Evaluation of Bt and Non-Bt Corn with and without Soil Insecticides for Control of Corn Rootworm

The purpose of this study was to evaluate the effectiveness of Bt corn and soil insecticides, either alone or in combination, for the control of corn rootworm. Evaluation of Bt hybrids included SmartStax, SmartStax with refuge in a bag, and Herculex XTRA. Soil insecticides evaluated were SmartChoice-SB, Counter-SB, Aztec, and Force.

Effects of Seed Treatments and a Soil-applied Nematicide on Corn Yields and Nematode Population Densities

Plant-parasitic nematodes are microscopic worms that feed on plants. Almost every nematode that feeds on corn is capable of feeding on many other plants. These nematode parasites are thought to be native to most Iowa soils and to have fed upon native plants before corn was grown as a cultivated crop. Population densities (numbers) of most species of plant-parasitic nematodes that feed on corn have to increase to damaging levels (called damage thresholds) before yield loss occurs.

Seasonal and Rotational Influences on Corn Nitrogen Requirements

This project was designed to study the N fertilization needs in continuous corn (CC) and corn rotated with soybean (SC) as influenced by location and climate. Multiple rates of fertilizer N were spring applied, with the intent to measure yield response to N within each rotation on a yearly basis for multiple years at multiple sites across Iowa. This will allow the determination of N requirements for each rotation, differences that exist between the two rotations, responses to applied N across different soils and climatic conditions, and evaluation of tools used to adjust N application.

Split Nitrogen Application Trial

Farmers understand it is best to apply nitrogen to the crop at or right before rapid growth occurs. However, 100 percent in-season nitrogen applications are faulted because of potential for unfavorable weather conditions delaying applications and subsequent deficiency occurring. This trial looks at how split nitrogen applications can be used to address environmental risks of pre-plant nitrogen application as well as unfavorable application conditions in-season.

High Tunnel Bramble Production

In 2006, a study was initiated at the ISU Armstrong Research Farm (ARF) to evaluate the potential for growing high-value floricane and primocane type raspberries and blackberries in a high tunnel. The objectives were to determine if a high tunnel could be used to improve over-wintering of cold sensitive floricane types, and if the harvest season of primocane types could be advanced far enough ahead that they could replace the floricane types in such a production system. A second objective was to determine if these crops could be grown in a high tunnel without pesticides or minimum pesticide usage. This report summarizes the results for the 2009 through 2011growing seasons.

Water Infiltration following Land Rolling of Soybeans

Land rolling of soybean fields has become a popular practice in north central and northwest Iowa during the past five years. Although this technique was first utilized to push rocks into the ground to avoid combine damage and aid in harvesting lodged crops in Canada, producers in Iowa quickly learned that pushing corn root-balls flat at the time of planting and pushing small rocks into the ground can increase harvest efficiency. Typically fields are rolled shortly after planting. One disturbing trend that was noticed, however, was that rolled fields tended to have more water standing between the rows after moderate or heavy rain events. This would imply that water infiltration was slower in fields that had been rolled compared with fields that had not been rolled. Infiltration measurements were taken on a few plots in 2010 at the ISU Northern Research Farm. It seemed that water infiltration was less on the rolled plots. However, we wanted more measurements before publishing any results. In 2011 infiltration measurements were taken on the research farm and on neighboring farms where soybeans had been rolled. The goal was to determine if water infiltration had been reduced by land rolling.

Evaluation of Fungicides and Herbicides for Management of White Mold of Soybean

Several new fungicide products are either available or will be available for management of white mold of soybean. This study was conducted at the Muscatine Island Research and Demonstration Farm, and one farmer’s field in northeast Iowa.

BioCentury Research Farm Update

The BioCentury Research Farm (BCRF) had a diversity of users in 2011. Iowa State faculty and staff from agricultural and biosystems engineering (ABE), agricultural systems technology (AST), agronomy, chemical and biological engineering (CBE), civil, construction, and environmental engineering (CCEE), food science and human nutrition (FSHN), horticulture, mechanical engineering (ME), and natural resource ecology and management (NREM) conducted research, teaching, and outreach at the BCRF. Private industry users included Avello Bioenergy, DCE, Frontline BioEnergy, and Virent, Inc.

Miscanthus Establishment and Survival

Rising costs of petroleum fuels and increased awareness of the adverse effects of greenhouse gases have spurred interest in renewable fuels and other ‘green’ products. Recent legislation has set goals of approximately 20 billion gallons of renewable fuel produced from non-corn starch sources by the year 2022. These driving forces have increased interest in dedicated bioenergy crops. Among perennial grasses, which have received an exceptional amount of attention as dedicated energy crops, one stands out: Miscanthus (Miscanthus x giganteus).

Longitudinal Study of Tree Swallows

Tree swallows (Tachycineta bicolor) are the most widely distributed of the Tachycineta species, extending from northern Alaska and Canada to the southern United States. They are semi-colonial, secondary cavity nesters, primarily aerial insectivores, and migratory throughout most of their range. Tree swallows are a widely used model organism for avian ecologists and environmental physiologists because their life history lends itself to longterm study. They can be readily and repeatedly trapped at nests, and losses to nest predators are low. Adults return to previous breeding sites with high fidelity, so individuals marked during or after their first reproductive season can be reliably captured in subsequent years, and return rate to the breeding area can be used as an index of survival. Swallows using nest boxes are extraordinarily resistant to the disturbance of handling, allowing repeated captures to obtain measurements, blood samples, etc., both within and between breeding seasons.

Southeast Research Farm Summary

Includes Farm and Weather Summary and Research Farm Projects.

Soybean Replant Study

Every spring, farmers are faced with the decision of whether to replant soybeans because of stand losses due to hail storms, soil crusting, and damping off. A common practice when faced with this decision is to “thickenup” the stand by planting additional seed into the existing stand. Although this practice is usually discouraged by agronomists, there has been little research done to compare this practice with keeping the existing stand or destroying the stand and replanting.

Weather and Growing Season Summary

Precipitation for 2011 was less than the longterm climate average. Early in the year, precipitation lagged behind normal, but then tracked close to the normal accumulation rate from mid-April through mid-August. After that time, precipitation amounts greatly lagged behind normal, and the year ended almost 7 in. behind the long-term average. (Figure 1). Overall, 2011 will be remembered for good moisture early, but ending the season with almost no rainfall.

Phosphorus and Potassium Rates and Placement Methods for Corn and Soybean Managed with No-till or Tillage

No-till management for corn and soybean results in little or no incorporation of crop residues and fertilizer with soil. Subsurface banding phosphorus (P) and potassium (K) fertilizers with planter attachments could be more effective than broadcast fertilization, because in no-till with broadcast fertilizer, both nutrients accumulate at or near the soil surface. A long-term study was initiated in 1994 at the ISU Northwest Research Farm to evaluate P and K fertilizer placement for corn and soybean managed with no-till and chiselplow tillage.

Squash Bug, Squash Vine Borer, and Striped Cucumber Beetle on Butternut Squash and Muskmelon

Alternative agricultural schemes are gaining attention as the demand for organic and sustainable products continues to grow. Pest insects pose a sizeable challenge to agricultural production because their activities reduce crop fitness and productivity. Effective management of pest-insects is, therefore, crucial for successful management, and increasingly entails a multi-dimensional approach.