Showing papers on "Azadirachta published in 1975"

Structure of the Insect Antifeedant Azadirachtin

Abstract: Preliminary studies using the leaf extracts of Azadiraehta indioa A, Juss (Melia azadirachta L., Melia indiea, neem or nim tree) collected in Mombasa, Kenya, showed that when the crude extract was applied to coffee leaves, its potency in causing morphological changes in Antestiopsis (coffee bug) was stronger than that of an equivalent weight of β-ecdysone (insect molting” hormone). It was during attempts to isolate the active compound that we encountered azadirachtin.

Alcohol Extract of Neem (Azadirachta indica L.) Seed as Nitrification Inhibitor

Abstract: After removal of the ethanol solvent, the extractive, which is rich in lipid associates, was incubated in soil with 200ppm NH4-N at rates of 5 to 30% of the NH4-N. NH4-N was supplied by ammonium sulphate and urea. Inhibition of nitrification depended on the amount of the seed extract applied and on time of incubation; application at 30% of the NH4-N was effective up to 75 days.

Neem kernel as an antifeedant against the tobacco caterpillar (Spodoptera Litura F.)

Abstract: Laboratory tests showed that neem (Melia azadirachta L.) seed kernel suspension in water at 3% was effective as an antifeedant against all the five instars of the tobacco caterpillar,Spodoptera litura F. The average leaf area consumed by larvae in each petri dish (replication) was 1.2, 3.2, 14.5, 32.5 and 33.3 cm2 in the treatment as against 7.4, 14.2, 58.9, 71.0 and 70.4 cm2 in the control, for twenty 1st, twenty 2nd, two 3rd, two 4th and one 5th instar larvae, respectively. Mortality was observed in the treatment, and to a lesser extent in the controls, only in the first two larval instars.

Labor-Versuche mit Neem-Samenextrakt zur Bekämpfung des Schwammspinners,Lymantria dispar L.

Abstract: Effects of neem-extracts on cater pillars of the gypsy moth, Lymantria dispar L. The effects of neem extracts(Azadirachta indica) (0.02%; 0.2% 0.5%) were tested on caterpillars of the gypsy moth (Lymantria dispar). The laboratory experiments showed, that these concentrations suppress the development and prohibit the moultin of caterpillars. The mortality reached 100% in all experiments. Addition test carried out under field conditions indicated that the activity of neem extract sprayed on oakleafs(Quercus robur) remained unchange after 12 days of application.

Zur Struktur einer Substanz aus dem Fruchtfleisch von Melia Azadirachta Linn / The Structure of a Compound Isolated from the Fruit Pulp of Melia Azadirachta Linn

Abstract: The isolation of a triterpenoid from the fruit pulp of Melia azadirachta Linn is described. Its structure is identified by synoptical evaluation of the data of elemental analysis, ¹H NMR, ¹³C NMR, ABS and IR spectra.