No report available

The objectives of this study were: (i) To study the population dynamics of Heliothis on the Darling Downs and to quantify the significance of the major controlling influences (predators, parasites pathogens, weather and host plant quality) on population changes within the species, and, (ii) To assess the potential for an area-wide management approach to the suppression of Heliothis populations through the identification of ecological bottlenecks and the practical manipulation of the controlling factors.

Aims: The aim of the project was to develop naturally occurring plant pathogens a s mycoherbicide biological control agents for Xanthium spp., Noogoora and Bathurst burrs.

Objective of Research Project: To provide growers with knowledge of the workings and relative merits of available marketing options by making them aware of each marketing methods' revenue potential and income stability. * Extent to which project objectives have been achieved: Given the results and the wide exposure they received when they were published in The Australian Cottongrower, it appears that the project objectives have been achieved. � *Research Results: It was concluded that no single marketing strategy would have returned significantly higher returns over the 1973-74 to 1987-88 period. Hence, the focus of the study became the price stability or risk characteristics of each alternative. The results indicated that a grower can trade off the costs of hedging through the call pool option provided by processors against the reduction in price risk that hedging provides compared to the alternative selling methods studied. This is because the basis risk faced when hedging is typically less than the price risk faced in the cash market In addition, it was concluded that yield variability must be taken into account when deciding on a marketing strategy. In certain circumstances, significant crop losses may expose the grower to additional financial loss.

ABSTRACT: When searching for an ideal mass screening technique for cotton plant antibiotic resistance to Helicoverpa spp., a 48 hour feeding on squares using final instar larvae bioassay was found to be the most suitable. It correlated better, than the other techniques trailed, with the Standard larval bioassay traditionally used as an antibiotic resistance measuring tool and was more energy efficient than the 'Standard'. An ideal mass screening technique using the two spotted mite (Tetranychus urticae on cotton seedlings failed to correlate with the 'Standard1 rendering it unsuitable for measuring antibiotic resistance to Helicoverpa spp ....The widely reported finding that gossypols are very important to the antibiotic activity against the cotton bollworm (Helicoverpa armigera was supported with highly significant correlations between gossypol content of plant material and percent larval weight gains. In contrast, condensed tannin content of 'fresh plant' diet incurred insignificant antibiotic activity against the cotton bollworm but important antibiotic activity against the two spotted mite (Tetranychus urticae).

No report available

Despite it's status as a pest of cotton (Gossypium hirsutum L.) in Central Queensland, the biology and ecology of the pink-spotted bollworm, Pectinophora scutigera (Holdaway), is poorly understood. This study was undertaken to gain a better understanding of the biology and ecology of P. scutigera in order to suggest ways of improving current control strategies. The approach I adopted was that advocated by Clark et al. (1967), whereby the life system of a pest is studied in an attempt to recognize key factors which control its abundance.

Heliothis armigera and H. punctigera are serious pests of cotton in Australia. Control of Heliothis is currently dependent on insecticides. Levels of resistance to several of the major chemical groups of insecticides is sufficient to threaten the long ter

The application of the chemical technique developed in DAQ27L in determining the age of field collected adults of Pectinophora scutigera (pinkspotted bollworm).

To conduct a critical examination of the ACCT data from 1974/75 to 1985/86 and to learn more about the relative behaviour of cultivars over the testing sites and the effectiveness of location to evaluate cultivar differences.