Testing and evaluation of planting methods on wheat grain yield and yield contributing parameters in irrigated agro-ecosystem of western Uttar Pradesh, India

1 Department of Agronomy, Sardar Vallabhbhai Patel University of Agricultuere and Technology, Meerut (U. P.), India. 2 Department of Pathology and Microbiology, Sardar Vallabhbhai Patel University of Agricultuere and Technology, Meerut (U. P.), India. 3 Department of Soil Science, Sardar Vallabhbhai Patel University of Agricultuere and Technology, Meerut (U. P.), India. 4 Department of Agronomy, Punjab Agricultural University, Ludhiana Punjab, India.


INTRODUCTION
Wheat (Triticum spp.) is one of the most important cereal crops in the world. It is grown across a wide range of environments around the world and has the highest adaptation among all the crop species. Worldwide more land is devoted to the production of wheat than any other crop. It is the main staple food of nearly 35% of the world population than any other food source. It is the only crop so far reported to produce more than 500 million tonnes of yield in a single year. Wheat is a rich source of protein, minerals, and vitamins amongst all the cereals. It *Corresponding author. E-mail: r.knaresh@yahoo.com contributes about 60% of daily protein requirement and more calories to world human diet than any other food crops (Mattean et al., 1970). In India wheat is the second most important food crop next to rice and it contributes nearly 35% to the national food basket. Among winter crops, it contributes about 49% of the food grains. During the crop year 2003 to 2004 the area under wheat was 26.58 000 000 ha with a production of 72.10 million tonnes, average productivity being 2710 kg/ha (Anon, 2005).
The assessment on the scientific, technical, and institutional issues associated with wheat crop is urgently needed. For the past 40 years, the growth in the productivity of wheat crop was the result of technological innovations in the form of green revolution. With the result, supply exceeded demand and real prices of food such as cereals went down. However, the yield growth rate of many crops especially cereals have started declining. Reasons for declining in the productivity growth rate are multiple (Duxbury et al., 2000).
Sustainability and profitability of wheat crop system in Indian agriculture is the lifeline and future of Indian economy with more than 60% people living in rural areas. The challenges are enormous ranging from conservation of natural resources to investment in new technologies based on biotechnology. Increasing food production of the country in the next 20 years to much population growth is a big challenge in India. It is more difficult because, land area devoted to agriculture will stagnate or decline and better quality of land and water resources will be divided to the other sector of national economy. In order to grow more food from marginal and good quality lands, the quality of natural resources like seed, water, varieties, and fuel must be improved and sustained.
On the other hand, establishment of optimum plant density, culture methods are important factors for securing good yield of crop, particularly in wheat. Variety plays an important role in producing high yield of wheat because different varieties responded differently for the genotypic characters, input requirement, growth process and the prevailing environment during growing season . Narrow row culture in wheat is supposed to be one of the most effective techniques of pre-serving resource base and has manifold advantages. It is the new concept in western Uttar Pradesh irrigated areas. This technique in wheat cultivation helps in saving moisture, reduces water requirement, increases yield, reduces lodging, increase sourse-sink relationship, allows better surface, basal and top dress, fertilizer placement and promotes rain water conservation.
The green revolution is one of the most striking success stories of post-independence India. The success was reflected through more efficient dry matter partitioning to reproduction and therefore, higher harvesting index with significant gain in the yield potential. It is the combination of green revolution varieties and their responses to external inputs, which produced meaningful advances in agricultural productivity. More than 90% farmers have adopted semidwarf wheat by 1997 (Pingali, 1999). It is not easy to escape a general relationship between grain productivity and fertilizer nitrogen especially after the evolution of semi-dwarf varieties. It is estimated that, irrigated lands have expanded to reach 268 m ha with 80% in developing countries and much in Asia. This expansion is now slowing down (FAO, 1998). In addition to nitrogen fertilizers and expansion of irrigation, there has been a consistent increase in the use of external inputs including pesticides.
Thanks to green revolution, the higher food availability without using the extra land represents a success story in agriculture. These were not varieties alone which transformed the food production scenario, but the response of these varieties to external inputs brought about a major change in the food production. The gross consumption of fertilizers increased 25 fold in developing countries to reach 91 mt in 2002, but only increased 2 fold in developed countries. The use and rates in the developing countries surpassed that in the developed countries in the early 1990s (Cassman et al., 2003). The green revolution has slowed down sharply, as has yield growth, since the 1980s. The slow down or even reversal has been due to water table lowering because of ever deeper tube wells, micronutrient depletion, monoculture, reducing biodiversity and buildup of insect, diseases and weeds, development of resistance against pesticides and high concentration of pesticides or fertilizer-derived nitrates and nitrites in water courses.
The amelioration of above factors adds to the cost of cultivation and, therefore, a decline in the total factor productivity. With the rise in input cost, the net profit of farmers has fallen even if the productivity is increasing slightly. Each farmer, therefore, needs to maximize earnings through alternate technologies. Seen from profitability point of view, it will be important to maintain natural resources. Resources Conservation that is, narrow row spacing, therefore, have become a critical component to growth in agriculture. Carver (2005) investigated the impact of different crop establishment methods, that is, conventional drilling, precision drilling and broadcasting in winter wheat. Broad-casting method produced the most effective spatial arrangements. However, there was no consistent relationship between any of the spatial arrangement and subsequent yield performance. Singh et al. (2005) concluded from a field experiment in Uttar Pradesh, India, that in wheat, strip drilling resulted in higher growth and grain yield (5.67 t ha -1 ), followed by zero tillage drilling, conventional sowing and bed planting. The broadcast sowing generally gave lower yield than sowing in rows Krezel and Sobkowicz (1996). However, Ahuja et al. (1996) recorded 5.08 t ha -1 grain yield with broad-casting while 4.75 t ha -1 with sowing in 23 cm apart rows, where as Raj et al. (1992), Abbas et al. (2009) found that, row spacing (15, 22.5 or 30 cm) had no effect on grain yield in 1986 to 1987 but the yields were lower in the wider row spacing (30 cm) in 1985 1986. Parihar and Singh (1995) revealed that, cross sowing increased grain yield by 4.3% compared with the normal method of sowing (line sowing). Keeping in view of irrigated environments and number of plants per acre, the study was conducted to determine the role of planting methods on wheat grain yield and yield contributing parameters in irrigated areas.
Most of the prototypes developed by the manufacturers do not possess appropriate beam size. As a result, the 22.5 cm apart row planting in wheat cannot be adopted by the farmers. They are adopting only 20 cm apart row planting. New prototypes which are available for planting consist of 13 and 18 tines also. For experimental purposes these prototypes have been used for achieving 22.5 cm row planting. Gupta and Gill (2004) investigated that, among different crop establishment methods, that is, conventional drilling, paired row planting, controlled traffic and zero till planting in winter wheat. Paired row planting resulted in 8 to 10% higher yield as compared to conventional drilling. Sharma et al. (2008) revealed that, conservation tillage practice is attractive source to farmers because the potential of reduction of production costs compared to conventional method of sowing. Botta et al. (2006), Kahloon et al. (2012) reported that, maximum increase in fuel consumption reduced the economic benefit of the farmers, so that tillage equipments are used in sowing of wheat. In case of zero tillage technique there is no need of soil preparation, it operates on fellow land at watter condition.
This paper presents results of planting methods onfarm experiment and observations from wheat grain yield and yield contributing parameters in irrigated agroecosystem of western Uttar Prades, India. The water table depth of the experimental sites is 23 m with very good quality of water. The climate of the area is semiarid, with an average annual rainfall of 765 mm (75 to 80% of which is received during July to September), minimum temperature of below 4°C in January, maximum temperature of 41 to 45°C in May to June, and relative humidity of 67 to 83% throughout the year. The experimental soil (0 to 15 cm) was sandy loam in texture, with a bulk density of 1.48 Mg m -3 , weighted mean diameter of soil aggregates 0.74 mm, pH = 7.9, total C = 8.3 g kg -1 , total N = 0.83 g kg -1 , Olsen P = 28 mg kg -1 , and K = 128 mg kg -1 .

Two
The

Fertilizer application
Recommended dose of NPK was applied according to treatments as urea, triple supper phosphate, and sulphate of potash, respectively. One third of urea and all other fertilizers were broadcasted and incorporated into the soil at the time of final land preparation. The remaining urea was top dressed in two equal splits. The first split was applied at crown root initiation stage (21 days after sowing) and 2 nd at maximum tillering stage followed by irrigation.

Weed management
The crop was maintained with weed free using following practices. Grassy weeds were controlled by spraying of sulfosulfuron at 35 g a.i. ha -1 at 30-45 DAS, and broad leaf weeds using 2, 4-D at 500 g a.i. ha -1 at 35 DAS.

Water application and measurements
Irrigation water was applied using polyvinyl chloride pipes of 15 cm diameter and the amount of water applied to each plot was measured using a water meter (Dasmesh Co., India).The quantity of water applied and the depth of irrigation were computed using the following equations: Quantity of water applied (L) = F × t Depth of water applied (mm) = L /A /1000 where F is flow rate (l s -1 ), t is time (s) taken during each irrigation and A is area of the plot (m 2 ). Rainfall data were recorded using a rain gauge installed within the meteorological station. The total amount of water (input water) applied was computed as the sum of water received through irrigation and rainfall (I+R). Water productivity (WPI+R) (kg grains m -3 of water) was computed as . However, statistically low germination was produced when crop was sown in T 6 22.5 cm spaced rows. During 2009 to 2010 and 2010 to 2011, T 2 that is, 15 cm planting method or spacing influenced germination significantly. Treatments T 3, T 4 , and T 6 were at par during the years. The mean of three years results showed that, statistically similar germination was recorded in (T 2 andT 3 ) 15, 17.5 cm apart planting method, however, T 3 17.5 cm, T 4 20 cm was also at par with planting in T 6 15:25 cm paired rows. Wheat planting at T 5 22.5 cm apart rows produced minimum germination per unit area. Hence, it can be concluded from the results that, in western U.P. area, germination were similar for (T 3 and T 4 ), 17.5 and 20 cm apart rows the planting methods. It might be attributed to the sandy loam soil and optimum soil moisture conditions, which played major role in germination of wheat crop.

Tillers (m 2 )
Neither planting methods that is neither broadcast nor drill planting nor row spacing of (15, 17.5, 20, 22.5 and 15:25 cm) influenced tillering in wheat during first year of the experiment. Moreover, the tillers during 2009 to 2010 and 2010 to 2011 the years individually or average of the years showed poor tillering in T 6 22.5 cm apart rows and T 1 broad-casting method treatments under study. Less tillering can be attributed to the low fertility status and less water holding capacity of sandy loan soils of the area Table 1.

Plant height (cm)
The data presented in Table 1 depicted that, during the year 2008 t0 2009, the maximum plant height of 104.5 cm was produced when wheat was sown in T 6 15:25 cm paired spaced rows, however, broadcast (99.3 cm), T 2 ,15 cm (100.6) and T 5 22.5 cm spaced rows (98.4 cm) were also statistically at par. The minimum plant height of 98.4 cm was produced at T 5 22.5 cm row spacing. During next year that is, 2009 to 2010, row spacing of T 6 15:25 cm paired row, T 4 20 cm and T 3 17.5 cm produced significantly similar but taller plants (105.1, 104.7 and 102.8 cm), while row spacing of T 5 22.5 cm was also statistically at par with broadcasting method (99.8 cm). Almost same trend was observed in 2010 to 2011.The average of three years data expressed the similar trend as in the year (2008 to 2009). The less difference of plant height in the planting methods can be described to the appropriate plant population and inherent varietal character of wheat variety PBW-343.

Number of spikelet spike -1
It is evident from Table 2 that, maximum number of spikelets spike -1 were recorded in T 6 15:25 cm paired rows planting method of seed placement during the year 2009 to 2010 (14.85) as well as average over three years (15.4). In 2008 to 2009, planting at T 6 15:25 cm paired rows produced the maximum number of spikelets per spike (16.25), although it was statistically at par and closely followed by the T 4 20 cm apart rows planting method (15.37). More number of spikelets per spike in T 4 20 cm and T 6 15:25 cm row planting can be referred to the ideal plant population in the both treatments which resulted in less crop plant competition.

Number of grains spike -1
It is clear from the data shown in Table 2 that, the number of grains spike -1 were produced in T 6 15:25 cm paired rows planting method during 2008 to 2009, 2009 to 2010, 2010 to 2011 and pooled of the years (54.0, 56.6, 53.8, and 54.8 respectively). However, drill planting at T 4 20 cm produced statistically similar number of grains spike -1 during individual years (53.0, 55.5, and 52.6) and average over the years (53.7). The lowest numbers (42.7, 43.8, 44.2, and 43.6, respectively) were produced when planting was done in T 2 15 cm spaced rows during the individual year and average of the years as well (P < 0.05).

grain weight (g)
It is clear from the data presented in Table 2, that during the year 2008 to 2009, and 2009 to 2010, the maximum 1000 grain weight of 42.8 and 43.1 g was produced by T 6 15:25 cm paired row spacing method. The row spacing of T 3 17.5 cm and T 4 20 cm also remained statistically at par with the above-mentioned treatments with 1000grain weight. Planting at a distance of T 2 15 cm and T 1 broad-casting produced the lowest weight of 36.7, 36.1 and 36.3, 35.7 g. The average of three years results showed similar trend as in 2008 to 2009.

Grain yield (kg ha -1 )
The data presented in Table 3 for grain yield revealed that, during 2008 to 2009, the maximum grain yield of 4491 kg ha -1 was produced when wheat was sown at T 6 15:25 cm paired rows. The maximum grain yield producing treatment, however, was at par with T 3 17.5 cm and T 4 20 cm apart rows planting method of sowing with a grain yield of 4316 and 4463 kg ha -1 . Planting at T 2 15 cm apart rows and T 1 broad-casting method produced grain yield of 3970 and 4083 kg ha -1 , which were statistically lower than the abovementioned treatments, although at par with one another. During next year, that is, 2009 to 2010 and 2010 to 2011, T 6 15:25 cm paired rows planting method produced the maximum grain yield of 4635, 4760 kg ha -1 than all the method and treatments, which produced 4567, 4470, 4369, 4292, 3840, and 4714, 4682, 4432, 4367, 3725 kg ha -1 of grain yield, respectively. The trend of average data for three years was similar to that produced during the year 2010 to 2011 with T 6 15:25 cm paired rows planting method at the top (4629 Kg ha -1 ). The T 6 15:25 cm paired row spacing obtained 7 to 10% higher yield as compared to conventional method that is, T 1 broadcasting method of wheat planting. The maximum grain yield in T 6 15:25 cm paired row spacing method of sowing can be described to higher number of spikelet's spike -1 , number of Table 3. Grain and straw yield (Kg/ha) of wheat as influenced by methods of planting in wheat.
Straw yield (kg ha -1 ) Straw yield was significantly influenced by planting method. The highest straw yield (4698 kg ha -1 ) was obtained from T 6 15:25 cm paired rows planting method and the lowest straw yield (3920 kg ha -1 ) was obtained from T 2 15 cm row spaced planting method. These results are in the agreement with that of Rahman et al. (2010).

Input water use and water productivity
The input water use includes both irrigation water applied and the rain water that fell during the wheat season (81 mm), but not the pre-cultivation/sowing/planting irrigations. The total input water in wheat varied with planting method (Table 4) due to differences in irrigation amount. The T 1 broad-casting method consumed about 9% more water (437 mm) than T 4 20 cm apart rows planting method (394 mm) with conventional tillage, and 5% more water than with T 5 conventional planting distance (22.5 cm) method (413 mm). The higher irrigation water use in wheat with T 1 broadcasting method was due more ploughing and undulated fields. However, input water productivity of wheat on T 4 20 cm apart rows planting method was significantly higher than in all other treatments. There was also a consistent trend for higher wheat input water productivity with rows planting method as compared to T 1 broad-casting method.

Conclusions
Grain yield depends on production of photosynthates and their distribution among various plant parts. The synthesis, accumulation, and translocation of photosynthates depend upon efficient photosynthetic structure as well as the extent of translocation into sink (grains) and also on plant growth and development during early stages of crop growth. The production and translocation of synthesized photosynthates are directly or indirectly depend on agronomic practices that are followed for the culture of crop. Cropping geometry coupled with selection of variety play significant role in the performance of crop. The row spacing of 20 cm and 15:25 cm paired rows made grain yield of wheat to increase progressively. The effect on straw yield was similar. Wider row spacing intercepted significantly more light than the normal spacing. This increased productive tillers significantly, and grains per ear and grain weight slightly. This observation confirms the results of our experiment. This also supports the direct relationship between grain yield and solar radiation absorbed because in the wider spacing, light falling on the ground was better utilized for longer period.