Effect of storage conditions and duration on the potency of Neem (Azadirachta indica A. Juss) seeds as a home-made Insecticide

Abstract

This work was carried out to investigate the effects of grinding, storage conditions and duration on the bio-efficacy of neem seeds as a home-made insecticide against the red flour beetle Tribolium castaneum. Samples of neem seeds (intact and ground) were kept in small jute sacks and stored in the sun, refrigerator (4ºC), and room temperature (28 ± 2ºC) for two, four and six weeks in each condition. After the respective storage period, a water extract (5%) was prepared and sprayed topically on the 3 rd instar larvae of the beetle as well as on the pupal stage. A significant mortality of 62.83% resulted from the neem seeds stored in the refrigerator on the 7 th day of exposure. The seeds stored in the sun caused a mortality of 48.49%. The water extract from the seeds which were stored at room temperature, resulted in significantly high cumulative larval mortality of 50.30%. The efficacy of neem seeds kept in the sun was negatively affected and correlated with the length of storage period. However, the efficacy of the neem seeds stored in the refrigerator was increased with storage time. The pupal mortality due to spraying with water extract from neem seeds stored in the sun, refrigerator and room temperature was 49.67, 68.12 and 69.43% respectively. The mortality in the control (water treatment) was 7.33%. The results indicated that grinding of neem seeds before storage seems to have no effects on their efficacy.

Simultaneous Extraction and Separation of Oil and Azadirachtin from Seeds and Leaves ofAzadirachta indicausing Binary Solvent Extraction

“…The sieved neem powder was then stored under vacuum in an airtight container at 4 o C prior to use. 9 Extraction and isolation -Ethanol (Merck, HPLC Grade) and n-hexane (Merck, HPLC Grade) were used as single and binary solvents in the Soxhlet extraction process. Soxhlet extraction (Buchi Extraction System2, B-811) was carried out with 4 units per run.…”

“…4 Among the various limonoid components, azadirachtin is the most important biologically active component which has many anti-infective, antibacterial, antifungal and antimicrobial properties. 9 Three derivates of azadirachtin are currently known of which azadirachtin is the most abundant (80%) and biologically active compound used as commercial botanic insecticide. 10 While azadirachtin impairs the insect growth regulatory system in all species tested, the effectiveness varies depending on insect order and species.…”

Harnessing Neem (Azadirachta indica A. Juss): A Sustainable Approach to Natural Farming

“…Nitrogen deficiency accompanied by ammonium and aluminium toxicities drove the detrimental effects of the neem leaf extract on lettuce [26]. There are issues with storage of plant extracts like neem as sunlight degrades their effectiveness as pesticides [27][28].…”

Acaricidal Properties of Four Neem Seed Extracts (Azadirachta indica) on the Camel Tick Hyalomma dromedarii (Acari: Ixodidae)

“…The dried clean neem seeds were roasted about 5 min to enhance extraction of oil, then crushed in a blender, and sieved to obtain particles ranging from 425 to 710 µm in size. The sieved neem powder was then stored under vacuum in an airtight container at 4 • C prior to use (45).…”