Effect of various levels of nitrogen fertilizer on some vegetative growth attributes of pea ( pisum sativum L.) cultivars

A field experiment was conducted for 2 consecutive growing years on few growth characteristics of four pea cultivars viz., Arkel, Climax, Green Feast and Olympia in response to different levels of N fertilizer under the climatic conditions of district Mastung, Balochistan. Six N fertilizer levels (0, 25, 50, 75, 100 and 125 kg N ha/sup -1/) plus a constant dose of 60+40 kg P/sub 2/O/sub 5/ and K/sub 2/ O ha/sub -1/ were prepared, and designated as T/sub 1/ to T/sub 7/, respectively. These N levels were applied to each sub-plot (except T/sub 1/ and T/sub 2/) in two split doses first at the time of flowering and second at the time of pod formation to quantify how much N fertiliser's required by different pea cultivars to realize the highest growth and yield. Results exhibited that in response to various levels of added N fertilizer, all mentioned growth attributes were found to be highly significant (P<0.01). However, cultivars response was found significant only for secondary branches plant/sub -1/, plant height and shoot moisture contents. A maximum number of primary branches plant/sup -1/ (6.94), secondary branches plant/sub -1/ (10.72), plant height (69.77 cm), number of leaves plant/sup -1/ (19.75), leaf length (11.81 cm) and shoot moisture contents (571.0 g kg/sup -1/) was recorded with application of 100 kg N ha/sup -1/. The interaction between fertilizer and pea cultivars was found non-significant for all mentioned attributes in the trial. Results further revealed that all growth parameters were slightly to highly significant and positively correlated among themselves as well as with their fresh pod yields. These attributes could be used a suitable selection criteria for predicting the fresh pod yield and also for breeding purposes in peas. (author)