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ISSUE 13   July 25, 2002



Moisture is critical at this time in both the corn and soybean crop in North Dakota and Minnesota. Below lists the various stages of each crop and what is happening at each stage of growth and development. The flowering stages are the most critical with yield being greatly reduced if water shortages occur during that time.




Silking (R1)

Silks visible, pollen shedding, no stress is best

Blister (R2)

Kernels just filling, resemble a white blister

Milk (R3)

Kernels of yellow corn are just turning color, milky white fluid fill

Dough (R4)

Kernel fluid has a pasty texture

Dent (R5)

Kernels are denting, cob may have changed color if red cobbed

Physiological Maturity
(R6 or PM)

Kernels are hard, maximum dry weight, no yield loss from frost




Beginning Bloom (R1)

At least one flower on the plant, no stress is best

Full Bloom (R2)

At least one of the two upper nodes has an open flower and the soybean has about 50% of its full height

Beginning Pod (R3)

A pod on the upper four nodes is 3/16 inch long

Full Pod (R4)

Beginning seed development

Beginning Seed (R5)

Seed is at least 1/8 inch long in one of the pods on the four upper nodes

Full Seed (R6)

The green bean or beginning full seed stage

Beginning Maturity (R7)

One pod on the main stem obtains mature color

Full Maturity
(R8 or PM)

95% of the pods have reached mature color and moisture drops to 15% with five or ten days required to drop to 13% for long term storage

Duane R. Berglund
NDSU Extension Agronomist 



Hot weather and drought has tended to push many crops to mature at an increased rate. Questions on when to swath and harvest certain alternative crops are being asked. Below are some comments and suggestions:


Other Information


Swath when lowermost pods are tan colored and rattle when shaken. Thresh when seeds test 18% moisture content or lower. Overdry lentils (8-10%) are hard and difficult to process or consume. Plants may still be green when pods are ripe. Crop typically matures in patches. Some shatter loss usually occurs.

Yellow Field Pea

Swath when peas and pea vines are yellow colored. Thresh when seeds are firm and can no longer be penetrated with thumbnail. 20% moisture content or lower. Some shatter loss usually occurs. Mixing wet soil with peas can cause staining - a discount grading factor.

Green Pea

Swath when peas are mature and have a good green color. Pea vines are yellow colored. If desiccating, apply when vein pattern of uppermost pods is easily recognized and 75% to 90% of the pods have turned to yellow tan. Seeds are firm but no longer penetrable with a thumbnail. Pea vines may or may not be prostrate depending on variety and conditions. 2% bleached peas is maximum. Bleached seeds are caused by high humidity, bright sunshine and warm temperatures.

Feed Pea

Swath when pea vines are yellow colored. Vines are often prostrate. Seeds are firm, but no longer penetrable with a thumbnail. Combine settings and operation are not as critical for feed peas as to human food peas. Admixture of various pea kinds are allowed. Some bleached peas, split, cracked or split peas, and earth tagged peas are accepted for feed peas.

Millet, Proso

Swath when seeds in the upper one-half of the panicle have matured. Seeds in lower portion will be in dough stage but will have less color. Harvest millet when its below 13% moisture. Shatters easily if not cut on time.


Swath when seed moisture content is 25%. Seeds are firm when pressed between fingers. Oriental-75% yellow seeds. Brown-60% reddish brown seeds. Yellow (White)-100% yellow seeds. Straight combine yellow mustard whenever possible. Watch for cracked seeds. Moisture content of seed should be 13% or lower. Swaths are fluffy and subject to wind damage. Lay swaths in direction of prevailing winds. Immature green seed will not change in color in the swath. Use swath roller.


Crop has finished blooming. Seeds heads are tan to brown in color. Leaves and heads are spiny with little green evident. Crop should be straight combined if evenly matured. Mature seed is striped or white and rubs freely from the heads.


75% of the seed coats have turned brown. Flowering is nearly complete. Difficult to penetrate seed with thumbnail. Seeds continue to fill in the windrow or after light frost for about 3 days. Bottom seeds will likely be lost due to shattering.


Straw is bleached, hulls are shiny and golden colored. Seeds are reddish_brown. Delay cutting canaryseed until it is fully mature. Canary seed will not thresh cleanly until the heads are dry. Canaryseed is resistant to shattering and weathering. Dehulled seed is severely discounted.

 Duane R. Berglund
NDSU Extension Agronomist




This is an alert to the effect that grazing or haying of droughty flax can result in problems of HCN poisoning( Prussic acid). Had a note from Dr. Jack Carter the expert on Flax and also former chair of our Plant Sciences Dept. Green flax straw should not be fed or grazed. The danger of prussic acid poisoning is much higher

also if the immature flax is frozen and then fed to livestock according to the Canadian flax literature.

He recalled that cattle had died when breaking out of fences and eating the flax strips on fallow which had been planted for wind erosion. The test for HCN in flax is different than it is for Sudangrass or Sorghum-sudan. Contact the NDSU Toxicology Lab. (701-231-8309) in Vet. Science if you have questions.

Duane R. Berglund
NDSU Extension Agronomist


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