Epidemics of plant viruses threaten the profitability of meat, wool and dairy industries by seriously reducing pasture feed-base productivity, e.g. widespread infection of subterranean clover pastures causes losses of more than AU$58 million per year to the Australian dairy industry alone. This article provides a comprehensive picture of current knowledge concerning the occurrence, losses caused, epidemiology, and management of virus diseases of annual pasture legumes growing in Australian pastures. Critical research and development gaps that need addressing urgently are identified.
Crop and Pasture Science
Volume 63 Number 5 2012
High temperature due to global warming is an important problem in chickpea production. High temperatures affect chickpea growth and development and may lead to a drastic reduction in grain yield. Generally, chickpea has a base level of heat tolerance. Therefore using various genetic approaches and adaptation mechanism of heat is possible for improving heat tolerance in chickpea.
Dual-purpose crops can be grazed by animals and then harvested for seed to increase food and fibre productivity, resource use efficiency while reducing production risk. Cereals have been traditionally used in this way, but our study reveals that canola is also an effective dual-purpose option. The management principles developed will provide opportunities for adoption in a wider range of mixed farming environments.
Aphids are serious insect pests of lupins and cause substantial yield losses due to feeding damage and spread of viral diseases. Alkaloids play a significant role in providing resistance against aphids and lowering the alkaloid level to the industry level (0.02%) has resulted in aphid susceptibility, but this study has identified certain genotypes of yellow lupin with moderate levels of aphid resistance in a low alkaloid background. These lines will offer a greater opportunity for developing aphid resistant yellow lupins.
CP12065Non-target site mechanism of metribuzin tolerance in induced tolerant mutants of narrow-leafed lupin (Lupinus angustifolius L.)
Herbicide tolerant crops enable efficient weed control during crop production. Induced lupin mutants with increased tolerance to metribuzin are good sources for breeding for herbicide tolerant cultivars. Sequencing of the target site of both mutants and wild type reveals mutation did not occur at the target site and the tolerance mechanism is likely involving P450-mediated metribuzin metabolism.
Commercially grown sugarcane varieties have normally been developed by nationally focused breeding programs. We found that there were moderate to high correlations between production environments in China and Australia for performance of a common set of sugarcane varieties. This suggests that data from selection trials and clones selected in one country could be useful for the other country, and is supportive of ongoing cooperative approaches between countries in development of cultivars.
CP12032Agronomic and environmental drivers of population size and symbiotic performance of Rhizobium leguminosarum bv. viciae in Mediterranean-type environments
Nitrogen (N) fixation capacity of field pea rhizobia in agricultural soils was measured and related to agronomic, soil and climatic factors. Fewer rhizobia were present and inoculation still likely to be beneficial where soil pH (H2O) <6.5, particularly when summers had been hot and dry and when a host had been absent for ≥5 years. New inoculation technologies and plant breeding will be required to overcome the large populations of poorly effective rhizobia that persist in some soils.
CP11332Phenological development and grain yield of canola as affected by sowing date and climate variation in the Yangtze River Basin of China
Canola is a major oil crop in the Yangtze River Basin of China, and its yield varies significantly from year to year. This study reveals that decline in canola yield was mainly due to late sowing dates causing shortened vegetative growth stages, and that inter-annual climate variability also led to significant yield variation. In the rice–canola double-cropping system, the late sowing time after rice harvest prevents canola from achieving its potential yield, transplanting remains important to overcome season shortage.
CP11256Photosynthesis of barley awns does not play a significant role in grain yield under terminal drought
Leaf photosynthesis the main process of carbohydrates production in cereals is reduced under terminal drought but the role of non-leaf organs such as awns on grain yield is unknown. The study evaluated the photosynthetic capacity of awns in six two-rowed barley commercial cultivars under well-watered and terminal drought conditions and it was found that photosynthesis of barley awns does not play a significant role in grain yield under terminal drought. Stem, leaves and awns produced and stored plenty of assimilates under both well-watered and drought conditions, but the sink size limited grain yield.