Maize production has increased nearly six-fold over the past six decades, but reactive nitrogen losses from maize fields have risen by a similar magnitude. A new study published in Science Bulletin argues that the next step in maize improvement must link yield gains with lower environmental costs.

The researchers introduced the concept of green and efficient, or G&E, maize varieties. These varieties are defined as relative to locally adapted conventional control varieties under comparable management, simultaneously increase grain yield while reducing at least one category of environmental input or reactive loss.

By integrating genetic evidence, reported varieties, field observations and global soil and climate data, the authors found that existing G&E maize varieties already increase yield and nitrogen utilization efficiency respectively by 10.1% and 16.7% on average. Under an ideal full-adoption scenario, such varieties could raise global maize production by 18.1% and reduce reactive nitrogen losses by 26.6%.

If global emissions continue unchecked, rising temperatures and shifting rainfall patterns could amplify tree pests and diseases across more than 80 per cent of North American forests within decades, jeopardizing critical carbon sinks, air quality and the forestry economy.

This is the key finding of a new UBC-led study published today in Nature Ecology & Evolution. The researchers found that insects pose the more immediate threat, with more than 60 per cent of the areas examined projected to experience 30 per cent more insect pressure by mid-century. Species like the spongy moth, already wreaking havoc in Canadian forests, could expand significantly in eastern North America by mid-century.

Tomato bacterial canker is a seedborne disease that spreads easily, but other beneficial bacteria can keep the pathogens at bay. Researchers have identified bacterial strains that both promote plant growth and antagonize the pathogens.