Source: http://vasat.icrisat.org/crops/pearl_millet/pm_production/html/m7_2.1/in...

Nitrogen Deficiency Symptoms

Nitrogen deficiency generally results from inadequate fertilizer application, or leaching loss due to excessive rainfall. Leaching occurs most commonly in sandy-textured plain soils during periods of excessive rainfall. Nitrogen is also lost through volatilization from surface applications during periods of hot, dry weather.

Nitrogen deficient plants are stunted, pale green to pale yellow, and grow more slowly Fig.). Eventually, the affected leaves become brownish, wither, die and hang down around the lower stem.

                    Note the pale green, yellow, and brown,
                                      lower leaves

Yellowing or chlorosis appears first on the lower leaves; the upper leaves remain green. The tendency of the young upper leaves remaining green is due to nitrogen moving towards the newly growing leaves.

                 N deficient plant on right and normal plant on the
                                                       left

The plants will be stunted in growth and with thinner stems. Greater red streaking can be seen on the lower leaf sheaths of the nitrogen deficient plant.