Growth parameters
The results indicated that all the growth parameters (plant height, number of leaves plant
-1, number of branches plant
-1, dry-matter production and number of nodules plant
-1) were higher for the crop sown during I FN of January followed by that sown during II FN of January (Table 1) with no significant disparity between them. This might be due to the favourable climatic conditions that prevailed during the crop growth period and might have been instrumental in boosting up the crop growth. Our findings are in agreement with the findings of
Kumar and Patel (2013) and
Ahmed et al., (2017). A lower stature of growth parameters was recorded for the crop sown during I FN of February.
Application of 60 kg P
2O
5 ha
-1 resulted in significant improvement in the growth parameters at all the stages of observation while the lowest value was recorded under the control (Table 1). Increase in the growth parameters with increasing phosphorus level can be attributed to the fact that phosphorus is required in large quantities in shoot and root tips where metabolism is high resulting in favourable effect on cell division/enlargement that is reflected on growth of the plant. Similar findings were observed with
Kumar (2011) and
Shekara et al., (2010). The interaction between time of sowing and phosphorus level influencing the growth parameters was observed to be non-significant.
Leaf to stem ratio and fodder yield
Higher leaf to stem ratio and green fodder yield of fodder cowpea was recorded when the crop was sown during I FN of January which was however on par with that of II FN of January (Table 2). The higher leaf to stem ratio and fodder output with earlier sowings could be related to higher leaf weight than green stem weight, as well as the fact that early seeded crops took the most calendar days to harvest, resulting in a longer vegetative period, which in turn reflected on the green fodder production. The results are in consonance with the findings of
Ashwathi (2016),
Ali et al., (2007) and
Ram et al., (2014). Fodder cowpea sown during I FN of February recorded the lowest leaf to stem ratio and fodder yield (Table 2).
The highest phosphorus level of 60 kg P
2O
5 ha
-1 resulted in significantly higher leaf to stem ratio and green fodder yield compared to the lower levels of phosphorus tested. The next best treatment was 40 kg P
2O
5 ha
-1 which was however on par with that of 20 kg P
2O
5 ha
-1 (Table 2). The lowest leaf to stem ratio and green fodder yield was recorded with control (Table 2). The higher leaf to stem ratio and green fodder yield may be due to adequate nutrient supply and efficient utilisation through an extensive root system developed by phosphorus application, which resulted in higher plant height, leaf area, number of leaves plant
-1 and number of branches plant
-1. These results are in line with the earlier findings as reported by
Shekara et al., (2012), Godara et al., (2016) and
Kumawat and Khinchi (2017).