Progress 10/01/06 to 09/30/12
Outputs
OUTPUTS: We continued in 2012 a study to examine the response of corn (Zea mays L.) to planting date and to the application of foliar fungicide at pollination (R1). The study was conducted at six locations in Illinois, representing a wide range of soil and climate. Planting dates in this study ranged from mid-March or early April through late May. Results from this study have been summarized and used in Extension presentations within Illinois and in other states. These sites (or plants taken from them) have been used as demonstrations during annual field days, and data will be shared with agronomists in other states. The information is added to the growing database on corn response to planting date, and is also contributing to our knowledge of how corn responds to foliar fungicide under varying conditions of weather and foliar disease. PARTICIPANTS: Not relevant to this project. TARGET AUDIENCES: The primary audience for the findings of this project is corn producers in Illinois, who are able to make better decisions regarding timing of planting, and how management might need to change when planting is delayed. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.
Impacts
The 2012 crop year was characterized by record or near-record drought conditions throughout most of Illinois, especially in the southern half of the state; average state corn yield in 2012 is estimated at only about 6.3t/ha, some 40% below trendline yield. This offers a unique opportunity to assess planting date and fungicide responses under stress. In one of six sites (Dixon Springs) yields were so low that the trial wasn't harvested. At Brownstown and Perry, yield averages were less than 2 t/ha, and there was a small tendency for yields to increase with later planting at these two sites. This unusual response probably occurred because small amounts of rain after pollination helped the later-planted crop more than early-planted one. At Urbana, where unusually warm and dry weather allowed us to add a mid-March planting, this crop was badly damaged by frost in April, and yielded 28% less than corn planted in late March. After high yields from both the late March and late April plantings, yields at Urbana fell off quickly, dropping linearly from late April through late May at a rate of 0.12 t/ha/day. This steep decline reflected the deteriorating mid-season moisture supply, with later-planted corn badly damaged by lack of water at pollination. At the Monmouth site, where stress was less severe, crop yield was flat at about 12.5 t/ha for the late March to mid-May plantings, then dropped only by about 1 t/ha for the planting in late May. In contrast, yields were above 12 t/ha for the mid-April and early May plantings at DeKalb, but were only 10.3 t/ha for the late March planting and 8.8 t/ha for the late May planting. Foliar fungicide had no effect on grain yield at any of the planting dates at any of the five sites. Data from previous corn planting studies under this project have typically shown maximum yields from plantings done in mid- to late April, with curvilinear yield declines, averaging about 0.06 t/ha per day of delay from early to late May. If drought conditions develop in mid-season as happened in 2012, the loss of yield from delayed planting can be double this. We have also found previously that, while planting in early April or in late April tend to produce similar yields, the earlier planting occasionally yields less than the planting later in April. We found lower yields from planting in late March or early April at only one of the five sites in 2012. We found, however, no advantage from planting earlier than mid- to late April at any site. This suggests that planting in early April, while it might occasionally get planting done earlier and so avoid planting delays, is not conducive to higher yields when compared to planting later in April. We also found in 2012 that planting in mid-March, even when conditions allow this, may subject the crop to risks of frost damage, which is likely to overcome any advantage of such early planting. The lack of response to foliar fungicide under the wide range of conditions experienced by different planting dates indicates limited ability of fungicide to relieve drought effects.
Publications
- No publications reported this period
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Progress 01/01/11 to 12/31/11
Outputs
OUTPUTS: We conducted a study in 2010 and 2011 to examine the response of soybean (Glycine max L. Merrill) to planting date, row spacing, and seeding rate. The study was conducted at six locations in Illinois, representing a wide range of soil and climate conditions. Planting dates in this study ranged from early April to late June, with a few dates in July in southern Illinois. Results are being summarized and will be used in Extension presentations within Illinois and in other states. These have been used as demonstration sites during annual field days, and data will be shared with agronomists in other states, and will be published in a refereed format. PARTICIPANTS: Nothing significant to report during this reporting period. TARGET AUDIENCES: Nothing significant to report during this reporting period. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.
Impacts
Output: The 2010 and 2011 growing seasons were relatively good for soybeans in northern Illinois, but wet conditions in the spring and lack of adequate rainfall in the second half of the growing season decreased yields in southern Illinois. The average soybean yield in Illinois was 3,461 kg/ha in 2010, and is estimated at 3,091 kg/ha in 2011. Across seven site-years in northern Illinois, the panting date response was estimated by the quadratic equation: Yield (kg/ha) = 5,163.5 - 4.2287d - 0.2208d2, where d is number of days past April 1 (R2 = 0.57**). This means that the planting date with the highest predicted yield was April 1, and yields declined by 6.4 kg/ha/day for the 10 days from April 1 to April 10, by 10.9 and 15.3 kg/ha/day for the second and third 10-day periods in April, by 19.7, 24.1, and 28.5 kg/ha/day for the first, second, and third 10-day periods in May, respectively, and by 32.9 kg/ha/day as planting was delayed during the first third of June. These penalties for late planting are greater than have generally been observed for soybean, and suggest that, at least under similar, high-yielding conditions, planting ought to start in April if possible. Across four southern Illinois site-years, the quadratic response equation fit (poorly) to the data (R2 = 0.18) revealed that the optimum planting date was in late May, but variability in the data means that this prediction has little value. Impact: Data from earlier soybean planting studies have shown that, under conditions conducive for only modest yields (2,500 to 3,000 kg/ha) planting date delays had minimal impact on yield, as long as the crop could be planted by the third week in May. The current results have revealed that waiting (or not hurrying) to plant soybeans can indeed cost yield and money, especially when growing season conditions are good to excellent. Because we cannot know growing season conditions at the time of planting, it seems prudent to get the crop planted as early as practicable. Using these data with current crop prices, losses from planting delays reach $10/ha/day of delay by mid-May, and by the end of May the cumulative loss exceeds $300/ha compared to planting at the end of April. Even if the past two years have produced unusually large planting date responses, it is clear that earlier planting may be more profitable than was previously believed.
Publications
- No publications reported this period
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Progress 01/01/10 to 12/31/10
Outputs
OUTPUTS: We conducted in 2010 a study to examine the response of two corn (Zea mays L.) hybrids differing in maturity to planting date and foliar fungicide. The study was conducted at six locations in Illinois, representing a wide range of soil and climate types. Planting dates in this study ranged from early April through late May or early June, with four dates spaced about 20 days apart. Results have been summarized and used in Extension presentations within Illinois and in other states. These have been used as demonstration sites during annual field days, and data on fungicide responses have been shared with plant pathologists in other states. PARTICIPANTS: Nothing significant to report during this reporting period. TARGET AUDIENCES: Nothing significant to report during this reporting period. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.
Impacts
The 2010 growing season was an unusual one, with most corn planted early, high rainfall amounts in May and June, and in July in some areas, high temperatures, and early maturity and harvest. The average corn yield in Illinois is estimated at only 9.8 t/ha, the lowest since 2005. At the two northern Illinois locations, the second planting date (20 April) produced 3 to 6% higher yields than the first planting date, with the third and fourth planting dates yielding about the same as the earliest date for the early hybrid, but with greatly decreased yields for the late hybrid planted late. We had previously noted lower yields from planting in very early April compared to planting 15 to 20 days later, and believe this may be related to cool temperatures following emergence; later plantings do not experience this. The poor yields of the later hybrid at the later planting dates are believed to be more related to the hybrid itself than to its maturity. In central Illinois, the highest yields came from the May planting dates, with relatively flat planting date responses. This is somewhat surprising in a year with high temperatures and dry conditions, but early-planted corn may have been injured more by wet soils in June, and this might have offset some of the advantages of early planting. In southern Illinois, where the study was disrupted by frequent rainfall, the earliest planting (13 April) yielded much more than subsequent plantings, producing more than double the yield of the latest (early June) plantings. Response to foliar fungicide was not very consistent among locations and planting date, with yield effects ranging from -4 to +9% and averaging about 3% in northern and central Illinois. In southern Illinois, yield responses to fungicide ranged from -7 to +22%, with somewhat greater positive responses at the earlier planting than at the later plantings. Impact: Data from earlier corn planting date studies were assembled and used to generate new predictive tables to relate planting date and plant population to yield, and to help make replant decisions when plant stands are poor. The current results have enabled us to confirm the earlier findings, but also to add a hybrid/maturity variable, and to see if delayed plantings should be targeted for foliar fungicide application. We do not find evidence to change our prediction of planting date effects on yield, but we continue to see a rather wide range of responses over years and locations. While hybrid choice is important, changing to earlier hybrids when planting is delayed not always indicated, though the later hybrid used at three of the northern Illinois locations in 2010 was greatly impaired when planted late, and such hybrids, if this is known, should not be used for late planting.
Publications
- No publications reported this period
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Progress 01/01/09 to 12/31/09
Outputs
OUTPUTS: We continued in 2009 a study to examine the response of continuous corn (Zea mays L.) to a set of crop inputs, including tillage, fertilizer (NPK), and, in recent years, foliar fungicide. This study has been underway (in continuous corn) for eight years, but treatments were changed in 2008 to include a comparison of conventional (fall chisel plow and spring field cultivator) versus strip-till. Strip-till is a recently-refined system that includes tilling a band of soil in the fall, then planting directly into this band without further tillage in the spring. Fertility treatments consist of a standard amount of NPK and an additional 112 kg N/ha plus additional P and K. Foliar fungicide is applied at the time of pollination. The study is underway at four locations in Illinois, in highly-productive soils. Results have been summarized and used in Extension presentations within Illinois and in other states. Trials have been used as demonstration sites during annual field days, and data on fungicide responses have been shared with plant pathologists in other states. Results are published in the Illinois Agronomy Handbook. PARTICIPANTS: Dr. Emerson D. Nafziger is PI and overall director of this project, Mr. Lyle Paul manages the trial at DeKalb, Dr. Eric Adee manages the trial at Monmouth, Mr. Mike Vose manages the trial at Perry, and Mr. Mike Kleiss manages the trial at Urbana. TARGET AUDIENCES: Crop producers, farm equipment manufacturers, crop consultants, and convervation personnel. PROJECT MODIFICATIONS: Not relevant to this project.
Impacts
In 2009, yields ranged from 8.8 at DeKalb to 14.6 t/ha at Monmouth. Tilled plots yielded significantly more than strip-tilled plots at both of these locations, by 8% at DeKalb and by 5% at Monmouth. Higher fertilizer rates increased yields significantly at all locations in 2009, and foliar fungicide increased yield at three of the four locations, by 8% at Monmouth, 4% at Urbana, and 7% at Perry. Response to higher fertilizer rates has been consistent, but the higher rate is higher than the optimal rate (of N), and so would in most cases not pay the added cost. Foliar fungicide has also provided a consistent yield increase among sites, even though foliar disease levels have ranged from light to moderately heavy. Results from these studies have been disseminated at producer and professional meetings. The strip-till system is considered a modification of no-till, but its incorporation into the continuous corn cropping system has not been the subject of much prior research. With most sites showing no difference in yield between strip-till and tilled plots, and with few interactions to suggest that strip-till needs to receive different levels of inputs than do tilled fields, we have demonstrated that strip-till is a viable alternative to no-till, which has been adopted slowly due to potentially negative responses. Strip-till alleviates the problem of heavy surface residue by moving such residue aside. Our results will be critically important in support of the movement toward no-till/strip-till as part of generating carbon credits in agricultural systems of the United States.
Publications
- No publications reported this period
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Progress 01/01/08 to 12/31/08
Outputs
OUTPUTS: We continued in 2008 a study to re-examine the response of corn (Zea mays L.) to planting date and plant population in Illinois. Such work was published from Illinois studies some 15 years ago, but changes in hybrids, including the use of those carrying transgenic traits for resistance to European corn borer and the Western corn rootworm, might be changing the optimal planting date and plant population. Results from this work in 2008 showed high yields at most locations and a rather typical response to plant population in northern Illinois locations, but substantially different response to planting date than we have seen in previous years in some southern Illinois locations. For example, yields at Brownstown actually rose by some 40 percent, to more than 14 t/ha, as planting was delayed from mid-April to early June. At Perry, in west-southwestern Illinois, there was hardly any change in yield as planting was delayed from April to late May. Combined data over the past four years (2005-2008) were used to generate response models describing the effect of planting date on grain yield. In northern Illinois, planting on 13 April produced the highest yield, and yields declined by 20 percent when planting was delayed to the end of May. In central Illinois, planting on 17 April produced the highest yield, and yields declined by 21 percent when planting was delayed to the end of May. The response to planting date at Brownstown in 2008 was so unusual that including those data changed the response curve from the typical quadratic (rising slightly then dropping in a curvilinear manner as planting date went from early April to early June) to nearly linear and slightly concave up, thus moving the planting date for highest yield from 11 April to 1 April, and decreasing the yield loss from planting at the end of May from 33 percent to only 22 percent. Across environments, the yield response to plant population was described well by a quadratic + plateau model. In southern Illinois, yields reached a plateau of 9.5 t/ha at a plant population of about 76,800 plants per hectare. In northern Illinois, the maximum yield of 13.5 t/ha was produced by 92,400 plants per ha. Applying economic optimization at current seed and grain prices resulted in optimum populations of about 7,000 plants per ha less than the populations required for maximum yields. Across trials, there was a rather weak but positive correlation between optimum plant population and the yield at that population. This revealed that in northern Illinois, each 1-ton increase in yield requires 3,700 more plants per hectare, while in southern Illinois this increase is about 2,000 plants per hectare. There was an interaction between plant population and planting date at some individual environments, but combined data showed that plant population should change little if any as planting is delayed. PARTICIPANTS: Not relevant to this project. TARGET AUDIENCES: Target audience is crop producers and agricultural professionals who advise crop producers. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.
Impacts
Results from these studies are being disseminated at producer and professional meetings. We are using the data from this work to examine, in the light of changes that have taken place in corn hybrids, whether or not the optimum planting time and plant populations have changed. Early indications are that planting date responses have changed little, although indications are that newer hybrids, perhaps in part because they carry traits such as transgenic, plant-produced protection against insects, might be somewhat more consistent under either early or late planting. Loss of yield from planting very early was minor as assessed using the combined data in these studies, though it was observed in some individual environments, particularly when there were cool temperatures after crop emergence. Compared to earlier work, we are finding that corn is responding to higher plant populations, and also that yields under good conditions are considerably higher. The lack of consistent interaction between planting time and plant population means that producers should attempt to establish similar stands regardless of planting time, certainly when planting occurs before mid-May. We are also learning that high levels of stress can reduce the optimum population, in some cases to less than 50,000/ha. This occurs only under low yields, and with better weather the same fields produce high yields and require relatively high plant populations. Our finding of a correlation between optimum yield and the population required to reach that yield lends some credence to the idea that variable-rate seeding might produce higher returns, as long as predicted yield levels in different parts of variable fields are actually attained.
Publications
- No publications reported this period
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Progress 01/01/07 to 12/31/07
Outputs
We continued in 2007 a study to re-examine the response of corn (Zea mays L.) to planting date and plant population in Illinois. Such work was published from Illinois studies some 15 years ago, but changes in hybrids, including the use of those carrying transgenic traits for resistance to European corn borer and the Western corn rootworm, might be changing the optimal planting date and plant population. Results from this work in 2007 showed high yields at most locations and a rather typical response to plant population, somewhat inconsistent interactions between planting date and plant population. As an example, the highest yield at Urbana, in east-central Illinois, was 15.6 t/ha from the highest population (111,150 plants/hectare) at the earliest planting date (April 2). Yields at this site, averaged over all plant populations (from 49,400 to 111,150 per hectare) were 14.2, 14.0, 13.5, and 11.0 t/ha from plantings made on 2 April, 20 April, 10 May, and 30 May,
respectively. Plant populations of 98 and 111 thousand produced the highest yields at each planting date, with only the last date showing a yield decline from the intermediate to the highest plant populations. Results at Monmouth were similar. At two locations in southern Illinois, where dry weather stress occurred and yields were relatively low, late planting greatly decreased yields and responses to plant population ranged from modest increases up to intermediate populations when planting was early to yield reductions with increasing plant population when planting was late. At Brownstown, for example, there was no response to plant population at any of the planting dates, and yields from planting dates April 20, May 2, and May 17 were 9.1, 5.9, and 3.6 t/ha, respectively. At Dixon Springs, the highest yield was at the lowest population at the late May planting, while the early June planting produced almost no yield. In a study of soybean planting rates ranging from 124 to 494
thousand seeds/ha, we found that yield was maximized at a seeding rate of about 370,000/ha in southern Illinois, but at only about 250,000/ha in central and northern Illinois. Results from these studies are being disseminated at producer and professional meetings.
Impacts
We are using the data from this work to examine, in the light of changes that have taken place in corn hybrids, whether or not the optimum planting time and plant populations have changed. Early indications are that planting date responses have changed little if any, although indications are that newer hybrids, perhaps in part because they carry traits such as transgenic, plant-produced protection against insects, might be more consistent under either early or late planting. Loss of yield from planting very early, which we have noted at one or two locations in previous years, was not observed in 2007, perhaps because of consistently warm conditions after early April. We did, however, observe reduced stands with early planting at one location. Compared to earlier work, we are finding that corn is responding to higher plant populations, and also that yields under good conditions are considerably higher than in previous work. The lack of consistent interaction between
planting time and plant population means that producers should attempt to establish similar stands regardless of planting time, at least when planting occurs before mid-May. We are also learning that high levels of stress can reduce the optimum population, in some cases to less than 50,000/ha. This occurs only under low yields, and with better weather the same fields will produce high yields and require relatively high plant populations. Balancing the risks and input levels will require more data. As soybean seed costs increase, our data are providing support for modestly lower seeding rates in order to maximize return to seed.
Publications
- No publications reported this period
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Progress 01/01/06 to 12/31/06
Outputs
We initiated in 2005 a study to re-examine the response of corn (Zea mays L.) to planting date and plant population in Illinois. Such work was published from Illinois studies some 15 years ago, but changes in hybrids, including the use of those carrying transgenic traits for resistance to European corn borer and the Western corn rootworm, might be changing the optimal planting date and plant population. Results from this work in 2006 showed wide differences among sites in the corn yield response to planting date and plant population. The two locations with the highest yields and the two with lowest yields all produced highest yields from the first planting date, which ranged from 5 April to 12 April. At the other two sites, corn planted on the earliest date, 30 March or 5 April, yielded less than did corn planted in late April or early May, perhaps due to the unfavorably low temperatures that the earliest-planted corn experienced after it reached a certain stage.
Interactions between planting date and population were usually not significant, and where they did occur it was usually due to low yields and less response to population at the latest date, which was in late May or early June. Plant population required to produce maximum yields was usually associated with yield level, which generally reflected the amount of water stress. At the two lowest yielding sites, where yields were only 7 to 8 tons per hectare, yields responded little to population, and maximum yields occurred at 50 to 75 thousand plants per hectare. At the higher-yielding sites, where average yields ranged from 11 to 13 tons per hectare, the population producing the highest yields at the earlier planting dates was usually the highest established population of about 100,000 plants per hectare.
Impacts
We are using the data from this work to examine, in the light of changes that have taken place in corn hybrids, whether or not the optimum planting time and plant populations have changed. Early indications are that planting date responses have changed little, although factors such as transgenic, plant-produced protection against insects might be more consistent under early planting than is insecticidal control. One area of ongoing concern, reconfirmed by the data from two sites in 2006, is that planting can be too early for optimum yield, due to factors other than plant stand establishment. Plant population responses are so far rather typical of those seen in earlier work, but with higher optimum populations under high-yielding conditions. The lack of interaction between planting time and plant population means that producers should attempt to establish similar stands regardless of planting time, at least when planting occurs before mid-May.
Publications
- No publications reported this period
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Progress 01/01/05 to 12/31/05
Outputs
Corn (Zea mays L.) hybrids carrying the trait for resistance to the Western corn rootworm (RW hybrids) were introduced in 2003. These hybrids offer the possibility of managing this important pest without the use of chemical insecticide, but at a higher cost for seed. We conducted a 3-year trial at three locations in Illinois in order to determine the proper plant population for a RW hybrid compared to its conventional counterpart. Averaged over 9 site-years, yields of the conventional and RW hybrids were maximized at populations of 87.8 and 90.5 thousand plants per hectare, respectively, at yields of 16.6 and 17.1 tons per hectare. When the price of corn and the cost of the seed were taken into account, the economically optimum plant populations for the conventional and RW hybrids were 81.6 and 82.5 thousand plants per hectare, respectively, with corresponding yields of 16.5 and 17.0 tons per hectare. Thus while optimum plant populations were virtually identical for
the conventional and RW hybrids, the modestly higher yield for the RW hybrid along with the need to apply little or no insecticide more than offset the additional cost of seed.
Impacts
In the two years since their introduction, corn hybrids genetically modified to resist damage by the Western corn rootworm have grown rapidly in popularity. Seed of such hybrids is more expensive, however, and it is important that these hybrids yield as much as their conventional counterparts, and that they respond similarly to agronomic practices. We showed that conventional and modified versions of one hybrid did not respond differently, and that the yield of the genetically modified hybrid at high plant populations was 2 to 3 percent higher than that of its conventional counterpart. Assuming that chemical insecticide and the extra cost of RW seed have the same cost per hectare, this additional yield represents higher profit when using RW hybrids. Rootworm-resistant hybrids thus appear to be a cost-effective way to manage this important insect pest.
Publications
- No publications reported this period
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Progress 01/01/04 to 12/31/04
Outputs
A study on the effects of deeper tillage, higher fertilizer rates, and increased plant population on yields of continuous corn (Zea mays L.) showed a significant yield increase (of 4 percent) from deep tillage at one location (Monmouth) but not at another (Perry), while greater soil nutrient supply, including 112 kg per hectare more nitrogen, increased yields at both Perry and Monmouth. Higher plant population (99,000 versus 79,000 per hectare) reduced yield by 4 percent at Monmouth but had no effect at Perry. Yields averaged 12.6 and 14.1 tons per hectare at Monmouth and Perry, respectively. A comparison of corn and soybean [Glycine max (L.) Merrill.] yields in a two-year, corn-soybean and three-year, corn-corn-soybean rotation showed that soybean yielded more following two years of corn than one year of corn. Corn in rotation yielded more than continuous corn, and the second year of corn in the soybean-corn-corn rotation yielded less than the first year of corn
following soybean. A study initiated in 2003 at three locations again showed that a new Bt corn hybrid effective against western corn rootworm produced yields and plant population responses similar to those of its non-Bt counterpart hybrid. Yields in this and other studies were very high in 2004, reflecting excellent growing conditions.
Impacts
With pressure on soybean due to international competition and uncertainties related to pest management, a large need has developed to assess both the effects of increasing corn area at the expense of soybean area to corn (this can only occur in most areas by increasing the percentage of corn area in which corn is grown following corn instead of soybean) and to try to find ways of reducing the anticipated yield loss when corn follows corn. We are early in these investigations, and it is clear that weather patterns and soil differences will affect such results. To date, we have not found a way to consistently reduce the anticipated 10 percent lower yield when corn follows corn instead of following soybean. We have, however, found some evidence that soybean following two years of corn may yield more than soybean following only one year of corn, suggesting the possibility of some lessening of the economic impact of the lower yield in the second year of corn in the 3-year
corn-corn-soybean sequence. We have shown that just increasing the corn plant population, from high to very high, cannot be counted on to increase yields.
Publications
- No publications reported this period
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Progress 01/01/03 to 12/31/03
Outputs
Results of a 4 year (1999-2003) tillage study at six Illinois locations showed that, while deep tillage in the fall after harvest of the previous crop significantly reduced the resistance to soil penetration, it had no consistent effect on yield of the following corn (Zea mays L.) or soybean [Glycine max (L.) Merr] crop. Deep-tilling in alternate years or only once at the start of the study also failed to affect crop yields. Secondary (spring) tillage in a few instances improved the plant stand marginally, although effects on yield were minimal. Resesarch on the effects of deeper tillage, higher fertilizer rates, and increased plant population on yields of continuous corn showed no effect of deep tillage, on yield at the higher fertilizer rates at Urbana, but a yield decrease from increasing the plant population at both Monmouth and Urbana. A study initiated in 2003 at three locations showed that a new Bt corn hybrid effective against western corn rootworm produced
yields and plant population responses similar to those of its non-Bt counterpart hybrid.
Impacts
The consistent lack of response to deep tillage, across six different soils and weather conditions over 4 years, casts considerable doubt on the usefulness of this capital-intensive practice by crop producers. It is possible that smaller equipment used on research centers decreases response to practices that relieve compaction, but our data indicate that producers might want to leave check strips when using deep tillage in order to test returns to this practice. The lack of response to secondary tillage indicates that corn and soybean can be produced effectively without soil disturbance in the spring.
Publications
- No publications reported this period
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Progress 01/01/02 to 12/31/02
Outputs
A study was conducted over 3 years (2000-02) to compare yield of corn (Zea mays L.) grown at the same plant population in two row spacings, 38 and 76 cm. Averaged over 17 site-years, yields from the two row spacings were virtually identical. Results of the first 3 years of a tillage study at 6 Illinois locations showed that, while deep tillage in the fall after harvest of the previous crop significantly reduced the resistance to soil penetration, it had no consistent effect on yield of the following corn or soybean crop. A soybean [Glycine max (L.) Merr] planting date study initiated in 2001 showed that planting in early April is unlikely to increase yields, and in fact led to yield decreases at several locations in Northern Illinois, probably due to effects of cold temperatures on young plants.
Impacts
Our work to date on corn row spacing shows clearly that, if plant density is kept constant, narrowing rows to less than 76 cm is unlikely to produce consistent yield increases under Illinois conditions. The lack of response to deep tillage, while somewhat surprising given the different weather conditions over the years and locations, nonetheless cast some doubt on the usefulness of this capital-intensive practice by crop producers. Results on planting date effects in soybean should help to decrease the practice of very early planting that has been adopted by a small number of producers, and should prevent others from initiating what is often an unprofitable practice.
Publications
- No publications reported this period
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Progress 01/01/01 to 12/31/01
Outputs
New research initiated in 2000 was designed to compare yield of corn (Zea mays L.) grown at the same plant population in two row spacings - 38 and 76 cm. In the first year of the research, yields from the two row spacings were virtually identical at all locations, and were not significantly different at any location, nor when averaged across locations. A tillage study initiated in 2000 at six Illinois locations showed that deep tillage in the fall after harvest of the previous crop significantly reduced the resistance to soil penetration, but had no significant effect on growth or yield of the following corn or soybean crop. A soybean planting date study initiated in 2001 showed that planting in early April is unlikely to increase yields, and in fact led to yield decreases at several locations.
Impacts
Our continuing work on corn row spacing is consolidating earlier indications that narrowing rows to less than 76 cm is likely to produce little or no increase in yield under Illinois conditions. While initial responses to deep tillage do not appear to increase yield, we expect seasonal weather to affect crop response to this treatment, and will be continuing that research for several more years. These results will help producers decide whether or not to invest in the equipment, fuel, and labor needed to conduct this operation. Results on planting date effects in soybean should help to decrease the practice of very early planting that has been adopted by a small number of producers.
Publications
- No publications reported this period
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Progress 01/01/00 to 12/30/00
Outputs
New research initiated in 2000 was designed to compare yield of corn (Zea mays L.) grown at the same plant population in two row spacings - 38 and 76 cm. Preliminary results indicate that yields were about 3 percent higher in the 38-cm rows at some locations, but were not significantly different at other locations. At Perry, corn in 38-cm rows produced 14.4 t /ha, while yield in 76-cm rows was 14.2 t/ ha. A continuing study on the effect of planting depth showed that planting depth had little effect on yield in 1999 and 2000, but deeper planting decreased yield in 1998. In 2000, corn planted in March emerged and grew well, but did not yield as well as corn planted in April. We also found that polymer-coated seed decreased emergence percentage and uniformity in early-planted corn. A new study initiated in 2000 at 6 Illinois locations showed that the effects of deep tillage in the fall after harvest of the previous crop had little effect on growth or yield of the
following corn or soybean crop.
Impacts
Our continuing research on corn row spacing is consolidating earlier indications that narrowing rows to less than 76 cm is likely to produce only small, if any, increase in yield. While initial responses to deep tillage do not appear to have increased yield, we expect seasonal weather to affect crop response to this treatment, and will be continuing that study for at least three more years.
Publications
- No publications reported this period
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Progress 01/01/99 to 12/31/99
Outputs
A study initiated in 1997 was concluded in 1999, in which two corn (Zea mays L.) hybrids were planted at two row spacings - 38 and 76 cm - and at plant populations ranging from 49,400 to 98,800 plants per hectare. Averaged over 9 environments, results showed that, averaged over plant populations, 38-cm rows produced 325 kg/ha (2.9 percent) more grain than 76-cm rows in hybrid Pioneer Br. 3489, but only 69 kg/ha (0.6 percent) in Pioneer Br. 3335. Optimal plant population was not consistent among hybrids and row spacing; over both hybrids and row spacings, the optimal population was about 71,200 plants/ha. A study conducted on the effect of planting depth showed that increased planting depth decreased yield in 1998, but not under improved emergence conditions in 1999. A preliminary study conducted in 1999 showed that polymer-coated seed and mixtures of coated and non-coated seed increased the time to emergence by about 10 days, and decreased grain yield by as much as 38
percent. In another study, we found that the space available in the row to individual corn plants did not affect the yield of individual plants.
Impacts
Narrowing the distance between corn rows produced small yield increases, especially in the earlier-maturing of two hybrids, but these increases may not be sufficient to pay for equipment changes needed. The finding that optimal plant populations did not increase when rows were narrowed shows that higher seeding rates need not be used when rows narrower than 76 cm are used.
Publications
- BULLOCK, D.G., BULLOCK, D.S., NAFZIGER, E.D., DOERGE, T., PASZKIEWICZ, S. CARTER, P., and PETERSON, T.A. 1998. Does variable rate seeding of corn pay? Agron. J. 90:830-836.
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Progress 10/01/97 to 09/30/98
Outputs
A study initiated in 1996 was continued in 1997, including two corn (Zea mays L.) hybrids planted at two row spacings (38 and 76 cm) and at plant populations ranging from 49,400 to 98,800 plants per hectare. Results showed that there was little effect of row spacing on grain yield at four locations, while at a fifth location the narrower rows produced yields about 0.7 Mg/ha (4.6%) higher than the wider rows. Grain yield reached a maximum at plant populations of about 75,000 to 80,000 plants per hectare at several locations, but was unaffected by plant population at two of the five locations. There was an interaction between row spacing and plant population at only one location. Another study initiated in 1997 showed that removal of tillers from corn plants had no effect on yield.
Impacts
(N/A)
Publications
- No publications reported this period
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Progress 01/01/97 to 12/31/97
Outputs
A study initiated in 1996 was expanded in 1997 to include three corn (Zea mays L.) hybrids planted at two row spacings - 38 and 76 cm - and at plant populations ranging from 49,400 to 98,800 plants per hectare. Results in 1996 showed that there was little effect of row spacing on grain yield, but that grain yield reached a maximum at plant populations of about 75,000 plants per hectare. There was no interaction between row spacing and plant population. Another study concluded in 1996 showed that interplant spacing variability of corn increased slightly as planting speed increased, but there was no effect of planting speed or plant spacing variability on grain yield. A study was initiated in 1996 to determine whether corn grain dry matter decreases as grain dries in the field. Results from 14 field harvests the first year showed that dry weight per kernel decreased significantly during field drying in three cases and increased in one case, but did not change in ten
cases nor when averaged over all locations. This study is continuing in 1997. A study conducted in farmer fields in 1995 and 1996 showed that a commercial firming device attached to planter units had little effect on corn plant stands.
Impacts
(N/A)
Publications
- No publications reported this period
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Progress 10/01/95 to 09/30/96
Outputs
The third and final year of N rate application was completed on a study designedto assess the effect of red clover seeded as a cover crop into winter wheat on the N response of the corn crop following wheat. Corn yields were lower, and the optimum N rate when corn followed red clover did not decrease as much in 1995 as it had in 1994. In a study designed to test the effect of mesocotyl detachment (simulated insect or disease injury) in young corn plants on subsequent survival and yield, results indicated a rather severe yield loss of individual plants when the mesocotyl is cut. Plants generally survived mesocotyl detachment, but yield decreases following mesocotyl detachment ranged from 35 percent when detached at the 4-leaf stage to 64 percent when detached at the 1-leaf stage. A 2-year study on the effects of missing and two-plant "hills" of corn was concluded, and results were published. Results showed clearly that, within a normal range of plant populations,
missing plants always decreased overall yield, while double plants increased yield. Because both missing and doubled plants contribute similarly to the standard deviation of interplant spacing, this measure of spacing variability is inadequate as a predictor of yield loss.
Impacts
(N/A)
Publications
- NAFZIGER, E.D. 1996. Effects of missing and two-plant hills on corn grain yield.J. Prod. Agric. 9:238-240.
- NAFZIGER, E.D. 1996. Corn yield following early season mesocotyl detachment. Agron. Abstr. p. 123.
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Progress 10/01/94 to 09/30/95
Outputs
The third year's red clover seeding and the second year of N rate application were completed in a study designed to assess the effect of red clover seeded as a cover crop into winter wheat on the N response of the corn crop following wheat. Clover seedings have survived and grown quite well at most on-farm locations throughout this study. The optimum N rate decreased 30 to 50 kg N per hectare when corn followed red clover in both locations in 1994. In a study designed to test the effect of mesocotyl detachment to simulate insect or disease injury in young corn plants on subsequent survival and yield, results indicated a rather severe yield loss of individual plants when the mesocotyl is cut. Plants generally survived mesocotyl detachment as early as the 1-leaf stage, but yields were severely decreased, especially when mesocotyls were detached early.
Impacts
(N/A)
Publications
- NO PUBLICATIONS REPORTED THIS PERIOD.
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Progress 10/01/93 to 09/30/94
Outputs
This was the fourth and final year of a study on the effect of plant population on the yield of several corn hybrids. Six corn hybrids were thinned to populations ranging from 24,700 to 86,450 plants per hectare at four Illinois locations. Light interception by the corn canopy during grainfill was also measured at one location. Results indicated that optimum populations were in the range of 60 to 75 thousand plants per hectare. Light interception was strongly correlated with grain yield. The second year's red clover seeding and the first year of N rate application were completed ona new study designed to assess the effect of red clover seeded as a cover crop into winter wheat, on the N response of the corn crop following wheat. Clover seedings have survived and grown quite well at most on-farm locations both years. Another study initiated this year is designed to test the effect of mesocotyl detachment (simulated insect or disease injury) in young corn plants on
subsequent survival and yield of those plants. Preliminary results indicate a rather severe yield loss of individual plants when the mesocotyl is cut.
Impacts
(N/A)
Publications
- MIAN, M.A.R., and NAFZIGER, E.D. 1994. Seed size and water potential effects on germination and seedling growth of winter wheat. Crop Sci. 34:169-171.
- MIAN, M.A.R., NAFZIGER, E.D., KOLB, F.L., and TEYKER, R.H. 1994. Root size and distribution of field-grown wheat genotypes. Crop Sci. 34:810-812.
- NAFZIGER, E.D. 1994. Corn planting date and plant population. J. Prod. Agr. 7:59-62.
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Progress 10/01/92 to 09/30/93
Outputs
This was the third of a multiple-year study on the effect of plant population onthe yield of several corn hybrids. Six corn hybrids were thinned to plant populations ranging from 24,700 to 86,450 plants per hectare at four Illinois locations. Light interception by the corn canopy during grainfill was also measured. Plant populations producing the highest yields were 60 to 75 thousand plants per hectare, and light interception showed a strong linear correlation with grain yield. Winter wheat N rate studies were conducted in small plots on farmer's fields in 10 locations in Illinois. Soil nitrate was also determined on samples taken in both the fall and spring. Wheat responded well to N rate in most of the locations in Southern Illinois, with optimum rates ranging 50 to 80 kg N per hectare. In Northern Illinois, with considerable disease and low yields, wheat responded little to N rate. Response to N rate was not related to soil nitrate content.
Impacts
(N/A)
Publications
- MIAN, M.A.R., NAFZIGER, E.D., KOLB, F.L. and TEKYER, H. 1993. Root growth of wheat genotypes in hydroponic culture and in the greenhouse under different soil moisture regimes. Crop Sci. 33:283-286.
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Progress 10/01/91 to 09/30/92
Outputs
This was the second of a multiple-year study on the effect of plant population on the yield of several corn hybrids. Six corn hybrids were thinned to populations ranging from 24,700 to 86,450 plants per ha at four Illinois locations. Results indicated that optimum populations were in the range of 60 to 75 thousand plants per ha. In cooperation with county Extension advisers and 11 farmers in NW Illinois, the effect of N rate on corn yield in farmer-conducted trials was tested. The growing season for the crop was good, but this part of the state had sub-optimal temperatures and delayed harvest. Some of the on-farm locations showed no N response, some produced optimal yields at less than recommended N rates, while others had optimal N rates very near those generally recommended. Two studies on seed size - one on wheat and one on corn - were concluded and published in 1992. In both of these studies, seed size had little or no effect on grain yield. Winter wheat N rate
studies were conducted in small plots on farm fields in 9 locations throughout Southern Illinois; an additional 8 locations were severely damaged by cold weather after planting. Soil nitrate tests taken in the fall ranged from 2.5 to 7.0 mg/kg, and those taken at the time of N application in the early spring ranged from 1.6 to 5.8 mg/kg. The growing season was favorable and wheat responded to N at all of the locations. The economically optimum N rate varied from 80 to about 150 kg N/ha, with an average of about 120 kg N/ha.
Impacts
(N/A)
Publications
- MIAN, A.R. and NAFZIGER, E.D. 1992. Seed size effects on emergence, head number, and grain yield of winter wheat. J. Prod. Agric. 5:265-268.
- NAFZIGER, E.D. 1992. Seed size effects on yields of two corn hybrids. J. Prod. Agric. 5:538-540.
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Progress 10/01/90 to 09/30/91
Outputs
This was the first year of a multiple-year study on the effect of plant population on the yield of several corn hybrids. Six corn hybrids were thinned to populations ranging from 24,700 to 86,450 plants per hectare at four Illinois locations. Preliminary results indicate that optimum populations differed considerably among hybrids and locations, but were typically in the range of 60 to 75 thousand plants per hectare. A study in cooperation with county Extension advisers and 15 farmers in NW Illinois was designed to test the effect of N rate on corn yield in farmer-conducted trials. As was also true in some small-plot studies in the same area, 1991 was a year of minimal response to N rate; about half of the on-farm locations showed no N response. Of the responsive sites, many showed optimal yields at less that the recommended rate of N. Winter wheat N rate studies were conducted in small plots laid out on farm fields in 10 locations throughout Illinois. As a part of the
study, soil nitrate tests were taken at the time of N application in the early spring. Results showed that soil nitrate in the upper 60 cm of soil varied from 4 to 63 kg N per hectare among the locations, and that soils with low N content tended to show less response to applied N. Of the 10 locations, 7 showed some response to N rate, with the optimum rate about 60 kg per hectare (in addition to fall-applied N) at most of the responsive locations.
Impacts
(N/A)
Publications
- TEYKER, R.H., GALERANI, P.R. and NAFZIGER, E.D. 1991. Analysis of xylem exudate by ion chromatography: influence of nitrogen and residue management on corn exudate composition. Commun. Soil Sci. Plant Anal. 22:785-793.
- NAFZIGER, E.D., CARTER, P.R. and GRAHAM, E.E. 1991. Response of corn to uneven emergence. Crop Sci. 31:811-815.
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Progress 10/01/89 to 09/30/90
Outputs
This was the fourth and last year of a study of the effect of planting date and plant density on the yield of two corn hybrids; in both 1989 and 1990, the study included no-till as well as conventional tillage. The optimum plant density at Monmouth was found to be about 75,000 plants per hectare, and was little affected by planting date. At DeKalb, the optimum density was about 80,000 plants per hectare. Tillage had no effect on yield at either location. Corn seed size studies were continued at Urbana and Monmouth in 1990, but the trial at Urbana was lost to flooding and disease. Average across the three trials in 1989 and 1990, the grain yields of the two hybrids used in this study were unaffected by seed size alone, or by within-row planting arrangements of different seed sizes. Winter wheat management studies designed to test the effects of nitrogen rate, seeding rate, ethephon growth regulator, and fungicides were conducted in 1990 at Belleville, Brownstown,
Urbana and DeKalb. In general, there was little benefit to the use of growth regulator. Foliar fungicide provided a yield benefit, averaged across locations for the two years of the study, of about 330 kg ha, thus proving to barely return the cost of the chemical and its application. Optimum nitrogen rates ranged from 0 at Urbana to about 80 kg ha at Belleville and Brownstown.
Impacts
(N/A)
Publications
- NO PUBLICATIONS REPORTED THIS PERIOD.
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Progress 10/01/86 to 09/30/90
Outputs
This four-year project has provided valuable information on management techniques for optimizing the production of corn and soft red winter wheat in Illinois. The use of some input-intensive strategies for wheat production have been invalidated by our results, in favor of a more moderate level of purchased inputs. In corn, the results of the planting date work will be used to develop and publish new guidelines on the proper plant populations to use when planting at different times. These studies, along with those in which hybrids were thinned at different times, have also yielded information valuable in defining the response of ear size to management techniques.
Impacts
(N/A)
Publications
- NO PUBLICATIONS REPORTED THIS PERIOD.
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Progress 10/01/88 to 09/30/89
Outputs
The fourth year of a study of the effect of planting date and plant density on the yield of two corn hybrids was enlarged to include no-till as well as conventional tillage in 1989. The optimum plant density at Monmouth, where yield levels were somewhat less than normal due to dry weather, was found to be about 75,000 plants per hectare at the optimum planting dates, but somewhat lower at the earliest and latest planting dates. Tillage had no effect at that location, but no-till yields at DeKalb were about 4% lower than in conventional tillage. At DeKalb, the optimum plant density was above 80,000 plants per hectare, and differed only slightly with planting date. Corn seed size and time of thinning studies were initiated at Urbana in 1989, and showed little effect of seed size on yield. Winter wheat management studies designed to test the effects of nitrogen rate, seeding rate, ethephon growth regulator, and fungicides were conducted at Belleville, Brownstown,
Urbana, and DeKalb. In general, there was little benefit to the use of growth regulator or fungicide.
Impacts
(N/A)
Publications
- NO PUBLICATIONS REPORTED THIS PERIOD.
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Progress 10/01/87 to 09/30/88
Outputs
The third year of a long-term study of the effect of planting date and plant density on the yield of two corn hybrids was much affected by drought at one of the locations--Monmouth--but conditions at the other location--DeKalb--were quite favorable. Even so, the optimum plant density at Monmouth, where yield levels were around 6 to 7 tons per hectare (or about 30 to 40% less than in normal years), was found to be about 55,000 plants per hectare, which is only 5 to 10% less than the optimum found in previous years. Planting date effects were quite unpredictable, but very early planting, which placed plants in very dry conditions during critical stages of development, resulted in fairly severe yield loss. The uneven emergence study on corn, which was conducted in seven Illinois environments during 1986 and 1987, was analyzed and results were reported. Corn row spacing x plant x ethephon, seed size, and time of thinning studies were initiated at Urbana in 1988, but were
much affected by the extremely dry weather, and yielded little useful information. Winter wheat management studies designed to test the effects of nitrogen rate, seeding rate, ethephon growth regulator, and fungicides were conducted at Belleville, Brownstown, Urbana, and DeKalb. Results confirmed that, at least when the spring weather is dry, there is little benefit to the use of growth regulator or fungicide.
Impacts
(N/A)
Publications
- GRAHAM, E. E. (1988). Effect of uneven emergence on corn yield. MS thesis, University of Illinois at Urbana-Champaign.
- HAISMA, T. M. (1988). Nitrogen rate, seeding rate, and ethephon effects on winter wheat. MS thesis, University of Illinois at Urbana-Champaign.
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Progress 10/01/86 to 09/30/87
Outputs
Corn planting date x hybrid x plant density studies at Monmouth and DeKalb showed the optimum planting date to be late April. The optimum density was about 30,000 plants per acre at DeKalb, but only about 25,000 plants per acre under lower-yielding conditions at Monmouth. The data x density interation was significant for yield at DeKalb only, with slghtly lower density optima at later planting dates. Hybrid interacted with planting date, with one hybrid showing a sharper yield decline with delayed planting than did the other hybrid. A study of uneven emergence of two hybrids was conducted at Urbana, Monmouth, and DeKalb. Three planting dates, 8 patterns of uniform-row emergence, 8 patterns of uneven within-row emergence, and 4 reduced-stand treatments were used. Alternating early- and middle-planted rows gave the same yield reduction (6%) as all-middle planting. Similarly, alternating early- and late-planted rows produced the same yield reduction (15%) as
all-late planting. In the uneven within-row emergence treatment, early-middle combinations all produced similar yields (about 7% lower than early planting), and early-late combinations produced yield decreases ranging from 11% when only one-fourth of the plants were late to about 24% when three-fourths of the plants were late. These results indicate that replanting of unevenly-emerged fields should be considered only when emergence of more than 25% of the plants is delayed by more than two weeks.
Impacts
(N/A)
Publications
- NO PUBLICATIONS REPORTED THIS PERIOD.
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