Enhancing productivity of late sown wheat with hydro-priming

A field trial was carried out to investigate the effect of seed priming on the productivity of late sown wheat during fall-2016. The experiment was laid out in randomized complete block design (RCBD) with split-plot arrangement having three replications. Two factors (sowing dates and priming) were tested in the experiment. Sowing dates (29 Oct, 10 Nov, 24 Nov, 10 Dec, 26 Dec and 10 Jan) were assigned to main plots, while priming (non-primed and primed) was allotted to sub-plots. Wheat variety “SIRAN-2010” was sown in a plot size of 1.8m x 5m. Results showed that wheat crop sown on 29 Oct resulted in early emergence (6 days), increased emergence m (139) plant height (101.61cm), spikes m (280), grains spike (46.63), thousand grain weight (44g), biological yield (9770 kg ha) and grain yield (4038 kg ha). Late sown wheat in (10 Jan) took lesser days (136) to maturity. In case of seed priming early emergence (11 days), more emergence m (102), taller plants (85.19cm), more spikes m 2 (216), higher grains spike (40.18), maximum 1000-grains weight (37g), maximum grain yield (3116 kg ha) and maximum biological yield (7630 kg ha) was recorded in plots sown with hydro-primed seed. However, dry sown seed took more days (163) to emergence. Hence it is concluded that sowing from 29 Oct to 10 Nov significantly increased yield and yield related components of wheat. Similarly seed priming is necessary for higher yield of late sown wheat.


Introduction
Wheat (Triticum aestivum L.) is an annual self-pollinated, long day cereal crop.It is a staple food and high value crop containing approximately 11-15% protein, 60-70% carbohydrates and traces of minerals [1].In Pakistan, wheat is grown on 68% of the total cropped area and is the major food item that fulfills 95% of the food requirements of the whole country [2].It is mostly grown in the northern hemisphere; North America, Europe, China and Russia, which account for more than 80% of the world wheat supply [3].The per capita wheat consumption is 125 kg year -1 , which is among the highest in the world.In Pakistan, area under wheat cultivation was 8.64 million hectares and production was 23.47 million tones with an average yield of 2714 kg ha -1 .In Khyber Pakhtunkhwa total area under wheat cultivation was 0.729 million hectares while its production was 1.13 million tones and average yield was 1550 kg ha -1 [4].
Sowing date is one of the important factors which directly affect growth and grain yield of wheat.Flowering, maturity, seed filling duration, seed weight and grains spike -1 are significantly affected by time of sowing.Too early sowing may utilize soil moisture accumulated in the fall.However, medium season seeding of winter wheat for any locality is usually favorable [5].Grain yield declined with delaying sowing with a loss of 200-250 kg grain ha

Materials and methods
The effect of hydro-priming on late sown wheat was tested at the Agronomy Research Farm, The University of Agriculture Peshawar-Pakistan during fall 2016-17.Two factorial experiment (sowing dates and seed priming with water) was carried out in a randomized complete block design (RCBD) with split-plot arrangement.Sowing dates (29 th October, 10 th November, 24 th November, 10 th December, 26 th December and 10 th January) were allotted to main plots, whereas seed priming (dry seed and water soaked seed) were allotted to sub plots.A sub plot of size 5m x 1.8m (with 6 rows 30cm apart) was used.Seed of wheat variety "SIRAN -2010" were soaked in water for six hours at room temperature and sown @150 kg ha -1 .All other agronomic practices were uniformly maintained for all the experimental units.Data ware recorded on days to emergence, emergence m -2 , plant height, days to physiological maturity, spikes m -2 , grains spike -1 , 1000-grains weight, biological yield and grain yield following the desirable standard procedure.Method applicable to the randomized complete block design (split-plot arrangement) was used for statistical analysis of the recorded data.For mean comparison in case of significant difference least significant difference (LSD) test at 5% level of significance was used [15].

Days to emergence
Sowing dates and seed priming significantly affected days to emergence of wheat (Table 1).More days to emergence (16 days) were taken by late sown pltant (10 th January), while wheat crop sown on 29 th October took lesser days to emergence (6 days).Increase in days to emergence with delay in sowing may be due to drop in temperature.Seed priming also showed a significant effect on days to emergence of wheat.More days to emergence (12 days) were taken by dry sown seeds (non-primed) as compared to seed primed with water which took less days (11).Similar results were also reported by [16] who found early emergence of wheat seed primed with distilled water and saturated gunny bags.Emergence m -2 Table 1 showed that sowing dates and seed priming significantly affected emergence m -2 of wheat.Interaction between sowing dates and hydro priming was found nonsignificant.Maximum emergence m -2 (139) was observed in plots sown on 10 th November, while late sowing (10 th January) gave minimum emergence m -2 (20).These results are in conformity with [17] who stated that different sowing dates had significant effect on germination.Delayed sowing for all varieties of wheat had negative effect on emergence per unit area [18].In case of seed priming, less emergence m -2 (94) was recorded in plots sown with non-primed seed, while more emergence m -2 (102) was recorded in plots sown with hydro-primed seed.The enhanced emergence in primed seed improved the stand of wheat crop, emergence m -2 and accelerated the chemical reactions in seed which are essential for emergence of seed [19].Plant height (cm) Plant height considerably varied by sowing dates and seed priming while their interaction was found non-significant (Table 1).Plant height significantly decreased (49.50 cm) in delayed sowing (10 th Jan), whereas taller plants (101.61cm) were observed in plot sown on 29 th October.These results are in agreement with [20] who stated that plant height decreased significantly as planting was delayed from mid-November to December.Taller plants (85.19 cm) were recorded by hydropriming, while non-primed seed produced dwarf plants (83.20 cm).Similar results were reported [21] who found taller plants in plots having seeds treated with phosphorous solution.Days to physiological maturity A significant effect of sowing dates on days to physiological maturity of wheat is presented in (Table 2).Seed priming and the interaction between sowing dates and priming was found non-significant.Delayed maturity (187 days) was observed in plots sown on 29 th October, while early maturity (133 days) was noticed in plots sown on 10 th January.Delaying sowing plants had less vegetative period due to long day nature of wheat crop and enter into reproductive stage earlier and thereby took fewer days to maturity.The results are in agreement with findings of [22], who reported that delay in sowing hastened physiological maturity.who stated that seed priming increased grains weight and biomass.
Grain yield (kg ha -1 ) A significant variation in grain yield of wheat was observed with different sowing dates and seed hydro-priming, while their interaction was found non-significant (Table 3).Early sown plants (29 th October) produced maximum grain yield (4038 kg ha -1 ), whereas minimum grain yield (1065 kg ha -1 ) was recorded in plots sown late (10 th January).A significant decrease in grain yield was also found by [28].
Likewise water soaked seed gave maximum grain yield (3116 kg ha -1 ) than that of dry sown seed which produced minimum yield (2779 kg ha -1 ).Our results are in conformity with the investigation of [29] who found significant increase in grain yield of wheat when seed was primed different agents (PEG, Na2SO4, KNO3 and hydro-priming).Biological yield (kg ha -1 ) Sowing dates and seed priming significantly affected biological yield of wheat (Table 3).Higher biological yield (9770 kg ha -1 ) was recorded in plots sown on 29 th October, while lower biological yield (3200 kg ha -1 ) was produced by the plots sown on 10 th January.
In case seed priming minimum biological yield (6983 kg ha -1 ) was obtained from dry seed (non-primed), whereas water primed seed gave maximum biological yield (7630 kg ha -1 ).Similar results were noticed by [28], who observed significant increase in biological yield by seed priming.

Table 1 . Days to emergence, emergence m -2 and plant height of wheat as affected by sowing dates and priming
Means with different letters differ significantly according to Least Significant Difference (LSD) test (P<0.05).NS stands for non-significant difference

Table 3 . Thousand grain weight, grain yield and biological yield of wheat as affected by sowing dates and priming
with different letters differ significantly according to Least Significant Difference (LSD) test (P<0.05).NS stands for non-significant differenceConclusionIt is concluded from the results that optimum sowing date (29 th Oct to 10 th Nov) significantly increased yield and yield related components of wheat.Similarly seed priming with water for at least six hours enhanced growth and yield of late sown wheat. Means