Invasive pests that gained entry into this cold arid region have caused catastrophic damage to commercial crops of agriculture and horticulture and forest trees. Due to climate change in the past few years, many invasive pests have hit the Ladakh region -- like many species of Alphids on cereals, vegetables and horticulture crops, yellow and brown rust in wheat and barley.
The villages of the lower belt of Leh are currently reeling under an infestation by an invasive insect. They are damaging fruit trees and forest trees. To safeguard food supply for our growing population, farming must become more sustainable in the future, and steps are taken up for optimization.
To know more about the future challenges for agriculture in Ladakh, we interviewed Dr. Vikas Sharma, scientist, plant protection, In this issue, he tells us about solutions to address farming problems.
Q. What are the major insect pests in this cold arid region?
The major insect pests in this cold arid region are codling moth in apple and apricot (Cydia pomonella), aphids in fruits and vegetable crops (Aphis spp.), cutworm in vegetables (Agrotis ipsilon), maggots in onion (Delia antique), powdery mildew in grapes (Uncinula necator), weevil in walnut (Alcides porrectirostris), loose smut in wheat and barley (Ustilago tritici), rust in wheat and barley (Puccinia spp.), fungal (Fusarium spp.) and bacterial wilt (Ralastonia solanacearum) in Solanaceous vegetables and several invasive species of moths.
Q. Codling moth is one of the regular and major insects of apple and apricot orchards in Ladakh? How much loss our farmers are facing due to this insect? How can we manage them?
Codling moth (Cydia pomonella), which cause severe damage to apple and apricot trees. It is the major insect of the Ladakh region. The government has imposed severe restrictions, through its order SRO 397 of 8 September 1981 under the Jammu and Kashmir plant and disease act 1973 on the movement of fresh fruit and saplings of apple and apricot from Ladakh so that it may not infest apple and apricot of other states of the country. Larvae of this insect enter the fruit especially at the calyx end and make small holes inside and eat the pulp. Damaged fruits fall prematurely.
If conditions are favorable the losses reported are 70-80 percent. We can manage this insect by integrating approach i.e by cultural, biological and chemical. The management is as under:
Scrap loose bark from trunks to eliminate shelter for overwintering caterpillars.
Proper sanitation should be maintained.
2-3 periodical releases of egg parasitoids i.e Trichogramma embryophagum or Trichogramma platneri from June onwards can effectively reduce the pest population.
Adult emergence can be monitored by using pheromone-baited traps which should be placed on the trees during mid May.
After complete petal fall when the moths start emerging, spray chloropyriphos or dimethoate @ 0.1 %. Repeat the spray after 2-3 weeks of the first spray on a community basis.
Q. How much percent of our agriculture products are lost due to pest infestation and weeds?
Globalization of trade in plants and plant products increased the risk of invasion by plant pests across the globe. The threats are likely to increase further as a result of rapid growth in agricultural trade. Due to pest infestation, 50-55 percent losses are reported and due to weeds, 30-35 percent losses are reported.
Q. Can you throw some light on how brown tail moth entered into Ladakh and when?
Browntail moth (Euproctis chrysorrhoea) insect is a newly introduced insect in Ladakh region which was reported a few years back. The insect gained entry in this cold arid region due to climate change in the past few years. The insect was reported in 2010 from Kargil district and in 2014 it was reported from Dha and Bhema. Due to climate change, we are able to grow many vegetables in open and in protected structures which were not possible years back but on the other side, many invasive pests were reported in this region which causes severe outbreak like locust, brown tail moth etc.
Q. Why nothing has been done so far when it was already identified in 2014 in Leh? What are the reasons behind that?
Several awareness camps were conducted by the agriculture university, line departments, NGO’S and in collaboration with each other in infested villages but the infestation is severe and the population of insect is very much in number which causes a severe outbreak. The other reasons behind this are the shortage of field functionaries in the district, non-availability of bio-pesticides, orchards of apple and apricot are not properly managed, non-availability of power sprayers in the villages, religious belief, and field sanitation in winters is not practiced in the district.
Q. The infestation of browntail moth causes a severe outbreak in the lower belt of Leh district. Which are the worst affected villages?
The infestation is severe in lower belt of District Leh. The villages which are worst affected by the infestation are Dha, Bhema, Achinathang, and Hanuthang. This year the insect was reported from Turtuk village also.
Q. Does it cause an allergic reaction to humans also? What precautions should be needed for the farmers who work in the field?
Yes, it causes severe allergic reactions to humans. When it comes in close contact with people, it can cause an allergic reaction, itching, rashes on their skin and breathing related which may be due to some toxins released by this insect in the air which we breathe or may be due to contact with the poisonous hairs of the insect. Contact of these hairs with human skin causes a rash that can be severe in some individuals. People can also experience respiratory distress from inhaling the microscopic hairs that blow around in the air. Direct contact with a caterpillar isn’t necessary for ill effects.
When the caterpillar molts, the barbed hairs break off and become airborne. These airborne hairs can lodge into people’s skin or be inhaled, and the hairs remain toxic for a year or more after they break away from the insect.
Wear appropriate protective clothing, which will ensure that there is no contact between the irritant hairs and the skin. If possible garments should be made tight at the wrists and ankles. Use gloves, a hood, goggles, long shoes, and a dust mask to ensure that bare skin is covered. It would be wise to keep windows closed to prevent caterpillars from entering into your house.
Q. Can we consume the apricot that has been infected by the brown tail moth?
It is not advisable to consume apricot which is infected by brown tail moth insect. The hairs of insect remain toxic for a year or more after they break away from the insect. It may cause respiratory distress by inhaling the microscopic hairs on apricot fruit.
Q. What are the biggest threats of climate change for the farmers in Ladakh? What are the greatest future challenges for agriculture?
Climate change is the biggest threat to the farming community because it will change our crop pattern. Future challenges are several pests which were reported may be ceased and several new may be reported. Some new races of the pathogen may report which may be aggressive. We should increase the population of natural enemies of insects like birds, predators and parasitoids by giving them a suitable environment.
Q. Why there is a sudden increase in insect pest attack in Ladakh?
Due to climate change, there is a sudden increase of pest attack in the Ladakh region. Continued world population growth has resulted in increased emission of gasses from agricultural waste, combustion of fossil fuels and industrial processes. This has caused changes in the chemical composition of the atmosphere. The evidence is emerging that increased solar ultraviolet-B (UV-B) radiation is reaching the earth’s atmosphere due to stratospheric ozone depletion. Carbon dioxide, ozone, and UV-B are individual climate change factors that have direct biological effects on plants. Such effects may directly or indirectly affect the incidence and severity of plant pests. Climate change would be likely to promote plant diseases like rusts, powdery mildews, leaf spots and leaf blights. Climate change has the potential to modify host physiology and resistance and to later stages and rates of development of the pathogen. New disease complexes may arise and some diseases may cease.
Q. Was there any meeting to curb this outbreak of brown tail moth in the recent time? If not, why?
Yes, On 28 May 2016 one meeting was conducted by Chief Horticulture officer Leh in his office in which officers of line departments and SKUAST-Leh participated. I wish in near future several stakeholder meetings will be conducted if any pest outbreak reported in the district.
Q. Onion maggot is a serious insect of onion and related Allium crops. Tell us about this problem in Ladakh?
Onion maggot (Delia antique) is a serious pest of onion and related Allium crops in the temperate region throughout the world. 50 percent losses were reported if crops are not protected. In Ladakh region, onion maggot are found in all major onion growing areas which cause severe damage to onion crop. The onion maggot larvae attack germinating seedlings, feeding on the developing roots and epicotyls and can continue to feed on the expanding bulbs during later stages of the growth. The insect can be managed by crop rotation, by growing resistant varieties, using yellow stick traps, dip seedlings in chlorpyriphos @ 0.2 percent i.e 2ml in 1 litre water before transplanting for 10-15 minutes, by application of carbofuran 3G 1kg a.i/ha before sowing and drench with chlorpyriphos @ 0.2 percent at early stages if symptoms observed in onion field. Don’t use insecticide at the time of harvesting or before harvesting due to its residual effect. The problem of onion maggot in Ladakh is very common and from several years.
Q. How important is it to keep the orchards clean? Do the farmers in Ladakh care about the sanitation of orchards?
It is very important to keep the orchards neat and clean. Sanitation is the precautionary method to avoid introducing a pest into a field. As we know prevention is better than cure. The farmers in Ladakh do not care about the sanitation of their respective orchards; it may be due to lack of awareness about pest and its life cycle. Always keep the orchard clean by removal and burying of fallen leaves, remove dried leaves from the trees and orchards in the winter as they can harbor eggs of the moth. Remove webs by pruning. Do this in the early morning or evening when the weather is cool and the moths are still in their webs. Dispose of the webs in a sealed paper bag in the garbage or compost pile or burying deep under the soil.
Q. What is integrated pest management and can we implement this in Ladakh?
Integrated Pest Management (IPM) is a systems approach to pest control that combines biological, cultural and other alternatives to chemical control with the judicious use of pesticides. The objective of IPM is to maintain pest levels below economically damaging levels while minimizing harmful effects of pest control on human health and environmental resources. Various IPM tools are available to reduce pest infestation. Integration of these tools with chemicals that include the use of various bio-agents, sex pheromones, light traps, biological formulations, Use of biodegradable or environmentally safe pesticides like plant extracts (Neem oil formulation, Datura stramonium and Garlic extracts formulation etc.) significantly reduce the pest infestation through eco-friendly approach. This is an elegant way of reducing the amount of pesticides residues on agriculture and horticulture crops. The major components of IPM are prevention, observation, and intervention. The IPM seems to be the only answer to counter some of the major pests of crops, which have become unmanageable in recent years.
Yes, we can implement this in Ladakh. The IPM is a little bit difficult but not impossible because it is a systems approach to pest controls that combines biological, cultural and other alternatives rather than a single approach.
Q. To safeguard the food supply for our growing population, farming must become more sustainable in the future. Comment
To bridge the ends of increased demands and limited productivity, we introduced high yielding varieties and hybrids seeds. This has resulted in dramatic changes in pest scenario leading to minor pests assuming a major status in the region. For sustainable agriculture and protection of our environment and human health, use of judicious and safe pesticides has assumed global importance after the earth summit. There are several eco-friendly ways available to reduce the pesticide use and to get the optimum produce in a short span of time. There is a need to realize the potential of indigenous bio-control agents and urgent attention should be given to conserving them by habitat manipulation. Use of IPM devices like sex pheromones should be intensified and disseminated among the farming community. Farmer’s participation is a key factor in making IPM a success at field level.
Message to the readers:
Like Swachh Bharat we should adopt Swachh Kheti in our farming system. The most basic and simple method of pest management is sanitation i.e cleanliness of our field. Insect lay eggs on the fallen leaves and that is the best time to monitor its population. Collect the fallen leaves and bury it properly in a pit. This method is very effective if all the farmers will adopt this practice. Clean up campaigns should be organized at their respective villages with the support of Sarpanch, Panch, and Goba.
The farmer should daily visit his field in morning hours if any incidence of pest infestation noticed then contact concerned department or concerned scientist. He or she rogue out and bury the infected plant or plant parts in early stages. In the early stages, it is easy to manage pest infestation. Crop rotation is also a very simple and cultural method to manage various insect pests of field crops. Do farming in a scientific way like line sowing, proper spacing, crop rotation, use well decomposed organic matter in the soil, regular watch and ward of the field, proper sanitation in the field, seed treatment before sowing, procure seed from reliable source etc. is the need of the hour. Always adopt cultural and biological practices in managing insect pest instead of chemical. When any pest causes severe outbreak and havoc then it’s important to use the chemical in a judicious way to manage that pest. Use chemicals as a last resort for managing insect pest.
• Awareness about IPM should be increased.
• The quality of bioagents should be maintained.
• Procedure for registration of biopesticides needs to be made simpler.
• Incentives for industries producing bio-pesticides.
• Monitoring of use of banned pesticides in the region.
• Region-specific modules should be developed.
• Farmers adopting IPM need to be encouraged.
• The premium on IPM produce should be given.
• Enhanced knowledge about pest and natural enemies of the pest.
• Increased biodiversity especially of predators & parasites in the region.