As in the promotion of green fertilization, the attempt to promote the planting of yellow corn is another example of "sowing beans and reaping squash." The Agricultural Mission, having noticed the poor nutrition of the people of Peten, conducted test plantings and evaluated the results for three years before introducing a variety of yellow corn with twice the protein of the white corn grown by local farmers.
除了綠肥的推廣不易，在黃玉米的推廣上，一樣發生「種豆得瓜」的情形，原來農技團看到北碇人營養不足，經過三年的試種及觀察，推出蛋白質兩倍於白玉米的黃玉米。