Asian Journal of Research in Botany,
Aim: Large quantities of wood ash released in the environment from the different industrial activities such as wood industries, paper industries, power plants, energy generation plant causes pollution or plant, are largely part of environmental pollutants. The objective of the study was to evaluate the efficacy of buttonwood (Conocarpus erectus) tree bark wood ash using as different (4, 8, 12, 16 and 20%) applications on seedling growth performance of an important legume crop cowpea (Vigna unguiculata) L. Walp. growing in different parts of Pakistan.
Study Design: The effect of buttonwood ash application on seedling growth performance in legume crop cowpea was recorded.
Place and Duration of Study: The experiment was conducted in the green house at the Department of Botany, University of Karachi, Pakistan, during the month of August – September and lasted for forty days.
Methodology: Ash of trunk and branches of buttonwood after burning, the buttonwood ash was collected in jars and the experiments were conducted in pots. The pots were filled up to 2/3 with soil. The concentrations of the button wood ashes taken in this experiment were 4, 8, 12, 16 and 20%, respectively. The growth experiment was conducted in pots filled with garden loam soil. The healthy seeds of cowpea were surface sterilized with 0.2% solution of sodium hypochlorite (NaOCl) for one minute to avoid any fungal contamination. In pot, the wood ash was applied in a concentration of 4, 8, 12, 16 and 20%. Ten seeds of cowpea were sown in each pot and pots were placed in an open field and watered when required. Without wood ash treatment, the plant was used as a control. For dry weights, the root and shoots were dried at 80ºC for 48 hours in the oven. The growth of cowpea was recorded in buttonwood ash including their germination percentage, length of shoot and roots, number of leaves and leaf size.
Results: In present studies, the significant (p<0.05) impact of button wood ash on shoot length, seedling growth and leaf area of cowpea was observed in pot system. Increase in concentration of buttonwood ash from 4 to 20% decreased root growth. Wood ash treatment at 4% concentration significantly (p<0.05) affected shoot dry weight of cowpea. All treatment also affected root, leaf and seedling dry weight of cowpea.
The seedlings of cowpea were tested for tolerance to different (4, 8, 12, 16, 20%) concentrations of buttonwood (Conocarpus erectus) ash. The seedlings of cowpea showed the varied response of tolerance to wood ash. The results showed that V. unguiculata seedlings showed a high percentage of tolerance at 12% and better at 4 and 16% of buttonwood wood ash treatment. The lowest percentage of tolerance in seedlings of cowpea to wood ash treatment was found at 20% concentration.
Conclusion: The results of the present studies concluded that the treatment of buttonwood ash at all level (4, 8, 12, 16, and 20%) responsible for the variation in seedling growth performances of cowpea. An increase in the concentration of buttonwood ash treatment 4 to 20% produced significant (p<0.05) effects on shoot length, seedling length and leaf area of cowpea as compared to control. The button wood ash treatment produced no marked effects on root growth, root dry weight, total plant dry weight and specific leaf area of cowpea as compared to without button wood ash treatment. The treatment of button wood ash decreased the tolerance indices with 8% buttonwood ash treatments. Overall, the results suggest that cowpea has a potential of high cultivation in the presence of buttonwood ash at less than 20% concentration.