MSc

Field experiments were conducted to evaluate the efficacy of bioagents
(Pseudomonas fluorescens, arbuscular mycorrhizal fungi, Trichoderma
vir i dae (3 per cent w/w) plant products (nee m oil (2%), neem leaf extract
(S%), neem oil + garlic (2%), neem leaf extract (4%)+ garlic (l %), botanical
pesticide, nimbecidine (0.2%), hot water treatment (SSoC) and organic
amendments (neem cake (200g/m2), coir pith (SOOg 1m2), sawdust (SOOg/m2),
neem leaf (7S0 g/rn ") as rhizome and main field treatments for working out an
eco-friendly management strategy against the nematodes (Meloidogyne
inco gnit a and Radopholus si milisi in the medicinal plant, kacholam,
Kaempfer ia galanga Linn. The efficacy of green leaf mulching was also tested
using locally available green leaves (neem, glyricidia, mangium, clerodendron,
calotropis, chromolaena) @ Skg 1m2 as mulch, to maximise the natural resource
utilization in the context of low cost farmer friendly technology.
To establish the potential of rhizome treatment with bioagents, botanicals,
plant products and hot water treatment a micro plot study (2 m x 2 m) was conducted
at College of Agriculture, Vellayani in sick plots having an initial population range of
100 to 160 M. incognita and 4S-6S R. similis per 100 g soil. The effect of the above
treatments were compared with the chemical, dimethoate (0.1 %) and untreated. The
results showed that maximum improvement in biometric characters like fresh plant
weight and root weight of kacholam plants was observed in rhizome treatment with
P. fluorescens. Next best treatments were AMF and hot water treatment and the
effect of these two were significantly better than the chemical, dimethoate. The
improvement in biometric characters due to above three treatments increased the yield
of kacholam to the tune of 87 to cent per cent. Regarding the reduction in nematode

population in root (root-knot count and number of females), P. jluorescens and AMF
were the best treatments. Next effective ones the hot water treatment and T. viride
were also better than the chemical, dimethoate. There was no significant variation in
the R. similis population in soil due to rhizome treatments.
The results on the effect of application of bioagents and organic amendments
in soil at the time of planting revealed that neem cake (200 g I m2) and AMF (300 g
inoculum I m") were on par in leaf production and nee m cake established its
superiority in improving the shoot weight also. Neem cake, AMF, sawdust and coir
pith were statistically on par in improving the fresh weight of plant. In all these cases
effect of the above treatments were on par with the chemical, carbofuran (lkg a.i.lha).
Regarding the improvement in yield also the best treatments (neem cake, AMF,
sawdust, P. jluorescens and coir pith) were on par with the chemical, carbofuran. The
superiority of carbofuran was maintained in reduction of nematode population only in root
(number of females and larvae). In all other cases (nematode population in soil at different
periods) the effect of nee m cake, AMF, neem leaf were on par with the chemical.
The results on the. effect of mulching with green leaves revealed that
neem and chromolaena leaves improved the fresh plant weight and yield of



kacholam.


Reduction in nematode population in soil was observed 111



glyricidia leaves also along with neem and chromolaena. The effect of nee m
and chromolaena @ Skg 1m2 leaves were on par in reducing the root-knot
count and number of larvae in root. There was no significant variation in
population of R. similis due to mulching with different leaves but minimum
population was recorded in neem leaf (4 MAP). Even the application of
mangium @ 5 kg/rn ' significantly reduced the nematode population in soil,
but the effect was inferior to other leaves, but superior to the untreated.