The Wall Street Journal explains the cost problems of GMO seed and the huge deals being consummated in the agricultural sector.

The dominance of genetically modified crops is under threat.

Since their introduction to U.S. farms 20 years ago, genetically engineered seeds have become like mobile phones—multifunctional and ubiquitous.

Scientists inserted genes to make crops repel insects, survive amid powerful herbicides, survive on less water and yield oils with less saturated fat, in turn eliminating farmers’ amateur chemistry. The U.S. Department of Agriculture estimates this year that 94% of soybean acres were planted with biotech varieties, and 92% of corn acres.

Today, farmers are finding it harder to justify the high and often rising prices for modified, or GMO, seed, given the measly returns of the current farm economy.

Pressures have touched off a frenzy of deal making among the world’s top seed and pesticide suppliers. Bayer AG on Wednesday said it agreed to buy Monsanto for $57 billion, creating one of the world’s largest agrochemical firms. DuPont Co. and Dow Chemical Co. are pursuing a merger that would eventually spin off a combined agricultural business, along with two other units. Syngenta AG agreed in February to a $43 billion sale to China National Chemical Corp., after turning down a takeover proposal from Monsanto.