heat stress condition

Dr Viola Devasirvatham undertaking a chickpea heat-tolerance field experiment at the Plant Breeding Institute at Narrabri... The discovery of heat-tolerant chickpea genotypes may improve the reliability of yields in the northern grainbelt of Australia and other semi-arid environments around the world... Crop phenology (days to first flowering, days to 50 per cent flowering, days to first pod and days to maturity), growth (plant height, plant width and biomass at harvest) and grain yield (including pod number per plant, filled pod number per plant and seed number per plant) were recorded in both seasons...

Armed with a purpose-built heat chamber, Dr Talukder and his supervisors, Dr Gurjeet Gill and Dr Glenn McDonald, took trials out of the laboratory and into the paddock to test the influence of short-term temperature extremes on six wheat varieties... "Almost all previous heat-stress research has taken place in controlled environmental conditions, so we wanted to develop an efficient methodology to simulate heat stress in the field to identify heat-tolerant varieties," Dr Talukder says... "We found a single day of heat stress just prior to flowering and at early grain fill significantly reduced the carbohydrate reserves in stems and decreased the weight and number of grains," he says...

The SAGIT funded project involves using a controlled environment assay that is run at Roseworthy, to identify and quantify the level of heat stress tolerance in current varieties, advanced breeders lines and exotic lines, as well as using 'gene mapping', to genetically dissect and understand the key sources of tolerance identified to date... Figure 1 illustrates the fertility and grain size response for a subset of varieties to heat stress in the controlled environment assay. In general heat stress causes a significant (p<0.05) reduction in both grain number and grain size, the two key yield components and ultimately grain yield... A subset of exotic introductions that have been screened for heat stress tolerance in the controlled environment assay, showing diverse levels of adaption...

Heat is a key abiotic stress... The effects of heat on grain yield are equally as important as drought and frost... Better adapted varieties also generally perform better in heat stress conditions, especially varieties from Southern Australia...

03 5441 6176 03 5444 4299 admin@orm.com.au CAUTION: RESEARCH ON UNREGISTERED PESTICIDE USE Any research with unregistered pesticides or of unregistered products reported in this document does not constitute a recommendation for that particular use by the authors, the authors' organisations or the management committee... If you have a blackleg problem and are growing a susceptible cultivar your first action should be to change to a cultivar with higher levels of resistance... In comparing while many farm decisions are made intuitive versus logical analytical under the influence of a DSS which provide learning reasoning he suggests the either/or approach to on a topic, they are not necessarily used every time the dichotomies is destructive and goes on to say a decision is made...

Gross margins achieved on-farm for wheat in 2011 may have been lower than shown in Table 2... The gross margin calculations depicted in Figure 5 assumed that canola yielded 50 % of wheat at that site in that year... In comparing while many farm decisions are made intuitive versus logical analytical under the influence of a DSS which provide learning reasoning he suggests the either/or approach to on a topic, they are not necessarily used every time the dichotomies is destructive and goes on to say a decision is made...

Gross margins achieved on-farm for wheat in 2011 may have been lower than shown in Table 2... The gross margin calculations depicted in Figure 5 assumed that canola yielded 50 % of wheat at that site in that year... In comparing while many farm decisions are made intuitive versus logical analytical under the influence of a DSS which provide learning reasoning he suggests the either/or approach to on a topic, they are not necessarily used every time the dichotomies is destructive and goes on to say a decision is made...