Effect of hot pepper plant extracts against aphids -

Effect of hot pepper plant extracts against aphids

Hot pepper extracts in water were prepared (concentrations (%): 1, 3, 5, 7 and 9) and sprayed on the crop. The observations were recorded on population of aphid before and after spraying. The results showed that the efficacy of different hot pepper aqueous extracts against aphids at different treatments for two weeks. Average reduction in the population of aphids were achieved using the highest concentration (9%). The best mortality rates were achieved after the first spray since the average mortality rate was 1.76, in comparison with 0.24 and 0.22, the averages for the second and third spray respectively.

Preparation of plant extracts

Hot pepper plant was air dried and ground using with electrical blender. 100 g of the ground pepper powder was placed in 1000 ml conical flask, 500 ml distilled cold water was added, the solution was stirred with a magnetic stirrer for 15 minutes, left overnight, covered to avoid the impurities, then filtered using filter paper, the solution was evaporated to dryness using the rotary evaporated at 50ºC, the residue was transferred to crucible and kept in a vacuum oven (50ºC) for overnight. To prepare the stock solution 10 g of the dried residue was dissolved in 100 ml distilled water to have concentration 10%, a series of diluted concentration was prepared using distilled water to get the following concentrations (%): 1, 3, 5, 7 and 9.

The crop was sprayed with the following treatments.

In order to investigate the relationship between the time period of spraying (the repetition of the spraying process, after a week and after two weeks) and the number of insects on each plant (3 replicates for each concentration), the standard deviations of aphids numbers before and after spraying and the average death rate were calculated.

Conclusions

Botanical insecticides are natural chemicals extracted from plants with insecticidal properties and used as an excellent alternative to synthetic or chemical pesticides for crop protection to avoid negative or side effects of synthetic insecticides. The extracts of the hot pepper plant in different concentrations were used to control the population reduction of aphids.

Spray against aphid pests using varieties hot pepper extracts was useful for reduction of the maximum population of these insects. The maximum reduction in the population of aphids was recorded by using the maximum concentration of the hot pepper extracts. This study proved that insect pests can be managed better in field with lower concentrations of the bio-pesticides. The best mortality rates were achieved after the first spray since the average mortality rate was 1.76, in comparison with 0.24 and 0.22, the averages for the second and third spray respectively, using the highest concentration of the hot pepper extract, namely 9%.

Reference:

Hasan, S.M. and Al-Jayashi, M.T., 2021. Effect of Hot Pepper Plant Extracts on Resistance to Aphids on Okra. Annals of the Romanian Society for Cell Biology, pp.547-557.