priciples of insecticide use in rice ipm

Insecticides in Rice IPM (DRR)
against dead heart damage caused by stem borers. As ULV, neem oil along with neem cake as basal
application gave grain yields lower than monocrotophos (Kalode and Krishnaiah 1987). Similar superiority
of monocrotophos over neem oil was reported from Punjab also (Jaswant Singh et al., 1990).
INEFFECTIVENESS OF NEEM PRODUCTS AGAINST GALL MIDGE
Gall midge incidence was lowered in Orissa, from 27% in untreated control to 20% in neem cake-urea
mixture (1:3 w/w) treated plots at 75 kg N/ha. However, the differences were not significant (Panda,1987).
In another study (Samalo, 1988) from Orissa, neem cake (100 kg/ha) and 3% neem oil spray recorded
a slightly less incidence of gall midge (21.2% to 21.5% silver shoots). In Chattisgarh, neem oil spray at
4% as high volume was ineffective against gall midge (Shukla et al., 1987). These results showed that
neem products are more or less ineffective against gall midge under field conditions.
LOW EFFICACY OF NEEM PRODUCTS IN MULTIPEST SITUATIONS
Green leafhopper population and tungro virus infection were significantly reduced in plots planted with
seedlings treated with neem bitters followed by weekly foliar sprays at 2500 ppm, but was not comparable
to monocrotophos (0.75 kg a.i./ha) (Kareem et al., 1988). Basal application of neem cake (150 kg/ha)
followed by 3% spray of oils (neem, mahua, pinnai or neem seed kernel suspension) were inferior
(Krishnaiah and Kalode, 1988b) to monocrotophos (0.50 kg a.i./ha) in checking leaf folder damage.
Shukla and Kaushik (1994) observed in a field experiment that NSKE (5%) resulted in 80% reduction in
population of WBPH in kharif compared to 53% reduction in rabi. Neem oil (3%) could reduce 77% and
32% respectively as compared to 91% and 66% in case of monocrotophos (0.5 kg a.i./ha). Korat et al.,
(1999a) evaluated the commercial neem formulations with different levels of azadirachtin like, Nimbicidine,
Neemax, Neem Gold, Econeem, Neem Azal T/S and Fortune-Aza and compared with chlorpyriphos. They
observed that these formulations were as good as chlorpyriphos against leaf folder, stem borer and
WBPH. Sudhakar (2000) from Rajendranagar observed that Neemorate, a granular neem formulation @
20kg /ha was more effective against stem borer, gall midge, whorl maggot and thrips, compared to two
spray formulations of neem viz. Repelin and Neemax. The effectiveness of all the formulations increased
when combined with chlorpyriphos.
SAFETY TO NATURAL ENEMIES
CRUDE FORMULATIONS OF NEEM
Botanicals such as neem oil, neem cake and other non-edible oils and cakes are considered to be safer to
natural enemies than synthetic insecticides.
Predators of leaf and planthoppers such as spiders, particularly Lycosa pseudoannulata and mirid bug,
Cyrtorhinus lividipennis were found unaffected by neem cake and urea (3:10) application to rice fields at
IRRI (Saxena et al., 1984). Neem oil (10 l/ha) as a high volume spray emulsified with detergent registered
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