Research Article
Effect of Foliar vs. Broadcast Application of Different Doses of Nitrogen on Wheat
Not Available
Jehan Bakht
Not Available
Muhammad Shafi
Not Available
Wajid Ali shah
Not Available
Population of the world in general and Pakistan in particular is increasing very fast. The primary challenge of this century is to meet the urgent need for food and fiber. Wheat plays an important role in Pakistans economy but its grain yield per hectare is much less than that of the other countries of the world. Continuous cropping without the application of nutrient elements (plant food) not only decreases soil fertility but also causes sustainable decrease in crop yield. Supply of plant food especially nitrogen through fertilizer application is one of the best methods to increase the yield. Due to high importance of fertilizer and the initial role of nitrogen, the present study was conducted to compare soil versus foliar application of various levels of nitrogen in wheat.
Various factors are responsible for better crop harvest, among which use of nitrogenous fertilizers (Lathwal et al., 1992). Campbell et al. (1977) reported that both root and shoot growth are reduced when nitrogen becomes limited. Need for balanced fertilizer in achieving true potential from varieties evolved for cultivation was emphasized by Raced and Salim (1992). Chandra et al. (1992) reported that Varieties, respond to their genetic makeup and physiological life process. Foliar application of nitrogen results in increased grain protein content and bread making quality of wheat when applied at or after anthesis (Gooding and Davies, 1992). Kettlewell and Juggins (1992) reported that leaf scorch from foliar nitrogen can be controlled by adjusting the number of spray applied. Mean grain yield of wheat increased with increasing nitrogen level. (Awasti and Bham, 1994). Rajput et al. (1995) concluded that foliar application in 3 split increased days to heading, maturity, grain and biological yield and gain highest return. Christianson and Lamoth (1995) reported that high rates of nitrogen applied early in growing season stimulated tillering but many of these did not produce spikes. Rimar et al. (1996) reported increase in yield when nitrogen was applied in liquid form.
An experiment was conducted to study the effect of foliar versus soil application of various doses of nitrogen on the yield and yield components of wheat at Malakandher Research Farms, NWFP Agricultural University, Peshawar during 1999-2000. The experiment was laid out in Randomized Complete Block (RCB) design with split plot arrangements, having four replications. The various levels of nitrogen (0, 100, 120, 140 Kg ha-1) were applied either as soil or foliar application at three different growth stages (3 weeks after sowing, heading and grain formation stage). Wheat variety Bakhtawar- 92 was used in the experiment using standard agronomic practices. For foliar application volume of water was doubled than required for sole spray of water. Data was collected on Days to emergence, days to maturity, days to heading, number of productive tillers m-1, number of non productive tillers m-1, spike length (cm), plant height (cm), number of grains spike-1, 1000-grain weight (g), grain yield (Kg ha-1), biological yield (Kg ha-1) and harvest index(%).
Days to emergence was recorded when more than 80 % plants emerged in each subplot. Days to heading data was collected from the date of sowing till when 80 % heads were emerged in each subplot and was then averaged. Days to maturity data was recorded from the date of sowing till when all the plants get matured in each subplot. To note number of productive tillers m-1 data were counted in an area of one square meter in each subplot, the number of productive tillers m-1. Data on non productive tillers m-1 was recorded as described for productive tillers m-1. To collect data on spike length, length of five spikes were randomly taken from each subplot and then their length was measured. To record data on grains spike-1, five spikes randomly selected were taken from each subplot, threshed and then number of grains were counted and averaged. From each subplot, 1000-grains were randomly counted and were then averaged to record 1000-grain weight. Grain yield, biological yield and harvest index in each subplot was determined.
The data collected during the experiment was analyzed according to RCB design and upon obtaining significant differences Least Significant Differences (LSD) test was applied (Steel and Torrie, 1980).
Statistical analysis of the data revealed that days to emergence were non significantly affected by different levels of nitrogen and their modes of application (Table 1). However, maximum days to emergence were recorded when nitrogen was applied as broadcast. When different rates of nitrogen were applied as foliar spray, maximum days to emergence were taken by those plots which received nitrogen at the rate of 100 Kg ha-1. While minimum days to emergence were recorded in plots treated with 120 or 140 Kg ha-1 (foliar).
Table 1: | Days to emergence, plant height, days to heading and days to maturity as affected by different doses of nitrogen on wheat |
Mean in the columns followed by different letters are significantly different at P<0.05 |
Table 2: | Number of productive tillers-1, number of non productive tillers-1, spike length and grains spike-1 as affected by different doses of nitrogen on wheat |
Mean in the columns followed by different letters are significantly different at P<0.05 |
Table 3: | 1000-grain weight, grain yield, biological yield and harvest index as affected by different doses of nitrogen on wheat |
In case of broadcast application, days to emergence were maximum when N was applied either at lowest or highest rates (i.e., 0 or 140 Kg ha-1). Days to maturity were significantly (P≤ 0.05) affected by nitrogen levels and their modes of application (Table 1). Mean value of the data showed that maximum days to maturity were taken when nitrogen was applied as foliar spray, while minimum days to maturity were observed in case of broadcast. It can be inferred from different levels of fertilizers applied either as foliar or broadcast that maximum (172.00) days to maturity were taken by those plots which received nitrogen at the rate of 140 Kg ha-1 (foliar). While control plots in broadcast or foliar application recorded minimum days to maturity. These results agree with those reported by Rajput et al. (1995). Analysis of the data indicated that days to heading were significantly (P≤0.05) affected by different nitrogen levels and their modes of application. It can be seen from the mean values of the data that maximum (129.44 ) days to heading were recorded when nitrogen was applied as foliar spray while minimum (128.00) days to heading were noted in case of broadcast application. Plots treated with 140 Kg ha-1 as foliar spray took maximum (132.50) days to heading. While minimum (125.25) days to heading were recorded in plots treated with 0 Kg ha-1(broadcast). Nitrogen accelerates vegetative growth and due to greater vegetative growth, days to heading are delayed. Similar results are also reported by Rajput et al. (1995). Statistical analysis of the data showed that number of productive tillers m-1 were significantly (P≤ 0.05) affected by different nitrogen levels and their modes of application as presented in Table 2. Mean values of the data revealed that maximum (316.94) productive tillers m-1 were produced by those plots which were treated with nitrogen as foliar spray while minimum of 304.38 productive tillers m-1 were produced when nitrogen was applied as broadcast method. It is clear from the data that maximum of 368.25 productive tillers m-1 were produced by those plots which received nitrogen at the rate of 140 Kg ha-1 (foliar), while minimum (234.25) productive tillers m-1 were recorded in control plots (broadcast). Shah and Saeed (1989) reported that productive tillers m-1 increased significantly in response to increasing foliar application of nitrogen. Number of non productive tillers m-1 were significantly (P≤0.05) affected by different nitrogen levels and their modes of application (Table 2). Data showed that maximum (14.44) non productive tillers m-1 were produced by those plots where nitrogen was applied as foliar spray, while minimum of 13.00 non productive tillers m-1 were produced when nitrogen was applied as broadcast. Similarly, control plots in case of foliar spray recorded maximum non productive tillers m-1 (31.50 ). While minimum non productive tillers m-1 were noted in those plots treated with 140 Kg ha-1 (foliar spray). Statistical analysis of the data also showed that spike length was significantly (P ≤ 0.05) affected by various nitrogen levels and their modes of application. Mean values of the data revealed that lengthy spikes were produced by those plots when nitrogen was applied as foliar, while shorter spikes were recorded when nitrogen was applied as broadcast (Table 2). It can be inferred from the data that maximum (12.50 cm) spike length was produced when plots were treated with 140 Kg ha-1 (foliar), while control plots in case of broadcast noted minimum spike length. Fillipov and Mangora (1992) reported that in winter wheat, spike length was increased by foliar application of N.
Grains spike-1 was significantly (P≤0.05) affected by various nitrogen levels and their methods of application (Table 2). Mean value of the data indicated that highest grains spike-1 was produced by those plots where nitrogen was applied as foliar spray. While lowest (44.87) grains spike-1 were observed when nitrogen was applied as broadcast. Plots treated with 100 Kg ha-1 recorded maximum grain spike-1. While minimum (38.75) grains spike-1 were produced by control plots (foliar). Sentlhas et al. (1987) reported that foliar application of N increased number of grains spike-1.
Fig. 1: | Net profit from different doses of Nitrogen and mode of application on wheat (kg ha-1) |
Statistical analysis of the data also showed that plant height was significantly (P≤0.05) affected by various nitrogen levels and their modes of application (Table 1). Taller (83.31 cm) plants were attained, when nitrogen was applied as foliar spray, while shorter (77.00 cm) plants were recorded by broadcast application of N. In case of different fertilizer rates, taller plants were attained by those plots, which received nitrogen at the rate of 140 Kg ha-1 either as foliar or broadcast method. While shorter plants were attained by control plots (0 Kg N ha-1). Statistical analysis of the data indicated that thousand grain weight was significantly (P≤0.05) affected by various nitrogen levels and their modes of application. Heavier (40.56 g) grains were recorded by those plots where nitrogen was applied as foliar spray (Table 3). In case of different fertilizer rates applied as foliar or broadcast, maximum (39.32 g ) 1000-grain was recorded by plots treated with 140 Kg ha-1, while minimum (29.69 g) 1000-grain weight was noted in control plots (foliar). Sentlhas et al. (1987) and Fillpov and Mangora (1992) reported that foliar application of N increased thousand grain weight. Analysis of the data indicated that different nitrogen levels and their methods of application had a significant (P≤0.05) effect on grain yield (Table 3). Mean value of the data revealed that maximum (2665.25 kg ha-1) grain yield was produced by those plots where nitrogen was applied as foliar. While minimum (2493.50 Kg ha-1) grain yield was produced where nitrogen was applied as broadcast. It can be seen from the data that maximum (3150.00 Kg ha-1) grain yield was produced by plots treated with 140 Kg ha-1 (foliar), while minimum (1660.00 Kg ha-1) grain yield was noted in control plots in case of broadcast. Shah and Saeed (1989) reported that grain yield of wheat increased significantly by foliar application of N. Fathi et al. (1990) and Szafranski (1995) reported that highest level of N applied in foliar form increased grain yield.
Statistical analysis of the data indicated that biological yield was significantly (P≤0.05) affected by various nitrogen levels and their modes of application (Table 3). Mean value of the data indicated that maximum (8306.00 Kg ha-1) biological yield was recorded by those plots, where nitrogen was applied as foliar spray compared to broadcast method. In case of different fertilizer rates applied either foliar maximum (10237.00 Kg ha-1) biological yield was produced by plots treated with 140 Kg ha-1 in case of foliar, while minimum (5272.00 Kg ha-1) biological yield were produced by control plots in case of broadcast. Similar results are also reported by Shah and Saeed (1989) and Fathi et al. (1990). Analysis of the data indicated that harvest index was non significantly affected by different nitrogen levels and their methods of application (Table 3). Mean values of the data revealed that maximum (32.52 %) harvest index was produced by those plots where nitrogen was applied as foliar spray. While nitrogen applied as broadcast recorded minimum harvest index . It is clear from the data that maximum of 34.84 % harvest index was recorded by plots treated with 100 Kg ha-1 (foliar) while minimum (30.12 %) harvest index was recorded by plots treated with 100 Kg ha-1 (broadcast ).
From the result presented in Fig. 1 it can be concluded that when N is applied at the rate of 140 Kg ha-1 as foliar spray had significant increased on all the yield components, thus resulted in an increased net income (26039 Rs.) when compared with other levels of nitrogen and broadcast method.