Evaluation location: Texas, United States
Accessions from the Cowpea Core Collection were evaluated for growth response to low phosphorus (P) soil conditions. The aspect of soil fertililty that most negatively affects crop production is phosphorus deficiency. The study was conducted in a glasshouse at the Texas AgriLife Research Station in Bushland, Texas. Soil used was a Betis sand which is similar to the seriously P deficient soils of the West African Sahel. The Betis sand had a pH of 4.7 in 1:1 water:soil mixture, and plant-available P level of 3 mg kg-1 using the Melich III method. No (0) phosphate treatment was added. After 8 weeks, plant height was measured and shoots were harvested, dried, and weighed. Total biomass (shoot dry weight + root dry weight) was calculated. Results were grouped into five categories from efficient to inefficient under low P conditions.