Effect of potassium and iron levels on plant height of rice bean
The plant height was recorded at 15, 30, 45, 60, 75, 90 DAS and at harvest with increase in crop age the plant height also increased (Table 1). At harvest, highest plant height (111.17cm) was recorded with application of 20 kg K
2O/ha +15 kg Fe/ha which was significantly superior over all the treatments except with application of 20 Kg K
2O/ha + 10 Kg Fe/ha (109.50 cm) and 30 Kg K
2O/ha + 15 Kg Fe/ha (107.17 cm) which were statistically at par with 20 kg K
2O/ha + 15 Kg Fe/ha. Plant height was significantly affected by different levels of potassium and iron levels plays a crucial role in meristematic growth. It may be due to its effect on the synthesis of phyto hormones. Among various plant hormones, cytokinin plays an important role in growth of plant specially plant height. Similar findings have been reported by
Brar et al., (2004) and
Singh et al., (2016).
Effect of potassium and iron levels on number of branches/plant of rice bean
Number of branches per plant was increased with crop age upto harvest. The number of branches per plant were recorded at 15, 30, 45, 60, 75, 90 DAS and at harvest are tabulated in Table 1. At harvest, maximum number of branches (23.40) was recorded with application of 20 Kg K
2O/ha + 15 Kg Fe/ha which was significantly superior over all the treatments except with application of 20 kg K
2O/ha + 10 Kg Fe/ha (21.80) and 30 Kg K
2O/ha + 15 Kg Fe/ha (21.67) which were statistically at par with 20 kg K
2O/ha +15 Kg Fe/ha. Increase in number of branches/plant might be due to application of potassium which helps cell division and cell expansion and increase the availability of nitrogen and phosphorus resulting in better plant growth and more number of branches /plant. Similar results were also obtained
Ali et al., (2007) and
Thesiya et al., (2013).
Effect of potassium and iron levels on number of nodules/plant of rice bean
Number of nodules/plant increased with crop age up to 60 DAS and thereafter that it declined upto harvest. The number of nodules/plant embodied in Table 2. Showed that at 60 DAS, highest number of nodules per plant (35.67) was observed with application of 20 Kg K
2O/ha+ 15 Kg Fe/ha which was significantly superior over all the treatments except with application of 20 Kg K
2O/ha + 10 Kg Fe/ha (33.87) which were statistically at par with 20 kg K
2O/ha +15 Kg Fe/ha. Different levels of potassium and iron were significantly influenced on number of nodules per plant were increased from 15-60 DAS. Increase potassium application increased the number of nodulation per plant
(Goud et al., 2014). Iron is an essential nutrient for both host legume and root nodule bacteria, whereas limiting quantity have negative impact on nodulation. Iron and potassium has major role on symbiotic nitrogen fixation there by increase in the number of nodules. These findings were also confirmed the results obtained by
Saini and Singh (2017).
Effect of potassium and iron levels on plant dry weight of rice bean
Dry weight of plant increased with crop age upto harvest. It was significantly influenced due to application of different levels of potassium and iron except at 15 DAS. Application of 20 Kg K
2O/ ha + 15 Kg Fe/ha, recorded maximum plant dry weight at harvest. The increase in plant dry weight might be ascribed to increase in rate of photosynthesis, leaf area and decrease in rate of respiration may be the reason of increase in dry weight of different parts of plants
(Kumawat et al., 2005) and also iron helps in assimilates transportation to sinks by this directly influence on dry matter production. This may include increase in carbohydrate synthesis. Similar effect iron was observed in cowpea in sandy loam soil of Kerala by
Anitha et al., (2005).
Effect of potassium and iron levels on yield attributes and yield of Rice bean
The yield attributes and yield of rice bean at harvest markedly influenced with potassium and iron (Table 3) represent significantly maximum number of pods/plant (26.20), maximum number of seeds/pod (7.93), maximum seed yield (1.67 t/ha), maximum stover yield (3.95 t/ha) were recorded with application of 20 Kg K
2O/ha + 15 Kg Fe/ha. Maximum harvest index (%) was obtained with application of 20 Kg K
2O/ha + 15Kg Fe/ha (29.69). The increase in yield and yield attributing parameters might be to the application of potassium and iron as basal application. The increase in yield described due to the application of potassium along with iron may be possibly due to increase in availability of soil nutrients and ultimately resulted in vigorous root development. This may be the plant leading to higher photosynthetic activity which results in better development of yield attributes and finally higher seed yield. These results were similar with findings of
Buriro et al., (2015).
Effect of potassium and iron levels on economics of Rice bean
Experimental results revealed that different levels of potassium and iron significantly increased the economics of Rice bean. Higher gross (INR 1,14,560.00/ha), net return (INR 81,155.60/ha) and benefit cost ratio (2.43) were recorded with the application of 20 Kg K
2O/ha + 15 Kg Fe/ha.