Cereals - Background to the characteristics

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Background information on cereal yield, grain quality, straw characteristics and diseases

Background to cereal characteristics

 

Yield

Yields of all varieties are expressed in the tables as percentages of the control. For all crops the control is calculated as the mean (average) fungicide-treated yield of the control varieties that are selected on a UK basis. Untreated yields are also expressed as a percentage of the mean of the fungicide-treated controls. Both fungicide-treated and untreated yields represent the mean performance of the varieties in trials during the five-year period 2010-2014.

Treated yields

Fungicide programmes are applied to treated trials to keep disease incidences below 5% infection of the leaf area.  Treated yields indicate the potential yield of the varieties in the absence of disease.  Plant growth regulators are also applied to treated trials of winter wheat, winter barley and winter oats where the risk of lodging is high.

Untreated yields

Growers have different approaches to the use of fungicides.  Some prefer a programme that protects completely against all disease infection.  Yields in the treated trials indicate which varieties are likely to give the best performances with this approach.  Others prefer to use chemicals as and when disease occurs.  Yields in the untreated trials indicate which varieties are likely to need fewer applications of fungicide in order to produce high yields and, conversely, where risks are greater if less-than-complete control of disease is achieved.

Grain quality

Information presented in the tables on specific weight and 1000 grain weight of spring barley, winter barley, winter wheat, spring oat and winter oat varieties and on kernel content of spring and winter oat varieties, is from the fungicide treated trials in Northern Ireland.  Specific weight, measured in kilograms per hectolitre (kg/hl), is an important quality indicator when selling grain. If the specific weight of a crop is low, it may not reach trading contract requirements.  For winter and spring oats, specific weight is determined on pre-cleaned grain.  Although individual crops will vary, the information on specific weight, grain weight and kernel content presented in this booklet, shows accurate relative values for the varieties.

Oat screenings can be important when selling grain to the quality market. Oat varieties are screened over a 2mm sieve for 15 seconds and the proportion passing through is recorded as a percentage.  These fluctuate greatly from season to season.  Empty husks (that is grains that fail to develop kernels) and free kernels may be present in harvested oats and are undesirable in milling grain.  Details are provided in the variety descriptions on the tendency to produce free kernels and/or empty husks.

Straw characteristics

Straw length is based on data from untreated Northern Ireland trials (except for winter oats where data from the fungicide-treated, but without plant growth regulator, trials are used).  Straw length is expressed in centimetres relative to Quench for spring barley, Granary for spring wheat, Firth for spring oats, KWS Cassia for winter barley, JB Diego for winter wheat and Dalguise for winter oats.

Straw yields are determined from one spring barley and one winter barley trial each year.  For spring barley, straw yields are from fungicide treated plots and are described as very low (less than 2.75 t/ha), low (2.75 – 3.0 t/ha), intermediate (3.0 to 3.25 t/ha), high (3.25 to 3.5 t/ha) or very high (greater than 3.5 t/ha).  For winter barley, straw yields are from the fungicide-treated plots in trials that also received a plant growth regulator and are described as low (less than 3.7 t/ha), intermediate (3.7 to 4.2 t/ha) or high (greater than 4.2 t/ha).

Standing power is calculated using both lodging and leaning data and expressed on a 1 to 9 scale, where a high figure indicates good standing power.  Straw characteristics, such as brackling (in oats and barley) and necking (in barley only), are referred to in the variety descriptions.  Brackling is buckling in the lower part of the stem and necking occurs directly below the ear.  Brackling need not be damaging unless the ears lie on the soil surface.  Necking can be more serious if a clean break occurs leading to ear loss in bad weather.  These straw characteristics are determined from untreated trial data.

Disease

Resistance of varieties to disease is expressed on a 1 to 9 scale in the tables.  A high figure means that the variety is very resistant to the disease whereas a low figure means that the variety is very susceptible. Resistance ratings to disease are drawn from naturally occurring field infections in trial plots in Northern Ireland to which no fungicides were applied.  Yellow rust scores for winter and spring wheat are taken from the HGCA Recommended List 2015 due to low disease incidences in Northern Ireland trials.  Disease incidences on cereal crops in Northern Ireland tend to be more variable from year to year and from crop to crop than in Great Britain.  There can also be a high degree of variability between trial sites.

Spring Barley

Rhynchosporium was recorded in all four spring barley trials in 2014. Infections were highest at Strabane with a maximum of 20% in Shada.  Only Westminster had no Rhynchosporium at this site. Infections were lower at Crossnacreevy and Newtownards with maxima of 5% in Waggon and NFC Tipple.  At Coleraine, many varieties had no Rhynchosporium with a maximum of only 1% in the new variety RGT Planet. Net blotch was prevalent in 2014.  At Strabane, infection reached 25% in Waggon and RGT Conquest, with all varieties affected.  At Crossnacreevy and Coleraine, infections were generally lower but the disease was present in most varieties.  Mildew was recorded at all four sites but only susceptible varieties, such as NFC Tipple, were affected.  Ramularia was also recorded at all sites and ranged from 23% in KWS Irina at Strabane, where all varieties were affected, to only trace amounts at Ballywalter Brown rust was found in trace amounts only at Ballywalter.

Spring Wheat

Septoria tritici infections were much higher in 2014 compared to previous years with an average of 18% across all varieties.  The highest level of infection of 35% was in Trappe with the lowest of 9% in KWS Alderon.  No other disease was recorded.

Spring Oats

Mildew, crown rust and Septoria avenae were recorded in the 2014 spring oat trial.  Mildew infections averaged 16% by the end of July with a maximum of over 30% in Atego whilst none was found in Canyon.  Crown rust was also present, with an average of 14% across all varieties and ranging from none in Rozmar to a maximum of 25% in Firth. Septoria avenae was found in trace amounts in several varieties.

Winter Barley

Rhynchosporium was recorded at significant levels (>5%) in all three trials in 2014.  The highest infection was recorded in KWS Tower at Hillsborough (23%) with maximum infections at Downpatrick and Limavady being 8.5% and 6%, respectively.  KWS Meridian was the only uninfected variety at all three sites.  Mildew infections were high in 2014. Saffron had the highest level of infection, reaching 25 and 6% at Downpatrick and Hillsborough, respectively.  At Limavady, where disease infections were on the whole lower, mildew was only found in trace amounts in Cassata.  Ramularia was found at all sites and in the majority of varieties.  Maximum infections of 25% (Flagon and Florentine), 13% (KWS Glacier) and 20% (Harlequin) were recorded for Downpatrick, Hillsborough and Limavady, respectively.

Winter Wheat

Septoria tritici was recorded in early May at both Limavady and Crossnacreevy.  Infections increased during the growing season to maximum levels of 13% (Gallant) at Limavady and 30% (KWS Cashel) at Crossnacreevy. At both sites, Alchemy had the lowest infection, with all varieties carrying some disease.  Yellow rust was recorded at Crossnacreevy, with KWS Kielder having the highest infection of 30%, whilst many varieties had none.  At Limavady, Fusarium was recorded on all varieties by the end of July with an average of 6% across all varieties. Maximum infections of Fusarium were recorded in KWS Croft, 22.5%, with the lowest being in Cordiale, 0.5%.

Winter Oats

Slight infection by crown rust was recorded in the winter oat trial in 2014. The average across all varieties was <1%.

Maturity

Spring barley varieties differ in maturity by approximately two weeks from earliest to very latest.  There are only minor differences in maturity amongst spring oat, winter barley, winter wheat and winter oat varieties.  Maturity of varieties is included in the tables for all crops as early (E), intermediate (I) or late (L) to ripen.

Sprouting

Germination of grain in the standing crop is extremely detrimental to the quality of the harvested grain.  Whilst it can occur in all crops, it is most commonly a problem of wheat.  Growers in the wetter areas of Northern Ireland have always taken account of this problem when selecting varieties.  The tendency to sprout is indicated in individual variety descriptions if it is a particular strength or weakness of that variety.