Impact of mirid (Creontiades spp.) (Hemiptera: Miridae) pest management on Helicoverpa spp. (Lepidoptera: Noctuidae) outbreaks: The case for conserving natural enemies

Creontiades spp. (Hemiptera: Miridae) are sucking pests that attack buds, flowers and young pods in mungbeans, Vigna radiata (L.), causing these structures subsequently to abort. If left uncontrolled, mirids can cause 25-50% yield loss. Traditional industry practice has involved prophylactic applications of dimethoate to control mirids at budding and again a week later. The present trial was initiated to highlight the dangers of such a practice, in particular the risk of a subsequent Helicoverpa spp. lepidopteran pest outbreak. A single application of dimethoate halved the population of important natural enemies of Helicoverpa spp., and caused an above-threshold outbreak of Helicoverpa spp. within 11 days. This shows that even a moderate (e.g. 50%) reduction in natural enemies may be sufficient to increase Helicoverpa spp. populations in mungbeans. As a result, prophylactic sprays should not be used for the control of mirids in mungbeans, and dimethoate should be applied only when mirids are above the economic threshold. Indoxacarb was also tested to establish its effect on Helicoverpa spp., mirids and natural enemies. Indoxacarb showed potential for Helicoverpa spp. control and suppression of mirids and had little impact on natural enemies.

Increase water use efficiency and productivity, and reduce energy and water usage and costs, of dairy and fodder enterprises, to reduce costs of milk production

Increase water use efficiency and productivity, and reduce energy and water usage and costs, of dairy and fodder enterprises, to reduce costs of milk production.

Increasing energy efficiency in Australian protected cropping

Management of environmental emissions is a significant challenge and opportunity for all of horticulture, including the protected cropping sector. Energy is a significant input in controlled environment horticulture and an important source of environmental emissions. Energy underlies this industry’s capacity to provide a consistent supply of fresh, quality, safe food in a changing global climate.

Australian Timber Pole Resources for Energy Networks. A review

More than 5 million timber utility poles are currently in-service throughout Australia’s energy networks. Most were produced from select native forest-grown hardwood species having the required structural characteristics and naturally-durable heartwood. Anecdotal evidence suggests that up to 70% of the timber poles that are currently in-service were installed over the 20 years following the end of World War Two, and these poles are likely to require replacement or remedial maintenance over the next decade. The purposes of this review were to clarify the supply and demand situation for traditional timber poles, and to investigate alternatives in terms of their potential availability and suitability.

Weeds of Direct-Seeded Rice in Asia: Problems and Opportunities

Rice production symbolizes the single largest land use for food production on the Earth. The significance of this cereal as a source of energy and income seems overwhelming for millions of people in Asia, representing 90% of global rice production and consumption. Estimates indicate that the burgeoning population will need 25% more rice by 2025 than today's consumption. As the demand for rice is increasing, its production in Asia is threatened by a dwindling natural resource base, socioeconomic limitations, and uncertainty of climatic optima. Transplanting in puddled soil with continuous flooding is a common method of rice crop establishment in Asia. There is a dire need to look for rice production technologies that not only cope with existing limitations of transplanted rice but also are viable, economical, and secure for future food demand.Direct seeding of rice has evolved as a potential alternative to the current detrimental practice of puddling and nursery transplanting. The associated benefits include higher water productivity, less labor and energy inputs, less methane emissions, elimination of time and edaphic conflicts in the rice-wheat cropping system, and early crop maturity. Realization of the yield potential and sustainability of this resource-conserving rice production technique lies primarily in sustainable weed management, since weeds have been recognized as the single largest biological constraint in direct-seeded rice (DSR). Weed competition can reduce DSR yield by 30-80% and even complete crop failure can occur under specific conditions. Understanding the dynamics and outcomes of weed-crop competition in DSR requires sound knowledge of weed ecology, besides production factors that influence both rice and weeds, as well as their association. Successful adoption of direct seeding at the farmers' level in Asia will largely depend on whether farmers can control weeds and prevent shifts in weed populations from intractable weeds to more difficult-to-control weeds as a consequence of direct seeding. Sustainable weed management in DSR comprises all the factors that give DSR a competitive edge over weeds regarding acquisition and use of growth resources. This warrants the need to integrate various cultural practices with weed control measures in order to broaden the spectrum of activity against weed flora. A weed control program focusing entirely on herbicides is no longer ecologically sound, economically feasible, and effective against diverse weed flora and may result in the evolution of herbicide-resistant weed biotypes. Rotation of herbicides with contrasting modes of action in conjunction with cultural measures such as the use of weed-competitive rice cultivars, sowing time, stale seedbed technique, seeding rate, crop row spacing, fertilizer and water inputs and their application method/timing, and manual and mechanical hoeing can prove more effective and need to be optimized keeping in view the type and intensity of weed infestation. This chapter tries to unravel the dynamics of weed-crop competition in DSR. Technological issues, limitations associated with DSR, and opportunities to combat the weed menace are also discussed as a pragmatic approach for sustainable DSR production. A realistic approach to secure yield targets against weed competition will combine the abovementioned strategies and tactics in a coordinated manner. This chapter further suggests the need of multifaceted and interdisciplinary research into ecologically based weed management, as DSR seems inevitable in the near future.

Immediate and residual effects of heat stress and restricted intake on milk protein and casein composition and energy metabolism

The effects of heat stress on dairy production can be separated into 2 distinct causes: those effects that are mediated by the reduced voluntary feed intake associated with heat stress, and the direct physiological and metabolic effects of heat stress. To distinguish between these, and identify their effect on milk protein and casein concentration, mid-lactation Holstein-Friesian cows (n = 24) were housed in temperature-controlled chambers and either subjected to heat stress HS; temperature-humidity index (THI) ~78 or kept in a THI < 70 environment and pair-fed with heat-stressed cows (TN-R) for 7 d. A control group of cows was kept in a THI < 70 environment with ad libitum feeding (TN-AL). A subsequent recovery period (7 d), with THI < 70 and ad libitum feeding followed. Intake accounted for only part of the effects of heat stress. Heat stress reduced the milk protein concentration, casein number, and casein concentration and increased the urea concentration in milk beyond the effects of restriction of intake. Under HS, the proportion in total casein of αS1-casein increased and the proportion of αS2-casein decreased. Because no effect of HS on milk fat or lactose concentration was found, these effects appeared to be the result of specific downregulation of mammary protein synthesis, and not a general reduction in mammary activity. No residual effects were found of HS or TN-R on milk production or composition after THI < 70 and ad libitum intake were restored. Heat-stressed cows had elevated blood concentrations of urea and Ca, compared with TN-R and TN-AL. Cows in TN-R had higher serum nonesterified fatty acid concentrations than cows in HS. It was proposed that HS and TN-R cows may mobilize different tissues as endogenous sources of energy.