Grafting better roots

From Farmonline: Tropical research beats the rot Australia
Tuesday, 15 November 2005

A powerful new scientific weapon against anthracnose - the soft brown rot that spoils avocadoes - is delivering $40 million in benefits to the nation's avocado industry.
As well, it's delivering higher quality fruit to consumers. The return on the avocado research is just a part of $150 million in benefits being delivered to the Australia's tropical farming industries from 10 research projects, according to a new economic analysis.

Professor John Irwin, chief executive of the Cooperative Research Centre for Tropical Plant Protection, says every dollar spent on these tropical agriculture research projects returned $11 in industry and wider benefits. The finding was made by economic research group Agtrans Research in a benefit-cost analysis of 10 CRC TPP research projects from 1992 to 2004.

"Bananas, avocados, sunflowers, cotton, lucerne, sugarcane, wheat - these are just some of an impressive list of crops where research has paid huge dividends," says Professor Irwin. "By using certain Guatemalan rootstocks for avocado tree graftings, growers can halve the incidence of anthracnose disease and enjoy an 80pc decrease in the severity of infection," he says.

Professor Irwin says: "Anthracnose is a fungal disease which affects tropical fruits such as avocados, mangoes and lychees, and results in significant loss of fruit in the marketplace.
"Our research has shown that resistance to the disease is associated with naturally occurring anti-fungal properties. "We have also found a link between excessive nitrogen fertiliser use, low fruit calcium levels, and anthracnose severity." Virtually all 'Hass' avocados - the most common commercial cultivar - are now grown on Guatemalan rootstock, compared with less than half before the study.