Maine Grain and Oilseed Newsletter - Vol. 1, No. 3 — June 2013
Vol. 1, No. 3
57 Houlton Road, Presque Isle, ME 04769
207.764.3361 or 1.800.287.1462
In consideration of the weather we’ve had for sowing spring cereal crops, this issue will address some important tools in which to help manage your crops. With the alternating wet and dry spells much of us have experienced during planting season, the result has been several different distinct planting periods. Most crop management practices rely upon the crop being in a certain developmental stage in which to achieve maximum benefit. Being able to identify these stages will be important this year as much of our crop will likely differ in developmental maturity for much of the remainder of the season. As a note, many early planted small grain fields are showing signs of nitrogen deficiency; a likely result of delayed emergence and excessive rainfall. Growers are encouraged to consider top-dressing a nitrogen source to supplement the remaining nitrogen should fields be displaying symptoms of deficiency.
If you are interested in growing organic grains, see the Organic Grain Twilight Meeting and BBQ, July 9, at the Aroostook Research Farm.
Andrew Plant, Extension Agriculture Educator
Ellen Mallory, Sustainable Ag. Specialist
Ellen Mallory, Sustainable Agriculture Specialist, UMaine Extension
Many management practices for cereal grains, such as tine harrowing for weed control and topdressing nitrogen to boost grain protein, require the crop to be in a particular developmental stage to be most effective. A number of numeric scales have been developed to describe the growth stages of cereal grains. The most commonly used scale is the Feekes scale, which divides the life of the plant from emergence of the first leaf through grain ripening into eleven developmental stages (Figure 1). The heading and ripening stages are then subdivided for greater detail.
Figure 1. Growth Stages of Cereals
B. Curran and D. Lingenfelter, cords., The Penn State Agronomy Guide (University Park: Penn State College of Agricultural Sciences, 2013).
Developmental Stages (Feekes Scale) and Associated Management Practices
Feekes 1 – Emergence and First leaf
This phase begins with the emergence of the first leaf and ends when tillering begins, usually after 3-4 leaves have emerged from the main stem. At this stage, check plants for uniform emergence and plant stands. If weeds will be managed with tine harrowing (i.e. Lely or Kovar), harrow either before the plants emerge (before Feekes 1) or after plants have 2-3 leaves, or at both times. Do not harrow when the plants have only 1-2 leaves because they are easily dislodged or buried. If managing weeds with herbicides, this is a good time to assess weed pressure.
Feekes 2-3 – Tillering
The main shoots of cereals produce side shoots called tillers. Each tiller can develop into a stem with a seed head although it is common for some tillers to die depending on growing conditions. Fall planted grains typically start tillering in the fall and resume tillering the following spring. If plant stands are thin in early spring, consider topdressing nitrogen as early as possible to enhance tillering and increase yields.
Feekes 4-5 – Pseudo-stem grows upright
After tillering, the plant’s pseudo-stem (formed by the sheaths of the leaves) begins to lengthen and grow upright. Topressing nitrogen at this stage to increases grain protein levels and yields. This is also the time to apply many post-emergence herbicides for weed control.
Feekes 6 – Jointing begins
The plant starts to grow upward via the extension of the stem between nodes. At this stage, the first node is visible at the base of the shoot indicating that the seed head is moving up the stem. This is the cutoff stage for applying certain herbicides. It is also the stage when driving over the crop starts to cause damage because the seedhead is now above the soil surface.
Feekes 7 – Second node of stem visible
Jointing continues with the extension of the stem under the first node. Two nodes are now visible.
Feekes 8 – Flagleaf visible
The flagleaf is the last leaf to emerge and is responsible for the majority of the photosynthesis for grain fill. To determine if an emerging leaf is the flag leaf, split the leaf sheath and observe the head’s placement. If the head is visible, and no additional leaves are inside the stem, the plant is at Feekes 8. Now is the time to decide if a fungicide application is warranted to protect the flagleaf once it is fully emerged.
Feekes 9 – Ligule of flagleaf visible
At this stage, the flag leaf has fully emerged from the whorl. The flag leaf sheath will extend and the head will begin to swell.
Feekes 10 – Boot stage, heading, and flowering
The plant enters the boot stage once the head develops and is visible as a swollen area of the leaf sheath below the flagleaf. The boot stage is further divided to describe the heading and flowering process. Some important stages are:
10.0 – Boot stage
10.1 – Awns just visible, heads emerging through slit of flagleaf sheath
10.3 – Heading ½ complete
10.5 – Heading complete – heads fully emerged
10.5.1 – Beginning of flowering (wheat)
10.5.4 – Flowering complete, kernel watery ripe
Cereal grains are most susceptible to Fusarium head blight (scab) during flowering. If fungicides will be used to suppress the disease, Feekes 10.5.1 for wheat, and 10.5 for barley is the optimum time to apply them.
Feekes 11 – Ripening
11.1 – Milky ripe – kernel exudes milky liquid when squeezed
11.2 – Mealy ripe – kernel contents are soft but dry
11.3 – Kernel hard – kernel is hard to divide with thumbnail
11.4 – Kernel is ripe for cutting and straw is dead
For more information see: University of Minnesota P.M. Growth and Development Guide for Spring Barley and Growth and Development Guide for Spring Wheat. These guides include a description of another commonly used developmental scale, the Zadok scale, and compare it to the Feekes scale.
Steven B. Johnson, Ph.D., Crops Specialist, UMaine Extension
Fusarium Head Scab
Fusarium Head Scab is caused the fungus Fusarium graminearum. The pathogen may infect heads of small grain (oats, rye, but most notably wheat and barley) from flowering through kernel development. The majority of the infection occurs during flowering or heading. Growing conditions with high rainfall and long periods of high humidity during grain flowering and early grain fill provide an ideal environment for the pathogen to infect small grain heads. Ripening grain fields under ideal infection conditions may show Fusarium Head Scab symptoms (photo 1). Field symptoms include premature bleaching of individual spiklets, some of the head or all of the head. Infected kernels are shriveled. Severe cases of Fusarium Head Scab may show a salmon-colored mass of the pathogen at the base of some glumes (photo 2). The disease will reduce yield and test weight (photo 3). More importantly, the pathogen produces a mycotoxin called deoxynivalenol (DON), more commonly know as vomitoxin. There are no resistant varieties but some do show more tolerance than others.
Click on the images below to view enlargements.
Weather is dominant factor in determining the threat of Fusarium graminearum infection when the pathogen is present. The dominant factor determining if the pathogen is present is the proximity to corn, especially no till or minimum till corn.
While the presence of Fusarium Head Scab does not mean the presence of vomitoxin, one can expect high levels of vomitoxin from grain with high levels of Fusarium Head Scab. Humans and animals can get sick from eating grain or grain products with vomitoxin present. Vomitoxin can cause feed refusal in animals and additional problems in lactating or breeding animals. Anyone eating or feeding grain should have the grain tested as varying end uses have varying advisory levels for vomitoxin.
The Food and Drug Administration has established vomitoxin advisory levels as follows:
Finished grain products for human consumption: 1 ppm
Cattle, over 4 months old (less than 50 percent of diet): 10 ppm
Poultry (less than 50 percent of diet): 10 ppm
Swine (less than 20 percent of diet): 5 ppm
Other animals (less than 40 percent of diet): 5 ppm
Other parts of the world have these levels as statutes. They are advisory levels in the US. Market forces often demand these or lower levels of vomitoxin. A laboratory test is the only way to confirm the level of vomitoxin in grain.
Selected Barley Plant Health Medicines
There are plant health medicines to reduce Fusarium Head Scab and vomitoxin levels. These have shown more benefit under milder epidemics and they all need the addition of a NIS at a 1% v/v. The timings of the applications are critical as is the nozzle angle. For example, barley planted from May 3, 2012 to May 9, 2012 was at Feeke’s growth stage 10.3 on June 29, 2012. Barley planted from May 18, 2012 to May 24, 2012 was at Feeke’s growth stage 5 to 6 on June 29, 2012. I am working on incorporating models into predictive system to predict the risk of Fusarium Head Scab as well as the timing of control materials.
Research has shown that tilting the nozzles at 30 to 60 degree angle has drastically improved control. I would recommend this if it is at all possible. The best control was obtained with forward and reverse facing nozzles.
Stratego (7 oz/A) can be applied up to when the ligule of the flag leaf emerges. This is up to Feeke’s growth stage 8.
Head scab and Net blotch
Prosaro (6.5 – 8.2 oz/A) is best applied when the heads are fully emerged. This is Feeke’s growth stage 10.5.
Data from 2011 appear in Table 1. Net returns from the application of controls for Head scab and Net blotch are in dollars per acre.
Table 1. 2011 field trials on Fusarium Head Scab control
|Treatment||Bu/A||Net Return over Untreated|
|Prosaro + Stratego||93.6||$90.39|
There are crop insurance policies for mycotoxin in grain. If a grower has such a policy, they need to contact their insurance carrier as there are specific requirements as to when the grain must be sampled.
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