SCREENING OF SIX RICE VARIETIES AGAINST YELLOW STEM BORER, Scirpophaga incertulus WALKER. SAID MIR KHAN*, GHULAM MURTAZA* and HINA MIR**

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1 Sarhad J. Agric. Vol. 26, No. 4, SCREENING OF SIX RICE VARIETIES AGAINST YELLOW STEM BORER, Scirpophaga incertulus WALKER. SAID MIR KHAN*, GHULAM MURTAZA* and HINA MIR** * Department of Entomology, Faculty of Agriculture, Gomal University, Dera Ismail Khan. ** Faculty of Molecular Biology, Department of Animal Sciences, Quaid-i-Azam University, Islamabad. ABSTRACT Studies were conducted on the relative resistance of six rice varieties (Basmati-385, IRRI- 6, Basmati Super, Basmati- 370, DR- 83 and KSK- 282) against the yellow stem borer (Scirpophaga incertulus Walker) in 2007, at the Research Farm of Agricultural Faculty, Gomal University, Dera Ismail Khan. Maximum dead-hearts (58.35%) and white-ear heads (13.67%) were found in Basmati Super whereas minimum dead-hearts (13.63%) and white-ear heads (2.35%) were found in IRRI-6 followed by DR-83 and KSK-282 with 20.06% and 25.74% dead-hearts and 9.45% and 4.97% white ear heads, respectively. IRRI-6 was found not only tolerant to rice stem borer attack but also showed maximum number of tillers (49.60), spike length (32.61cm), grains spike -1 (132.8), thousand grains weight (35.67g) and yield hectare -1 (6.53 tons). However, it showed less plant height (97.22 cm) compared to other tested varieties. Over all, results showed that fine varieties (Basmati) were highly susceptible to the yellow stem borer compared to the coarse varieties tested. Key Words: Scirpophaga incertulus, relative resistance, rice varieties, pest Citation: Khan, M., S. G. Murtaza and H. Mir Screening of six rice varieties against the yellow stem borer, scirpophaga incertulus walker. Sarhad J. Agric 26(4): INTRODUCTION Cultivated rice, Oryza sativa L. is one of the world s most important crops, providing staple food for nearly half of the global human population (FAO, 2004). It is an important source of employment and income-generating crop in the rural areas of Asia. It is high valued cash crop accounting 6.7% in value added items in agriculture, 1.6% in GDP and also a major export commodity for Pakistan accounting for 6.1% of total export earnings (Sheikh and Kanasro, 2003). In Pakistan, during the cropping season of 2005, total area under rice crop was about 2.62 million hectares with a total production of 5.54 million tons. In the North West Frontier Province (Khyber Pakhtunkhwa), the area under rice crop during this season was 59,400 hectares with a total production of 117,500 tons. In Dera Ismail Khan, its cultivated area increased during the season to 5,200 hectares with a production of 14,700 tons (Anonymous, 2007). The yellow stem borers, Scirpophaga incertulus Walker and white stem borer, Scirpophaga innotata (Walker) are the most serious pests in South and South East Asia (Rehman et al., 2002). Yellow stem borer alone causes yield losses upto 10 million tons and accounts for 50% of all insecticides used in rice fields (Huesing and English, 2004). It attacks the crop from seedling to harvesting stages and causes complete loss of affected tillers (Salim and Masih, 1987; Atwal, 1976). Dead hearts are produced when the insect attacks at vegetative stage while white ear heads appear when the stem borers attack at the time of ear development (Bashir et al., 2004). Control of stem borer in rice involved application of pesticides, varietal resistance and the use of natural enemies (Kiritani, 1972; 1977; 1979). Although cultural practices are helpful in reducing crop damage due to borers, however, other methods are required (Loevinsohn et al., 1988) to keep these pests below economic injury levels. Rice borers cannot be controlled with use of pesticides alone because these are protected inside the grass stem throughout most of their life cycles. Emphasis has been focused on the development of stem borer resistant rice varieties because this approach is considered economical and environment friendly (Abro et al., 2003; Chaudhary et al., 1984; and Heinrichs, 1986). Cultivation of resistant varieties of rice will play a significant role in integrated management systems in rice (Shafique et al., 2000).

2 Said Mir Khan et al. Screening of six rice varieties against the yellow stem borer 592 Present study was conducted with a specific objective to compare the relative resistance of different rice varieties against the yellow stem borer, Scirpophaga incertulus. MATERIALS AND METHODS A trial was conducted in a randomized complete block design with three replications to assess resistance/tolerance of six rice varieties (Basmati-385, IRRI-6, Basmati Super, Basmati-370, DR-83, KSK- 282) at the Research Farm of Agricultural Faculty, Gomal University, Dera Ismail Khan, under field conditions against the yellow stem borer during rice season Nursery of these varieties was raised in 2nd week of April For this purpose seeds were soaked over night and then broadcasted in standing water the next morning in respective plots assigned to each variety. Recommended dose of fertilizer (Nitrogen in the form of urea and phosphorus in the form of DAP) was applied. Thirty days old nursery plants of each variety were transplanted in the experimental units (each 2 x 3 m 2 ) with row-to-row and plant-to-plant distance 22cm and 20cm, respectively. All other agronomic practices were performed alike in all fields. Yellow stem borer s infestation was recorded by checking dead hearts and white ear heads at boosing and panicle stage and converted to percent infestation. Plant morphological and agronomical data based on plant height, number of tillers, spike length, grains spike -1, thousand grains weight and yield plot -1 (converted into tons hectare -1 ) were also recorded. The final data were analyzed with analysis of variance (ANOVA) and means were separated using least significant difference (LSD) test. RESULTS AND DISCUSSION The results (Table I) revealed that minimum dead hearts (13.63%) and white ear heads (2.35%) were recorded in IRRI-6 followed by DR-83 and KSK-282 with and 25.74% dead hearts and 9.45 and 4.97% white ear heads, respectively. Whereas maximum dead hearts (58.35%) and white ear heads (13.67%) were found in variety Basmati Super followed by Basmati-370 and Basmati 385 with 58.07% and 49.22% dead hearts and 12.64% and 13.20% white ear heads, respectively. On the basis of dead hearts, Basmati Supper and Basmati-370 were not significantly different from each other. Similarly, variety DR-83 and KSK-282 were also found non-significantly different from each other. IRRI-6 was found highly resistant/tolerant against rice stem borer, followed by variety DR-83. IRRI-6 and Basmati Super were found highly significantly different from each other in case of borer attack. Overall it was found that fine varieties were highly susceptible against rice stem borer compared to coarse varieties. Data regarding plant morphological and agronomic characteristics of different varieties (Table II) revealed that maximum mean plant height (146.3cm) showed by the variety Basmati-370 whereas maximum number of tillers (49.60) and spike length (32.61cm) was found in variety IRRI-6. Similarly lowest mean plant height (91.44cm), number of tillers (29.50) and spike length (22.55cm) was found in Basmati-385, KSK-282 and Basmati Super, respectively. On the basis of plant height, cultivar Basmati- 385, IRRI-6 and Basmati Super were found non-significantly different from each other. The number of tillers produced by all the tested varieties was found non-significantly different from each other except IRRI-6. On the basis of number of tillers, Basmati Super and KSK-282 were found significantly different from each other. As far as number of tillers and spike length are concerned, variety IRRI-6 showed maximum number of tillers and spike length as compared to other tested varieties. Table-I Percent infestation of yellow stem borer in six rice varieties cultivated in Dera Ismail Khan. Varieties Dead hearts White ear heads BASMATI b a IRRI d 2.35 d BASMATI SUPER a a BASMATI a a DR cd 9.45 b KSK c 4.97 c

3 Sarhad J. Agric. Vol. 26, No. 4, Table-II Comparison of Plant height (cm), Number of tillers and spike length among different tested varieties of rice. Varieties Plant Height (cm) No. of Tillers Spike Length (cm) BASMATI d bc cd IRRI d a a BASMATI SUPER d b d BASMATI a bc b DR c ab d KSK b c bc Yield data of different varieties (Table III) revealed that variety IRRI-6 produced significantly maximum number of grains (132.8 spike -1 ), thousand grains weight (35.67g) and yield per hectare (6.53 tons), followed by KSK-282 which produced grains spike -1, 28.0g thousand grains weight and 5.38 tons hac -1 grain yield. The number of grains spike -1 of all other tested varieties were found non significantly different from each other except KSK-282. As far as thousand grains weight and yield of tested varieties were concerned, Basmati Super produced minimum thousand grains weight (17.67g) as well as yield hectare -1 (0.36 tons). Results showed that all fine (Basmati) varieties were found non-significantly different from each other. Table-III Comparison of grains per spike, thousand grains weight and yield per hectare among different tested varieties of rice. Varieties Grains spike -1 Thousandgrains weight (gm) Yield (Tons hac -1 ) BASMATI c cd 0.89 d IRRI a a 6.53 a BASMATI SUPER c d 0.36 e BASMATI c c 0.64 de DR c b 4.92 c KSK b b 5.38 b The results of present study revealed that coarse varieties were found less susceptible to yellow stem borer than fine varieties; as maximum infestation and less grain yield was found in all tested Basmati varieties. Minimum larval infestation, more grain yield and yield related parameters were found in coarse variety IRRI-6 followed by KSK-282 and DR-83. Our results are in line with that of Khan et al., (2003) who also stated that variety KSK-282 was resistant while Basmati-385 was susceptible to the attack of rice stem borer under the agro ecological conditions of Dera Ismail Khan. Abdullah et al., (1996) found more unfilled grains in fine variety Basmati-283 followed by IRRI-6 and KSK-282. They further reported that varieties KSK-282 & IRRI-6 gave highest yield as compared to other fine varieties. Shafiq et al., (2000) reported that the coarse rice varieties IR8-151, IR6-20, B/94, IR and IR6-25 B/94 were comparatively resistant to borer attack and produced high yield/ha. CONCLUSION AND RECOMMENDATIONS Akram et al., (1994) observed that Pakhal was a resistant variety of rice to stem borer (Chilo suppressalis) and leaf folder (Cnaphalocrocis medinalis). According to them it provided 58.8% head rice recovery compared to 55.2% for JP-5. Gul Hassan et al., (1999) reported that cultivar KS-282 was the tallest, produced highest number of tillers, panicles plant -1, spikelets penicle -1, 1000 grains weight and yield plot -1 compared to other tested cultivars. Khan et al., (2003) screened eight rice varieties JP-5, Swat-1, Swat-2, Dilrosh-97, Basmati-385, KS-282, Gomal-6 and Gomal-7 for their resistance against rice stem borer. None of the tested varieties was free from the attack of rice stem borer. However, variety KS-282 was found resistant as compared to other tested cultivars. The current investigation confirms that the coarse varieties of rice were comparatively highly resistant to the yellow stem borer s attack as compared to the fine varieties tested in our study. IRRI-6 and KSK-282 were found comparatively highly resistant to the yellow stem borer and eventually more yields were produced as compared to other tested varieties. Therefore, we recommend these two varieties to be cultivated at large acreage which may reduce pest infestation, stabilize ecosystem and eventually farmers will have benefits in achieving higher rice yields.

4 Said Mir Khan et al. Screening of six rice varieties against the yellow stem borer 594 REFERENCES Abdullah, K. and G.S. Shah Effect of different sowing dates and rice cultivars on the incidence and damage by rice stem borers. Second Int. Cong. Entomol. Sci. pp Abro, G.H., G.M. Lakho and T.S. Syed Relative resistance of some rice cultivars to yellow, Scirpophaga incertulus and Pink, Sesamia inferens stem borers. Pakistan J. Zool., 35(2): Akram, M., M. Ashraf, F.M. Abbasi and M.A. Sagar Pakhal: a high yielding, short duration rice variety for Hazara division in Pakistan. Int. Rice Res. Notes. 19: 18. Anonymous, Agriculture Statistics of Pakistan, Govt. of Pakistan Ministry of Food Agric. and Live St. pp Atwal, A.S Agricultural pest of India and South East Asia, Kalayani publishers. Ludhiana, India. 153p. Bashir, K., H. Tayyab, F. Tahira, L. Zakia, S.A. Mehdi and R. Sheikh Field evaluation and risk assessment of transgenic indica basmati rice. Molecular Breed. 13 (4): Chaudhary, R.C., G.S. Khush and E.A. Heinrichs Varietal resistance to rice stem-borers in Asia. Insect Sci. Applic. 5: Food and Agric. Org. of the United Nations (FAO) The state of food security in the world. pp Hassan, G. M., Qureshi, N.H. Shah and I. Awan Performance of six rice cultivars under direct seeded condition of Dera Ismail Khan. Pak. J. Biol. Sci. 2(4): Heinrichs, E.A Perspectives and directions for the continued development of insect resistant rice varieties. Agr. Ecosyst. Envir. 18: Huesing, J. and L. English The impact of Bt crops on the developing world. Agric. Biol. Forum. 7(1-2) Khan, M., A.U.R. Saljoqi, A. Latif and K. Abdullah Evaluation of some rice varieties against rice stem borer. Asian J. Plant. Sci. 2(6): Kiritani, K Strategy in integrated control of rice pests. Rev. Plant Prot. Res. 5: Kiritani, K Recent progress in the pest management of rice in Japan. JARQ. 11: Kiritani, K Pest management in rice. Ann. Rev. Ent. 24: Loevinsohn, M.E., J.A. Litsinger and E.A. Heinrichs The Entomology of indigenous and naturalized systems in Agriculture. Rice insect pests and agricultural change. Westview Press, Boulder, CO. In: M. K. Harris & C. E. Rogers (eds.). pp Rehman, A., E.U. Haq and C. Inayatullah Impact of tillage practices and cropping system on the survival of over wintering rice stem borer larvae. Pak. J. Agric. Res. 17(2): Salim, M. and R. Masih Efficacy of insecticides against rice stem borer at NARC, Islamabad. Pak. J. Agric. Res. 8(4): Shafique, M., M. Ashraf, M. Bux and M. Tofique Screening of rice genotypes for resistance to stem borers. Pak. J. Zool. 32(2) Sheikh, M.A. and H.A. Kanasro Production, consumption and export of rice. Press release the daily Dawn. http//dawn.com, March 10.

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