Quick Facts...
- Seeds are one of the least expensive but most important factors influencing yield potential.
- Seed quality is determined by germination and purity analysis.
- By law, all crop seeds must be labeled for germination percent,
crop seed, weed seed and inert matter content, and the date of
germination test.
- Purchase seed stock from a reputable seed dealer who has proper cleaning, handling and storage facilities.
Seeds are one of the least expensive but most important factors influencing yield potential. Crop seeds contain all
the genetic information to determine yield potential, adaptation
to environmental conditions, and resistance to insect pests and
disease.
One of a farmer's most critical management decisions is the selection of seed source and variety. The cost of
seed stocks usually is less than 5 to 10 percent
of total production costs. Yet seed stocks can
affect the yield potential of a crop more than any other input
factor.
Seed Quality
Seed quality is determined by many factors, principally seed purity
and germination. However, many other factors, such as the variety, presence
of seed-borne disease, vigor of the seed, and seed size are important
when considering seed purchase.
Seed purity is determined by the amount of unwanted material
present in the pure seed. Contaminants such as noxious weed seed, unwanted
crop seed or inert matter not only increase production costs, but also
substantially reduce the quality and quantity of the harvest. If you purchase
seed that has not been properly conditioned to remove unwanted weed seed,
include in your decision-making the increased herbicide cost to control
newly introduced noxious or common weeds.
Seed germination tests assess the ability of the seed to produce a
healthy plant when placed under favorable environmental
conditions. Germination tests are conducted for a prescribed time
period under laboratory conditions that assure optimum moisture,
temperature and light. Unfortunately, these conditions are seldom
encountered in the field, and field emergence may be overestimated by standard germination tests.
Seed lots that have low germination also are less vigorous
due to seed deterioration. As seeds deteriorate, loss of vigor
precedes loss of viability, so seeds with low germination usually
will be less vigorous. Hence, in seed lots with poor germination,
those seeds that do germinate often produce weaker seedlings with
reduced yield potential. However, some species (such as many
native grasses) have inherently low germination potential and
cannot be assumed to have poor vigor due to low germination.
Varietal purity indicates genetic purity of the seed. This
factor is extremely important in obtaining pure stands of a
specific variety. Varietal mixtures can cause uneven maturity,
lower yield potential, increased susceptibility to disease and
insect pests, and be less adapted to specific environmental
conditions.
Varietal mixtures are difficult to detect through
examination of the physical characteristics of the seed. Seed
certification programs and many seed companies rely heavily on
inspection of the seed production field to assure varietal
purity. When choosing seed stocks, select those that are labeled
by variety name, preferably certified seed. When you purchase
certified seed, obtain proper documentation to prove that the
seed has been certified, such as a certified seed tag or bulk
sales certificate that shows the variety by name.
Seed vigor usually cannot be assessed by the Consumer.
Germination and seed size (in the case of cereal grains) often
are good indicators of seed vigor. However, in the case of hybrid
varieties, seed size or plumpness is sometimes not related to
seed vigor. Research in Kansas and other states shows significant
yield increases when large seeds were compared to small seeds
from the same lot. These differences were accentuated when deep
planting was used and point out the need to remove the small seed
during seed conditioning.
Seed Labeling
State and federal laws require that all agricultural seed be labeled. Labeling
requirements for some flower, tree and shrubs may differ. If the seed
has been treated a label must state the seed has been treated, the commonly
accepted coined chemical name of the applied substance, and if the substance
in the amount present is harmful to human or other vertebrate animals,
a caution statement such as “Do not use for food, feed, or oil purposes.”
Toxic substances shall be labeled with a poison symbol. Terms that must
appear on the label are:
- varietal name and kind of seed;
- lot number;
- percentage by weight of pure seed;
- percentage by weight of all weed seeds;
- percentage by weight of all crop seeds;
- percentage by weight of inert matter;
- name and number per pound of restricted noxious weed seeds; and
- the date of the germination test.
Terms that appear on the label are:
Variety name: The name of the kind or kind and variety for each
agricultural seed component present in excess of 5 percent of the whole
and the percentage of each. If the variety is not stated, the label shall
show the kind and the words “Variety Not Stated” or “VNS”.
Hybrids shall be labeled as hybrids.
Lot Number: A lot number or other lot identification.
Origin: State or foreign country of origin if known, if not known,
the origin is not unknown and the fact shall be stated.
Pure seed: The percentage by weight of crop seed compared to
other components. The best quality seed is nearly 100 percent
pure. To meet certified seed standards for small grains, seed
must be more than 98 percent pure.
Other crop seed: The percentage by weight of any other crop seed
in the test sample.
Inert matter: The percentage by weight of sand, sticks, broken
seed parts and other foreign material in the seed. This
percentage is small in high-quality seed. Higher percentages of
inert material will increase the cost of the remaining pure, live
seed.
Weed seed content: The percentage by weight of weed seed. State
seed regulations do not allow any prohibited noxious weed seeds
to be present. Any restricted noxious weed seed content must be
listed on the label.
Germination: The percentage of germination, exclusive of
hard or dormant seed. The percentage of dormant or hard seed if present
and the calendar month and year the germination test was completed. The
date of test should be within the previous 13 months on the time of sale
to ensure the quality of seed and to comply with seed laws.
Labeler: The name and address of the person who labeled the seed,
or who sells, offers or exposes the seed from sale within the state.
Purchasing Quality Seed Stock
High quality seed can be purchased from any reputable seed
dealer who has experience in producing, conditioning (cleaning)
and storing seed stocks.
During seed production, proper fertilization, adequate water, sufficient isolation
(for cross pollinated Crops), proper roguing of off-types, and timely
harvests are all important factors. Care also must be taken to clean harvesting
equipment, trucks, and storage and handling facilities to prevent contamination.
During the conditioning and packaging process, the seed must be handled
carefully to avoid contamination and damage.
Proper seed moisture at the time of packaging and seed
treatment also are important considerations. Seed storage
conditions must maintain the vigor and quality of the seed.
Excess humidity or heat can cause severe damage to seed in a
short time.
Seed dealers should have the capability and facilities to
provide the conditions listed above. Their reputation as quality
seed dealers usually is a good indicator of the quality of seed
offered for sale. Don't hesitate to ask questions regarding the
origin of the seed and appearance of the seed field. If the
dealer is a neighbor, ask to see the seed production fields prior
to harvest.
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