Ghanaian black cowpea , packet of 100g cost is $6, shipping $10, phyto cert $12

Ghanaian Black cowpea
Yields 800kg – 1000kg/acre

How to increase yield:

Seed rate: 12kg/acre, 30kg/ha
Spacing: 60cm x 20cm 2seeds/hole when there is low rainfall. Or 80cm by 40cm; 2seeds/hole when there is high rainfall.

Weed control:

If spraying with cowpea selective weedicide. It is advisable to spray at 7-10days after planting.
If weeding, then intra and inter row weeding should be done at 14-12days after planting.
Pest control
Start spraying insecticide at 30 days after planting. This should be done at 7days interval until harvesting.
Harvesting
Start harvesting your cowpea when you observe that they are totally dried.

Qualities:

High yielding variety
Early maturity
Black grains 
Easy drying and threshing
Tolerant of poor soils and drought conditions
They are drought resistant
They are suitable for long term storage
They are easy to cook and have pleasant taste