Biochemical studies on some Plant extracts as pesticides

Abstract

This work was carried out t(,) study the pesticidal activity of some plant extracts such as lemon grass and rhubrab •the extracts (ethanol, ethylacetate and hexane) were tested against plant pathogenic fungi such as Fusarium oxysporium and Rhizoctonia solani. The inhibition achieved 100% at 10% citral (the main componant of lema grass oil) and essenti:tl oil concentrate. On the other hand the ethanol extract in both lemon grass and rhubarb was highly effect than the other solwnt extract!! but hexane extract from lenion j!rnss and ethanol extract from rhubarb has mo••e effect on P. solaneacum bacteria than other solvent extract either lemon grass or rhubarb. The inhibition achieved 75% compared with control treated with stryptomycin. The organic solvent extracts from both lemon grass and rhubarb did not effect on the snails Biomphalaria ale.-candrina at> 1000 ppm, but essential oil have LC50 42 ppm and LC90 51.8 ppm. The essential oil and its major components citral and myrecene also effect on the mortality of 2"d instar larvae Agrotis ipiston achie\'ed 60.42 and 77.08% at 1.25 iutd 1.5 % concentration

I'CSIICdh•dy. The ethanol leaf and roots extracts from lemon grass and rhubarb have more effect than ethyl acetate extracts but hexane extracts have no effect of all concentration with two plant extract The acth'e com1wnents ofdillct•ent cxtrncts wer-e studied by IR, NMR, MS and GC/MC. Biochemical studies of azadirachtin as the main active ingredient in neem tree and its formulation (nemix) 4.5% daily stomach administration and dermal lliiJ)Iication of male nlbino ntt!l. This stuc,ies obtained increases in cholesterol, total lipids and decreases in total protein, albumin, triglycerides, and bilirubin with inueases of GOT, GPT and AP activities in animals were treated compared with control. The accumulation of azadirachtin in the different organs in the order lh'er > hcar•t > testis, spleen > lung > brain. After 12 weeks histophathological study clarified that greatly changes in liver, kidney and testis compared with control.