Arunachalam, V.

Bala Ravi, S.

English

Publications of the IAS Fellows

· STER NEGATIVE BER: 09296.44 
Arunachalam, V. and Bala Ravi, S. 
Conceived Conclusions in Favour of G 
Cotton? A Riposte to a Paper in Science. 
Current Science, 85 2003 : 1117 -1119. 
Record no. D-I08 
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Conceived conclusions in favour of GM cotton? - A riposte 
to a paper in Science 
Conflicting scientific. public and farmer 
opinion on the henefits of GM crops is 
well known and widely documented. The 
science hehind GM crops is not under 
dispute, hut their adaptation to the target 
site, consequent changes in the hio-envi-
ronment, promised benefits and their sus-
tainability certainly arc. 
A recent article that appeared in Sci-' 
{'!lee by Qaim and Zilberman (Q&Z)I has 
resuscitated the controversy hy drawing 
questionable results and incongruous in-
ferences from an analysis of yield trial 
data. 395 trials were laid during 2001 on 
farmers' field across seven Indian states 
(names not given) by the Mahyco-Mon-
santo group to test their Bt-cotton hybrid. 
A non-Bf counterpart and a popular 
check (details not given) were also raised 
in contiguous plots of 646 m2 each. 
Evaluating a sampJe of 157 trials from 
three states, Q&Z observed a reduction 
in pesticide use by 70% in Bt cotton and 
yield increase by 80 and 87% over non-
lJt cotton and popular check. Interpreting 
that .. · a general germplasm effect (not de-
fined) was more or less negligible' and 
'the yield gains are largely due to the BI 
gene itself, Q&Z concluded that 'it will 
be important' for India 'to release addi-
CURRENT SCIENCE, VOL. 85, NO.8, 25 OCTOBER 2003 
tiona I Bt cotton hybrids so that the tech-
nology yield gains for farmers are not 
curbed by a general germplasm dis-
advantage' . 
Unconvinced by the conclusions, scanty 
details and a numher of bugs in the table 
presenting yield and insecticide data in 
the paper, we contacted the senior author 
who kindly answered all our queries. We 
present below our critical review in the 
new light of the author's response (mostly 
in italics). 
The data are not only from actual field 
trials but also from those of a survey by 
the authors since they did not entirely 
1117 
CORRESPONDENCE 
rely Oil Mahvco trial record, alld needed 
- . 
addi!ional illformation Oil input-olltput 
relationships alld farm alld farmer char-
acteristics. OUI of the sevell slates, Maha-
raShtra, Madhya Pradesh, Tamil Nadu, 
Andhra Pradesh, Karllataka, Gujarat alld 
Rajasthall, the former Ihree were selec-
ted. Resource constraint led to a random 
choice of 157 trial participants (out of 
395) who were from more than 25 differ-
ent districts. The sampled states occupied 
45% of the total area under cotton2. This 
led Q&Z to believe that the sample 
should be pretty representative for cOttOIl 
growing in celltral alld southern India. 
The Indian Council of Agricultural 
Research has classi fled the seven states 
into three zones for varietal evaluation 
based on varied edaphic and climate 
conditions. Unless specific premises ex-
ist for wide adaptation, varietal perform-
ance will be evaluated only in specific 
zones. Andhra Pradesh, as a state with 
large area under cotton and widely afTec-
led by its failure, must have been in-
cluded on its own right in the study. The 
exclusion of Andhra Pradesh and Gujarat 
has skewed the findings towards Maha-
rashtra, incidentally housing the seed 
source of Bt-cotton hybrid. Further the 
sample, instead of being just random, 
must have been to a design to ensure that 
it was representati ve. Just the area cov-
ered with no break-up even of the 157 
trials across the sampled states, cannot 
justify its credibility. It is strange that 
many important details, gathered by us, 
were missing in their paper. Moreover. in 
a study seeking to test the benefits and 
efficiency of a new hybrid in farmers' 
fields, everyone of the 395 trials ought 
to have been included and an analysis of 
variance followed by valid statistical test 
of significance of differences in yield 
done. Precluding a particular trial, could, 
for example, preclude the poor yield of 
the test hybrid in a farmers' plot. There 
is no room for a free mix-up of survey 
and field data. Logistics and funding re-
strictions are quite common but they 
cannot override scientific requi remcnts. 
The restricted and skewed sampling 
would not leave any scope for applying 
the results of the study even to cotton 
growing southern and central states of 
India, let alone whole of India and the 
developing countries. 
Gross plot size was used to extrapolate 
yield per ha from the data on kapas col-
lected by farmers themselves from vari-
able pickings lind kept with them. Instead, 
11 18 
yield must have been estimated on net 
plot sizes that should have been kept 
constant. The study by masking variable 
net plot and adjusting yield for uniform 
gross plot size has vitiated the conclu-
. SIOns. 
Variation between the treatments 
(though stated to be minimal within far-
mers) and between farmers' practices 
was very much present. Q&Z say that al-
though the Bt cotton trials were carried 
Ollt within a designed set-up, they were 
!lot controlled experiments. Farmers 
conducted the trials ill their own way UIl-
influenced by the monitoring by agro-
nomists. But, regardless of farmers 
harvestillg several times Oil each plot, 
according 10 their own timing, Q&Z ob-
serve econometric estimates reflected net 
yield effects. It is unreasonable to convo-
lute the objective of testing the perform-
ance by farmers in their fields to bypass 
the basic minimum of required standards 
for test trials. Lack of norm· for trials 
conducted by farmers, poor choice of 
non-8t checks, mUltiple harvest of each 
plot suiting farmers' own timing, non-
accounting for the variable number and 
the physiological stage of pickings, using 
uni form gross plot sizes for per hectare 
yield estimation ignoring variation in net 
plot sizes. obtaining yield data from ka-
pas kept by farmers in their own way 
with possible deficiencies and. above all. 
econometric estimation of net yield ef-
fects are a few calamitous infirmities of 
the paper. 
In an analysis of actual trial data, there 
is no scope for yield estimation, econo-
metric or otherwise. No logic exists for 
expecting a regular distribution of farm-
ers' yields, that too under a variety of 
acknowledged variation present in the 
study. Yet the figures in the paper show 
a smoothed distribution of yield-density 
functions and the relationship between 
insecticide use and crop losses. Though 
the density functions are not given, the 
very concept stands on infirm ground. 
In terms of inputs other than pesti-
cides, the paper states there were no sig-
nificant differences between the three 
treatments. But the coefficient of varia-
tion (cv) for 8t hybrid, non-8t counter-
part and non-Br check in the table of the 
paper is very high at 57.1 %, 68.70/0 and 
71.2%, respectively. Scientifically, no 
field experiment showing such high cv 
for yield will be considered fit enough 
for any worthy conclusion. But Q&Z say 
that such an observation would be valid 
ollly for controlled e.rperimellts (if the 
experiments are not controlled for valid 
comparison, what validity inferences can 
have is a moot question!). They explain 
that solid differences that existed across 
different farmers illade the standard devi-
atio1ls lvithin each treatment pretty high, 
sllch a high cv would be very typical for 
farm survey data, alld not surprising at 
all. The econometric estimates of pro-
ductioll fUllctiolls lIsed ill the paper 
. helped to control them! The authors con-
tinued that, what was importa1lt theil, 
was to carry out rigorous statistical tests 
for differences. When dOlle, regardless of 
assumptions abollt (Ull-) equality of the 
o variance, the differences were statisti-
cally significant, !lot ollly at 5% but also 
at J % significance. Thus the conclusions 
are lotally valid. The mix-up of survey 
data with field trial data and blatant over-
ruling of fundamentals of statistics and 
inference stand testi mony for the low 
scienti fic base of the paper. 
In the table of the paper, there are in-
stances where the yields of popular 
check hybrids were inferior to the non-Ht 
counterparts. We argued that this anom-
aly would not have occurred if a proper 
choice of check hybrids were made in 
every location. In reply they say that, 
while the names of all hybrids for the in-
dividual locations were available, they 
were /lot quite sure who exactly selected 
the popular checks. 71,ey were definitely 
Ilot the best flew hybrids for a particular 
location, but hybrids that local farmers 
were already familiar with. Most of these 
check hybrids are /lot from the Maltyco 
breeding program. Without even con-
firming whether controls in the farmers' 
trials were appropriately chosen, the paper 
has made inferences on the test hybrid 
nullifying any scientific validity. 
Regardless Q&Z insist that the BI gene 
is of great value under the local condi-
tions and should be incorporated in many 
di fferent hybrids and varieties so that 
farmers under all agro-ecological condi-
tions can benefit. This message at best is 
speculati ve. 
We finally highlight the authors' advi-
sory suggestion that the Indian reguJa-
tory authority should approve additional 
BI-cotton hybrids well adapted to the 
agro-climatic conditions since the gen-
eral germplasm effect of cotton on its 
yield is negligible in the absence of Bt-
gene. If the single BI-hybrid has such all-
pervasive yield superiority across Indian 
'subcontinent (first and then all deveJop-
CURRENT SCIENCE, VOL. 85, NO.8, 25 OCTOBER 2003 
ing countries), it should preclude the 
need for more hyhrids as long as Bt-gene 
is the same in all hyhrids! The response 
of the authors was a diabolical turn 
around. They say they did not extrapo-
late Ilumerical findings across India or 
other regions of the world alld did not 
argue that the existing lIt hybrids are 
suitable for all parts of India. Bt-hybrids 
showed also problems of coping with o 
drought and viruses in a commercial 
scale but not related with the Bl genc. 
The 8t gene (alld olher effective pest-
resistance mechal/isms) call lead to im-
portant yield effects in regions where 
pest pressure is high and is /lot \\!ell COIl-
trolled by chemical pesticides. This hy-
pothesis is backed by crop protectioll 
theory and empirical evidence from other 
COlllltries. This i5 {l \'ery logical alld sim-
ple statemellt, bur it has 1I0t previollsly 
been articulated very clearly. Generally 
speaking, these cOllditiolls are oflell 
found ill poor coulltries of the tropics 
and sub-tropics, especially ill the small 
farm sector. Agaill, exact !lumbers should 
/lot be extrapolated. It is then evident 
o 
that they exhorted what they wanted re-
gardless of the non-supporti ve data they 
analysed in support. It is perplcxing that 
such a study could find its way to a jour-
nal like Science and it has come in handy 
to outscore a different reality of 8r cot-
ton3. 
A study in Andhra Pradesh details the 
failure of Bl cotton hybrid. 81 Mech 162 
(whether the same hybrid was used in the 
study of Q&Z is not known) both in 
small and large farms. A grievous farmer 
observed that BI cotton fetched Rs 1300 
a quintal compared to Rs 2600 of the 
popular variety Bunny. As the lint was 
less, seeds \vere more and the staple 
length was a clear 10 mm less than 
Bunny, there were not many buyers for 
HI colton. Despite being a newspaper rc-
port, it cites cotton scientists v/ho con-
curred wi th the unfavourable market 
traits of BI cotton. Similar results were 
also recently reported3. 
Reliable and consistent data in favour 
of G~1 cotton have yet to emerge from 
fair and . large scale farmers' trial exe-
cuted with every scientific norm. Equally 
CORRESPONDENCE 
important is the need to analyse all rele-
vant data including quality parameters 
and markct and marketability charactc-
ristics. Until then, GM crops and GM. 
cotton can only enjoy a preferential 
lobby with little translation to ground re-
ality. 
). Qaim. M. and Zilberman. D., Sciellce. 
2003.299,900-903. 
2. Agricultural SI(1/1Jllc.\· at a GlalJce, Depart-
ment of Agriculture and Cooperation. Di-
rectorate of Economics and Statistics. 
Ministry of Agriculture, Government of 
India, 200 I. 
3. Sahai. S., Curro Sri., 2003.8",,974-975. 
V. ARUNACHALAM· 
S. BALA RAVI 
M. S. Swamillatlzall Research Foundation. 
3rd Cross Road. 
Taramalli Illstilutiollal Area, 
Chell/wi 600 113. India 
*For correspondellce. 
e-mail: varllllachalam@mssrfres.in 


Conceived conclusions in favour of GM cotton? - a riposte to a paper in Science

http://repository.ias.ac.in/89419/1/106P.pdf

Conceived conclusions in favour of GM cotton? - a riposte to a paper in Science

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