Source: http://vasat.icrisat.org/crops/pearl_millet/pm_production/html/m9_3/index.html

Seed rate in Paerl Millet

Seed rate

 

The amount of seed required per unit area depends on:

• Optimum plant stand required per unit area
• Plant type i.e. tall or short plants
• Weight of seed
• Quality of seed in terms of germination.

Seed rate should be determined based on the optimum number of plants required in unit area (acre or hectare or sq ft or sq m) for good yields. The optimum plant population for pearl millet can vary between 150,000 to 250,000 plants/ha. If the plant population is on the higher side of 150,000 plants, the reduced panicle and seed size is compensated by the higher number of panicles per unit area. The recommended plant stand for pearl millet under normal conditions is 180,000 plants per ha or 18 plants per sq m or 72,000 plants per ac. Under irrigation or high levels of management on highly productive soils, a population of 225,000 plants/ha (100,000 plants per ac) is recommended. On extremely sandy, droughty soils, a population of about 90,000 plants/ha (40,000 plants per ac) is desirable.

Estimation of seed quantity per hectare: 

Given:  Pearl millet seed with 75% germination, 1000-seed mass of 12 g, and the required plant population is 180,000 plants per ha.

Step 1 Since the germination percentage is 75, we need to adjust for this deficiency.
Number of seeds needed to get 100 seedlings                              100 x 100   
                           ------------  =  134 seeds
                                 75           

Step 2        To get 100 seedlings, 134 seeds are required, then, the number of seeds required for 150,000 plants:                                   180,000 x 134
                           -----------------  =  241,200 seeds
                                    100 Thus, 241,200 seeds are needed to establish 180,000 plants per ha.

Step 3      The quantity of seeds(seed rate) required for 241,200 seeds, based on 1000 seeds weight of 12 g.                                 241,200 x 12 g
                         ------------------  =  2894 g or 3 kg
                             1000 seeds Thus, 3 kg of seeds are needed per ha to establish 180,000 plants per ha.

If germination % of seeds is not known, then the seed rate is determined by adding additional 20% of seeds to cover any seed germination problems.

Example: Given:  pearl millet 1000-seed mass of 12 g, and the required plant population is 180,000 plants per ha.     

Step 1                           Based on 1000 seed mass of 12 g

                                  12 g X 180,000 plants
                                -------------------------  =  2160 g or 2.2 kg
                                           1000 seeds

If germination % of seeds is not known, then the seed rate is determined by adding additional 20% of seeds.

Step 2 Based on 20% more seed requirement for any seed germination problem i.e 120% required 

                                   120 X 2.2 kg
                              --------------------  =  2.64 kg of seed
                                          100

Thus, 2.64 kg of seeds are needed per ha to take care of any seed problem and to establish 180,000 plants per ha.

The seed rate varies from 2 to 12 kg/ha.

The seed rate in clayey black soils is usually 3 to 4 kg/ha , and in other soils it may vary from 6 to 11 kg/ ha. If seeds are carefully drilled, only 2 to 2.5 kg/ha will be sufficient. But the weight of seed planted is not a good measure of population since seed weight varies considerably i.e. 5.5 to 14.5 g per 1000 seeds among various hybrids and improved varieties. Establishing optimum plant population in unit area is more important than the seed rate.