screening elite genotypes and ipm of defoliators in groundnut

2. REVIEW OF LITERATURE
The review of literature pertaining to biology and integrated pest management of
Spodoptera litura on groundnut are presented in the following paragraphs.
2.1 Screening of groundnut genotypes
Moss (1980) reiterated that research done on the utilization of wild species of Arachis
in U.K. has been of immense help in the ICRISAT programme. Fifty cultivated genotypes
were screened for resistance to defoliators in the AICRP on groundnut at Dharwad during
kharif 1985.Among them 40 entries recorded injury rating 3 while 7 entries were under rating
2(Anon., 1985).
Further, GBPRS-312 and ICG-5240 were found to be resistant to S.litura in the
laboratory trails at ICRISAT, Hyderabad (Anon., 1995). The cultivated groundnut genotypes
such as ICG-7948, 8081, 8232, 8781, 8977, 9012, 9039, 9449 and 9961 were grouped as
promising by Kulkarni, (1989). Dark green leaves and rough texture were associated with
resistance, while light green and smooth texture with susceptibility.
During kharif 1995-97 at Jalgaon, Maharashtra, India, S. litura larval damage to
foliage was recorded in 32 genotypes. The lowest leaf damage (5%) was recorded in ICGV
86156, ICGV 86400, ICGV 86528, ICGV 87128, ICGV 87141, ICGV 87290, ICGV 87411 and
ICGV 91214 (Dharne and Patel, 2000). Fifty groundnut genotypes were screened for
resistance to S.litura in All India Co-ordinated Research Project on Oil Seeds at Dharwad
(Anon., 1985). Due to low level of infestation during kharif 1985, majority of entries (40) fell
under injury rating of 3. However, 7 entries were under injury rating of 2 and three entries
sustained higher damage with a rating of 4. At Hissar, GC-79 and GC-333 were observed to
be from S. litura damage (Anon., 1985). Of the 50 cultivated groundnut genotypes screened
for resistance to defoliator, 22 entries fell below injury rating scale of 2, thirteen below rating
3, three below rating 4,six below rating 5 and one below rating 6 (Anon., 1986).
Fifteen A. hypogaea genotypes were screened in laboratory using choice test for
resistance to H. armigera (3 rd instar) and S. litura (1 st , 3rd and 5 th instar). Of them, only BG2 a
Virginia bunch variety was resistant to both the pests (Singh et al. 1993). Based on
oviposition and feeding performance test conducted with the seven cultivars, NC Ac 343 was
least preferred, while the UPL Pn 2 was the most preferred and EG Pn 13 occupied an
intermediate position (Xie Jia Li, 1987). The cultivar C-501 was most resistant and M-145 was
the most susceptible among the nine groundnut varieties tested in laboratory at Pantnagar on
the basis of growth and development of S. litura (Tiwari et al. 1989).
Preliminary screening to assess the resistance to S. litura was carried out in the field
on six Virginia bunch and 18 Virginia runner accessions and higher resistance was recorded
by Virginia runner varieties NC Ac 17840, NFG 79 and EC 21989 (Rajgopal et al. 1988). In
screening study by Patil et al. (1991), entries ICGV 87264 and 86598 have recorded the least
damage (< 17.5%) and entries ICGV 86598 and 86125 have also recorded less damage
(