Genomics and Applied Biology 2016, Vol.7, No.1, 1-9
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decreased with test cultivar with later transplanting dates.
The average reduction in panicle length was found from early to delayed transplanted crop was 5.92% from 2011
to 2014. Highest reduction (8.79%) was obtained in 2011 and lowest (2.73%) in 2013. Similarly, mean difference
in panicle length were 2.5 cm, 1.7 cm, 0.7 cm and 1.5 cm from 2011 to 2014 respectively (Figure 4). Reduction in
panicle length in delayed transplanting from the early one may be due to lack of full photosynthesis during its
growing period, inability of roots to absorb minerals from soil. This result reveals the findings of Hussain et al
(2005) and Shah (2001) who reported that maximum number of panicle was produced by line transplanted method
in early transplanting. This might be due to adaptation with climate, well adopted root system and well adopted
leaf structure and canopy having optimum light absorption, nutrients uptake and synthesis of more carbohydrates.
Average increase in fertile grain number per plant was 21.51% from delayed to early transplanting from 2011 to
2014. Maximum increase was 46.2% in 2012 but there was decrease in fertile grain number by 6.6% from early to
delayed transplanting in 2013. The difference in fertile grain number was 14, 67, -8 and 53 from 2011 to 2014
respectively (Figure 4). These results resembles to the findings of Akram et al. (2007) and Kameswara and
Jackson (1997) who reported that number of kernels per panicle were significantly affected as sowing date is
delayed. Awan et al. (2011) also reported that reasons for low yield and less grain number are use of imbalance
inputs at improper time, transplanting of aged rice nursery and imbalanced use of fertilizer etc. However these
results are contrary to that of Habibullah et al. (2007) who reported that sowing date had no significant effect on
number of grains per panicle.
There was 2452.45 kg (38.44%) decrease in mean grain yield from early to delayed transplanting from 2011 to
2014. Maximum decrease in yield was 63.41% in 2014 and minimum was 4.22 in 2013. The mean grain yield
difference were 1375.2 kg (23.45%), 3149.6 kg (62.65%), 1043.11 kg (4.2%) and 4241.9 kg (63.45) from 2011 to
2014 respectively (Figure 3). These results supports the findings of Hwang et al (1998) who reported that paddy
yields deteriorated as planting date was delayed. Shah (2005) also reported that June 15 seeding recorded
significantly the highest paddy yield and decreased with the delay in planting time. In the same way, Iqbal et al
(2008) reported that the highest yield was obtained when the rice crop was sown earlier in the season. Similarly,
according to Baloch et al. (2006) among planting dates, June 20
th
planted crop gave highest paddy yield. Somato
et al. (1961) concluded that early transplanting of seedlings resulted in higher yield of grain than late transplanting.
This concept is further supported by Khan and Baloch (1970) and Pirzada et al. (1962) who revealed that sowing
of nursery in the month of April and transplanting in June produced the highest yields which reveals the results of
Bali and Uppal (1995) who concluded that rice crop transplanted on 10
th
July gave 9.4 to 17.9 % higher grain
yield than 30
th
July transplanting due to higher root density, NPK uptake and head rice recovery. Khakwani et al.
(2006) also suggested that highest paddy yields are obtained in early transplanting. The reason could be that this
might be due genotype genetic superiority, appropriate temperature for growth and development, nutrients
absorption, proper root system of the genotype and proper time of transplanting which leads to provide optimum
duration for seed filling.
5 Conclusion
On an average 38.44% decrease in yield was found from early to delayed transplanted rice from 2011 to 2014.
Comparison of different parameters of rice from 2011 to 2014 showed that late transplanted aged rice seedlings
had always lower yield than early transplanted rice which might be due to aged seedlings, improper root growth
and development causing less absorption of nutrients from soil, shorter duration of photosynthesis during grain
filling period and cold during grain maturation time. So this might be the possible reason to have high yields in
earlier transplanting. Climate change and irratic rainfall pattern has pushed away the planting time of rice. Labor
scarcity and delay in monsoon also causes delay in transplanting. Thus farmer’s field have lower yield because of
delayed transplanting of aged rice seedlings. The yield reduction of farmer’s field can be minimised by
transplanting rice in appropriate time with recommended package of practices.
