I recently attended the WSU Wheat University. They had a diverse agenda of subject matter, with presentations from researchers at Washington State University, Oregon State University, and University of Idaho. Concurrent classes were going, and I didn't get to all the presentations. From those that I did attend there were several things that I found important, hence, chronicle here.
Water Movement: --Soil type effects rate of moisture infiltration, shown by a demonstration using Walla Walla and Ritzville soil types. --Soil particles are quickly transported by surface water and block passages into the soil profile, sealing the surface. Runoff begins at that point. No-till fields have more channels into the soil profile than cultivated fields and usually more surface residue. --Surface residue retards water flowing across the soil surface. The more residue the better. Even though some moisture is trapped and evaporated from the residue, more residue translates to more moisture in the profile. --The demo. in the pic above, shows a Ritzville soil with two containers of soils from a cultivated field. One container had surface residue, the other did not. The third container of Ritzville soil is from a no-till field. The no-till container had no water loss from the simulated rain event. The cultivated containers both had water loss but the container with residue had less loss and notably less soil loss. --Water is held under tension until a path or condition breaks the tension. Water is attracted to surfaces, going down the sides of channels into the soil profile.
Nutrients in straw: --A ton of wheat straw ranges from $10-$19 in nutrient value. Straw nutrients vary depending on nutrient level found in the soil plus the amount applied, and the value placed on the various nutrients. --Rough estimate for straw residue is 100# per bushel of grain. --Swath and bale removes approximately 50% of the residue. Feeding baler directly from combine increases the loss of leaves and chaff raising the total loss a couple of percentage points. (A 100bu/ac yield translates to ~$25 to $47 per acre loss of nutrients). --When a field is burned, you lose nearly all the C-N-S, and less of the remaining elements if the ash has not blown away. --K & P can be washed out of the residue from rainfall or irrigation.
Crop Insects:
--Wire worms: come in three species (Great Basin - Western - Sugar beet). --The are identified by the shape of the little pincer type protrusion on their tail. --The Western feeds actively in April & May. --Sugar beet variety feeds later in the season. --You may not encounter the Great Basin variety at economic levels. --Seed treatment works pretty good on the Western. --Check edges of bare areas for dead and dying new leaves on cereal plants, then dig around plant crowns. --Wire worms prefer spring wheat over winter wheat. It is probably a worm life cycle issue. --They are found mostly in bottom land and may not need treating on hills. --Wire worms are attracted to cereal grains, with the exception of oats. --They have little attraction to Pulses, Brassica's, or chemical fallow. --Wireworms may feed in chem fallow fields but they will not lay eggs. --Proximity to CRP fields will likely increase wireworm pressure. -- ≥ 45ºF worms will be active.
--Hession Fly: The female population is what does the damage. She lays the eggs in the stem. --The fly does not move far. --The fly overwinters in grain (not oat) residue. --Cereal plant resistance to Hession Fly is declining. We need to pay attention to cultural practices like expanding crop rotation to help keep losses from this fly to a minimum.
--Weevils: Pea Weevil (not a true weevil because it has no elbow in it's antenna), Pea Leaf Weevil, Cabbage Seedpod Weevil are the three main types that cause economic damage in peas and canola. The pea weevil scallops the lower leaves weakening the plant making it more susceptible to aphid attack. These don't seem to be as prevalent as the pea leaf weevil. The cabbage seedpod weevil lays eggs in the pea and canola seedpods. In canola the pods become misshapen when attacked.
--Aphid: They tend to attack weakened plants/stands due to nutrition deficiencies or weevil attack. --Scout field edges for infestations. It's possible you will only have to treat the border which will minimize damage to beneficial insects. --When possible spray late in the day to minimize impact on beneficial insects (specifically bees).
Water Movement: --Soil type effects rate of moisture infiltration, shown by a demonstration using Walla Walla and Ritzville soil types. --Soil particles are quickly transported by surface water and block passages into the soil profile, sealing the surface. Runoff begins at that point. No-till fields have more channels into the soil profile than cultivated fields and usually more surface residue. --Surface residue retards water flowing across the soil surface. The more residue the better. Even though some moisture is trapped and evaporated from the residue, more residue translates to more moisture in the profile. --The demo. in the pic above, shows a Ritzville soil with two containers of soils from a cultivated field. One container had surface residue, the other did not. The third container of Ritzville soil is from a no-till field. The no-till container had no water loss from the simulated rain event. The cultivated containers both had water loss but the container with residue had less loss and notably less soil loss. --Water is held under tension until a path or condition breaks the tension. Water is attracted to surfaces, going down the sides of channels into the soil profile.
Crop Insects:
--Wire worms: come in three species (Great Basin - Western - Sugar beet). --The are identified by the shape of the little pincer type protrusion on their tail. --The Western feeds actively in April & May. --Sugar beet variety feeds later in the season. --You may not encounter the Great Basin variety at economic levels. --Seed treatment works pretty good on the Western. --Check edges of bare areas for dead and dying new leaves on cereal plants, then dig around plant crowns. --Wire worms prefer spring wheat over winter wheat. It is probably a worm life cycle issue. --They are found mostly in bottom land and may not need treating on hills. --Wire worms are attracted to cereal grains, with the exception of oats. --They have little attraction to Pulses, Brassica's, or chemical fallow. --Wireworms may feed in chem fallow fields but they will not lay eggs. --Proximity to CRP fields will likely increase wireworm pressure. -- ≥ 45ºF worms will be active.
--Hession Fly: The female population is what does the damage. She lays the eggs in the stem. --The fly does not move far. --The fly overwinters in grain (not oat) residue. --Cereal plant resistance to Hession Fly is declining. We need to pay attention to cultural practices like expanding crop rotation to help keep losses from this fly to a minimum.
--Weevils: Pea Weevil (not a true weevil because it has no elbow in it's antenna), Pea Leaf Weevil, Cabbage Seedpod Weevil are the three main types that cause economic damage in peas and canola. The pea weevil scallops the lower leaves weakening the plant making it more susceptible to aphid attack. These don't seem to be as prevalent as the pea leaf weevil. The cabbage seedpod weevil lays eggs in the pea and canola seedpods. In canola the pods become misshapen when attacked.
--Aphid: They tend to attack weakened plants/stands due to nutrition deficiencies or weevil attack. --Scout field edges for infestations. It's possible you will only have to treat the border which will minimize damage to beneficial insects. --When possible spray late in the day to minimize impact on beneficial insects (specifically bees).
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