Focus on Bollgard benefits at Bourke

21 December, 2004

___The first of a series of early season regional Bollgard® II cotton field days has been held at Bourke, which is eagerly awaiting a fresh flow in the Darling River from heavy storm rains upstream._

A joint initiative of the Cotton CRC extension network’s insect focus team and Cotton Seed Distributors, the field day was attended by 15 local growers and agronomists, representing major cotton producers in the region.

Pictured left: Trudy Staines from CSIRO explains the merits of using beat sheets to sample for the presence of pests and beneficial insects in cotton.

Topics included:

p. · mirid damage and ecology (Brian Duggan CSIRO)
· early season sampling methods, including a demonstration of the beat sheet method for pest and benefical insects (Trudy Staines CSIRO)
· assessing crop development using the online (CRC) Early Season Diagnosis tool (Adam Kay CSD) and
· monitoring fruit retention comparing traditional first position retention and the new Fruiting Factor method (Greg Kauter CRDC).

There was also a healthy in-field discussion on crop progress, insect pressure and control measures, irrigation timing and managing for limited water.

The field day attendees were advised that when relying on plant monitoring it can be difficult to determine whether fruit loss is due to pest damage or stress.

Shedding of young squares early in the season is sometimes attributed to the fact that the plant’s vascular system is not fully developed and it’s difficult to get enough resources to the young fruit in times of high demand, such as very hot conditions.

_Pictured below: Brian Duggan, crop physiologist with CSIRO, addresses the Bourke Field Day.

__Greg Kauter said a cotton plant will not naturally keep all of its fruit, even under ideal conditions.
“In normal crop conditions, less than 50 per cent of the total fruit initiated by the crop will make it through to harvest, but using these plant monitoring techniques gives you more information about your crop when considering insect control options.

“Traditionally when first position fruit retention falls below 50 per cent, it should signal some caution, but certainly not panic. Many people have experienced very low fruit retention and still achieve good yields. For this reason it’s also important to consider other fruit besides 1st position (such as 2nd and 3rd),” he said.

The Fruiting Factor, which was calculated by participants in the field at Bourke, is a new plant monitoring method that considers all the fruit that the crop is carrying, and is very useful in Bollgard as well as conventional cotton.
More information can be obtained by searching the CRC web site and practical examples of the application of these crop development tools can be found on the CSD web site under *Trials on Line. *

Further Information: *Robert Eveleigh**, John Marshall, Craig McDonald or David Kelly