlated negatively with Al, Ca, Fe, Mg, S and Si but positively with P and Zn contents in dead leaves whereas leaf injury index showed positive correlation with Fe, K, P, Si, Zn, S but negative with Al, Ca and Mg contents. These observations provided evidence of higher F uptake and associated impairment in nutrient and trace metal accumulation which caused leaf injury accompanied by powdery mildew infestation in wheat. However, further research in the region is required to confirm the relationship between F pollution, leaf injury and trace metal accumulation in crops under field conditions. [Display omitted] • Effects of soil F (0, 10, 20, 50, 100, 200 mg kg−1) were investigated on wheat. • Fluoride reduced plant height, number of leaves and biomass. • Fluoride in live and dead leaves correlated positively with soil F. • Leaf injury index and dead leaves correlated positively with soil F. • Trace metal and F accumulation encouraged powdery mildew infestation. [ABSTRACT FROM AUTHOR]