Pest Complex of Potato (Solanum tuberosum L.) with Special Reference to Management of White Grub in Northern Districts of Kashmir Valley

The investigations entitled “Pest complex of potato (Solanum tuberosum L.) with special reference to management of white grub in northern districts of Kashmir Valley” were undertaken at Baramulla, Kupwara and Bandipora districts for two cropping seasons 2011 and 2012. A total of 12 pests were recorded on the cropright from sowing upto harvest which were Flea beetle (Chaetocnema spp.), Semilooper (Thysanoplusia orichalcea), Aphid (Macrosiphum euphorbiae), Cutworm (Agrotis ipsilon), White grub (Brahmina coriacea and B. poonensis), Wireworm (Melanotus horticornis), Earwig (Euborellia annulipes), Stunt nematode (Tylenchorlynctus kashmiriensis Mahajan), Lens nematode (Basirolaimus indicus Shamsi), Spiral nematode (Helicotylenchus dihystera Sher. and H . indicus Siddiqi), Root lesion nematode (Pratylenchus spp.) and Dagger nematode (Xiphinema basiri Siddiqi). In vivo observation revealed that Imidacloprid (70WS) as seed treatment registered 97.33, 96.66 and 96.66 per cent good tubers at Kunzer, Budnambal and Ajas, respectively followed by Bacillus thuringiensis, Metarrhizium anisopliae and Beauveria bassiana. Whereas, Mustard cake as soil amendment recorded lowest good tubers of 76.00, 76.66 and 76.66 per cent at Kunzer, Budnambal and Ajas against 74.66, 75.33 and 74.66 per cent in control, respectively. The overall performances in descending order of different pesticides/cultural practices on the basis of per cent good tuber were Imidacloprid (96.88%) > Bacillus thuringiensis (93.55%) > Metarrhizium anisopliae (91.10%) > Beauveria bassiana (89.33%) > Cultural practices (81.33%) > Azadirachta indica (80.66%) > Phalada-111C1(77.10%) > Brassica species (76.44%) against control (74.88%).


Introduction
Potato, Solanum tuberosum L. the king of vegetables also known as white or Irish potato is a native of South America. As per literature it is the most important vegetable crop ranking fourth after rice, wheat and maize being a major staple food crop. Different varieties of potatoes are grown in more than 150 countries of the world and more than a billion people eat it worldwide. The top ten producers in the world are China, Russia, India, USA, Ukraine, Germany, Poland, Belgium, Netherlands and France which together contribute about 70 per cent of the total production (Anonymous, 2011a). India ranks 4 th in terms of area and 3 rd in terms of production of potato across the globe, producing around 42.34 million tons from an area of 1.86 million hectares (Anonymous, 2011a). In Kashmir province, potato is grown over an area of 1.7 thousand hectares with a production of about 34.00 thousand tons (Anonymous, 2011b). It is cultivated in large tracts and in home gardens as well.
The potato tubers are highly nutritive, rich in carbohydrates, proteins, phosphorus and minerals such as calcium, potassium and also vitamin A and C. It also contains significant levels of phenolic compounds and vitamin C as potent antioxidants (Brown, 2005) which inactivate reactive oxygen, reducing oxidative damage, lead to improved immune functions and reduce risk of cardiovascular disease, cancer, cataract, diabetes and aging (Kaur et al., 2004). to 52 genera all over the world. Out of these, 80 arthropods and 93 species of nematodes fall under 40 genera have been reported from India alone (Pandey, 2007). Important insect pests which feed on both above and underground parts of potato include, cutworm, flea beetles, tobacco caterpillar, aphids, potato leafhopper, lygus bugs, potato tuberworm, whitefly, wireworm, earwigs, white grub etc. while as nematode species, Globodera and Meloidogyne are among the nematodes that are also reported as endoparasitic on potato crop (Waliullah, 1992). Among the insect pests, white grubs of Holotrichia species belonging to soil pests have been noticed as serious threat to this crop particularly in the high hills. Further it has been also deemed that actual damage to potato tubers is done by 2 nd and 3 rd instars grubs making large, shallow and circular holes thus rendering tubers to low market value. It is reported that this pest may cause 15.5 to 80.0 per cent losses of tuber yield in endemic areas located at the higher hills of Himachal Pradesh, Uttar Pradesh, Jammu and Kashmir and also in North-eastern hills of India (Mishra, 1995;Misra, 2003).

Survey on Pest Complex of Potato
For this purpose, survey was carried out in northern districts of Kashmir Valley namely Baramulla, Kupwara, and Bandipora, where three locations in each district were selected at three different levels of elevations (plains, mid and high hills). The crop was observed throughout the season 2011 and 2012 to record the pest complex associated with potato. The localities are:

Collection and Preservation of Pests
The pests of potato were collected from different localities by using sweep nets, light traps and also by hand picking. The collected samples were pinned or preserved in 70 per cent ethyl alcohol and got identified at IARI and SKUAST Kashmir by the taxonomists.

Sampling of Nematodes
The soil samples at the mentioned localities were collected from around the roots of the potato crop by digging upto 25 cm depth with the help of Khurpi throughout the cropping season. The soil samples were processed by using Baermann's funnel technique for isolating the nematodes. Samples were preserved in FA 4:1 formalin (10 ml), acetic acid (1 ml) glycerol (3 ml) and water (100 ml) as hot fixative (Cobb, 1918;Christie & Perry, 1951). Roots of potato crop were examined under binocular at 40X in the economic laborarory/Nematology laboratory of Division of Entomology, SKUAST-K, Shalimar campus.

Management of White Grub Damaging Potato
Management of white grub damaging potato was carried out by selecting one location indicating high damage by white grub from district Baramulla (Kunzer), Kupwara (Budnambal) and Bandipora (Ajas) during the year 2012. For this purpose randomized block design (RBD) was used for different treatments and each treatment was replicated thrice. The different treatments were:

Treatment Application
The treatments were given by using different methods of application viz.,  Imidacloprid used as seed treatment.
 Beauveria bassiana, Metarrhizium anisopliae, Bacillus thuringiensis and Phalada-111 C1 drenched around the roots of standing potato crop at an interval of 65 and 80 days after sowing.
 Neem and mustard cakes used as soil amendment at the time of field preparation.
The efficacy of individual treatments was worked out on the basis of percentage of good tubers at final harvest and compared with good tubers in control i.e., both percentage good tubers in treated and in untreated plots.

Pest Complex of Potato
A random survey was carried out in northern districts of Kashmir Valley namely Baramulla, Kupwara and Bandipora where three locations in each district were selected at three different levels of elevations (plains, mid and high hills). The crop was examined throughout the season to record the pest complex associated with potato. A total of 12 pests including 7 insect pests and 5 nematode genera were found to be associated with the crop right from sowing/germination upto harvest which were Flea beetle (  Among foliage feeders, semilooper was absent at Budnambal (Kupwara) and Gurez (Bandipora) while as, earwig and wireworm as tuber feeders were completely absent at Kunzer and Yarikhah of Baramulla district. In addition earwig was also absent at Budnambal (Kupwara) and Gurez (Bandipora) as depicted in Table 3.

Manag
The field e 2012 to w  Vol. 8, No. 3;2016 seed), Beauveria bassiana (5 g/litre of water), Metarrhizium anisopliae (5 g/litre of water), Bacillus thuringiensis (3 g/litre of water), Phalada-111 C1(1 ml/litre of water), Neem cake (300 kg/ha), Mustard cake (300 kg/ha), Cultural practices and untreated check (control). The per cent good tubers in treatments were compared with per cent good tubers in control to work out the most effective treatments for the management of white grub.
Observations on per cent good tubers recorded at Kunzer (Baramulla) ( Present findings are in line with the work conducted by Sharma et al. (1998), Chandel (2005, 2007), Chandel et al. (2005), Zaki et al. (2006Zaki et al. ( , 2007, Keller and Schweizer (2007), Wani (2009) and Chelvi et al. (2011) reported that imidacloprid was the effective control measure followed by bioagents for the control of white grubs infesting potato in India and other parts of the world.