Akhtar et al., J. Anim. Plant Sci. 22(4):2012 1163 EFFECT OF LATE PLNTING ON EMERGENCE, TILLERING AND YIELD OF VARIOUS VARIETIES OF WHEAT M. Akhtar, N. Ahmad, M. Nasrullah, B. Ali, * A. R. Zahid and ** M. I. Shahid Agronomic Research Station, Bahawalpur * Agricultural Research Station, Bahawalpur ** Regional Agriculture Research Institute, Bahawalpur Corresponding author’s e-mail: makhtar780@yahoo.com ABSTRACT A field experiment was conducted to evaluate the effect of late planting on yield of different varieties of wheat, in agro ecological conditions of Bahawalpur zone. The study included four sowing times starting from 1 st December to 16 th January during the year 2007-08 with an equal interval of fifteen days. Four wheat varieties viz. Inqlab-91, Punjab-96, MH-97 and Bhakkar-2002 were included in the experiment. The experiment was laid out in randomized complete block design with Split Plot arrangement having four replications, keeping sowing dates in main plots and wheat varieties in sub plots. The plot size was 2.4m x 8 m. The data were analyzed statistically using computer statistical program MSTATC. Analysis of variance was applied to test the overall significance of the data. Tukey’s honestly least difference test at 5% probability level was used to compare the differences among treatment means. Sowing dates and varieties both significantly affected the germination, tillering and grain yield. Among time of sowing, 1 st December sowing gave significantly maximum mean grain yield of 4412 kg ha -1 against the minimum mean grain yield of 2197 kg ha -1 for 16 th January sowing. Among wheat varieties Bhakkar-2002 gave significantly maximum mean grain yield of 3445 kg ha -1 , whereas MH-97 was the lowest yielder 3185 kg ha -1 . Emergence impaired due to delayed sowing owing to low temperature for germination, resulting in poor stand establishment and reduced the number of productive tillers and ultimately the final grain yield. Key words: Time of sowing, wheat varieties, germination, tillering and grain yield. INTRODUCTION Wheat (Triticum aestivum L.) is the most important cereal crop in the world. In Pakistan 70-80% wheat is planted after 25 th November as most of the wheat area comes after cotton, rice and sugarcane, which is late planting. Temperatures below or above normal alter plant functions and productivity. In late planted wheat, low temperature prevailing during germination substantially affects the germination and seedling emergence. Germination is a critical process and temperature below 12°C results in poor and uneven emergence (Timmermans et al., 2007). Therefore, the rate of emergence and final emergence percentage are important factors in determining the crop potential in various temperature of wheat production cropping systems. In late planting season, temperature of soil may be below 10°C, which affects the seed germination and stand establishment. Poor crop establishment results in few tillers and finally decreased grain yield (Farooq et al., 2008). Sowing times (Dec. 1, 15 and 30) and varieties of wheat both significantly affected the number of fertile tillers. Maximum grain yield (4289.54 kg ha -1 ) was obtained when crop was sown on 1 st December against the minimum grain yield (2109.50 kg ha -1 ) in case of late sowing i.e. 30 th December. Among the varieties, Inqlab- 91 gave significantly maximum grain yield (3550.44 kg ha -1 ) while minimum yield (2932.59 kg ha -1 ) was obtained by AS-2002 (Tahir et al., 2009). Late sowing of wheat significantly decreased the germination percentage (Hussain, 2007). Sowing of wheat after 15 th November decreased the number of fertile tillers and grain yield significantly (Akhtar et al., 2002 and 2006). Maximum number of tillers m- 2 and grain yield were recorded when wheat was sown on 30 th November where as minimum tillers m- 2 and grain yield were recorded on 15 th December (Malik et al., 2009b). Wheat variety Shafaq-2006 exhibited the highest germination count m -2 (131.55) while Bhakkar-2002 exhibited the highest number of tillers m- 2 (370.11) and grain yield (39.58 q ha- 1 ) (Malik et al., 2009a). Among different planting time maximum grain yield of wheat (5600 kg ha -1 ) was recorded from 10 th November sowing while minimum grain yield 4256 kg ha -1 was recorded from 25 December sowing in Dera Ismail Khan zone (Baloch et al., 2010). It has been observed that early sowing of wheat gave high grain yield than late sowing due to longer growing period (Tanveer et al., 2003). Keeping in view all these, this study was conducted to find out the effects of late sowing on germination, tillering and grain yield of wheat crop. The Journal of Animal & Plant Sciences, 22(4): 2012, Page: 1163-1166 ISSN: 1018-7081