Cultural Practices and Resistant Varieties in Potato Dr. S.K. Dutta & Dr. Badal Bhattacharyya Department of Entomology Assam Agricultural University,Jorhat-13

Summer deep ploughing (end of July to middle of August) to expose the different life stages of soil insect pests to expose them to predatory birds and desiccation by sunlight Fig. 1. Predatory birds feeding on insects exposed by summer deep ploughing Fig. 2. White grubs collected after summer summer deep ploughing Source: www.ainpwgosa.com

Follow crop rotation to avoid pest infestation in potato Crop Sequence: Rice-Rice-Potato Summer Rice – potato Rice-Potato-Cowpea Rice-Potato-Green gram

Adjustment of planting and harvesting time for avoidance of insect infestation Fig. 3. Harvesting of potatoes Source:http://www.angelicorganics.com/Newsletters/2008Week16VegNewsWed.html

Source: AINP on White grub, Assam Agricultural University, Jorhat-13 Maintain weed free crop initially up to six weeks after planting by resorting to two hand hoeing / earthing up operations at 3rd and 6th weeks of planting Fig. 4. Earthing up in potato field Source: AINP on White grub, Assam Agricultural University, Jorhat-13

Ensure growing of healthy crops with optimum plant population (1,30,000 plants/ha ) by using recommended seed rate (22.5-25 q/ha) and balanced doses of fertilizers (NPK @ 60:50:50 in rainfed and 60:100:100 in irrigated condition) Adjustment of planting time of summer crop in hilly areas to prevent aphid attack

Source: AINP on White grub, Assam Agricultural University, Jorhat-13 Prepare high ridges to avoid exposure of seed tubers to egg laying by potato tuber moth Fig. 5. High ridging in potato Source: AINP on White grub, Assam Agricultural University, Jorhat-13

Fig. 6. Cut worms exposed from under green grass Keeping plant debris/green grasses at different locations of cut worm infested field in the evening, which serve as hiding places for cut worm larvae , where they could be destroyed next day Fig. 6. Cut worms exposed from under green grass Source: http://www.google.com/imgres?imgurl=http://www.saferbrand.com/resource

Allow time for previous crop residue to decompose Fig. 7. Decomposition of crop residues Source: http://www.google.com/imgres?imgurl=http://farm2.static.flickr.com

Rouging of volunteer potato plants to reduce aphid infestation Fig. 8. Rogueing of volunteer potato plants Source: http://www.google.co.in/search?hl=en&biw=1090&bih=462&gbv=2&tbm=isch&sa

Fig. 9. Potato tubers infested by tuber moth Removal and destruction of infested tubers to check tuber moth infestation in both storage and field conditions Fig. 9. Potato tubers infested by tuber moth Source: http://thesecondgreenrevolution.blogspot.com/2009_11_01_archive.html

http://www. hrefresh.com/ Fig. 11.Potato infested by tuber moth Do not keep harvested potato tubers in the field to prevent egg laying by tuber moth X Fig. 10. Keeping harvested potato in field Source:http://www.google.com/imgres?imgurl= http://www. hrefresh.com/ Fig. 11.Potato infested by tuber moth Source:http://www.google.com/imgres?im gurl=http://www.inra.fr/hyppz/IMAGES

Fig. 13. Proper pulverization of soil decreases wire worm population Grow potato in well pulverized soil. Proper soil pulverization decreases wireworm population both by direct injury and by exposing them to desiccation or predation by birds Fig. 12. wire worms Source:http://www.google.co.in/imgres?imgurl=http://www.fruitandveggie.com Fig. 13. Proper pulverization of soil decreases wire worm population Source:http://www.google.co.in/imgres?imgurl=http://cdn.wn.com

Standing water for short period before sowing can help to eliminate the eggs of mole crickets Fig. 14. Keeping standing water in field for short period Source: http://photography.nationalgeographic.com/photography/photo- tips/landscape-photos/#/potato-field-india_21021_600x450.jpg

Fig.15. Construction of raised potato nursery Construct raised nursery to reduce the seedling damage by mole crickets Fig.15. Construction of raised potato nursery Source: http://www.kvktuensang.org.in/gallery.html

Potato crop irrigated at 30 and 60 days after germination reduces red ant infestation in potato Fig. 16. Irrigation in potato field Source: AINP on White grub, Assam Agricultural University, Jorhat-13

Liming @ 3.5 quintal/hectare prior to sowing of potato tubers reduces red ant infestation Fig. 17. Lime Source: http://www.google.com/imgres?imgurl

Fig. 18. Burning of potato plants Pulling and burning of heavily mite infested potato plants Fig. 18. Burning of potato plants Source: / http://evapm.deviantart.com/art/Burning-Potato-Stems-139402088

Source http://www.google.com/imgres?imgurl=http://ddandkw.com Abundant ground water, straw retention technique and soils with high organic matter content provide ideal moisture level and shelter to snails and slugs. In snail endemic areas such conditions may be discouraged to a preferable extent or kept at optimum. Fig. 19.Snails and slugs Source http://www.google.com/imgres?imgurl=http://ddandkw.com

Avoid planting new crops downwind from those infested with mites, as the mites will be spread to the new crop by the wind. Resistant variety Kufri Chandramukhi may be grown in aphid/leaf roll/ potato virus Y endemic areas