RA 00048.pdf - OAR@ICRISAT

crops against ravages of pests and diseases w a s
just 30 0 0 0 t o n n e s of technical material. It is
e x p e c t e d to be 52 0 0 0 t o n n e s in 1 9 8 0 / 8 1 (Gove
r n m e n t of India 1981). T h e projections m a d e by
N C A (1976f) indicate that by 1 9 8 5 / 8 6 , t h e level
should reach 0.14 million t o n n e s . This s h o w s that
t h e t e m p o of d e v e l o p m e n t is not as it should be.
T h e increase s u g g e s t e d by t h e N C A is in v i e w of
t h e n e e d for preventing t h e losses c a u s e d to
various crops.
Present Position
A n u m b e r of diseases and p e s t s including w e e d s
are k n o w n to be responsible for l o w e r i n g t h e grain
a n d fodder yield of s o r g h u m . The insects a n d
disease-causing o r g a n i s m s have b e e n studied in
detail in different parts of t h e w o r l d and various
control m e a s u r e s have b e e n d e v e l o p e d and advocated
for adoption by farmers. The m e a s u r e s as
r e c o m m e n d e d are being a d o p t e d in India only
w h e n t h e pests o r diseases a s s u m e serious
proportions.
S o r g h u m has never received m u c h attention
insofar as c r o p p r o t e c t i o n is c o n c e r n e d , e x c e p t in
t h e case o f s m u t s for w h i c h s e e d t r e a t m e n t w i t h
sulphur has b e e n t h e m o s t e f f e c t i v e m e t h o d .
S e e d t r e a t m e n t has b e c o m e popular in t h e
c o u n t r y since it is a very simple and c h e a p m e t h o d
to control s m u t disease. As a result, t h e severity
of this disease is on t h e decline.
W h e n e v e r polyphagus pests like a r m y w o r m s
or grasshoppers have infested particular areas in
a n e p i d e m i c f o r m , control m e a s u r e s have b e e n
a d o p t e d on a c o m m u n i t y basis under t h e provisions
of pest control acts enacted by various state
g o v e r n m e n t s . It w a s only w i t h t h e introduction of
hybrids in 1964 that t h e s o r g h u m g r o w e r s in t h e
c o u n t r y b e c a m e conscious of t h e fact that sorg
h u m also n e e d s protective m e a s u r e s . The spectacular
yields of hybrids, reported in t h e beginning,
attracted t h e attention o f s o r g h u m g r o w e r s
all over t h e c o u n t r y a n d t h e r e w a s a s c r a m b l e for
s e e d w h i c h w a s sold at Rs. 15-207 kg. T h e e n t h u ­
s i a s m resulted in indiscriminate s o w i n g of t h e
C S H - 1 crop, in a n d o u t of season, u n m i n d f u l of
t h e fact that i t w a s susceptible t o m a n y p e s t s
especially w h e n i t w a s s o w n i n certain parts o f t h e
year. Shoot fly w a s very d a m a g i n g w h e n t h e c r o p
w a s s o w n b e t w e e n July and October. T h e crops
s o w n b e t w e e n February a n d J u n e w e r e c o m p a r a -
tively free f r o m pests. Earhead p e s t s and diseases
a s s u m e d serious d i m e n s i o n s in later years.
A n evaluation s t u d y o f t h e High Yielding
Varieties Program for 1 9 6 7 / 6 8 a n d 1 9 6 8 / 6 9 ,
carried out by t h e Project Evaluation Organisation
of t h e Planning C o m m i s s i o n , indicated that t h e
loss d u e t o p e s t s a n d diseases o n s o r g h u m hybrid
w a s as m u c h as 1 1 - 1 2 % in 1967 and 2 9 - 4 2 % in
1968 (NCA 1976f). The severity of s o m e p e s t s
w a s so great in s o m e parts of t h e country that it
has left a p e r m a n e n t scare about p e s t s on hybrids
in t h e m i n d s of g r o w e r s . Even n o w , t h e popular
feeling is that s o r g h u m hybrids are very susceptible
to p e s t s and diseases, including t h e Striga
parasite, and that g r o w i n g hybrids w i t h o u t an
adequate k n o w - h o w and financial support is a
very risky affair. The fact that hybrids g r o w n in t h e
normal season, w h e n t h e traditional varieties
w e r e g r o w n , are as safe is still to be driven h o m e
e m p h a t i c a l l y a n d convincingly. T h e seasonal
aspect of shoot fly incidence is being increasingly
u n d e r s t o o d and a d j u s t m e n t s are being m a d e in
s o w i n g dates t o t h e extent possible. Chemical
m e t h o d s are also being a d o p t e d under certain
c i r c u m s t a n c e s . The earhead p e s t s and diseases,
h o w e v e r , are taking a heavy toll in h u m i d areas
especially if t h e rains occur w h e n t h e crop is in t h e
grain formation and d e v e l o p m e n t stage. In certain
areas, t h e Striga parasite is b e c o m i n g serious.
A t t e m p t s m a d e to control it w i t h chemicals is not
proving to be very popular or rewarding.
Constraints in Using Chemicals
It is necessary to state again that t h e risk bearing
capacity of s o r g h u m g r o w e r s in general, and
t h o s e in t h e l o w rainfall areas in particular, is l o w .
T h e n e t w o r k of supplies and services organizations
is t o o sparse in t h e s o r g h u m - g r o w i n g areas
to ensure t i m e l y supplies and services. Credit
availability is also not adequate a n d timely. Under
t h e circumstances, it is natural to e x p e c t a
solution t o t h e s e p r o b l e m s f r o m t h e plant breeders
in t h e f o r m of resistant varieties. A g r o n o m i s t s
a n d plant protection specialists can also m a k e
their contributions in t h e w a y of suitable agronom
i c practices a n d other s i m p l e m e t h o d s w h i c h
w o u l d help in keeping t h e s e maladies under
control at less c o s t and effort. It is e x p e c t e d that
t h e r e will be major breakthroughs in t h e e n s u i n g
years in this respect. Even t h e n , t h e r e m a y not be
a n y escape f r o m using chemicals for saving t h e
c r o p f r o m t h e s e ravages.
The m a i n r e q u i r e m e n t t o m a k e s o r g h u m g r o w ­
e r s plant-protection conscious is to arrange for t h e
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