August 27, 2013

                The heat is on! This past week we have been lucky enough to receive some much needed rain around the area. With rain falls ranging from .6” to 1.9” throughout the area this might be just what the doctor ordered.

                We have been busy scouting soybeans for aphids. Within the past week we have noticed an increase in the aphid population. We have been treating fields where the economic threshold has been reached. The economic threshold for soybean aphids according to Iowa State is 250 aphids per plant. Aphids generally start on the field boarders and work their way into the field as time goes on. A good place to start to look is on the newer growth on the bottoms of the plant. Generally there under the leaves but as the infestation gets worse they will work their way up the plant and infest the stems.

                Economic thresholds are appropriate until the plants reach the R5.5 stage. Spraying at R6 or later has not produced a consistent yield benefit, according to Iowa State University. A good majority of the beans that we have been scouting are anywhere from R2-R4. Below is a good picture of what the bean pods look like at numerous stages.

 

                On the corn end of things we haven’t been noticing a great amount of disease in the corn plant. Where fungicide was sprayed the common rust has been held at bay. We are seeing a little more gray leaf spot every week and would have to say while northern corn leaf blight is out there it really has yet to spread in the canopy.

Company Plot Days:

                Jackson Junction Plot Days: August 29, 2013, At Ernie’s starting at 11 A.M.

                Bremer’s Plot Days: August 29, 2013, 4.5 miles North of Bremer on V21 starting at 4:30 P.M.

                Fredericksburg’s Plot Days: August 28, 2013, Along Highway 18 starting at 11:30 A.M.

July, 24 2013

                What a spring and summer we have had so far this year. With the spraying season slowing down and summer finally here we cannot forget a few important agronomic topics, fungicide and insect scouting.

                 With corn in the area starting to tassel an important topic to discuss is a fungicide treatment at the VT stage. There are some questions we must ask ourselves when making this management decision. First, what was the previous crop? Many of the foliar pathogens survive in corn residue. With this being said the risk for foliar diseases increases when corn is planted into a field following corn. Next question is what has the weather been like? Rainy and/or humid weather is most favorable to foliar diseases. In growing seasons when these conditions prevail, the risk for disease development increases. The last question is what is the disease history in the field? Have the past years corn crops been prone or shown a heavy disease pressure. We also have to take into consideration what the weather forecast looks like for the grain fill period. For disease to happen, or continue to develop, certain environmental conditions need to occur. Below is a table of what weather conditions favor certain disease development.

 

               

              Along with scouting disease in the corn we are also keeping a close eye on the soybean crop. Are main concern on the insect front as of now would be aphids. We have not seen much of an infestation as of yet but there are a few out there. There have been some reports of heavy pressure where treatment was necessary around the Burr Oak area. A good place to start to scout for aphids would be in any bean fields where a seed treatment was not used. Aphids start on the bottom of the bean plant and work their way up. The first place you will find them is on the lower canopy on the plants new growth. With the outbreak of spider mites last year people have also been concerned about them. What we can say is spider mites like hot and dry weather. Something we have not really experienced recently. We have not seen any this year and the probability of them showing up this year is very slim.

                With all this being said these next few weeks scouting corn and beans will be critical for optimum yield this fall. Thanks for stopping by.

June 27, 2013

                This past week we have once again been sidelined with some heavy rains. The southern locations have been a bit on the dryer side and able to work through some of the rain fall. The northern locations have been saturated with rain and in some cases flash flooding. These wet soils have led to many questions about the survival of crop and nitrogen loss.

                First let’s talk about the survival of corn and beans in the flooded or saturated areas. There are several factors that corn survival depends on: length of time flooded, partially submerged or completely submerged, temperature, and stage of development. Basically, corn in flooded soils depletes its available oxygen in 24 to 48 hours. Continued survival is better with cool temperatures, cloudy days and clear nights. Also, partially submerged crops can withstand flooding considerably longer than completely submerged crops. The crops which do survive may have disease problems later in their lifecycle. Soybeans follow almost all the same guidelines. They will only be able to survive for 24 hours without oxygen, and completely submerged fields will suffer a greater loss than partially saturated fields.

                The next big question is; “What is happening to my nitrogen?” There are a few different considerations one must look at. First, some areas where apparent nitrogen loss appears to be showing up may be a lack of oxygen to the corn roots. Oxygen is needed for normal root development and for efficient uptake of nutrients by the roots. Oxygen levels will be depleted in flooded soils and foliar symptoms can be exhibited that may look similar to nutrient deficiencies.  Second, we need to look back to when the nitrogen was applied. Early fall applications will obviously have the greatest risk of leaching, whereas late spring or side dress nitrogen will be the most likely to still be available. When the decision comes to rescue apply nitrogen we will have to take into consideration, timing, cost, current crop condition, yield potential and application method.

                Just last night we observed some of the first lighting bugs in the area. As most know when the lighting bugs show up we should start to be concerned with the root worm and corn borer hatch. According to Iowa State University the corn rootworm egg hatch typically occurs from late May to the middle of June, with the average hatching date around June 6^th. Egg development is driven by soil temperature, which is measured by degree days. Iowa State research suggest about 50% of egg hatch occurs between 684-767 accumulated degree days based on a soil temperature of 52 degrees. The map below shows the heat unit accumulation at Iowa State rootworm stations on 6-14-13. On an average summer day in northeast Iowa we accumulate approximately 18 heat units. This leaves us roughly 13 days from 6-14-13 until the hatch will begin.

Thanks for reading and if there are any questions about the topics discussed above please stop and ask one of the agronomists at a location near you.

June 13, 2013

                With the talk of preventive planting sweeping the country side there are several questions being asked about what to do with the preventive plant acre. Many of the questions will have to be answered by either your insurance man/women or county FSA office but there are plenty of cover crop questions the agronomy team at FFC would be happy to discuss. The three crops we are recommending as a fallow ground cover crop would be oats, rye and tillage radish. These three crops all are going to keep the soil working and nutrients available for next year’s growing season. The supply on these crops is all over the board with oats being very hard to get, rye being available but in a tight supply and tillage radish having a good supply. Feel free to stop by any location and talk to an agronomist about what cover crop would best fit your acre.

                The few days it hasn’t been raining we have been busy spraying post emerge corn, pre emerge corn, and pre emerge beans. A few things we have been noticing are that although the weather hasn’t been very favorable for vegetative corn or bean growth it seems that weeds in some fields have not slowed down. As difficult as it’s going to be to get in the fields this year to spray we are going to have to make sure we are using extra precautions for the best kill possible. This may mean slowing down, increasing gallons per acre and spiking in some extra chemical to make sure it kills the larger weeds.

                The scouts at FFC have been busy these past weeks covering many acres. They have been seeing a little bit of everything in the fields. In some areas the weed pressure is starting to develop and in other fields weed pressure is minimal. There hasn’t been much bug pressure yet but we expect that to be coming. The number one issue out there now is flooded out fields. In these flooded out or extremely wet fields we have discovered some rhizoctonia in beans and pythium in corn. Both diseases strive in the cool wet soils we have been experiencing. The only way to help combat these problems is selecting a good seed treatment. Although it is late in the season and some are leery about spending the money on a seed treatment, we are still recommending it on all bean acres. Below is an interesting picture of a farmer who was using treated beans and finished up the last of the field with some untreated beans. The beans on the left were treated and the beans on the right were untreated.

 

       Thanks for taking the time to read the blog and let’s keep our fingers crossed for some dry weather!

June 3, 2013

                Wet, that seems to be the theme to this spring season. After coming off a record amount of moisture in May one can only hope June will bring warmer, dryer weather. With most planting conditions not being ideal due to the great amount of moisture we have accumulated this past May, soils are left saturated. Saturated soils will pose a challenge not only at planting time but, for the rest of the growing season.

                Fungicide at V5-V7 is going to be more important this year because of the wet soils. The more moisture in the soils, the more prone the early stage corn is to disease. The main disease this fungicide application would be targeting is anthracnose stalk rot. Anthracnose survives in the residue and turns the bottom half of the corn plant a black color. Although the plant is infected in June one will not see the rot show up until August. Fungicides are a great tool to help prevent the start of anthracnose.

Anthracnose Stalk Rot

                The spring rains have also delayed planting of corn and soybeans. Since the calendar reads June 3, most everyone has had to make the decision to switch corn or bean maturities. When it comes to switching corn we are at the point of the year where one must take a good look at the GDU’s (Growing Degree Units) till physical maturity, or black layer. The less GDU’s till black layer the sooner it will be ready in the fall. Our main concern is if we were to get an early frost.

When looking at soybean maturities we believe one should wait till at least June 15 before looking at switching to earlier maturities. In a later planting scenario, like this year, a soybean variety of 0.5 to 1.0 shorter maturity group is recommended after June 15. Also since soybeans are photoperiod sensitive, they will flower at the same time despite planting date and relative maturity. Earlier planted soybeans simply have more nodes and greater yield potential. There has been some research done at Iowa State's research farm located in Nashua. The graph below shows you that with the research gathered the late maturity varieties had greater yield potential across all the planting dates.  A few other tips when planting beans after June 1^st would be to increase populations by 10%. The increase in population will help get more nodes in the field and the increased plant density will hasten canopy closure, make the beans taller and increase the number of pods per acre. The use of narrower rows has also been proven to be better with the later planting date.

 



Influence of planting date on soybean yield of early (1.7) and late (3.0) maturity varieties (2004-2008).

May 9, 2013

                This past week northeast Iowa has gone through all four seasons in 7 days. The way the year has been going it’s not a surprise. From snow last Thursday to 75 degree weather yesterday this spring continues to throw us many curve balls. Take the 2-4” of rain along with 2-4” of snow we have received this past week and we are at another standstill. There has been some fertilizer spread, anhydrous applied and some corn planted but the general consensus is it’s wet. As you can see below the seven day does look fairly dry and with a little luck we can miss the showers on Wednesday be back on track with spring field operations.

                With planting right around the corner there are a few things we should remember about corn germination and emergence. Corn requires approximately 120 to 125 growing degree units (GDUs) from planting to reach emergence, depending on soil temperatures. Corn must absorb 30% of its weight in water to germinate. Seeds can absorb water at temperatures below 50 degrees Fahrenheit, but growth will not occur until soil temperatures are 50 degrees or higher. As temperatures increase, the process required for germination to progress occurs at a faster rate, leading to more rapid emergence. Under ideal conditions, corn will emerge in ten days or less, but with cooler soil temperatures the process may take three weeks or longer.  The formula to calculate GDU’s is simply the daily high temperature plus the daily low temperature minus 50 and then divided by 2.

                Also this week at our Jackson location the construction on the dry fertilizer shed has almost been completed. The construction of the building is complete now they are waiting on the equipment to be installed inside the shed. The liquid fertilizer tank is also nearing completion, the only steps left being to plumb the unload/load system.

               Thanks for reading this week’s blog post. Don’t forget to stop by next week where hopefully we are discussing planting progress in northeast Iowa.

May 1, 2013

                What a difference a year makes. As of this morning there was estimated only 5% of corn planted in Iowa and Ohio. The 5 year average this time of year is 31%. As we all know the weather has us a little behind the 8-ball this spring. This past Thursday began the start of the real push into spring field work. Anhydrous is being applied throughout the area along with fertilizer and some liquid nitrogen. The long term forecast seems to be favorable for the farmer.

 When we look at the calendar, the typical suitable days for fieldwork for the next week or so, and the optimum Midwest corn planting dates, it is apparent that there will be a stacking up of various field operations this spring. As soon as conditions are favorable there will be a lot of pressure to get spring time anhydrous applications and planting operations moving. When these two tasks are crunched into a short period of time there are greater risks of corn seed and seeding injury from ammonia.

                The question that comes to mind is how soon after anhydrous ammonia application can corn be planted. There are several factors that come to mind to determine this time frame. Some of these include the application depth, soil texture and moisture, rate, distance between knives and direction of application compared to corn rows. Generally it is recommended that growers wait a week after applying ammonia to plant their corn. However, if soil moisture conditions are good, the application depth is 7-9” deep and the anhydrous is applied at an angle to the corn rows, corn can be planted 3-5 days after ammonia application with minimal potential for injury.  Below is interesting graph of the effect of nitrogen rate, application depth and time between ammonia applications and planting, along with some pictures of the damage caused by ammonia burn.

 

Table 1. Effect of applications depth, time of planting, and ammonia toxicity on corn stands. Depth of Application (inches)						Days Delay in Planting after Anhydrous Ammonia Application
0		7		14		0		7		14
200 lbs N/Acre						400 lbs N/Acre
-------------------------------- Plant Population (% of Normal) -------------------------------
4	60		96		100		35		60		90
7	100		100		100		80		100		100
10	100		100		100		100		100		100
(Source: University of Illinois)

 

Corn injury after spring applied anhydrous ammonia

Corn injury after spring applied anhydrous ammonia

 Thanks for reading and don’t forget to stop back next week when we will update you on spring progress.

 

Citation

            http://www.agronext.iastate.edu/soilfertility/photos/mphotosnitrogen.html