AgAlerts 2001 From Griggs County
By John Swenson, Griggs County Extension Agent

Issue # 3, May 16, 2001

Crusting of Emerging Crops
Go Slow on Wet Soils
Ammonia at Time of Seeding
Tick Season is Here
Be Careful With Lawn Clippings Treated With Herbicides

Crusting of Emerging Crops

    The hot weather combined with windy conditions has caused some early planted small grain fields to become crusted. This has lead to emergence problems and stand reduction. Crusting, sufficient to prevent the coleoptile of a germinating small grain plant to penetrate the soil surface, can result in severe stand loss. When the crust is not broken, the first leaf of the seedling will break through the coleoptile and grow under the crust. Once this has happened seed nutrient stores are quickly depleted, since the seedlings are not photosynthetically active, the plant will die. Crusting can be a critical time issue especially during warm weather.  The plant will not survive as long under warm condition verses cool conditions. So the longer you wait the more stand reduction can occur.
    The least expensive and usually the most successful solution is a gentle rain. But this might not be feasible due to the wet conditions already hampering seeding. Mechanical manipulation is the remaining solution. Equipment like a harrow, rotary hoe or a double disk grain drill can be used successfully to break the crust and allow the seedlings to emerge. It is important that any mechanical operation not disturb the sub-soil as this could tear out the plants and cause root damage.
    Less than desirable crop stands caused by crusting or wind damage to the newly emerged plants, brings up the question of replanting. Small grains have a large capacity to compensate for stand reductions through tillering and increased head size. Leaf damage on young plants will be replaced but once the plant has reached the jointing stage, its ability to produce new leaves and tillers is lost.
    Optimum plant population for both wheat and barley is 30 plants/sq.ft.. Stand reductions will reduce yield but not in a proportional manner. Under favorable growing conditions, plant populations of 10 plants/sq.ft. have had good yields. NDSU recommendations for minimum stands are 8 - 14 plants/sq.ft. or 30 - 40% of normal before replanting decisions should be made. Weed control becomes more critical under reduced stands due to the lack of crop competition.
    One other factor should be taken into consideration when making replanting decisions. Planting delays for small grains past May 15th typically result in yield reductions on the order of 1.5 to 0.5% per day. If replanting is needed, plant as shallow as moisture conditions allow. This will aid in time of emergence and help reduce the affects of late planting dates.
    The following pictures were taken after a harrowing operation. Note the yellow seedlings. These seedlings would probably not have survived if the operation would not been done.
            (click on pictures to enlarge)

Go Slow on Wet Soils

A late spring may encourage tilling soil when it is too wet. Spring planting should only begin when soil conditions are favorable for good stand establishment. But this is not always possible due to the amount of acres that need to be planted. The problems that arise with tilling soil that is too wet include excessive clod formation, soil compaction, poor herbicide incorporation and a poor seed bed resulting in erratic seedling emergence and poor plant stands. When seeded in compacted wet conditions, seed is put in an anaerobic environment. The lack of oxygen can result in the death of the seed. When germination does occur, the compacted conditions will hinder coleoptilar emergence and soil penetration of the radicle thus retarding root development. These factors contribute to reduced plant stands and ultimately reduced yield.

Ammonia at the Time of Seeding

Ammonia applied at the time of seeding it is important to have separation of the ammonia band and the seed. But there can always be exceptions depending on soil types and conditions. In loam soils and heavier, there should be at least 2 inches of separation. In sandier soils, ammonia can move greater distances, so at least 3 inches of separation. If ammonia is being applied with another applicator with seeding to follow, plant at an angle to the ammonia application. Do not plant in the same direction. Ammonia applied at the time of seeding can cause some stand reduction. Monitor your planting conditions to see if there is ammonia existing the soil. This might mean that the band is not sealing and possibly getting into the seed zone. Many producers have been successful in seeding and ammonia at the same time. It can be done but be sure to monitor the operation.

Tick Season is Here

    The most common tick in our area is the American dog tick. There are about four or five species of ticks present in this region, according to Phillip Glogoza, NDSU Extension Entomologist. One tick that has drawn considerable attention in the past few years is the blacklegged (deer tick). The blacklegged tick can transmit Lyme disease while the American dog tick can transmit Rocky Mountain spotted fever. Tick transmitted disease is not something that we see very often in North Dakota. However, Minnesota is one of the states where Lyme disease is a concern.
    Regardless of life-cycle, tick behavior is similar among species. The insects populate areas where warm-blooded hosts are likely to frequent. Ticks clime vegetation and from this perch simply wait for a host to pass by to attach them selves to. Adult female ticks feed on hosts in order to produce their eggs, which they lay in late spring to mid-summer. The resulting larvae do not feed on warm-blooded hosts until the following spring, when they feed, molt, develop into nymphs, feed again and then become adults, thereby completing the cycle. The nymphs of the blacklegged ticks are extremely difficult to detect because they are about the size of a fleck of pepper. The adult blacklegged tick is about one half the size of the American dog tick. American dog tick nymphs are often confused with blacklegged ticks due to their size.
    The combination of protective clothing and repellents work best for people who are working or recreating in grassy or wooded areas. Long sleeve shirts and long pants with cuffs tucked inside of socks prohibit tick access to the skin. Repellents containing DEET are applicable to either clothing or skin, but repellents containing permethrin should be restricted to clothing only. When removing a tick, it is important not to squeeze a tick's abdomen. This may cause the insect to inject fluid into the host, an action that could bring about infection. After removal, try and apply an antiseptic such as rubbing alcohol or iodine.
    For pets there are several short or long term products to repel ticks. Contact a veterinarian or pet store for products available in your area.

Be Careful With Lawn Clippings Treated With Herbicides

Each year we receive calls concerning herbicide damage to ornamental and garden plants. In most cases, lawn clippings were applied as a mulch around the plants in question. The clippings still had herbicide residues that caused the problem to occur. Tomato is especially susceptible to most herbicides used for broadleaf weed control in lawns. Weed and Feed fertilizers can also cause problems. These products contain similar formulations that are in the liquid products such as Weed-B-Gone. If mulches are going to be used, composted materials are safer. The composting process will help breakdown the herbicides through heating and time. To avoid possible herbicide injury, do not use clippings from recently treated lawns with either a broadleaf herbicide or a Weed and Feed fertilizer.