Soil Study

Battling the blight Bean blight's reach expands to both tropical and temperate regions of the world. Shree Singh, a professor at the University of Idaho, has spent his career researching ways to generate cultivars of common bean resistant to diseases. According to Singh, "Common blight is by far the most severe and widely occurring bacterial disease that adversely affects common bean production worldwide." Common blight is caused by two species of bacteria belonging to the Xanthomonas genus. It is a difficult disease to attack. The bacteria can move along with seeds and plant matter. "When contaminated seeds are planted, the bacteria can then go on to infect the germinating plant and spread further," says Singh. Infected plant matter left behind after harvest can also infect the next cycle of crops. Complicating matters further, different strains of the bacteria can exist on the same seed. In fact, "A single field in Wisconsin yielded more than...

Dramatically Dynamic Genomic Evolution of a Mighty Mite As a major natural enemy of several damaging agricultural pests, the predatory mite Metaseiulus occidentalis is used in many agricultural settings as an effective biological control agent. Some of its favorite prey include spider mites that feed on and destroy various fruits including strawberries, apples, peaches and grapes. "I have been studying the behavior, ecology, and molecular biology of these mites for more than 40 years," said Prof. Marjorie Hoy lead author from the University of Florida USA, "so I was very keen to sequence the entire genome to reveal the full catalogue of genes." To explore the unique biology of this agriculturally important predator the researchers focused their studies on genes putatively involved in processes linked to paralysis and pre-oral digestion of prey species and its rather rare par haploid sex determination system, as well as how it senses chemical cues from its surro...

Modern Corn Hybrids More Resilient to Nitrogen Stress In an analysis of 86 field experiments, agronomists found that corn hybrids released after 1990 prove more resilient than their predecessors in multiple ways. Modern hybrids maintain per-plant yield in environments with low nitrogen, can bounce back from mid-season stress and have an improved ability to take up nitrogen after silking, even if they suffered from nitrogen deficiency during flowering. The study suggests reserving a portion of nitrogen fertilizer to apply later in the season could be a good bet for growers, said Tony Vyn, professor of agronomy. "This is like insurance," he said. "Previously, withholding some of your nitrogen for later could be perceived as a risky venture -- you don't want to inadvertently cause nitrogen deficiency. But this paper suggests that with modern hybrids, that risk is lower." Nitrogen is an essential building block of plant proteins and plays a vital role...