Effect of Nitrogenous Fertilizer on the Vegetative Growth and Yield Attribute of Pea (Pisum sativum L.)

An experiment was conducted to study the effect of chemical fertilizer on the pea growth and yield attributes. Therefore, the main objective of this study was to investigate the effect of chemical fertilizer alone and in combination. This study consists of three different nitrogen levels (90, 100 and 110 kg haas urea), three different levels of phosphorus (60, 70 and 80 P2O5 kg ha as DAP) and their combination. Treatments were arranged in a complete randomized block design with three replications. The results showed that both the single and combined application of nitrogen and phosphorus fertilizer increased the growth and yield attribute of the pea plant. Maximum number of primary (6.91) and secondary branches per plant (7.97), number of leaves per plant (12.50) and plant height (51.24 cm) was attained by the combine application of P80+N110. Similarly, the maximum increase in yield parameters such as pod length (7.5 cm), number of pods per plant (7.23), pod weight (12.50 g) and number of grains per pod was obtained in P80+N110. In general, combined application of fertilizers significantly increased all the growth and yield attribute of the pea plant when compared to fertilizers applied alone with respect to control.


Introduction
Pea (Pisum sativum L.) is an important edible fresh vegetable growing throughout the world in the winter season, but it can also be grown in the summer season in the hilly areas of the world. Pea is also a cheap and valuable vegetable that grown in Pakistan as compared to the other developed countries (Akhtar, 2003). It is considered an important legumes crop after soybean, groundnut and beans, legumes crop also play a vital role in organic forming by fixing the atmospheric Nitrogen (N) that help in the production of grain protein while also improving the soil N for the coming crop (Alam et al., 2010;Corre-Hellou & Crozat, 2005). In the world trade pea contributed about 40% of the total pluses and can occupy the third position among the legumes in Pakistan (Oram & Agcaoili, 1994;Aslam et al., Published by SCHOLINK INC. measured with the help of meter rod and number of leaves were count manually per plant. For pod length we select 50 pods per treatment and then the length was measured in centimetres and average was calculated. The number of pods were measured in each treatment on the middle row and average pods/plant were calculated. Pod weight were measured by selecting fifty pods in each treatment, measured and average were calculated. Number grains were calculating by taking fifty pods form each treatment and the number total seeds was recorded and average was calculated.

Statistical Analysis
For each parameter the data were individually analysed by using SPSS 20.0 package, through randomized complete block design. The means were compared by using Least Significant Difference (LSD) test at 5% level of probability (Steel & Torrie, 1980).

Results and Discussion
Data taken on different vegetative growth parameters indicated that pea crop treated with phosphorus and nitrogen significantly (P=0.05) affected in terms of its growth (Table 1). Treatments gave significant effect when compared to control. In case of primary branches, the maximum number (6.91) was achieved when combine treatment of P 80+N 110 was applied which was followed by statistically same but numerically lower value (6.43) in case of P70+N110 treatment. Generally, it was noticed that both nitrogen and phosphorus fertilizers gave non-significant effect when compared with their combine effect. The lowest number of branches (4.81) was found in control treatment having similar effect with phosphorus and nitrogen applied alone. The same results were reported by Achakzai (2012) that with the application of chemical fertilizer the primary branches of garden pea increased. Similarly, our results were also in accordance with Kakar et al. (2002), who investigated the role of fertilizers on vegetative growth of pea. Studies have shown that nitrogen improves vegetative growth, while, phosphorus has a role in providing energy in transferring photosynthates from source to sink. High energy phosphates are the constituents of ATP and adoneine diphosphate (ADP) that drives many chemical reactions in plants. Therefore, the improved growth and higher number of branches was noted in adequate level of nitrogen and phosphorus fertilization (Ahmad et al., 2017). Plant height were slightly increased by the single application of both fertilizers, while the plant height significantly increased under its combined application as compared to control. The single application of chemical fertilizer also showed nonsignificant results within in the treatment except the 60 kg P ha, -1and 90 kg N ha -1 . Whereas at the highest combined application the plant height significantly increased as compared to other treatments and control. The maximum plant height (51.24 cm) was recorded at P 80+N 110 followed by P 80+N100 and the minimum plant height (36.68 cm) was that of control. Our results are in agreement with Achakzai (2102) who reported that with application of chemical fertilizer the plant height increased. The application of different levels of nitrogen fertilizer increase the quality and growth of the maize (Amin, 2011).
In the current study number of leaves were significantly increased by the application of N and P fertilizers. Within in the treatments of single and combined application of fertilizers number of leaves showed significant results. As the rate of the fertilization increased the numbers of the leaves increased.
From the Table 1 it is cleared that the combined application will be more suitable for the growth of the plant. In our present study the highest number leaves was recorded at combined application (P 80+N100 and P 80+N100) 12.50 and 12.41 respectively, while the lowest was recorded at the control It is clear from the Table 2 that the single application of phosphorus and nitrogen slightly increase the length of the pods. When the phosphorus and nitrogen were in combination the pod length was significantly increased as compared to their single application and control. Within the treatments both the combined and single application of fertilizer significantly increased the pod length. The maximum pod length was recorded at the higher level (combine) of fertilizers P 80+N 110 (7.5 cm) followed by the P 80+N100 (7.3 cm), P80+N 90 (6.8) and the lowest values was recorded at control. The data revealed that the combine application of chemical fertilizers have significant effect as compared to their single application. The increase pod length might be due to the reason that nitrogen increases vegetative growth, which in turn results in increase in photosynthesis. On the other hand, phosphorus improves energy transfer in plants. Akhtar et al. (2003) also found the same results and reported that, with the application chemical fertilizer the pod length of the garden pea increased as compared the control. Kumar (2011) also investigate that as the application of phosphorus increased the length of the pods become increased, our results also showed the same trend and the pod length increased as the of the fertilizers increased.