One method for refining nitrogen (N) application in corn is use of in-season crop sensing. To aid producers in making decisions regarding N rate adjustments, a calibrated relationship between sensor-derived information and expected N application need should be established. Nitrogen rate trials were conducted at multiple sites across Iowa in 2001-2003. Nitrogen was applied at or shortly after co...

The planting of transgenic crops expressing Bacillus thuringiensis endotoxins is widespread throughout the world; the prolific increase in their application exposes nontarget organisms to toxins designed to control pests. To date, studies have focused upon the effects of Bt endotoxins on specific herbivores and detritivores, without consideration of their persistence within arthropod food webs....

this research has been done for studying the effect of split application of nitrogen fertilizer on growth indexes and yield of three hybrids of grain corn in shahrood. a split plot experiment based on randomized complete block design with four replications was carried out in 2007. three hybrids of corn (double cross 370, single cross 447, single cross 499) were placed in main plots and split ap...

Ryegrass is the probably the most damaging weed to winter wheat over a large part of the high rainfall area in the central, north and east Texas. Economic losses in wheat occur through reduced grain yield, quality, foreign matter, and harvest efficiency. Yield loss can exceed 90% in heavy infestations. In addition to yield reduction, reduced harvest efficiency results in lower test weight, high...

There is interest in the identification of the best seeding density for new corn hybrids and on reduced use of herbicides for weed control. The objective of this study was to evaluate the effects of seeding density (30, 50, 70, and 90 thousand plants ha) and weed control on green ear yield and grain yield in corn cultivar AG 1051. A completely randomized block design was adopted with split-plot...

Final soil manipulation before seed germination occurs during the planting operation. Contact force of depth‐gauge wheels adjacent to the seed opener potentially alters the environment for corn seed germination and early plant growth. A field experiment was conducted measuring seed spacing, spacing variability, seed depth, emergence rate, plant dry matter, final stand, crop growth stage, and ex...

Corn silage is a major ingredient of diets for dairy cattle. Environmental factors can affect the yield and composition of corn silage. Drought and heat are two common environmental factors that affect silage yield and quality. Corn silages with low concentrations of dry matter, high concentrations of protein, high concentrations of fiber, and low concentrations of starch indicate that the crop...

in order to evaluate the yield and advantage of two- and three-species intercropping of sunflower with corn and soybean, an experiment was conducted at the research farm of faculty of agriculture of tabriz university in tabriz, iran 2011. the experiment was arranged based on randomized completely block design with 6 treatments and three replications. treatments were included the pure stand of s...

In the southeastern U.S. Coastal Plains, supplemental irrigation is required to reduce the impact of short‐term droughts and yield‐reducing plant water stress that can occur at least biennially. Sprinkler irrigation is commonly used to water agronomic crops in the region. Microirrigation is typically used for high value fruit and vegetable crops. In recent years and at some locations, microirri...