• In the dry conditions there was no significant differences between the two pea varieties and no significant difference between the faba bean varieties. The yields for all of the varieties was disappointing and is due in part to the hot dry conditions at flowering but also due to the late sowing of the beans. There are also some indications that a frost may have had some affect on the final yields.
• For further conclusions please see the attached trial report.

• In the dry conditions there was no significant differences between the two pea varieties and no significant difference between the faba bean varieties. The yields for all of the varieties was disappointing and is due in part to the hot dry conditions at flowering but also due to the late sowing of the beans. There are also some indications that a frost may have had some affect on the final yields. 
• For further conclusions please see the attached trial report.

• Frost and heat shock events can cause significant damage to grain crops during flowering and grain filling.
• To reduce the risk of frost or heat events reducing yield, it is advisable to sow different varieties with different maturity lengths right through the sowing window to ensure that not all he wheat sown on hte farm flowers at the same time.
• An alternative practice would be to sow a mix of two different maturity length varieties in the same paddock. 

  Key findings:

Yield in the presence of crown rot was generally barley > bread wheat > durum across both sowing times, but significant differences were evident between varieties.

• Barley, bread wheat and durum varieties differ in their extent of yield loss from crown rot and their actual yield and grain quality (screenings) in the presence of this disease.
• However, all varieties are susceptible to crown rot infection and will not significantly reduce inoculum levels for subsequent crops. Variety choice is not a sole solution to crown rot.

Conclusions

• Sowing date and variety maturity choice is a balance between frost risk and terminal heat stress in the northern grain region. Both can have a significant impact on grain yield. No frost damage was evident at this site in 2014 with either sowing time but terminal heat stress did occur which was more severe during grain filling with the second sowing time. A three week delay in sowing time resulted in an average 24% reduction in yield across the winter cereal entries.  Later sowing pushed grain-fill too far into hotter conditions. This can reduce yield by itself but if there is also an underlying issue with crown rot then delayed sowing significantly exacerbates the expression of this disease with negative impacts on both yield and grain quality.

  Varieties do differ in their extent of yield loss from crown rot and in their relative yield in the presence of high levels of infection, which is often referred to as tolerance. This is a function of a varieties level of partial resistance to infection but appears to also interact with its environmental adaptation and maturity relative to the timing of stress (moisture and heat) which exacerbates the expression of crown rot. Generally quicker maturing barley, durum and bread wheat entries were higher yielding in the presence of crown rot infection in this trial. This does not necessarily mean that these varieties have improved levels of resistance to crown rot infection but rather their quicker maturity allowed them to minimize stress during grain filling relative to longer season entries, reducing the expression of crown rot.

  If forced into planting a cereal crop in a high crown rot risk situation then some barley varieties may provide a yield advantage over bread wheat in that season, as long as early stress does not occur. Some of the newer bread wheat varieties do appear to be closing this gap to some extent. Barley tends to yield better in the presence of crown rot infection due to its earlier maturity relative to bread wheat, providing an escape mechanism which reduces its exposure to moisture stress during the critical grain filling stage. However, a key message is that this decision is only potentially maximising profit in the current season. Growing barley over bread wheat will not assist with the reduction of crown rot inoculum levels as barley is very susceptible to infection. Significant yield loss is still occurring in the best of the barley and bread wheat varieties in the presence of high crown rot infection. Variety selection can improve yield in the presence of crown rot, though all varieties still suffer yield loss, which can maximise profit in the current season but this will not reduce inoculum levels for subsequent crops. Winter cereal crop and variety choice is therefore not the sole solution to crown rot but rather just one element of an integrated management strategy to limit losses from this disease.

• Very high yields were achived in Revenue which indicates the benefit of an early sowing (23rd April). To achieve high yields in Revenue sowing should be undertaken as early as possible. this variety has a strong vernalisation requirement which means that flowering will occur at approximately the same time of year irrespective of sowing date, thereby not increasing the frost risk.
• For further take home messages please see the attached trial report.

2018 Season

• Deep ripping to alleviate compaction and allow better water absorption has improved crop yields at 4 of the 5 EPZ Ripper Gauge demonstration sites in 2018.
• Not all ripping responsive soils required ripping to the same depth.
• While early season dry conditions were challenging and total growing season rainfall was low at the Dunn Rock demonstration site, the deep tillage treatments applied to the site’s sandy gravel over clay soil were a profitable means of increasing barley yield.
• Early season conditions were dry at the Cascade demonstration site. The results collected suggest deep tillage to 300mm or 600mm in the heavy sodic soils present at this site did not improve wheat yield. The rip to 600mm strip achieved an operating gross margin of less than half of both the control strips and the rip to 300mm treatment.
• While the mixing effect of the TopDown achieved a gain of 0.28t/ha when compared to the control, gains in yield were not as large as the effects of deep ripping, spading or a combination on the gravelly sand over clay soil type present at the Coomalbidgup site. The latter tillage treatments improved wheat crop yield by 0.51t/ha to 0.78t/ha when compared to the control strip average of 3.75t/ha, equating to a gross margin increase of between $54/ha and $174/ha.
• The loamy clay to circle valley sand over clay soils present at the Salmon Gums site showed an increase in crop yield of almost 0.91t/ha from ripping to 450-540mm depth. While both the control and shallow deep ripping (ie to 300mm depth) treatments yielded 2.5t/ha of wheat, the deepest tillage treatment yielded approximately 3.4t, equating to a gross margin increase of $316/ha.
• Tillage of the Neridup site’s sandy gravel over clay soils to 300mm increased canola yield compared to the control by 0.41t/ha which equated to a gross margin increase of $179/ha. Tillage to 600mm reduced canola crop yield by 0.35t/ha when just ripped and by 0.9t/ha when exposed to ripping to 600mm combined with a Topdown.

2019 Season

• Tillage treatments applied in 2018 to alleviate compaction and allow better water absorption (ranging in ripping depth from 100mm to 600mm) did not significantly affect crop yield when compared to site controls, regardless of the predominant soil type present at the site or the ripping equipment used. This is likely due to the much dryer than average rainfall conditions that prevailed at all sites in 2019 and the impact of severe frost at two of the demonstration sites (Salmon Gums and Cascade).
• Although the ripping treatments did not significantly improve or reduce crop yield at any of the Ripper Gauge demonstration sites in 2019, gross margin analysis did indicate tillage to 600mm depth plus use of a Topdown slightly improved operating profit at the Neridup site, when compared to the site control. Ripping to 540mm depth also improved financial performance at the Salmon Gums site when compared to the control.
• Ripping to 300mm and 600m depth reduced financial performance at the Coomalbidgup and Cascade Demonstration Sites, compared to the site controls. Two of the tillage treatments also reduced operating profit at the Neridup site compared to the site control.

As the climate is changing to warmer conditions and the atmosphere contains more CO2 (also called CO2 fertilisation), crops grow more quickly and mature earlier. It is important to be aware of these effects on crops so that the risk of frost or heat shock reducing crop yield can be better managed. Even though the climate is warming, it is not clear whether the occurrences of frosts are reducing. In fact, there is anecdotal evidence that frost severity and frequency are not changing, which could be because there is reduced moisture in the atmosphere. If this is the case, it will have implications for sowing time and variety choice. Through the use of PA and VR, growers are able to sow different varieties on more frost prone areas. Without this technology, growers would either need to sow different zones separately, reducing efficiencies, or treat the paddock as a whole, which may see reduce yields and risk in various zones. To demonstrate the advantages of this strategy, over the past two seasons, BCG and SPAA have undertaken paddock scale trials. Two demonstrations were undertaken to compare two varieties of different maturity at two different sowing times.

Insufficient frost events occurred at Wickepin during the susceptible windows in 2014 to cause significant frost damage. Temperature results demonstrated that low in the landscape retained stubble increased the severity of the frost in one of the 10 frost events, but also increased the duration of frost events. Results from 2014 were not conclusive at Wickepin to demonstrate whether retaining stubble increases the incidence or severity of frost.

Although the Wickepin site did not experience damaging frost events in 2013, results show that the severity (minimum temperature) and duration (hrs <0°C) of frost increased at positions lower in the landscape and was less severe under cultivation. Standing stubble treatments also showed colder temperatures than removed stubble treatments. These results also supported the two other trials conducted in Western Australia during 2013 that showed stubble can have an influence on crop canopy temperature.

• During 2014 stubble treatments imposed late in fallow generally had no impact on N response. • During 2014 generally farmers in the absence of frost or unusual rainfall events during the season were able to reliably predict final yield before sowing. Where a site was N responsive, an N fertilizer rate of 20kg actual nitrogen/ha/per tonne of expected yield produced the most profitable result. • During 2014 split N applications only improved yield and protein at Nyngan which experienced a well above average growing season rainfall. • During 2014 split N applications would have possibly reduced risk at two sites, Lake Cargelligo and Ungarie where a decision not to apply the final 1/3 topdressing may have been made due to soil moisture and rainfall outlook. • The benchmark of 20kg/ha of actual N per tonne of expected grain yield assumes unrealistic N recover rates from soil and fertilizer but never the less it continues to be a widely used “number” during the commercial decision making process to topdress crops.

• During 2014 stubble treatments imposed late in fallow generally had no impact on N response. • During 2014 generally farmers in the absence of frost or unusual rainfall events during the season were able to reliably predict final yield before sowing. Where a site was N responsive, an N fertilizer rate of 20kg actual nitrogen/ha/per tonne of expected yield produced the most profitable result. • During 2014 split N applications only improved yield and protein at Nyngan which experienced a well above average growing season rainfall. • During 2014 split N applications would have possibly reduced risk at two sites, Lake Cargelligo and Ungarie where a decision not to apply the final 1/3 topdressing may have been made due to soil moisture and rainfall outlook. • The benchmark of 20kg/ha of actual N per tonne of expected grain yield assumes unrealistic N recover rates from soil and fertilizer but never the less it continues to be a widely used “number” during the commercial decision making process to topdress crops.

Two NVT barley trials were sown in the South Eeast (SE) region of South Australia (SA) in 2018. The Keith trial was
sown on the 16th May and the Bordertown trial site was sown on the 6th June. Long term yield performance (2014
– 2018) from the trial sites are shown in Tables 1 and 2. Both sites experienced frost conditions and extreme heat
conditions throughout the flowering period. Interpret results with caution.

Full NVT data including individual site yields and grain quality can be accessed online at www.nvtonline.com.au.
All NVT data shown is sourced from this site and varietal information is sourced from the 2019 SARDI sowing guide

(https://grdc.com.au/resources-and-publications/all-publications/publications/2019/south-australian-crop-sowing-
guide).

 

• As demonstrated by the results table (see attached trial report), yields of 5-6 t/ha where achieved in a year which included frost at the Streatham site. 
• A number of breeding lines and control varieties are included to enable comparison between yield and growing characteristics.

• In a season characterised by low frost severity, Nuseed Diamond was the highest yielding variety for all three sowing dates.
• In a low frost severity season, earlier sowing on 27 March and 11 April achieved a higher grain yield compared with the later sowing on 30 April.
• Triazine tolerant varieties were generally lower yielding compared with other varieties with a similar phenology.
• Winter type canola yield and oil performance were comparable with spring types when sown before mid April and could be worth considering as a dual-purpose crop due to the additional value generated from grazing.

• Seasonal conditions, characterised by low frost incidence combined with heat stress and terminal drought conditions, significantly affected grain yield and quality responses.
• The highest yields were associated with earlier flowering; there was a significant yield penalty associated with later flowering of slower developing genotypes or when sowing was delayed.

• Bean yields at Conmurra were significantly lower in 2011 than in 2010.
• This trial was located in much shallower soil in 2011 than 2010, and yield was suppressed by dry conditions and several frost events during September and October.

• Early sowing has maximised yields of field peas over the last three years at field sites in SA
  representing low, medium and high rainfall pea growing areas.
• Early sowing has been paramount for economical field pea production in low and medium rainfall areas over this period and continues to be the best management strategy providing consideration for black spot, weeds and frost risk occurs.

The high nitrogen rates caused the plants to burn off in early August. Grain fill of earlier season varieties was affected by frost damage.

• Grazing stubbles with sheep speeds up N cycling and reduces N tie-up by the stubble.  When yield is N limited, tyhis increases grain yield and quality.
• Burning stubble decreased the amount of water stored over the summer fallow and the crops used by 8 to 21 mm, but this did not always decrease yield due to frost damage, N limitation or adequate subsequent recharge.
• Over the six year experiment grazing and then retaining (not burning) stubble has been the most profitable treatment.

• Reducing stubble loads can reduce the severity and duration of frost events under certain conditions. However, under the situation of multiple and severe frost events the influence of stubble is less defined and stubble reduction does not reduce risk.
• In the Mallee, most stubble management practices carried out prior to seeding to increase stubble incorporation or breakdown (cultivation, slashing) did not reduce stubble loads enough to reduce frost severity and duration.
• In the Wimmera, reducing stubble loads did not consistently reduce frost severity or duration possibly due to a combined effect of greater canopy closure with higher yield potential (2014) and higher stubble break down with low stubble levels (2015).
• Stubble management in frost prone areas is not about complete removal of stubble, but reducing it to a level that minimises your risk.

High stubble loads appear to increase frost damage by reducing the amount of heat radiated from the soil at night, leading to lower canopy temperatures and greater frost severity, duration and damage.

Preliminary results have shown that the removal of stubble can reduce frost severity and duration. However, this does not advocate the complete removal of all stubble on farming properties. The removal of stubble may be beneficial in low lying frost prone areas of paddocks.

Temperature results from both sites have demonstrated that stubble loads above 2t/ha increased the severity and duration of some frost events. Analysis of results on yield and frost damage is ongoing and will be presented.

Temperature results from both sites have demonstrated that stubble loads above 2t/ha increased the severity and duration of some frost events. Analysis of results on yield and frost damage is ongoing and will be presented.

Tedera did not have enough biomass to take in any of the two samples in August and November, which was due to frost damage.Balansa and Serradella produced the same amount of biomass, and both were more productive than ryegrass. However, it was observed that ryegrass was severely grazed by kangaroos, so samples were not reflective of what the true biomass would normally be.

• There was no significant difference in field pea yield between the treatments.
• The yield only reached 20% of potential, according to WUE principles.
• A severe frost in late September resulted in massive pod damage.

In this trial we observed no response to the non-nitrogen test products, either on the low or high fertilizer at seeding treatments.  However we cannot say that they will not work under other site, season and management conditions.  Unfortunately the promoters can rightly say that we did not give their product the best opportunity to perform and so it was an invalid test.

Such a reply has implications for the promoters rather than the testers. The promoters have an obligation to state under what conditions they expect their product to work and those conditions  have to be readily recognized by potential local users. It is not good enough to list a range of processes which the product “improves” or even to quote circumstances from elsewhere where the product has worked. Any new product (and agronomic practice for that matter) has to be  extensively tested under local conditions so that the promoters can say what the chances of success are if used by local growers.

We, the testers are able to state that the product did not work under our conditions and in the Popper sense of “falsification” have disproved any statement about how generally useful the product might be. That is, 100% of our observations say it does not work, but that is hardly useful. We could have had a drought year and nothing would have worked. We could have been wiped out by      frost or we may have chosen a site with the wrong levels of fertility. We did not test across a full range of conditions and so have too limited information for invalidating the all claims made for the products. This problem is equally true for validation by the product developers.

Products MUST be tested across a wide range of local conditions before it can be promoted with confidence to the broader agricultural community.

In short, any new product (or agronomic practice) requires a major investment in validation trials which are ranged across the full set of management, site and season conditions experienced in the new environment. Otherwise, general promotion of those products should not be believed until such work has been done.

• Variety phenology and sowing date need to match to avoid plants flowering and podding during periods of severe frost. The highest yield in 2017 came from the 6 April sowing of the long season varieties Archer and ATR WahooA that flowered in early August.

• ATR Stingray and Nuseed® Diamond flowered earlier than the optimum start of flowering (OSF) date (28 July) from both the 6 April and 20 April sowing dates with significant frost damage incurred at both sowing dates.

• Canola varieties have the ability to recover from severe frost damage where soil water is not limited.

• Although time of heading and flowering are considered the most sensitive stages for frost damage in cereals, sensitivity to early frost damage occurs from the start of stem elongation and is referred to as ‘stem frost’.

• Stem frost can be minimised by matching sowing date and cultivar phenology so that stem elongation starts after the period of greatest frost risk.

• Varieties that started stem elongation early (fast developing varieties sown early) were exposed to an increased number of frosts during the susceptible development stages, whilst winter types sown early had an extended vegetative period and were not exposed to the same frost risk, which reduced damage from stem frost.

• Crops can recover from stem frost where there is moisture available to support new tiller growth. However, the resulting effect on phasic development stage synchrony leads to delayed maturity and harvest issues.

• There was no observed difference in frost tolerance of specific cereal species observed in 2017.

Executive summary

Recently interest in the role of renovation cropping in the farming systems of the Western Australian wheatbelt has increased.  It has been proposed as a means of addressing the apparent decline in soil quality in some intensively cropped areas and the increased incidence of herbicide resistance. 

Renovation cropping involves either turning a crop into the soil at flowering or cutting the crop and leaving it on the soil surface.   This is done to maximise the amount of organic matter added to the soil and to control weeds most effectively.  In the Western Australian wheatbelt the focus has been on using pulses, although a range of crops can be used.  The pulse phase of a rotation is favoured as pulses improve the nitrogen status of the soil. In addition the returns to pulses are lower relative to cereals and canola, so the forgone profit in the year of renovation cropping is lowest.

Renovation cropping leads to changes in soil conditions that persist for at least the following season.  It reduces weed numbers in the following crop by reducing seed set, increases the availability of nutrients and may improve soil structure.  Lower weed numbers reduce the carry-over of root diseases thus providing a disease break for the following cereal crop.  Recent trials have shown likely yield increases of 20-30% above those after a pulse crop and increased grain protein levels in the following cereal.

The main cost of green manuring is the income lost by sacrificing grain production.  The loss in income plus any additional costs associated with soil renovation need to be recouped in the following season(s).  Therefore the income from the yield increase(s) in the subsequent year(s) needs to be equal to or greater than the total costs of renovation, including the income forgone.

Despite the increase in interest in renovation cropping, no comprehensive economic analysis has been undertaken to determine its role in Western Australian farming systems.  This study investigates circumstances under which renovation cropping is likely to be profitable and estimates the needed increase in farm profit, given the variability of yields that result from seasonal influences.

To investigate the consequence of risky yields historical rainfall data was used to generate yield distributions for different rainfall zones, soil types and crops.  The yield distributions were used as input to a simulation model to determine the distribution of income, resulting from renovation cropping, in a lupin:wheat:wheat rotation.  The mean yield boost resulting from renovation cropping was estimated to be 3% based on trial results (F. Hoyle, pers. comm.). 

The results of the analysis showed that there is a 30-40% chance of increasing profit if yield is increased by 30% on average.  However, the results were very sensitive to the average increase in yield.  The probability that profit will be increased was halved when yield boost was reduced to 20%. 

The yield increase required to make renovation cropping profitable can vary between 100% under the worst case and below 10% under the best case.  The variability depends on grain prices, grain yield in the renovation phase (if a commercial crop had been was harvested), and the cost of renovation and grain yields in the following crop phase.

The likelihood that profit will be increased depends largely on minimising income forgone relative to the increase in income in the following years.  Therefore green manuring will be most profitable when done in years when the grain yield of the pulse crop is low, and/or when the following cereal yield is very high. 

Weather forecasts are not yet sufficiently developed to predict potentially good years over 12 months ahead, so renovation needs to be undertaken in poor years to maximise the chances of increasing profit.

Identifying poor yielding years prior to renovation does present some difficulty although weather forecasts may improve the chances of undertaking renovation in the 'right' year.  .  Also yield potential is determined directly by biomass of the crop, so this may be used as an early indicator of yield.  Where waterlogging or disease has caused low vegetative growth, resistant weeds are widespread in a paddock, or where frost has damaged the crop green manuring is more likely to be a profitable option. 

This suggests a role for tactical use of renovation cropping so that it is undertaken in years where the forgone income is minimised (i.e. it is done in poor yielding years).  The results of the analysis show that only small yield increases in the following cereal crop are necessary to break even in these circumstances. 

The analysis highlighted gaps in the knowledge of the impact of renovation cropping that may be important for more comprehensive economic analysis, or information that may improve the grower’s ability to undertake the practice profitably.  Further research into green manuring could include:

• Determining whether the profitability of green manuring can be increased using long term weather forecasts.  Improving the estimates of the probability of achieving different yields may allow farmers to renovate soils in years that have lower risk.
• More information on the effects of green manuring on yield and protein for different crops under different conditions is required to better assess the economic advantages of green manuring
• The profitability of green manuring relative to other methods of improving sustainability of cropping also needs to be addressed.

 

Executive summary

Recently interest in the role of renovation cropping in the farming systems of the Western Australian wheatbelt has increased.  It has been proposed as a means of addressing the apparent decline in soil quality in some intensively cropped areas and the increased incidence of herbicide resistance. 

Renovation cropping involves either turning a crop into the soil at flowering or cutting the crop and leaving it on the soil surface.   This is done to maximise the amount of organic matter added to the soil and to control weeds most effectively.  In the Western Australian wheatbelt the focus has been on using pulses, although a range of crops can be used.  The pulse phase of a rotation is favoured as pulses improve the nitrogen status of the soil. In addition the returns to pulses are lower relative to cereals and canola, so the forgone profit in the year of renovation cropping is lowest.

Renovation cropping leads to changes in soil conditions that persist for at least the following season.  It reduces weed numbers in the following crop by reducing seed set, increases the availability of nutrients and may improve soil structure.  Lower weed numbers reduce the carry-over of root diseases thus providing a disease break for the following cereal crop.  Recent trials have shown likely yield increases of 20-30% above those after a pulse crop and increased grain protein levels in the following cereal.

The main cost of green manuring is the income lost by sacrificing grain production.  The loss in income plus any additional costs associated with soil renovation need to be recouped in the following season(s).  Therefore the income from the yield increase(s) in the subsequent year(s) needs to be equal to or greater than the total costs of renovation, including the income forgone.

Despite the increase in interest in renovation cropping, no comprehensive economic analysis has been undertaken to determine its role in Western Australian farming systems.  This study investigates circumstances under which renovation cropping is likely to be profitable and estimates the needed increase in farm profit, given the variability of yields that result from seasonal influences.

To investigate the consequence of risky yields historical rainfall data was used to generate yield distributions for different rainfall zones, soil types and crops.  The yield distributions were used as input to a simulation model to determine the distribution of income, resulting from renovation cropping, in a lupin:wheat:wheat rotation.  The mean yield boost resulting from renovation cropping was estimated to be 3% based on trial results (F. Hoyle, pers. comm.). 

The results of the analysis showed that there is a 30-40% chance of increasing profit if yield is increased by 30% on average.  However, the results were very sensitive to the average increase in yield.  The probability that profit will be increased was halved when yield boost was reduced to 20%. 

The yield increase required to make renovation cropping profitable can vary between 100% under the worst case and below 10% under the best case.  The variability depends on grain prices, grain yield in the renovation phase (if a commercial crop had been was harvested), and the cost of renovation and grain yields in the following crop phase.

The likelihood that profit will be increased depends largely on minimising income forgone relative to the increase in income in the following years.  Therefore green manuring will be most profitable when done in years when the grain yield of the pulse crop is low, and/or when the following cereal yield is very high. 

Weather forecasts are not yet sufficiently developed to predict potentially good years over 12 months ahead, so renovation needs to be undertaken in poor years to maximise the chances of increasing profit.

Identifying poor yielding years prior to renovation does present some difficulty although weather forecasts may improve the chances of undertaking renovation in the 'right' year.  .  Also yield potential is determined directly by biomass of the crop, so this may be used as an early indicator of yield.  Where waterlogging or disease has caused low vegetative growth, resistant weeds are widespread in a paddock, or where frost has damaged the crop green manuring is more likely to be a profitable option. 

This suggests a role for tactical use of renovation cropping so that it is undertaken in years where the forgone income is minimised (i.e. it is done in poor yielding years).  The results of the analysis show that only small yield increases in the following cereal crop are necessary to break even in these circumstances. 

The analysis highlighted gaps in the knowledge of the impact of renovation cropping that may be important for more comprehensive economic analysis, or information that may improve the grower’s ability to undertake the practice profitably.  Further research into green manuring could include:

• Determining whether the profitability of green manuring can be increased using long term weather forecasts.  Improving the estimates of the probability of achieving different yields may allow farmers to renovate soils in years that have lower risk.
• More information on the effects of green manuring on yield and protein for different crops under different conditions is required to better assess the economic advantages of green manuring
• The profitability of green manuring relative to other methods of improving sustainability of cropping also needs to be addressed.

 

• Stubble rentention increased the severity of frost events in experiments over two years
• There was no difference in floret sterility due to stubble treatment, but grain yield was highest where stubble was removed by burning. 
• Stubble rentention reduced the amount of heat stored in the soil during spring. With less heat stored there is less capacity for energy release at night to buffer against frost damage.
• Consider management strategies that avoid frost (e.g. crop choice, sowing date, variety choice) where high stubble loads are retained at sowing. 

For some, 1993 waws the best year ever. For others a disaster caused by mice, frost and the decision to plant a majority of barley crop.

Cu fertiliser greatly increased yield from 0.6 t/ha to 1.60 t/ha.  

In general oxide source was equal to or superior to the sulfate source in wet mixes. In dry mixes in the same trial Cu oxide was only 66 % as effective as the sulfate.

A recent development in diagnosing Cu problems by a technique of using the youngest fully emerged leaf. Copper concentrations of less than 1.3 ppm (mg/kg) in the yougest fully emerged tissue , suggest that soil Cu deficiency will reduce grain yield .

The tissue testing technique was used on arange of Cu trila in the district to confirm the method (UWA Lonragan, Robson , Snowball)

For the first time it has been possible to distinguish crop damage caused by Cu deficiency from that caused by other factors such as frost, drought and root rots which produce similar symptoms.

Cu fertiliser greatly increased yield from 0.6 t/ha to 1.60 t/ha.  

In general oxide source was equal to or superior to the sulfate source in wet mixes. In dry mixes in the same trial Cu oxide was only 66 % as effective as the sulfate.

A recent development in diagnosing Cu problems by a technique of using the youngest fully emerged leaf. Copper concentrations of less than 1.3 ppm (mg/kg) in the yougest fully emerged tissue , suggest that soil Cu deficiency will reduce grain yield .

The tissue testing technique was used on arange of Cu trila in the district to confirm the method (UWA Lonragan, Robson , Snowball)

For the first time it has been possible to distinguish crop damage caused by Cu deficiency from that caused by other factors such as frost, drought and root rots which produce similar symptoms.

• At Streatham, no variety was significantly higher yielding than Currency, however at Hamilton, both Credit 1 and Everist were superior in yield. 
• It would appear that no Triticale variety has any better frost tolerance than any other variety and that susceptibility or otherwise to frost is mainly governed by when flowering occurs relative to the timing of the frost. Any variety which flowers when there is a frost will be badly affected. Many varieties with poor yield were badly frosted. 

Four triticale varieties and lines were evaluated and one composite line (Tahara/Breakwell). Grain yields were highly correlated with the degree of frost damage around ear emergence and flowering. The late flowering Breakwell avoided most frost damage from October frosts and yielded significantly higher than all other varieties. Crackerjack and the composite line were also significantly higher yielding than Tahara and Tickit. The latter varieties were both severely affected by frost damage.

• Over the last 5 years later maturing lines (flowering mid-November) have generally significantly out-yielded Tahara. The exception was 2000/01 where Tahara was 10-25% higher yielding than nearly all other lines due to both the absence of frost damage and the sharp finish to the season. With this season's good spring rains Tahara was back at the bottom of the pile at Symmons Plains and less dominant at Riccarton. However the fact that this year the later lines were not the highest yielding in such a favourable season suggests that the main advantage of these lines is through avoiding frost damage at flowering. 
• For further conclusions please see the attached trial report.

• Triticale yields were surprisingly good at Symmons Plains being on average higher than all except the best wheats. In contract at Riccarton the wheats tended to be higher yielding possibly due to a small amount of frost damage in the triticale. 
• It has been difficult to select a new triticale variety that is consistently higher yielding than Tahara. This appears to be complicated by greater variety x site as well as variety x year interaction in comparison with wheat trials. The front runners after several years of trials appear to be Wig, W47, Treat, Tickit and AT509. 
   

Birchip: The site was located in a paddock with moderate subsoil limitations (40 to 70cm layer had chloride reading of 1800ppm, and an EC of 0.6dS/m). The site had a previous legume history and was high in soil available N (prior to sowing the soil contained 230 kg available N/ha to 1m depth).

Kooloonong: The site was located on a Mallee land system, on a flat to sloping rise with a sandy loam soil to a depth of 40cm and at greater depth a sandy clay loam to at least 130cm. The soil has no subsoil limitations but because it is light and sandy, leaching of nutrients can be a problem. 2010 had a growing season rainfall of 329mm (decile 10).

Sowing cereals in early April on a soil profile full of water is possible if:

• long season varieties are planted to ensure that the crop does not flower before the high-risk frost period has passed,
• the topsoil is moist at seeding to ensure that the crop germinates and allows for early root growth down into the stored water in the subsoil, and
• weeds can be controlled.

Traditionally sowing wheat in Western Australia was not recommended until after Anzac Day.  A date based on the yield performance and maturities of commercially available wheat varieties in the 1990s. Since then growers have seen the release of Mace, a high yielding and very adaptable variety which at 67% dominates the area sown to wheat in WA in 2015 (Data courtesy of CBH group). Growers are now set up and keen to take advantage of any summer rainfall, but there is limited information on which wheat varieties to grow with a very early sowing opportunity.

Research carried out by James Hunt et al. (2014) suggested that the faster maturing winter wheat Whistler appeared well adapted to WA. When sown in mid-April Whistler was able to yield equivalent or better than Mace planted in late May (Crop Updates 2015). Results from Dandaragan and Katanning trials do support this suggestion but this research also suggests there are commercial varieties currently available in WA which can yield similar or higher and have a superior grain quality classification compared to Whistler. However these varieties can still be at the risk of frost and grain quality problems associated with very early sowings.

At all three sites in this trial series, barley out yielded wheat with both the mid-April and the early May planting (note we have included the predicted yield for barley with mid-April planting at Dandaragan of 7t/ha in this assessment). Barley was over 1.5t/ha better than wheat with both mid-April and early May planting. Whilst this research continues to highlight the need for a wheat variety which is more suitable for early sowing opportunities in Western Australia, growers looking for a cereal to sow in April could consider barley as being their new wheat variety until such wheats are released. Whilst this is only one year of observations there are many reasons to consider barley particularly with mid-April planting ahead of planting a wheat variety, including reduced (but still possible) frost risk.

The feed barley varieties Lockyer, Oxford, Rosalind and Urambie did not provide any yield advantage over those with a ‘malt’ classification at Dandaragan in 2015. The ‘malt’ varieties would therefore have been more profitable than the feed varieties as they were received with a premium over the feed barley varieties (either Malt 1 or Malt 2) at a similar grain yield.

With any early planting opportunity growers need to factor in increased fungicide costs. At Dandaragan powdery mildew and barley leaf rust in the barley plots and yellow spot in the wheat plots had to be controlled, particularly in the mid-April planting.

 

Pre sowing comment: good moisture. Small amount of capeweed and lupins.

Early season comment: dry period after emergence. Some lupins present and a small amount of radish.

Mid season comment: dry periods after frost.

Pre harvest comment: severe frosts during grain fill effected earlier maturing lines.

• The flowering time response of varieties was influenced by sowing time. 
• Managing a varieties sowing time to target flowering within a flowering window is one tool to manage risk of reduced yield reduction and frost damage risks. 
• The estimated flowering window in the northern districts is August 16th to September 9th.  Early maturing varieties such as Emu Rock, Bonnie Rock, Supreme and Westonia achieve 50% flowering before August 18th when sown on May the 9th
• Mid –long maturing varieties such as Calingiri, Cutlass and Zen, flowered after September 9th when sown on the 2nd of June.
• Mace wheat is a parent of Scepter, and both are considered mid-long maturing wheats.  However, the development of Scepter wheat at the trial site in 2016 was longer than Mace.  Scepter reached the start of flowering approximately 6 days after Mace when sown in either May and June.  It yielded similarly to Mace at the first sowing time but significantly better at the second sowing time.
• The cooler temperatures and the higher rainfall have benefited production of the longer maturing wheats which have some adaptation for the northern region. 

In spite of a warm and very dry October combined with 3 frosts over the site, the winter wheat varieties performed well. Tennant, with the longest maturity of the 4 winter wheat varieties was the variety most affected by the dry, hot October. MacKellar performed extremely well, with a yield of 5.9 t/ha. The spring wheat varieties all produced high screenings as well as high protein. This was the result of the later sowing coupled with the seasonal conditions. Silverstar, an early maturing variety, produced an outstanding yield, possibly being affected less by frost than the other varieties.

Wheat varieties were evaluated at Campbell Town (dryland) and Longford (irrigated). At Campbell Town frost damage at ear emergence and flowering was the factor most influencing yield. All the later maturing lines avoided some of this damage and were the highest yielding. Grain yields at the Longford site were exceptionally high (average of 10.2 t/ha). The CSIRO line 95102.1 was particularly impressive yielding 12.0t/ha. Two other CSIRO lines also yielded very well and the good run of these lines continues. The best performing “named” varieties were Mackellar and Alberic, the latter also yielded well at Campbell Town being late flowering. An additional 50 kg/ha topdressed nitrogen tended to increase yields of all lines at Longford and this effect was close to significant. The very high yields at Longford, both in the trial and commercial crop illustrate the potential for high input crops with irrigation and provide some light in an otherwise very ordinary season.

• In 2015, seasonal conditions tended to favour shorter season varieties. When selecting varieties,need to ensure long-term data and varietal disease profiles is considered in addition to the annual trial results.
• The new variety Scepter has the highest long-term production value for the region, followed by Corack, Cosmick and Trojan.
• Foliar disease had little impact on varietal performance in 2015, but frost combined with terminal drought affected south east trials.

Match the maturity of a variety with sowing date to maximise biomass accumulation, flowering during the optimum time and maximise grain yield potential: – “If sowing early, sow long, or don’t sow wheat at all”.

• There is an opportunity cost and yield penalty of sowing short-mid season varieties too early (early to late April) in the central and southern production zones, similar to sowing mid-long season varieties too late.
• If sowing mid-April in the northern, eastern and southern wheatbelt without frost risk sow mid-long season varieties. If sowing in late May sow short-mid season wheats.
• If sowing in areas of frost risk in the northern, eastern and southern wheatbelt, don’t sow wheat in April, in early May sow mid-long season varieties in areas of low to moderate frost risk and sow areas of severe frost risk in late May to mid-long varieties.
• Highest yields at all sites have typically been achieved by mid-long maturing varieties sown from late April onwards, and short-mid maturing varieties sown in mid-May. At moderate to severe frost prone sites and with disease pressure, however, delaying sowing of mid-long maturities into mid-May, and the use of winter/long wheats when sowing in early to late April, is essential to minimise frost and disease risk.

• Sowing date and variety maturity choice is a balance between the risk of frost versus terminal heat stress.
• Earlier sowing can increase frost risk, but also generally maximises yield potential and reduces the extent of yield loss from crown rot.
• Cereal crop and variety selection can have a significant impact on yield where there are high levels of crown rot infection.
• Durum wheat, barley or bread wheat varieties with increased susceptibility to crown rot, should only be grown in paddocks known to have lowrisk inoculum levels based on testing (e.g. PreDicta B).
• All winter cereal varieties are susceptible to crown rot infection and will not significantly reduce inoculum levels for subsequent crops. Cereal crop and/or variety choice is not the sole solution to crown rot.

The model was very accurate at the actual soil site location. Inaccuracies can be due to a number of reasons - namely weed burden at the site, frost, variations of soil type across the paddock and variations of rainfall received in the paddock versus the recording location. Furthermore, if the soil classification is slightly different in the model than is actually the soil physical properties, this could cause deviation as well. Lastly, as crop phenology can vary from cultivar to cultivar, this can cause discrepancy too.

• The quicker maturing varieties LRPB DartA, HatchetA LivingstonA, MaceA, SceptreA, MitchA and SuntopA were generally lower yielding than other entries at SD1, but were more yield competitive with other entries at SD2 and SD3.
• The longer season varieties EGA WedgetailA (6.08 t/ha) and EGA EaglehawkA (5.88 t/ha) were the highest yielding varieties at SD1, followed by CutlassA (5.51 t/ha) and LRPB FlankerA (5.36 t/ha).
• The mean yield at SD1 (4.89 t/ha) was not significantly different from SD2 (4.63 t/ha), but SD3 (3.56 t/ha) was significantly lower yielding than either SD1 or SD2.
• All varieties yielded their lowest from SD3.
• Protein percentages were low to moderate (mean of 9.8% for SD2 and 10.3% for SD1) with no significant difference from SD for any of the entries

• There have been findings that Wyalkatchem is generally more frost prone than other varieties.
• If you are cropping a high frost risk area, good management would suggest minimising input costs (e.g. fertiliser) in these areas.
• Due to the large LSD there were no statistically different treatments. However there seems to be a trend that the lower seeding rate improved yield.
• There was no significant yield difference between retaining stubble and burning the stubble at both seeding rates.

• Coefficient of variation was unacceptably high therefore results will not be presented.