NON-CHEMICAL APPROACHES FOR THE MANAGEMENT OF ...

5. DISCUSSION
Investigations on the non-chemical approaches for the management of shoot fly
Atherigona soccata Rondani with reference to management through botanical seed treatment,
botanical sprays and traps carried out during kharif 2008 are discussed hereunder:
5.1 Management of shoot fly through seed treatments with
organics
5.1.1 Number of eggs per plant
On 7 DAE, among botanicals, NSKE (5%), Azagro 5 per cent (1 ml/l) and neem oil
(2%) proved best recording 0.40, 0.40 and 0.43 eggs per plant. Next best results were given
by B. monosperla seed extract (5%), B. monosperma leaf extract (5%), garlic bulb extract
(5%), pongamia leaf extract (5%), pongamia oil (2%) and P. julifera leaf extract (5%) which
recorded 0.46, 0.46, 0.50, 0.46, 0.46, 0.46 eggs per plant, respectively. least eggs were
recorded in Endosulfan 35 EC (0.07%) and Imidacloprid (2 g/kg) treatments (0.33 egg/plant
each). Botanicals proved inferior to Endosulfan 35 EC (0.07%) and Imidacloprid (2 g/kg)
(Fig.1).
On 14 DAE most effective seed treatment among organics was found neem oil (2%)
treatment (0.50 egg/plant) and it was also on par with insecticides Endosulfan and
Imidacloprid (0.46 egg/plant each) and next best were NSKE (5%) treatment (0.73 egg/plant),
Azagro 5 per cent (1 ml/l) treatment (0.63 egg/plant), P. julifera (5%) treatment (0.73
egg/plant) and plant mixture (5%) treatment (0.63 egg/plant) all being on par with each other.
On 21 DAE also chemical seed treatment was superior (0.66 egg/plant) and next superior
were NSKE (5%), Azagro (5%), neem oil (2%) and plant mixture (5%) all recorded one egg
per plant. The supremacy of neem products and plant mixture in reducing oviposition by
shoot fly was also noticed in late sown sorghum (Fig.2).
There was no such document to support these findings. However, it can be
compared with the studies of Kareem et al. (1989) who found that fewer first instar
Nephotettix virescens (Distant) nymphs reached the adult stage on rice raised from seeds
treated before sowing with > 2.5 per cent neem kernel extract or with 2 per cent neem cake.
5.1.2 Per cent deadhearts
14 DAE in timely sown sorghum chemicals recorded least per cent deadhearts (5.33
and 6.66% in Endosulfan 35 EC (0.07%) and Imidacloprid (2 g/kg) respectively), NSKE (5%)
was on par with Imidacloprid recording 8 per cent deadhearts and it was also on par with
Azagro (5%), neem oil (2%) and plant mixture (5%) which recorded 9.00, 9.33 and 10.33 per
cent deadhearts respectively. On 21 DAE also, chemical seed treatment remained best and
neem products and plant mixture remained next best to it NSKE (5%), Azagro (5%), neem oil
(2%) and plant mixture (5%) were on par and superior of all other organic treatments by
recording 16.33, 18.33, 15.66 and 17.00 per cent deadhearts, respectively. All the botanicals
except castor leaf extract (5%) were superior over untreated control but cow urine (5%) and
vermiwash (5%) were ineffective (53.33 and 50.33% deadhearts, respectively) being on par
with untreated control (53.00% deadhearts). On 28 DAE the next best to chemicals was
NSKE (5%) treatment (31.00% deadhearts) and it was also on par with Azagro 5 per cent
neem oil treatment (33.00% deadhearts), 2 per cent neem oil (32.33% deadhearts) and 5 per
cent mixture (36.00% deadhearts) (Fig.3). In late sown sorghum this trend remained almost
similar (Fig.4).
These results were not in agreement with the findings of Praveen (2005) who
reported that okra seed treatment with neem oil at 80 ml/kg seeds recovered least per cent
fruit damage (68.82%) followed Gaucho 600 FS @ 12 ml/kg (74.34) and thiamethoxam 70
WS @ 10 g/kg (76.00%).
5.1.3 Yield
Higher grain yield obtained in among botanicals was NSKE (14.72 q/ha), Azagro
(14.14 q/ha), neem oil (15.21 q/ha) and plant mixture (14.57 q/ha) all being on par with each
other. Next best were B. monosperma seed (5%), B. monosperma leaf (5%), V. negundo leaf