Responses of maize to different levels and sources of phosphorus application

Improper phosphorus management is a major factor contributing to low yield. An experiment comprising four levels (90, 120, 150, and 180 kg ha) and three sources of phosphorus (SSP, DAP, NP) was designed with the purpose to identified the best phosphorus level and source to gain higher yield of maize. The experiment was conducted at agriculture research farm Plato of The University of Agriculture Amir Muhammad Khan Campus Mardan during summer 2016 by using RCBD design replicated three times. The result indicated that phosphorus sources and control vs. rest influenced significantly (P<0.05) on plant height (200.2cm), biological yield (12556.3 kgha), grain yield (3481kgha), thousand grain weight (231.7g), harvest index (32.2 %) while had no significant effects on grain rows ear(14.3). DAP (46% P) source increase number of ear plant(1.5), plant height (5.4m), biological yield (12556.3 kgha), grain yield (3481kgha), thousand grain weight (231.7g) and harvest index (32.2 %). It is concluded that the application DAP source produces maximum yield of maize crop.


Introduction
Maize (zea mays L.) ranked 2 nd on global scale after wheat in total production and categories third among the cereals.It was extensively grown on temperate, tropical and region of the world.Maize is an important crop because of its food and fodder value.Maize is one of the valuable crops in Khyber Pakhtunkhwa (KPK) province.It is used in many things as ingredient like bread making, corn, flakes, corn starch, corn syrup, paper making, and textile and food industries.The kernel contains 77% starch 2% sugar 9% protein and highly saturated fatty acid.On the total crop area and value of agriculture output about 4.8% and 3.5% accounts for maize respectively.Due to exhaustive property of maize it absorbs large quantity of nutrient from the soil as compare to other cereals.Phosphorus is one of the vital nutrients for high yield among the essential nutrients for high yield [1] and mainly controls plant growth parameters [2].Usually phosphorus is the succeeding essential and yield restraining nutrient after nitrogen.Phosphorus affects significantly plant growth including grain yield; whereas similar effect of phosphorus submission on physiological characters such as leaf area, plant height, leaves per plant, and on dry matter yield It is readily translocate within the plants, during the vegetative growth of the plant like formation of cells, roots developing, stem and leaves etc it move from older to younger tissues.Phosphorus applications stimulate blooming, seed formation and increased yield [3].The P deficiency is most common in the soil of Pakistan [4].Lake of phosphorus affects plant growth especially leaf growth, earlier and to a greater extent than photosynthesis per unit area [5].Many sources of P fertilizers are available on the market, and the three most popular fertilizers used by farmers are single superphosphate (SSP), NP, and DAP.Differences among these fertilizers include their solubility and nutrient concentrations.Increased fertilizer costs, new P enhancer products in market, and challenges of corn production prompted this investigation of ways to enhance the effectiveness of P fertilizer and to decide the best source and suitable level of P fertilizers for high maize yield.Therefore, it was imperative to study the effects of phosphorus on maize yield and its components.Keeping in view the important effect of phosphorus application, the present study was undertaken to evaluate the usefulness of P on yield.

Materials and methods
To study the effect of level and sources of phosphorus on yield of maize an experiment was conducted at Agricultural Research farm Palato, Amir Muhammad Khan Campus Mardan during the kharif season 2013.The experiment was lay out randomized complete block design (RCBD), with 3.75 m x 3 having row to row (R-R) distance of 0.75 m and plant to plant (P-P) distance of 0.25 m and the field was ploughed with one moldboard plough and rotarvator.Both Phosphorus levels and sources were studied.Maize variety Azam was sown and apply N at basel dose at crop knee height stage knee at the rate of 120kg/ha.Phosphorus sources SSP, DAP, and NP was incorporate before sowing with desire levels of phosphorus.

Statistical analysis
The recorded information were subjected to examination of difference strategy for the data recorded on each parameter was subjected to analysis of variance (ANOVA) practice appropriate for a RCBD through MSTATC PC program.By applying (LSD) test at 5% probability value as proposed by Steel and Torrie [6].

Results and discussion
Plant height (cm) Data regarding plant height given in the Table 1 indicated that in control vs. rest phosphorus had significant effect on plant height (cm) whereas non-significant influenced were showed by phosphorus level, sources and on their interaction.Long stature plants (200.2 cm) were recorded by in control plots whereas short stature (170 cm) of plants was found in rest plots.Phosphorus enhances the root development which greatly affects the general plant development execution; in this way the P in rest plots brought about the higher stature plants.Advancement impact of high P level on plant tallness was presumably due to increment in P application.Plant stature of maize expanded with increment in P application by Arain et al. [7].

Number of grain rows ear -1
Statistical analysis of the data shown in the Table 3 indicated that control vs. rest was found non-significant, followed by P-level, sources and their interaction.Maximum of (14.3) rows ear -1 was recorded from rest as compare to control with the minimum of (13.0) rows ear -1 .Presumably at the season of number of grain columns per ear development there was no opposition between physiological sink for-up of assets.Grain yield (kg ha -1 ) Grain yield data shown in Table 5. Statistical analysis showed that phosphorus levels and sources significantly influenced on grain yield of maize.The interaction was also found significant.Control vs. rest found significant.The source DAP revealed greater grain yield (3481kg ha -1 ),followed by NP (3360 kg ha -1 ) whereas lower grain yield (2831kg ha -1 ) was observed from SSP, similarly higher grain yield of (3324kg ha -1 ) was recorded in rest plots as compare to control (2184kg ha -1 ).The expansion in grain yield because of NP application was additionally revealed by Khan et al. [11], the grain yield of maize expanded with increment in P application [10].That is the reason the grain yield was the most minimal in the control plots since absence of P decayed the roots development of the plants which adversely influenced the other physiological elements of the maize plants in the control plots.Thousand grain weight (g) Statistical analysis of the data on1000 grain weight shown in Table 6 indicated that phosphorus sources significantly influenced on thousand grain weight (g).P-level and their interaction with sources was found non-significant.Control vs. rest found significant.Greater thousand grain weight (231.7 g) was reported from DAP ,followed by NP (200.8 g) whereas lower thousand grain weight (195 g) was recorded in SSP treatment, similarly higher thousand grain weight of (209.4 g) was recorded in rest plots as compare to control recorded (136.7 g).

Table 7 . Harvest index of maize as affected by level and sources of phosphorus
Khan MA, Abid M, Labar HN &  Masood MU (2005).Effect of phosphorous levels on growth and yield of maize (zea mays L.) cultivars under saline Conditions.Int J Agric and Bio 7(3): 511-514.