Fusarium head blight in wheat crops – FAR has advice on what should be done

Fusarium head blight is showing up in many wheat crops and should be taken into account during harvest, the Foundation for Arable Research (FAR) advises.

There have been widespread recent reports of fusarium head blight (FHB) in wheat crops throughout Canterbury, the foundation says.

Fusarium head blight of wheat, also known as head scab, is most easily recognised on immature heads where one or more spikelets in each head appear prematurely bleached. Sometimes large areas of heads may be affected, and where infection is severe, pink or orange spore masses can be seen on diseased spikelets.

Fusarium-damaged grains are pink or chalky white and shrivelled.

This disease can cause significant yield losses where conditions favour it and grain from affected crops may be less palatable to stock than healthy grain, perhaps containing mycotoxins (a toxin produced by fungi).

The Foundation for Arable Research says it is important to know that not all species of Fusarium produce mycotoxins. F. crookwellense, F. culmorumand F. graminearum can produce mycotoxins but other species are not considered major producers.

The incidence of different species of Fusarium fungi in New Zealand grain varies from year to year and by grain type, harvest date, region and the weather conditions in the season.

A survey in 2000 found that the Fusarium species present in Canterbury were not major producers of mycotoxins. Samples from two wheat crops grown near Methven in December 2018 were identified as Monographella nivalis (snow mould), a species usually included with the Fusarium group of fungi that does not produce mycotoxins.

But because FAR does not know if all the recent reports of FHB are caused by non-mycotoxin producing species, growers are advised to take precautions to minimise the risk of harvesting and storing Fusarium-contaminated grain.

Wet weather promotes Fusarium development and during flowering (GS60-69) crops are particularly susceptible to head blight infection. The higher the rainfall through flowering the higher the risk.

Rainfall through December was high in Canterbury ranging from 62 mm at Chertsey to 177 mm at Methven. At harvest, Fusarium mycotoxins may increase if wet weather causes delays. Also, mycotoxins may increase if the grain has a high moisture content in storage.

Suggested Actions:

  • Harvest Fusarium-affected wheat crops as soon as possible once ripe.
  • Consult the combine manual. Combine adjustments should follow the manufacturer’s manual when first going to the field. Once in the field, operators should invest the time to sample the grain and make adjustments.
    • The most important adjustments include concave clearance, screen openings and cylinder and fan speeds. This is particularly important when dealing with compromised grain quality.
    • If it is determined that grain quality is not an issue, more conventional settings should be used to minimize grain loss.
  • Fan speed
    • Many, but not all, Fusarium-infected kernels are shrunken and have lower densities. Increasing the combine’s fan speed can greatly increase the number of lighter kernels blown out the back of the combine.
  • Harvest and store grain with fusarium contaminated grain separately.
  • Good farm practices will minimise the risk of mycotoxins. Damp grain needs to be dried to minimise risk.

Source: Foundation for Arable Research


EPA considers fungus with potential to promote growth and yield in crops

The Environmental Protection Authority (EPA) is considering an application from a Spanish company to release a new microorganism, the fungus Glomus iranicum var. tenuihypharum. The fungus, and products derived from it, are claimed to promote growth and yield in agricultural and horticultural crops.

The applicant, Symborg Business Development, has developed products overseas using this fungus in various forms. They are used for agricultural and horticultural applications where soils are depleted through intensive use.

In powdered form, the fungus can be dissolved in water and applied through irrigation systems, or as a seed coating. In granular form, it can be spread in furrows.

The EPA’s General Manager of Hazardous Substances and New Organisms, Dr Fiona Thomson-Carter, says the fungus is not a genetically-modified organism and cannot be cultured in a laboratory in the absence of a plant host.

The applicant notes that closely related species have already been found in New Zealand.

“The fungus itself propagates by contact with the roots of a host plant, so its spread is confined to the application zone,” Dr Thomson-Carter says.

The applicant says the fungus is highly saline-tolerant. High salinity is often a feature of soils subject to intense agricultural and horticultural use, and heavy application of fertilisers. Products derived from the fungus have been shown to alleviate the negative effects of salt stress on plants such as lettuce. They also promote drought resistance, Symborg says.

The fungus grows in association with the roots of plants in a symbiotic relationship. Its network of hyphae, or long, branching filaments, improve plant growth through increasing nutrient absorption. They also promote soil stability, by binding tiny particles into coarser fragments. These factors can assist in reducing erosion, and improving plant productivity, Symborg adds.

Symborg Business Development has consulted with the HSNO Komiti of several iwi, and with the EPA’s Te Herenga Network. It discussed concerns that were raised over the possibility of the fungus displacing native species, or forming a symbiotic relationships with invasive species.

Links to the application and information for submitters are provided HERE. 

Source:  Environmental Protection Authority

iHemp Summit aims to kick-start industrial hemp economy

New Zealand’s first iHemp Summit will be held in July with the aim of kick-starting a home-grown iHemp (industrial hemp) economy.

Building on global interest in hemp business opportunities and fuelled by changing legislation, the summit will explore the potential for New Zealand to be the best in the world at growing and using hemp for food, fibre and medicine.

The iHemp Summit is open to companies, farmers, scientists, funders, community leaders, economic development representatives, regulators and others wanting to look at opportunities to collaboratively develop the New Zealand industrial hemp economy.

Richard Barge, chairman of the summit and Treasurer of the NZ Hemp Industries Association Inc (NZHIA), says New Zealand has a fantastic opportunity to create a brand new primary industry based on hemp and now is the time for an informed discussion.

“iHemp is being recognised as a sustainable source of food, fibre and medicine and this creates opportunities for companies to make it part of their future business plan and be part of what is projected by some analysts to be a $NZ75 billion global industry by 2025,” he says.

At the summit experts will share local and international knowledge on hemp, identify the local and export opportunities available to companies entering the industry, highlight the barriers to success within the market and develop strategies and relationships that will help the industry to overcome them.

The lineup of speakers an be found HERE.

New Zealand food safety authorities are considering following Australia by allowing hemp seed to be used in food by changing regulations under the Food Act, the Misuse of Drugs Act and the Medicines Act. These law changes, expected later this year, will allow hemp seed to be sold as a food in New Zealand, in addition to the current legislation allowing the local sale of hemp seed oil.

Andrew Davidson, Director of Midlands Seed and Midlands Nutritional Oils, says:

“Demand for our Cold Pressed hemp seed oil is being fuelled by interest in its beneficial health properties. It’s rich in essential fatty acids such as Alpha-linolenic acid (ALA, Omega 3) and Gamma-linolenic acid (GLA). These are the sort of speciality products that are also attracting the rapidly growing market of vegetarian and vegan consumers looking for new protein sources.

“There is enormous potential in hemp food products and the market is growing around 25% year on year. Legislative changes that will allow other hemp seed based foods will open up new sources of income and markets for the crop, potentially tripling plantings in the next few years.”

The summit is being co-ordinated by the NZ Hemp Industries Association Inc, which has been promoting the iHemp industry since 1997, with sponsorship and support from Midlands Seed/Midlands Nutritional Oils, Agmardt, Hemptastic, Hill Laboratories, Ligar, KiwiNet, Nutrient Rescue and Plus Group Horticulture.

The inaugural iHemp Summit will take place at in Wellington on July 5 and 6.

Details can be fund HERE.


Drought will bring more crop disease, scientists warn

New Zealand’s land-based primary industries need to get ready for increasingly serious crop disease as climate change causes more and longer droughts, according to new research.

In the journal Australasian Plant Pathology, the authors of the study say climate change is expected to bring more droughts in many parts of New Zealand, and more droughts are “likely to increase the severity of a wide range of diseases affecting the plant-based productive sectors”.

Scientists from the Bio-Protection Research Centre, Scion, Lincoln University, AUT University, Landcare Research and the University of Auckland analysed the potential impact of climate-change-induced drought on several commercial plants and their diseases.

They found that in most instances “increased drought is expected to increase disease expression”.

The probable negative effects of drought include

“…a predisposition of hosts to infection through general weakening and/or suppressed disease resistance”. More frequent and more severe droughts could also lead to “emergence of enhanced or new diseases of plants that can reduce primary production”.

New plant disease pressures are expected to occur

“… with potentially devastating impacts for New Zealand’s productive sectors.”

But the news is not all bad.

“Drought may reduce the severity of some diseases, such as Sclerotina rot of kiwifruit and red needle cast (RNC) of radiata pine,” the scientists said.

And in some cases it could “activate systemic defence mechanisms resulting in increased resistance to infection”.

In an extended case study the authors said that the effects of increased drought on New Zealand’s Pinus radiata industry would depend on many factors, including whether drought happened early or late in the season.

“There is urgent need to study the impacts of the different levels of drought and different levels of RNC severity to understand the thresholds at which radiata pine plantations would still accomplish their economic and ecological roles.”

Lead author Dr Steve Wakelin, of the Bio-Protection Research Centre and Scion, said it was essential that more research was carried out so each industry could prepare for the effects of drought.

“Many industries, such as agriculture and horticulture, may have time to gradually change over the next 20 or 30 years, to avoid the worst effects of drought or even take advantage of any opportunities the changing climate may bring.

“However, plantation forestry does not have the luxury of flexibility. What is planted now will need to not just survive but thrive in whatever climate and disease conditions are prevailing in the next 20, 30, or 40 years.

“It’s essential that primary industries with a long production cycle start assessing and addressing the risks and opportunities a much drier climate will bring.”


Wakelin, S.A., Gomez-Gallego, M., Jones, E. et al. Climate change induced drought impacts on plant diseases in New Zealand Australasian Plant Pathol. (2018) 47: 101.

Source: Bioprotection Research Centre

US researchers find corn hybrids with high yields come with more variability

The agriculture industry is challenged with feeding a growing population while minimising its environmental footprint. For corn breeders, this means improving nitrogen-use efficiency and crowding tolerance, all while maximising yield.

A new study from the University of Illinois affirms that the first step is understanding the genetic yield potential of current hybrids.

Fred Below, professor of crop physiology in the Department of Crop Sciences at the university and co-author on the study, says growers and breeding programmes need to understand which hybrids have stable yields across environments or are able to produce greater yields with more fertiliser and higher plant populations.

A hybrid with high-yield stability is less responsive to the environment — it will perform consistently in sub-optimal and optimal conditions.

It’s a workhorse – dependable, but not flashy, Professor Below says.

“Alternatively, a hybrid with high adaptability will yield like gangbusters when planted in optimal conditions, but may let farmers down in a bad year. It’s more like a racehorse: it’ll go, but it’s finicky,” he says.

The problem is that current commercial breeding programmes develop their elite hybrids under optimal conditions — high levels of nitrogen fertiliser and plenty of space between rows — and only test yield responses to different crop-management practices at the pre-commercial stage. This means there is a limited understanding of each hybrid’s stability and adaptability under variable conditions.

To fill the gap, Professor Below and his team evaluated 101 commercially available elite hybrids at two planting densities and three nitrogen fertiliser rates across several years and locations.

“The objective was to measure the interactions of the hybrid with the environment and management style by evaluating an extensive assortment of current maize hybrids for yields and classify them for yield stability and crop-management adaptability to improve future breeding programs,” he says.

The researchers found the amount of applied nitrogen fertiliser had a much greater effect on yield than planting density, but they emphasise that the consistency of the yield response was more important.

Hybrids that combined above-average yield under unfertilized and low-nitrogen conditions exhibited more consistent yields regardless of the environment, even when grown with high rates of nitrogen. These workhorse hybrids would be best used in nitrogen-loss prone areas, or when yield stability is more desired.

In contrast, other hybrids yielded more under high-nitrogen than low-nitrogen conditions, but their yields were more variable, due to a greater sensitivity to environmental conditions. These racehorse hybrids have potential for greater yield return when provided the optimal management and environment, but also carry a higher risk of underperformance in yield when faced with less-than-ideal conditions.

“Selecting hybrids with both high yields and yield stability may be challenging, since yield levels under lower nitrogen availability and yield increases with high nitrogen fertilization were negatively correlated,” Below says.

Hybrids that are adaptable to high plant density and nitrogen conditions exhibited greater yield potential, but also greater yield variation.

Journal Reference:

  1. Adriano T. Mastrodomenico, Jason W. Haegele, Juliann R. Seebauer, Frederick E. Below. Yield Stability Differs in Commercial Maize Hybrids in Response to Changes in Plant Density, Nitrogen Fertility, and EnvironmentCrop Science, 2018; 58 (1): 230 DOI: 10.2135/cropsci2017.06.0340

Source: ScienceDaily

Finding alternatives to herbicides: early-killed rye shows promise in edamame

With the rise of herbicide-resistant weeds in most grain and vegetable crops, American farmers are looking for alternatives to herbicides to control weeds.

Cover crops offer one potential weed management tool. Their use in specialty crops is limited, and no testing has been done so far in edamame.

But a new University of Illinois study (see here) reports that early-killed cereal rye shows promise for edamame growers.

“Early-killed rye reduced weed density by 20 per cent and suppressed early-season weed growth 85 percent,” says Marty Williams, an ecologist with the Department of Crop Sciences at U of I and the USDA Agricultural Research Service.

Edamame is notoriously hard to get started. The soybean variety’s large seeds make them good for eating — edamame seeds are consumed at an immature stage, when they’re firm and green — but the crop can suffer from low seedling emergence in the field.

Williams wasn’t sure that asking them to struggle through a layer of cover crop residue would work.

“The question was: Can we find a cover crop management system that provides some amount of weed suppression without causing a problem for the crop? Edamame is far more sensitive to soil conditions during emergence than grain-type soybean,” he says.


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Global warming could cause key culinary crops to release seeds prematurely

British researchers show that higher temperatures accelerate seed dispersal in crop species belonging to the cabbage and mustard plant family, limiting reproductive success.

This effect is mediated by a gene called INDEHISCENT. The findings appear this week in the journal Molecular Plant.

“In many crops, such as oilseed rape, premature seed dispersal is one of the major causes of crop loss. In the context of climate change, this could become increasingly severe,” says co-senior author Vinod Kumar, a plant developmental biologist at the John Innes Centre in Norwich, England.

“This study exposes the potential vulnerabilities of crop production in the warming world and paves the way for addressing this problem.”

Plants have an extraordinary ability to adjust their life cycle to suit a range of environmental conditions. For example, despite day-to-day changes in weather and temperature, the release of seeds stays in tune with prevailing seasonal conditions.

“Seed dispersal is also a key trait that must be controlled when domesticating plants for food production,” says co-senior author Lars Østergaard, a plant geneticist at the John Innes Centre.

“With the prospect of climate change affecting crop performance, we wanted to understand how environmental signals such as temperature affect seed dispersal.”

One clue came from the observation that Arabidopsis plants, which belong to the Brassicaceae (mustard or cabbage) family, mature and open their seed pods faster when grown at elevated temperatures. Inspired by this observation, Xin-Ran Li, a postdoctoral researcher with Kumar and Østergaard and first author of the study, set out to investigate.

They found a rise in temperature, from 22ºC to 27ºC, accelerated pod shattering and seed dispersal in Arabidopsis plants and important Brassicaceae crops such as oilseed rape, a key ingredient in vegetable oil. Moreover, elevated temperatures accelerated seed dispersal by enhancing the expression of the INDEHISCENT gene, which is known to regulate the development of seed pod tissue and promote fruit opening.

“We speculate that such mechanisms have evolved to facilitate proper seasonal timing of dispersal to ensure that seeds are released under conditions that are both timely and climatically optimal for germination,” Li says. “There could perhaps be a selective advantage in early maturation and dispersal in the wild.”

Beyond the evolutionary implications, the findings could have broad relevance for maintaining yields of important crops. Oilseed rape is one of the largest sources of vegetable oil in the world and is also used for biofuel and animal feed.

More generally, the Brassicaceae family includes many economically valuable agricultural crops, including cabbage, mustard, broccoli, cauliflower, collard greens, Brussels sprouts, bok choy, kale, turnip, radish, and rutabaga.

“We were excited by the discovery that what we found in the model plant Arabidopsis also holds true for both crop plants, such as oilseed rape, as well as non-domesticated species from the Brassicaceae family,” Kumar says. “This highlights the significance of our findings both in the wild as well as in the field.”

Based on their study, the research team suggests new strategies for preparing crops for global warming. For example, plant breeding efforts could focus on developing temperature-resilient varieties capable of coping with climate change. Moreover, gene-editing tools, such as the CRISPR/Cas system, could be used to reduce the expression of the INDEHISCENT gene, thereby delaying seed release and reducing crop loss.

For their own part, Kumar and Østergaard plan to further investigate the molecular mechanisms underlying temperature-induced changes in seed dispersal.

They hope that by understanding this in detail, they will be better equipped to devise strategies to breed for crop resilience to climate change.