CRDC undertakes an annual survey of cotton growers to gather information about farming practices and growers’ views on research, development and extension. This information helps to inform CRDC about the benefits of the research it invests in. Change in industry practice can be quantified by comparing information across the surveys conducted over the past 20 years. Previous surveys have included a number of core annual questions and then a number of focus areas to investigate specific aspects of the farming system.

Techniques for mass rearing egg parasites on eggs of the factitious host Sitotroga cerealella (Angoumois Grain Moth - AGM) were further developed and refined. AGM egg production peeked at 330,000 per day during November 1991, but was inconsistent. An automated egg collection system was developed and constructed, and commenced operation in December 1991. A Morrison unit for rearing egg parasites was constructed in July and has the capacity to rear one million parasites per day, provided there are sufficient host eggs available.

This project was a feasibility study undertaken to determine if feeding of Helicoverpa larvae could be inhibited by polyclonal antibodies raised against gut tissues

Mirids have always been and will continue to be key pests of GM cotton for the foreseeable future. Despite huge investments into RD&E over several decades, mirid management practices are still highly variable, contentious, and largely inconsistent with best practice. A key output of this project was a comprehensive review of all mirid-related RD&E over the last few decades. This review has provided the CRDC with a definitive analysis of prevailing mirid management practices and the value of past investments in mirid-related research from a scientific and quality control perspective. The mirid research review report proposes a new R&D framework, including new methodology to quantify mirid damage, that will be required to develop and promote best management practice into the future. A new, futuristic mirid management system will require fresh investment in RD&E with outcomes potentially 3-5 years into the future. In view of the theoretical, methodological and technological problems inherent in the mirid research done in the past, interim management guidelines based on “revised” mirid damage thresholds have been made available to the cotton industry as a stop-gap measure.

The project’s activities in years 1 and 2 have confirmed the widely-held belief that mirids are among the most difficult animals to work with. A key challenge lies in the production of “ecologically and biologically competent” individuals for use in experiments in the glasshouse as well as in the field. Researchers have typically relied on individuals reared on artificial diets or organic vegetables such as beans and corn, in insectaries maintained in laboratories. There is evidence from the project and published information suggesting that laboratory reared individuals are not as robust as their field dwelling counterparts. An immediate implication is that outcomes of prior research done using cultured individuals may be largely inaccurate. Ironically, the use of field caught mirids for experimental work is also problematic because physical damage sustained during capture typically results in high mortality rates, and individuals are of unknown age, which can result in highly variable feeding activity and damage.

Thus, a significant challenge for mirid research going forward is the requirement to produce sufficient numbers of mirids (adults and juveniles) of known age and stage that are readily available throughout the year and, most importantly, are equivalent to their field grown counterparts in terms of ecologically competence – biological and/or physiological vitality and damage capability. This will require a move away from rearing of mirids on beans and corn (nutrient dense resources) in the laboratory to rearing on mixtures of (potted) plants within large cage enclosures in the glasshouse or other appropriate enclosed facilities with appropriate lighting and nutrient regimes to facilitate healthy plant growth, or insectaries established on plants growing in the field. The logistical aspect of this challenge is also likely to be significant, and will require the allocation of time and resources in future research projects.

The project’s activities on mealybug predators have addressed an important gap in management best practice for this pest – options that better exploit non-chemical, environmentally sustainable means of pest control. Predators and other natural enemies are important elements of the control strategy for most if not all field crop pests. However, in most instances the ability of crop managers and growers to exploit these agents of natural mortality (ecosystem service) has been extremely limited. Based on the predator assessment work undertaken in this project, crop managers and growers will be able to use commercially available mealybug predators to control mealybugs in a strategic way. However, further research (including cost-benefit analyses) and practical assessments of predator releases under field conditions will be required to give growers and crop managers confidence in the expected outcome.

Background

The project ‘Feasibility study of managed aquifer recharge [MAR] for improved water productivity for Australian cotton production’ is investigating the potential to implement MAR at a regional scale in established and emerging irrigated cotton growing regions of Australia. The broad aim of the project case studies was to evaluate how MAR might be feasible for irrigated cotton production and associated cropping systems in the focus regions, and make recommendations on further work to evaluate local hydrogeological conditions, plan the necessary site-specific infrastructure, and establish the legal, social and organisational conditions for implementation of MAR.

The focus of this report is the third case study of the MAR feasibility project, the Lower Namoi valley in the Namoi River catchment. This case study experiments with using a desktop analysis to initiate discussion from an operational, site specific perspective based on currently available data that draws on, but distinguishes it from, the previous work on MAR in the catchment. The area of interest (AOI) for our sub-regional analysis is the area of previously mapped high MAR suitability in the east of the Lower Namoi groundwater source (between Narrabri and Wee Waa). This area is part of a highly developed irrigated agriculture industry (where cotton is an important crop) that already makes use of large capacities of farm dams, conjunctive surface and groundwater use, and flood water management.

The broad approach taken was to draw on evidence from a holistic feasibility assessment to scope a set of plausible but widely different opportunities (“scenarios”) for MAR, and to test and refine these scenarios with local stakeholders and state government stakeholders. Given the developed nature of the AOI, any new water management solution (in this case MAR) is an attempt to optimise an existing capability rather than an initial attempt at meeting a need. In this respect, gains from optimising the status quo are unlikely to provide new water, but rather to provide greater control over where and when water is available.

CRDC undertakes an annual survey of cotton growers to gather information about farming practices and growers’ views on research, development and extension. This information helps to inform CRDC about the benefits of the research it invests in. Change in industry practice can be quantified by comparing information across the surveys conducted over the past 20 years. CRDC has published the results of this survey in two formats: a PDF of the survey report; and an interactive online digital dashboard, available at: www.crdc.com.au/publications/growersurvey