Why this Kolaveri-di syndrome in cotton?

This article was published as 

Kranthi K.R. 2015. Why this Kolaveri-di syndrome in cotton?. CAI-Vol 31: 3rd November 2015. Cotton Statistics and News, Published by Cotton Association of India, Mumbai

Why this Kolaveri-di syndrome in cotton?

K. R. Kranthi

On 16^th November 2011, A Tanglish (Tamil-English) song ‘Why this Kolaveri di’ sung by film star Dhanush, went viral on the net. I learnt that ‘Kolaveri’ meant ‘urge to kill’. While I heard the song, it occured to me that in India, we actually kill good technologies with a drive for ‘Kolaveri’ over-kill much before they are destined for a natural death. The genetically modified (GM) Bt (Bacillus thuringiensis) based Bt-cotton is one such good technologies that is being dragged to the altar due to the Kolaveri syndrome. Other technologies such as hybrids, new GM genes, insecticides and fertilizers are also pushed under the Damocles’ sword.

But, we haven’t as yet lost the battle. Bt continues to do its job of keeping the dreaded bollworms under control. Despite the hue and cry with whitefly in Punjab, this year, whatever one might say, India is poised for a good record yield that would get close to 400 lakh bales. I have no hesitation in saying that India could have harvested more, much more than the current low national average of 500 kg lint per hectare. How do we do it and when? If China can get 400 lakh bales from 44 lakh hectares, why can’t India do the same from its 54 lakh hectares of irrigated cotton out of its total 128 lakh hectares of area under cotton? Whatever cotton we may get from the remaining rain-fed 74 lakh hectares would be additional bonus. I realize that many colleagues get uncomfortable with the thought that the conditions in other countries are completely different and cannot be compared with India. But, the fact is that India has the best of all ideal conditions as are required for cotton, -better than those that any country can ever have for cotton cultivation. In fact the dry regions of Vidarbha and Telangana with good sunshine, heat units and assured rainfall of 600-900 mm during Kharif season are ideal for great cotton yields. If anything, many major cotton growing countries suffer from climate related disadvantages for cotton cultivation. For example, Brazil has excess rain of about 2000 mm that is not at all suited for cotton. China has odd rainfall distribution in its cotton regions and lesser sunshine in its northern regions, which are not actually good for cotton. There are many such examples, where the yields are high in regions with climate that is not very suitable for cotton. Then how is it that these countries harvest more than three-fold as compared to India? The simplest answer is: short duration varieties. It is easier to fit a short duration variety into a window where the weather conditions in a short frame of time can be suitable for its production. The average range of cotton duration in the major cotton growing countries such as China, US, Australia, Mexico and Brazil is about 140 to 180 days. Indian cotton is cultivated for 180 to 240 days. Some farmers even extend the crop all round the year. I dwelt on this aspect in my previous articles. I firmly believe that the answers for India’s cotton problems are: short duration varieties + early sowing + resistance to sap sucking pests + compact architecture + high density planting of at least 40,000 per acre. If the varieties are endowed with any good technology such as Bt, we win the battle hands down, primarily because it helps in working into the mindset of farmers who have seen the Bt benefits for bollworm control. Farmers wouldn’t be worried about bollworms and it would be easily possible to grow the short duration, sucking pest resistant Bt cotton varieties with least chemical inputs for very high yields. While ICAR-CICR is working its way to give shape to these ideas, let me get back to the Kolaveri syndrome again, with an idea to sensitize whoever matters on what is going wrong in the cotton fields in India.

THE HYBRID SATURATION KOLAVERI

With 95% area under Bt-cotton and more than 1600 Bt-hybrids, the technology developers and the seed companies are overzealously hell bent for overkill –The Kolaveri effect. Knives are getting closer to the golden goose. These days, hundreds of hybrids are created each year, but most of them die as a name even before they are born. It looks more like a lottery ticket. When any one hybrid clicks, the company goes full throttle for a couple of years. Then one fine day the hybrid is replaced by another lottery winner. Many a times, scientists are asked as to why a set of package of practices are not standardized for the Bt-hybrids. I wonder, if this could work at all, with hundreds of new hybrids with odd characteristics of differing growth habit, different duration under different conditions and all of them competing with each other for the same space? It is difficult for any scientist to standardize any kind of package of practices for such ephemeral systems where even the best of hybrids do not live for more than 3-4 years and are replaced with new ones. But that is not all. Saturation of the entire cotton area with Bt-cotton hybrids, without any non-Bt cotton as refugia, is part of the over-kill. Surveys conducted by ICAR-CICR showed that there were only a few standard companies who were packing proper non-Bt hybrid seeds in a 120 g pack that are provided with the 450 g pack of Bt seeds. While others tossed the refugia into the sky. Some of the non-Bt refugia seeds had very poor germination, some were F-2 Bt seeds, some had varying proportions of Bt:non-Bt seeds, some were of Gossypium arboreum. One company even supplied Gossypium herbaceum  in the 120 g pack as refugia seeds in north India. The common refrain is that farmers are not serious about refugia. There is clear evidence with ICAR-CICR that many seed companies are also not serious about refugia. This over-kill with scant regard for regulatory guidelines does shorten the life of the technology itself.

With more than 1600 Bt-hybrids the problems of insect pests become acute with so many hybrids in the same village or the same region, because of the continuous availability of vulnerable plant parts such as tender foliage, squares and flowers in one or the other hybrid within a narrow geographical range, which actually attract and sustain a number of insect pests. Insect hot spots develop in the regions and spread all over.

THE BOLLGARD-II OVER-KILL

When Bollgard-II was introduced into the market, our observation was that some of the ‘Bollgard single gene Cry1Ac based hybrids’ were actually much better than the corresponding ‘double gene Cry1Ac+Cry2Ab Bollgard-II hybrids’ of the same brand. The Bollgard hybrids were relatively stable and uniform. It is quite likely that the overzealous over-drive of the technology providers to replace Bollgard with Bollgard-II, may not just be because of the technological advantage of the two gene product, but IPR issues may have played a role. Seed companies were in a competitive race to launch their new BG-II hybrids in a rapid fast-forward mode in a bid to capture the market early. This went for a toss. Though BG-II was approved in 2005, the area under BG-II increased from 8% in 2007 to 90% in 2012. It was this rapid replacement of BG with BG-II that may have unsettled the cotton scenario. An assessment of the hybrid qualities on the field showed that there are many companies who were actually not geared up to develop good quality homogenous BG-II hybrids. Handling two genes to develop homozygous parent material, identification of good heterotic (hybrid) combinations, testing their suitability for various agro-eco regions and development of commercially viable BG-II hybrids in a short time is a technological challenge that many seed companies are not properly equipped with. As a result the market was flooded with half-baked products introduced in a mad-rush in a cut-throat competition. The results are there for everyone to see. There was a reasonable good progress during the years 2004 to 2007, but the scenario was disrupted during 2007 to 2012.

Scenario during 2004 to 2007

1.    The area under BG Bt-cotton increased from 5.7% in 2004 to 67% in 2007. 92% of the Bt cotton area was under the single gene BG hybrids.

2.    A total number of 62 Bt hybrids were approved in 2006 and were available in 2007.

3.    Cotton yield increased from 453 kg/ha in 2004 (6% Bt area) to a National record of 567 kg/ha in 2007.

4.    Insecticide usage declined from 1.12 kg/ha in 2004 to 0.6 Kg/ha in 2007.

5.    Expenditure on insecticide decreased from Rs 1543/ha in 2004 to Rs.1238/ha in 2007.

6.    Fertilizer usage increased from 98 Kg/ha in 2004 to 140 kg/ha in 2007.

Thus the data clearly show that until 2007, yields were on the rise, insecticide usage on cotton was on a decline and fertilizer use had marginally increased. The scenario changed drastically within four years after 2007, a period that was characterized by a total replacement of BG with BG-II. Was this sudden massive replacement beneficial to the cotton farmer? Data from the Ministry of Agriculture, Government of India showed that during the period 2007-2012 input usage increased drastically as also reflected in high cost of production. The figures 1 to 7 show the trends in insecticide usage, fertilizer usage, yields and production cost. The following points highlight the drastic changes in inputs and the yield decline during the period 2007 to 2012.

Scenario during 2007 to 2012

1.    The area under BG-II increased to 90% of the Bt area in 2012 from a meagre 8% in 2007.

2.    The number of Bt hybrids increased from 62 in 2006 to 1097 in 2012.

3.    Yields declined from 567 kg/ha to 496 Kg/ha in 2011 (CAB data).

4.    The National average expenditure on fertilizer increased from Rs 2400 per hectare in 2007 to Rs 7400 in 2012.

5.    Fertilizer quantity increased from 140 kg/ha in 2007 to 222 kg/ha in 2011.

6.    Seed cost was Rs 1793/ha in 2004, which increased to Rs 2023/ha in 2007 followed by a massive increase to Rs 3842/ha in 2012.

7.    Insecticide usage increased from 0.6 kh/ha to 0.96 kg/ha in 2013 (Kranthi, unpublished data)

8.    Expenditure on insecticide increased from Rs 1238/ha in 2007 to Rs.2417/ha in 2012.

9.    Cost of cultivation increased from Rs 23,987/ha in 2004 to 29,196/ha in 2007, but increased drastically to Rs 63,751/ha in 2012.

Thus it is now becoming clear that introduction of a new gene does not necessarily mean that farmers would be benefitted. There is no doubt that the unwarranted over-kill to launch one thousand hybrids within the 5 year period during 2007-2012 also may have unsettled an otherwise probable positive growth curve. If this is not Kolaveri, then what is?

THE INSECTICIDE KOLAVERI

Commercial chemical and seed companies ‘make hay while the sun shines’. They instantaneously burn the hay into ashes too. Insecticides such as imidacloprid could have been a very useful tool if retained only as cotton seed treatment. But the spray formulations of the neonicotinoid group of insecticides such as imidacloprid, thiomethoxam, acetamiprid, clothianidin etc., went for an over-kill. Today almost all the sucking pests have developed high levels of resistance to the entire class of neonicotinoid insecticides. Sucking pest infestation is high at just about the squaring and flowering period. Neonicotinoid sprays at the flowering time harm pollinators especially honey bees. With just seed treatment and without foliar sprays of neonicotinoids, we could have preserved the efficacy of this group of insecticides in an ecologically acceptable manner. This isn’t the first time that we killed a technology with the Kolaveri syndrome. Synthetic pyrethroids were killed with the Kolaveri factor of rapid indiscriminate overuse to the point of death. Many other useful insecticides such as spinosad, emamectin and indoxacarb are also getting into the Kolaveri clutches. Insect resistance to insecticides prompts farmers to resort to higher doses and excessive repeated usage. This continues finally into cocktail tank mixtures of several groups of insecticides. Disaster follows -as was seen in Punjab this year.

It must be remembered that, somewhere in a dark alley, some worms are waiting for their turn, while some arrive and have a field day. The whitefly made a grand early entry this year and painted Punjab red and blue. Farmers were unanimous that more they sprayed -more were the flies that came back with vengeance. While the tiny insects leave a bloody mark all around like a powerful enemy, the battle field looks deserted without any semblance of defence. All insecticides failed. Most of the insecticides, especially the cocktails mostly killed the beneficial natural enemies that keep the whiteflies under check, and couldn’t control whiteflies because these insects hide under the leaves and have a protective waxy coating. Thus, it may be probably correct to say that the enemy used up insecticides for their advantage for resurgence and outbreaks. Waiting in the wings, the pink bollworm is bracing itself up for the next great innings starting this week in Saurashtra belt of Gujarat. The un-sustainability factor runs high. As new hybrids come and go one after another, new insecticide molecules are also on a high. Nobody knows how the new hybrids behave under the changing climate and also with interventions of new chemicals. Many a time new insecticide molecules may cause critical disruptions in ecological balance by devastating the naturally occurring biological control and cause resurgence of insect pests. The recent case of the whitefly could have been because of one or two new molecules that were released recently and were used extensively during the past three years, albeit more in Punjab. There is a need to do a ‘Sherlock Holmes’ to unravel the mystery of the whitefly menace in Punjab. Though not unexpected, there are many surprise elements in the story. Some explanations seem plausible based on experimental results, but reasons for the humongous scale of damage need to be carefully unravelled. Was it just susceptible hybrids? Was it late sowing? Was it the early hot and humid weather? Was it excess urea? Was it indiscriminate insecticides? Or, was it a combination of any of these factors? Or could it be just the overuse of any particular new insecticide that may have been introduced recently and used extensively either alone or in tank mixes. Why this Kolaveri, and until when.

As many in the seed industries still naively wait for that unknown miraculous gene, something like the Cry1Ac, which could turn their fortunes overnight. But, there seems to be nothing in sight which can now cause a breakthrough for high yields. Unfortunately, the dreams of many seed companies now seem to be driven only by mirage of new genes, that too from lands, far away. The Indian seed companies seem to be waiting for the knight in shining armour, the only hope, the hero on the white horse from yonder lands to rescue their business. Seed companies were indeed banking on new genes in the form of Bollgard-III or wide-strike or twin link or round-up ready flex and on and on. On the same side of the fence but knights of a different kind, the pesticide companies were depressed for a while, but not anymore. The silver lining expanded and for them -happy days are here again. One after another, insect pests take turns to bring cheers to their business. The mealy bugs, thrips and jassids kept them in good humour until recently. The whitefly returned and signed blank cheques for the insecticide industry. And, now the bollworms are likely to be back in business soon. No wonder the cotton crop is repeatedly forced to listen to the Kolaveri song.

Which new genes, new technologies have the potential to break the stagnant yield graph of India, no one knows. But, it is clear that the questions are tough and the challenges are rough. The commercial technology providers seem to have lost the plot. But we must not lose hope. All of us in the public and private must work together to bring cheer to the farmer. There is a need for robust solutions that will lead us to sustainable cotton farming for high yields with low inputs. From the Kolaveri song we must move over with hope to our old but beautiful song “We shall overcome, we shall overcome, we shall overcome one day.”

The three Mistakes in Cotton's Life

This article was published as 

Kranthi K.R. 2015. The three Mistakes in cotton's life. CAI-Vol 27: 6th October 2015. Cotton Statistics and News, Published by Cotton Association of India, Mumbai

The three mistakes in cotton’s life

K. R. Kranthi

Are there just three mistakes? Certainly not! How many I don’t know but in my perception this list of three is a recipe for disaster. You may not agree with me. Many may even strongly feel that this list of three actually holds the secret for successful cotton farming in India. But, discuss, we must, and argue, we will. This is an attempt to highlight at least three commonly known factors, which I am referring to, as mistakes, primarily with an intention to trigger a new way of thinking that may find new remedies. I must mention here that amongst the three mistakes the first one ‘long duration varieties’ is the actual monster and other two nurture the devil.

The three mistakes in tandem

1.       Long duration varieties

2.       Excess urea

3.       Early use of systemic insecticides

LONG DURATION VARIETIES:  The average crop duration in India is 210 days, which is about 30-50 days more than other major cotton growing countries. Long duration varieties (210-240 days) suffer from two major disadvantages. 1. The crop suffers moisture stress during boll formation and 2. The crop has a long vulnerable flowering window that invites bollworms. The long duration varieties also have excess foliage that serves as an excellent host for the sap-sucking insects. Cotton crop needs about 2 mm water and 0.5 to 1.0 kg/ha Nitrogen per day during vegetative phase and needs about 6-7mm water and 3-4 Kg/ha Nitrogen per day during flowering and boll formation stage. Thus longer the duration of fruiting phase, more is the demand for water and nutrients. In rain-fed regions of central India, when the crop is sown in July, flowering and boll formation stage in late duration varieties extends from mid-September to the end of November and sometimes even into December. Water and nutrient requirement is most crucial during this period. Nutrient uptake depends on the availability of soil moisture. In rain-fed regions of central India, rains recede by the second week of September and the soil becomes almost dry, especially in shallow soils, by the beginning of October. The crop suffers moisture and nutrient stress all through October and November and does not retain bolls properly. The long 60-80 day flowering period from September to mid-November also invites bollworm moths continuously. Indeterminate varieties have excessive foliage all through until harvest. Sap sucking pests which are generally limited to early vegetative phase, continue into the flowering and fruiting phase if the crop continues to put forth fresh leaves, as it happens with indeterminate long duration varieties. Farmers are forced to spray insecticides all through the season. India chose long duration varieties and farmers had to use more fertilizers and also spray 14-28 applications per season. No other country had to suffer insecticides in cotton as much as India did. Clearly this happened due to the long duration varieties in India.

All cotton hybrid varieties in India are of indeterminate habit with a long duration that extends from 6 to 8 months at least. Hybrids inherently are endowed with hybrid vigour which makes them grow in a prolific manner during the vegetative phase, which makes them respond to fertilizers and water to put forth luxuriant and excessive foliage. This generally results in wastage of nutrients. This is also one of the reasons as to why cotton hybrids in India are planted at only 4000 to 6000 plants per acre. The plant density in major cotton growing countries across the world is 40,000 to 60,000 plants per acre. Hybrid cotton seed is very expensive at Rs. 0.15 per seed and is therefore planted at the low density. Because of the low plant density, each plant is expected to produce a large number of bolls per plant as opposed to a few number of bolls per plant in other countries. For example each plant in India has to produce 100 bolls of 4g each to produce 1600 kg seed-cotton from 4000 plants in one acre. Whereas, in other countries where the plant density is 10 times higher at 40,000 plants per acre, each plant is expected to produce only 10 bolls of 4g each for a similar production of 1600 kg seed-cotton per acre. Plants in such systems take a short time of 15-20 days to complete flowering that is adequate to produce 8-10 bolls per plant. Thus the flowering phase is short and reduces the challenge of insect pests.  The flowering in India is at least of 60-80 days duration which is in contrast to a much shorter flowering period in other countries. The short duration in other parts of the world enabled countries to achieve higher per day productivity. They produce more cotton in a short time with less pest problems due to a short flowering window and less need for fertilizers and water in a short reproductive window. There is no doubt that the long duration of cotton in India has resulted in moisture and nutrient stress, more insect pests, diseases, need for more insecticides and low yields.

It is interesting that irrespective of India’s low average National yields, many experts still believe that long duration varieties are best for India. The theory was that, -if the early fruiting parts were damaged by bollworms, the crop would recover to produce new flush and thus continue to produce in an indeterminate manner, thus enabling risk aversion. The duration of such varieties extends beyond six months and can go on and on, even up to a full year, especially if water and nutrients are made available. In line with this theory, almost all the varieties developed in India were designed to be indeterminate. Needless to mention, Cotton is basically an indeterminate crop. It has a perennial habit and many varieties can grow like trees, if left to survive. However in stark contrast almost all the major cotton growing countries of the world, developed short duration varieties of 150-180 days, with determinate habit of synchronous boll formation especially to suit machine picking. Experts in India also believe that drip irrigation can solve India’s problem of low yields, not just in rain-fed regions, but also in irrigated states of north India. Undoubtedly, drip irrigation saves water and fertilizers in addition to enabling controlled application of water and fertilizers as and when needed by the plant. However, drip irrigation systems are expensive despite subsidies and need maintenance. How well these systems suit the marginal rainfed conditions of Vidarbha and Telangana is a matter of debate. Experts agree that countries which are harvesting 3-4 times higher yield than India have achieved high productivity levels not necessarily by using drip irrigation in their countries. The main technology that they have adapted to get high yields is ‘ADJUST COTTON FLOWERING WINDOW TO FIT INTO THE SOIL MOISTURE REGIMEN’. Beyond doubt, India MUST develop short duration cotton varieties of 150-160 days duration, with synchronous boll formation of 8-10 bolls. Such varieties if sown at a density of 40,000 to 50,000 plants per acre, earliest with the onset of monsoon in central India can complete the short flowering and boll formation window for 8-10 bolls within a short span of time before soil moisture become limiting, with least requirement of water, nutrients and insecticides.

UREA DELAYS FLOWERING AND INVITES INSECT PESTS AND DISEASES: Sequence of events happen with urea application that actually push the crop into a problem that is not easily realized by farmers. When applied at initial reproductive stage of 45-60 days after sowing, urea switches off the reproductive phase, triggers excessive foliage, delays flowering, delays crop maturity and makes the crop conducive to sap sucking insects. These effects get aggravated when the crop suffers from deficiency of phosphorus (P) and potash (K). Studies across the globe clearly show that the uptake of water and nutrients in cotton plants is highest at 90-110 days after sowing, which is generally the peak boll formation stage. However in India, almost all fertilizer recommendations for cotton make a mention that at sowing time or at 20-25 days after sowing half the recommended N+K and full dose of P₂O₅ should be applied as basal dose followed by application of the remaining half N+K at 45-60 days after sowing. About 5 tonnes of Farm Yard Manure or 1.0 ton of compost per acre is recommended at sowing time. Since urea is heavily subsidized, it is cheaper and farmers use it extensively. There is a misconception in India, especially in north India that a lush green cotton crop at vegetative phase will produce high yields.

Application of urea in excess at the peak vegetative stage of 45-60 days after sowing forces the crop to become lush green with excessive foliage. Under normal circumstances, majority of the varieties or hybrids start producing squares from 45-60 days. This first part of reproductive phase is disrupted due to urea application. With urea, the plants switch off ‘squaring-flowering’ and return back to the leafy vegetative phase. This delays flowering and maturity by at least 15-20 days. Phosphorus deficiency also causes delayed flowering and maturity. A combination of more urea and less phosphorus can result in prolonged vegetative phase and delay in the initiation of squaring and flowering window. Further, urea application in a crop that suffers from deficiency of potash invites sap sucking pests such as leaf hoppers, thrips, whiteflies and aphids. Also, there are a few diseases that get triggered with urea application. With urea induced vegetation, sap sucking pests proliferate more rapidly in varieties / hybrids that are susceptible to sucking pests.

MANY SYSTEMIC INSECTICIDES INDUCE CROP VEGETATIVE PHASE AND DELAY FLOWERING :  Insecticides that are absorbed by the plant and translocated to other parts of the plant are known as ‘systemic insecticides’. Majority of the insecticides belonging to the organophosphate group, for example monocrotophos and acephate and the neonicotinoid group of insecticides are systemic in nature and induce the crop towards vegetative phase. Insecticides belonging to the ‘organophosphate’ group and the ‘neonicotinoid’ group are the ones that are recommended mainly for the control of sap sucking insect pests. Sap sucking pests occur in the early vegetative phase of the crop especially in varieties or hybrids that are susceptible. As mentioned earlier, urea application in 45-60 days old crop triggers vegetative phase, delays flowering and invites sap sucking insects. Sprays of some of the systemic insecticides during the early crop stage further induce ‘vegetative leafy phase’ and delay flowering and crop maturity.  Early application of some insecticides induces insect pest outbreaks and necessitates repeated application of systemic insecticides for pest control, which further delays flowering phase and crop maturity.

There are three ways in which some insecticides and tank mixes can cause insect pest resurgence. 1. Broad spectrum insecticides and mixtures kill naturally occurring biological control of insect pests. 2. Insecticide induced vegetative phase and physiological changes in plants that suit insect pests 3. Insecticide induced physiological changes ‘hormoligosis’ in surviving insects which lay fertile eggs in excess. Nature is endowed with many insect species that are known as parasites, parasitoids and predators which kill insects that feed on the crop. These insects are useful to the farmer and are generally referred to as ‘natural enemies’ or ‘naturally occurring biological control’. Except a few insect growth regulators (IGR), botanical pesticides and biological insecticides, majority of the synthetic insecticides have a broad spectrum toxic action on naturally occurring biological control in fields. Some insecticides have a mild effect on natural enemies whereas a few have very strong effects. Insecticide tank mixes can have devastating effects on natural enemies that can easily result in insect pest resurgence. When natural enemies are destroyed by the insecticide and if the populations do not revive, insect pests get an advantage of easy survival, which results in insect pest resurgence. There are cases where a few insecticides alter the physiology of plants, which suits some insect species thus resulting in pest outbreaks. Yet another mechanism known as ‘insecticide induced hormoligosis’ also can result in insect pest outbreaks. Hormoligosis is a phenomenon whereby some insecticides cause physiological changes in surviving insects to an extent that the survivors lay fertile eggs in excess which leads to outbreaks. Application of broad spectrum systemic organophosphate and neonicotinoid insecticides to control the resurgent insect pests further delays flowering and crop maturity.

CONCLUSION : Cotton crop benefits most when it can take up nutrients at flowering and peak boll formation stage. Nutrient uptake happens only if the soil contains adequate moisture at the flowering and peak boll formation stage. In rainfed regions of Vidarbha and Telangana, soil moisture is generally available until end of September or mid October depending on the soil type. Deep black cotton soils retain more moisture compared to shallow soils. Therefore in these rainfed regions, flowering in August and boll formation in September to mid October can help the crop to take up nutrients when applied, thereby leading to good boll setting, good retention and good yields. If the flowering gets delayed and happens over a long window that is spread over 50-80 days during September to November, boll formation gets further spread over during October to December. Flowers and bolls that form after mid-October suffer moisture and nutrient stress thus resulting in poor boll setting and low yields. Therefore any decisions and interventions that lead towards late flowering and late boll setting in cotton are to be considered as mistakes. First mistake is the choice of a system that aims at achieving more bolls per plant. More bolls per plant, means longer time of flowering and boll setting and long duration. Second mistake is the application of urea without adequate P and K. This intervention delays flowering further and extends the reproductive phase further into a weak soil moisture phase. Application of urea during the early squaring phase also invites sap-sucking insect pests. Third mistake is the sprays of systemic organophosphates and neonicotinoid insecticides which induce leaves, further delay flowering and in some cases trigger insect pest resurgence thus necessitating more sprays and more delay in flowering and boll setting. Therefore the keys to the success of cotton cultivation in the dry rainfed regions of Vidarbha and Telangana are 1. Early sowing of early maturing varieties in June 2. High density planting at >44,000 plants per acre with a target of 8-10 bolls per plant for an early narrow flowering window 3. Intercropping with nitrogen fixing short duration legume crops such as green gram or black gram or cow pea or soybean. Legume crops fix nitrogen and support integrated pest management. 4. Application of balanced nutrients at peak flowering and boll setting stage and 5. Careful choice of ecologically acceptable pest management interventions mostly with bio-pesticides to ensure that the crop reproductive phase is uninterrupted and that the natural enemies are least disrupted. Thus a narrow short flowering window of 15-20 days in August can help the squares and flowers to escape American bollworm that generally starts in September and also crop harvest before November helps the crop escape pink bollworm which starts in mid-November. 

WHITEFLY -THE BLACK STORY

This article was published as 

Kranthi K.R. 2015. Whitefly-The Black Story CAI-Vol 23: 8th September 2015. Cotton Statistics and News, Published by Cotton Association of India, Mumbai

WHITEFLY –THE BLACK STORY

K. R. Kranthi

Three years in a row, the whitefly has been on a song in north India. Two weeks ago, I went to Punjab, Haryana and Rajasthan. Clearly the whitefly was on a high. There was hardly any cotton hybrid that was unaffected with the whitefly and the cotton leaf curl virus disease that it transmits. Some hybrids were more susceptible. A few hybrids were tolerant to whiteflies and the leaf curl virus disease as well. August is generally not the peak month for the whitefly. Late September and October are expected to have the highest peaks of the insect. Are we to expect a menace of the whitefly in north India by this month-end? If proper timely steps are not initiated, this insect will grab the national headlines in the next 4-5 weeks time.

WHITEFLY: The whitefly was first reported in Greece 125 years ago. It became a major pest on cotton in India only after 1984. Whitefly is a small white insect of 1.0 mm length. It feeds on more than 500 plant species and transmits a range of viral diseases in plants. Whiteflies suck sap from under surface of leaves causes yellowing and upward curling of the leaves. Though, the ideal conditions for growth are 27^oC and 71% relative humidity, hot and humid conditions favour the insect. The insect excretes sticky honeydew which promotes a fungal sooty mould formation on leaves and cotton bolls. The black mould interferes with photosynthesis in leaves and reduces quality of the cotton fibre. Sticky cotton is not accepted by ginners and the textile industry. Cotton losses were estimated to be in the range of 15-20% and sometimes up to 30%.

The scientific name of the whitefly is Bemisia tabaci. But in 1994, a new aggressive biotype ‘B biotype’ was debatably categorized as a new species Bemisia argentifolii. In 2011 De Barro et al., stated that "Bemisia tabaci is a complex of 11 well-defined high level groups containing at least 24 morphologically indistinguishable species."

The presence of a wide range of hosts such as vegetables, pulses, citrus all the through the year helps the whiteflies to survive and proliferate. But clearly, it is human interventions that aggravate the crisis.

COTTON LEAF CURL VIRUS (CLCuD): The whitefly transmits the dreaded cotton leaf curl virus disease in Pakistan and north India. There are no control measures for the leaf curl virus. Disease affected plants are stunted with fewer number of bolls and reduced yields. Infected plants serve as source of inoculum and infestation for the remaining healthy fields. Almost all the Bt-cotton hybrids in north India were found to be affected by the disease. However a few hybrids were found to be tolerant to whiteflies and the virus. Interestingly, early sown crop was found to be less affected.

INSECTICIDE INDUCED WHITEFLY OUTBREAKS: Why is the whitefly having fun in north India? It is interesting that this small insect emerged as a major menace on cotton in India only after 1984. There were severe outbreaks in 1987-88 in Andhra Pradesh and later in Maharashtra, Gujarat and Punjab. Clearly the trigger was a group of insecticides called ‘synthetic pyrethroids’ that were introduced into the country in 1981. There was clear evidence that indiscriminate use of the pyrethroids was aggravating the problem. A small experiment conducted in Arizona almost two decades ago by Peter Asiimwe showed that when acephate was sprayed four times at biweekly intervals, the treated plots sustained heavy damage from whiteflies leading to plant death. Imagine a tank-mix of pyrethroid + acephate being sprayed repeatedly. This leads to a quick surge in whiteflies resulting in outbreaks. This is what happens more frequently in north India. There have been many such cases with many insecticides that aggravate whitefly infestation in crops, especially in cotton. DDT was known to have caused it in several parts of the world. Fipronil is a recent insecticide that was found to cause whitefly resurgence in north India. Thus it is clear that broad spectrum insecticides and insecticide mixtures cause high levels of whitefly resurgence.

WHAT CAUSES OUBREAKS: Whitefly is an invited guest and an induced pest. Human interventions are responsible for the insect to survive, reproduce, spread and proliferate. A combination of factors such as a) susceptible hybrids, b) hairy or bushy genotypes, c) late sowing, d) high nitrogenous fertilizers, e) inadequate phosphorus and Potassium in the soil, f) indiscriminate use of pyrethroids, acephate, fipronil and mixtures, g) whitefly resistance to insecticides, i) scant regard for proper choice of control measures, j) improper spray application methods and k) favourable weather. 

HOW CAN INSECTICIDES INDUCE PEST OUTBREAKS?: Of course they do. At CICR we found that synthetic pyrethroids and acephate induce bollworms and whiteflies and; spinosad induces mealybugs. Insect pests, including whiteflies are naturally controlled by predators and parasites called ‘natural enemies’ in the field. The natural enemies are generally more susceptible to insecticides than the insect pests. For example, the whiteflies have a waxy coating over the body which protects against insecticides; but its natural enemies are not protected. The whiteflies feed from under surface of the leaf where insecticides do not easily reach. The natural enemy predators and parasites are generally present all over the plant and get exposed to insecticides. Insect pests become resistant quickly to insecticides whereas natural enemies take a longer time for resistance development. Additionally there is a phenomenon reported with whiteflies and American bollworms, called ‘hormoligosis’ which causes insects to rapidly reproduce and multiply when the surviving insects perceive chemical stress, especially at sub-lethal doses. An insecticide mixtures such as cypermethrin+profenophos was found to induce strong hormoligosis in bollworms in our laboratory. Some reports also describe insecticide-induced physiological changes in the plant which become more favourable to insect pests. Thus more the insecticide sprays -more the problem.

CURRENT STATUS: During the cotton season 2015-16 an epidemic of whitefly incidence was noticed during August in the cotton growing areas of Haryana, Punjab and Rajasthan. The white fly populations were above economic thresholds in almost all the regions surveyed in Punjab, Haryana and Rajasthan. Whitefly infestation and the CLCuV disease were first noticed in early June. The menace increased in July-August. The insect infestation and whitefly incidence were higher than the previous three years. The virus caused leaf curl symptoms during August in >90% of the hybrids surveyed in the three states, except in early sown crop. Whitefly incidence ranged from 1.6 to 90 adults /3 leaves during July-August in Sirsa. Thus far, high levels of whitefly infestation were noticed in the second week of August in all the three states.

Fields sprayed with repeated insecticide sprays, insecticide mixtures, fipronil and pyrethroids had the highest levels of whitefly infestation. In Rajasthan, the initiation of whitefly infestation started in the last week of June. The white population ranged between 20- 140 whiteflies/3leaves. In Punjab, whitefly incidence was very severe in Abohar, Faridkot, Fazilka, Muktsar and Mansa districts, to an extent of about 60 -90 insects per leaf in some fields. Infestation was also severe in Hansi and Hisar region of Haryana mainly due to planting of susceptible Bt cotton hybrids.

SOME BITTER FACTS: Global experimental data affirms that majority of recommended insecticides disrupt naturally occurring biological control thereby leading to whitefly outbreaks in cotton across the world. This season insecticides such as fipronil and synthetic pyrethroids were used frequently also as mixtures with organophosphate insecticides (monocrotophos, acephate and triazophos) in north India right through July-August. These insecticides severely aggravate pest populations leading to resurgence and outbreaks.

Majority of the Bt-cotton hybrids grown in north India are susceptible to whiteflies and the CLCuV. This year, in many parts of the north, there was delay in sowing by 15-20 days, which helped the whitefly. High levels of urea (nitrogenous fertilizer) were used mostly in Haryana and Punjab. Insecticide mixtures mostly with pyrethroids plus acephate were sprayed indiscriminately. Spray application methods were bad. Deficient rainfall of less than 100 mm up to July coupled with cloudy conditions and high humidity created favourable weather for the insect pest. Everything is working out well for the whitefly.

Bt cotton hybrids cultivated in north India were released directly without subjecting them to rigorous screening for tolerance to whitefly and the leaf curl virus. More than 90% of the Bt-cotton hybrids under cultivation are highly susceptible to the whiteflies and the cotton leaf curl virus.

The weather during July 2015 was ideally suited for whiteflies. Prolonged cloudy conditions and intermittent scanty rains caused high humidity and hot weather leading to whitefly outbreaks.

Late sowing after second week of May caused high levels of CLCuV infestation coupled with whitefly outbreaks. This year sowing was delayed due to late harvesting of wheat and late release of canal water. Therefore the CLCuV disease is high.  As per the CICR survey conducted during the third week of August 2015, crop sown before the first fortnight of May is relatively healthy and crop sown subsequently  was stunted and more vulnerable to whitefly and the CLCuV disease. Late sown crop has tender foliage in June-July which coincides with whitefly peaks thus leading to higher pest infestation. Whitefly incidence at high levels early in the season caused sooty mould in some hybrids due to the honey dew excreted which resulted in poor growth of plants.

Whiteflies are present continuously in north India due the availability of wide range of crops all through the year. Crops such as rice, guar (cluster bean), and moong, groundnut and kharif vegetables are predominantly grown during the season. Both guar and moong crop are a good alternate host of whitefly. The insect is continuously subjected to selection pressure by insecticides used for its control. Several weeds serve as hosts for the whitefly and the CLCuV disease. Severity of the disease depends on the level of weed infestation in the vicinity of fields.

INSECTICIDE RESISTANCE: Studies conducted by CICR showed that whiteflies in north India have developed resistance to all the commonly used insecticides. ‘Neonicotinoid’ group insecticides are most commonly used in north India. Whitefly resistance to the neonicotinoid insecticides is high in north. There are very few insecticides that are effective. This has resulted in excessive indiscriminate insecticide sprays that disrupted ecosystems, which led to the severe whitefly outbreaks and further development of resistance.

CICR is monitoring for insecticide resistance development against 12 insecticides in whiteflies and jassids collected from 24 locations across the country. Insecticide resistance monitoring carried out by CICR showed high level of insecticide resistance to acetamiprid, thiomethoxam, imidacloprid, monocrotophos, clorpyriphos, triazophos and acephate. The institute is also monitoring for resistance development in bollworms to Bollgard-II. Based on the results, IRM strategies will be developed and disseminated across the country.

HYBRID SUSCEPTIBILITY: CICR is conducting a multi-location experiment with 143 Bt-cotton hybrids this year at five locations (Hisar, Sirsa, Sriganganagar, Bhatinda and Faridkot) in the three north India states of Haryana, Rajasthan and Punjab to evaluate for tolerance/susceptibility to CLCuV and whiteflies. Recommendations of tolerant Bt-cotton hybrids to be preferred for 2016, will be finalized from the trial data.

RECOMMENDATIONS FOR MANAGEMENT: For effective management of the pest, crop ecosystems must be least disturbed. Never use Fipronil, synthetic pyrethroids or any insecticide mixtures. Avoid excessive urea application. Use NPK mixed fertilizers as split doses. Plant yellow sticky traps at 5 traps per 100 sq metre. For best long term results, neem-oil and castor oil based insecticides, soap sprays and insect growth regulators are recommended. Initially use vacuum suction traps followed by a sequential use of water sprays, soap sprays and neem-oil based neem seed kernel extracts. If needed insect growth regulators such as difenthiauron, buprofezin, spiromesifen, and pyriproxifen can be used after mid-August. These insecticides are effective on whiteflies and are relatively safer to its natural enemies.

NEED FOR A ROBUST POLICY: If cotton has to survive in north India, it is important that some policies are formulated. 1. Never allow CLCuD susceptible varieties/hybrids to be permitted for cultivation. 2. Create facilities for early sowing before the end of April by providing irrigation and enforcing a ban on sowing after 7^th May. 3. Insect pest management must be based on sticky traps, reflective sheets, suction traps, soap emulsions of neem oil, castor oil, fish oil rosin soap and insect and insect growth regulators. 4. Appropriate spray methods must be used to ensure that the spray fluid covers the under-surface of leaves. 5. Fields and vicinity must be kept weed free

I must mention here that during my visit to north India in August, I was delighted to see that all the varieties of the Desi cotton species Gossypium arboreum were immune to the virus and were absolutely unaffected by the whitefly. In fact there were hardly any whiteflies on the Desi varieties. But the area under Hybrid cotton is about 1.46 million hectares in north India, while the Desi cotton species is now cultivated in just about 0.04 million hectares. My respect for Desi cotton jumped a few notches above than the current high levels. Desi cotton species Gossypium arboreum is immune to CLCuV. Desi cotton species Gossypium arboreum is highly resistant to the whiteflies. Therefore, for next year, farmers should be advised to choose either Desi cotton varieties or whitefly tolerant and CLCuV tolerant varieties / hybrids in the American cotton species, Gossypium hirsutum and sow early.

Insect war in cotton battle fields

This article was published as 

Kranthi K.R. 2014. Insect war in the cotton battle fields. CAI-Vol 44 28th January 2014. Cotton Statistics and News, Published by Cotton Association of India, Mumbai

 

Insect War in Cotton Battle Fields

K. R. Kranthi

I remember, twenty years ago, a cotton farmer said ‘it is a war between man and insects’. I was on a field visit to Guntur district of Andhra Pradesh to collect bollworms for insecticide resistance monitoring. Farmers were angry, frustrated and crest fallen. One farmer had a bunch of receipts. Unbelievable but true, there were about forty bills in the bunch. He had purchased insecticides, mixed them as cocktails and sprayed through the season at weekly intervals. And the cause for frustration was that…the American cotton bollworm refused to die. Within ten years from 1980 to 1990, the bollworms emerged as major pests of cotton and by 1990 had become resistant to all the recommended insecticides sprayed with an intention to kill them. They were resistant to an extent that even when the bollworm caterpillars were dipped directly into the insecticide formulation, which would otherwise be diluted in 1000 liters of water before spraying, the insects still wouldn’t die. This was a pathetic story that had several facets to it. The farmer was actually responsible for the bollworm to become almost invincible to insecticides by spraying insecticide cocktails desperately and repeatedly. But, it was also scientists and pesticide companies who lead the tragic story unwittingly. The recommendation was -spray insecticides for higher yields. Initially farmers got good yields because the target pests died and so did the beneficial insects that used to kill the target insect pests. After a few seasons, when insect pests developed resistance to insecticides, they survived but the beneficial insects were still being killed by the pesticides. The war was based on poor science and therefore helped the target win the war eventually.

 

I need to explain. It is important to know that insecticides kill all kinds of insects, but are more toxic to some species. There are insects that eat plants and cause economic damage. These are called ‘pests’. There are other insects in the same fields that eat pests. These are categorized as ‘beneficial insects’. To complicate, there are also insects that eat beneficial insects and are ‘undesirable insects’. And, there is a constant ongoing war between insects in cotton fields all through the season. When a farmer sprays an insecticide, he is actually interfering and disrupting the war only to tilt the balance in favour of some types of insects. Newly introduced chemicals, when used initially, generally kill more than 90% of all types of insects and thus make farmers happy. After a few seasons, some insect types get used to the insecticide rapidly whereas others are slow. When the pests develop resistance rapidly, they get an edge over the beneficial insects and use the advantage to win the war, especially when the insecticide is used regularly. Farmers also help pests by cultivating insect-susceptible varieties, which give the pests good food so that they can keep fit. Many chemicals used as insecticides also affect plant physiology that sometimes makes plants ‘green-phase’ or take them to senescence. This also tilts the balance in favour of pests.

 

 

 

It is important to know that the American bollworm, Helicoverpa armigera was not a major pest of cotton in India before 1980. It was induced by a group of insecticides called ‘pyrethroids’ which were introduced into India in 1980. A combination of factors such as ‘wide-spread cultivation of American cotton hybrids’ coupled with ‘extensive use of synthetic pyrethroids’ and ‘high toxicity of pyrethroids to beneficial insects’ eventually helped American bollworms attain the status of ‘incorrigible-invincible-intractable-insect pest’. There are other stories related to mealybugs which are small insects with a wax coating on their body. Insecticides do not affect them as much as they kill beneficial insects. Thus mealy bugs survive and spread more when insecticides are used to control them.

What makes insects invincible? Why is it that insect have the capacity to develop resistance to any kind of chemical that scientists invent. Several biotypes of mosquitoes and houseflies are now known to survive the deadly DDT and BHC, which were thought to decimate them, when used first. It is often said that a nuclear war can decimate all living beings, but cockroaches could survive. That brings home the point that the war will be won by insects because of their evolutionary strength. Scientists often remind that it is a fallacy to think that insects can be wiped out. It is important to remember that the earth belongs to insects. The planet earth has been inhabited by insects for more than 330 million years. Human beings evolved only 1.5 millon years ago. Insects survived everything that decimated the dinosaurs and many other species on earth. Insects are probably destined to win the war, but human intelligence should find ways to live with them without getting affected.

 

 

 

How do insects develop resistance? When an insecticide is used first, it actually kills about 99% of the insects of the same species. The insects that survive are likely to have resistance genes in them. These insects later become the source for resistance through recurrent survival from the repeated onslaught of insecticides and thus gain advantage to finally evolve into an insecticide-resistant species. The world health organization (WHO) defined resistance as “the inherited ability of a strain of some organism to survive doses of a toxicant that would kill the majority of individuals in a normal population of the same species”.

Thus far there are more than 12,000 documented cases of insecticide resistance in 168 countries from 596 insect species to 421 different insecticides. Cotton insect pests find their place in 10 out of the 20 most ‘resistance-prone’ insect species. Five cotton pests are in the top six ranks. Interestingly the cotton bollworm tops the list with the highest number of resistance cases. More than 63% of insecticide resistance cases are from agriculture and 28% of cases from insects of medical importance. This is because of the extensive use of insecticides in agriculture and public health. The highest number of resistance reports was from USA with 2400 cases followed by 850 from Pakistan, 700 from China, 600 from Australia and 400 from India.

Indian farmers continue to use deadly insecticides in cotton fields and on food crops. Several insecticides being used the country are considered to be extremely hazardous to the environment and which have been severely regulated by the FAO (Food and Agricultural Organization), WHO (World Health Organization) and the UNEP (united Nations Environment Programme). Insecticides such as monocrotophos, phorate, methyl parathion, dichlorvos, carbofuran, methomyl, triazophos and metasystox and phosphamidon are highly hazardous and extremely dangerous to human beings and the environment. Unfortunately several state agricultural universities in India still recommend them for pest management in cotton and other food crops. These insecticides have been banned and phased out by several countries across the globe. The above listed insecticides pose acute hazard to developing countries where the lack of protective clothing and mechanical equipment makes it vulnerable to direct contact with chemicals. Medical effects include nausea, diarrhoea, blurred vision, and, in severe cases, respiratory depression, convulsions and death. Effects reported in workers repeatedly exposed to methyl parathion include impaired memory and concentration, disorientation, severe depressions, irritability, confusion, headache, speech difficulties, delayed reaction times, nightmares, sleepwalking, drowsiness and insomnia. Some of these chemicals fulfill one or more of the following criteria: highly acutely toxic, known/probable carcinogen, known groundwater pollutant or known reproductive or developmental toxicant, unacceptably high risk to workers, to wildlife, especially avian and aquatic species, and to trade. It is a pity that these chemicals are still being used extensively for pest control in cotton.

 

The strategies listed below come from relatively simple thinking and can create a win-win situation for all warring groups in the cotton battle field. First of all

 

1.    It needs scientific selection of the most appropriate chemicals that can be as specific as possible to kill insect pests with least effects on beneficial insects. Bt cotton is an excellent example of such a pest specific management strategy.

 

2.    It is necessary to reduce insecticide interventions so that selection pressure is reduced.
 

3.    Farmers should not use the same chemical group for more than once in a season.

 

4.    It is important to design a rational and sensible sequence of insecticides that are effective on the target species, cause least disturbance to beneficial fauna and minimize selection pressure.

5.    It is better to depend more on pest resistant varieties, natural control, biological control with least interference of insecticides.

 

Strategies such as cultivation of sucking pest tolerant varieties and chemical seed treatment help in delaying the first spray, thereby conserving the initial build-up of beneficial insects as natural enemies. Avoidance of insecticide sprays initially in the season to prevent disruption of the beneficial insect ecosystems early in the season. The use of neem-based products and biological pesticides also helps to control sap-sucking insects.

Bt cotton is highly effective in controlling bollworms in an ecologically acceptable manner. For non-Bt varieties, apart from other cultural and biological control methods, the newly introduced insecticides can be effectively used to keep the bollworms under check. Spray of Spinosad or Indoxacarb or Chloantraniprole or Flubendiamide for bollworm control. Spray of synthetic pyrethroids for pink bollworm management during late fruiting phase. Expensive insecticides such as spinosad, emamectin and indoxacarb may be used in irrigated regions with high input use, wherein bollworm infestations are more severe.

Conclusion: The insect war will continue in the cotton battlefields. We need to get rid of many poisonous insecticides from the country so that cotton farmers, food crops and our environment can breathe free of the extremely hazardous pesticides that are being used now. We must strengthen our science to develop pest varieties that can allow insects to survive without causing economic damage to the crop produce. In other words: If you can’t beat them, join them. Thus the final message is MAKE PEACE WITH INSECTS.