A Survey of Five Stem-Feeding Insect Pests of Wheat in the Northern Great Plains
The wheat stem sawfly, Cephas cinctus Norton, the wheat stem maggot, Meromyza americana Fitch, the Hessian fly, Mayetiola destructor (Say), the wheat jointworm, Tetramesa tritici (Fitch), and the wheat strawworm, Tetramesa grandis (Riley), have long been considered wheat pests in the northern Great Plains. This paper reports results of surveys for these pests conducted over 3 yrs in parts of Montana (10 counties), North Dakota (14 counties), South Dakota (1 county), Nebraska (4 counties) and Wyoming (1 county). Fields were randomly selected and a mean of 191 stems were sampled from each field. The percentage of stems infested with each pest was recorded. The percentage of parasitized wheat stem sawfly larvae also was noted. The wheat stem sawfly, wheat stem maggot, and Hessian fly were the most commonly encountered pests, recorded in nearly every county. Wheat stem sawfly density was twice that of wheat stem maggot (7% vs 3.2%) in infested fields. Wheat stem sawfly densities exceeded 10% in 4 counties: Da...
Wheat Stem Maggot in Spring Wheat-Alfalfa Intercrops With Different Crop Management Intensities
Larval infestations and adult counts of wheat stem maggot (Meormyza americana) were each compared among plots of intercropped spring wheat and alfalfa grown under high, intermediate, or low crop management inten­ sity (CMI). CMI varied primarily in the amounts of nitrogen fertilizer, herbi­ cide, and tillage used. Inf station of wheat plants was measured from 1990 through 1993 as the percentage of white grain heads caused by larval feeding within the stems. Adult counts were made from sweep net samples within plots 3 to 5 times per year from 1991 through 1993. Larval infestation varied among years but not by CMI. The mean percentages of white heads in 1991 (2.0%) was greater than in other years (each :s; 1.3%). Counts of adult M. americana differed among sampling dates within years but not by CML The number of adults collected was bimodal, peaking on the first and last sam­ pling dates each year. The interpretation of our results is discussed in the context of cropping systems research. Wheat stem maggot (Meromyza americana Fitch) is an insect pest that occasionally causes economic dam ge to spri g wheat (Triticum aestivum L.) in South Dakota (Gilbertson 1925, Kieckhefer and Morrill 1970). Adu t M. americana first appear in spring wheat fields in South Dakota from late May to early June and deposit eggs on leaves near the stems of wheat plants (Gilbertson 1925, Kieckhefer 1974). Larvae feed and tunnel w thin the stems, resulting in sterile white heads among infested stems (Morrill 1995). Adults emerge from stems in July, a d second and partial third generations follow (Gilbertson 1925). M. americana is polyphagous, and the larvae may feed on many grassy weed species in addition to small grain plants such as wheat, barley, and rye (Gilbertson 1925, Morrill 1995). Thus, suppression of grassy weeds through tillage and herbicides can aid in management of M. americana (Gilbertson 1925, Morrill 1995). Crop rotation also limits damage from M. americana in small grain fields (Gilbertson 1925, Morrill 1995). Spring wheat, an annual row crop, is sometimes intercropped with alfalfa (Medicago sativa), a perennial forage crop, in eastern South Dakota and sur­ rounding areas. Wheat produces a harvestable crop within one season. Al­ falfa establishes during the first year and is maintained for an additional one to three years. Spring wheat and alfalfa are often part of a arger crop rota­ tion system that includes corn and soybeans in eastern South Dakota. INorthern Grain Insects Research Laboratory, USDA-ARS, 2923 Medary Ave., Brookings, SD 57006-9410. 1 Hesler and Kieckhefer: Wheat Stem Maggot in Spring Wheat-Alfalfa Intercrops With Differe Published by ValpoScholar, 2000 34 THE GREAT LAKES ENTOMOLOGIST Vol. 33, No.1 Spring wheat-alfalfa intercrops may be produced in cropping systems that vary in the kinds and intensity of crop management practices. Such practices may include nitrogen (N) fertilizer application(s) to i crease grain yield of wh at; early season, post-emergent herbicide applications (particu­ larly for broadleaf weeds); and tillage for seedbed pr paration and additional weed control. Individual crop ma agement practices can vary in intensity by the amount, frequency, or degree to which they are used within a particular cropping system. Some crop management practices used for improving fertility or weed control may have inadvertent effects on populations of insect pests such as M. americana. For instance, the use of N fertilizer generally increases the growth rate and fecundity of phytophagous insects (van Emden 1966, Mc­ Neill and Southwood 1978, Mattson 1980). Weed control may also affect in­ sect population levels by eliminating alternate host plants for larvae and sources of pollen and nectar for adults. Studies have not been performed in the north central US in regard to the effects of varying crop management intensity on levels ofM. americana in in­ tercropped spring wheat and alfalfa. Moreover, information about M. ameri­ cana infestations in South Dakota was obtained more than 25 years ago pri­ marily in wheat monocultures (Gilbertson 1925, Kieckhefer and Morrill 1970, Kieckhefer 1974). Our goals were to determine the incidence of M. americana in eastern South Dakota among rotated spring wheat-alfalfa plots and to compare the incidence under high, intermediate, and low crop man­ agement intensities. MATERIALS AND METHODS Research was conducted at the Eastern South Dakota Soil and Water Re­ search Farm (ESDSWRF) near Brookings, South Dakota from 1990 through 1993. Our research was part of a series of studies at this site designed to measure insect, crop and soil fertility to various crop management treatments (Ellsbury et al. 1998, Riedell al. 1998, Hesler et al. 2000). Our studies were conducted within 30.5 by 30.5-m plots that were part of a four­ crop rotati n with variable crop management intensities established in 1990. The rotation included annual crops of corn, soybeans, and a spring wheat-al­ falfa interplanting, 'with the alfalfa crop continuing an additional year. Plots were farmed under one of three levels of crop management intensity (i.e., high, intermediate and low eMI). Plots were arranged in a randomized block design, and each crop-eMI level combination was replicated three times per year. Each block represented a replication. Details about crops and eMI treatments are given in Table 1 nd in Hes­ ler et al. (2000). Briefly, high eMI plots received rates ofN fertilizer designed to achieve relativ ly high yield goals (e.g., 3.0 MgJha wheat), broadcast appli­ cations of herbicides, fall moldboard plowing and spring disking, and spring field cultivation of corn fields. Interm diate eMI plots received one-half the amount of N fertilizer applied to high eMI plots, and labeled rates of herbi­ cides broadcast prophylactically in spring wheat-alfalfa plots and banded along rows of preceding crops of corn and soybean as needed based n weed seed counts in soil cores. Intermediate eMI plots received fall moldboard plowing in years preceding corn and wheat and fall chisel plowing in oth r years. In the spring, these plots were disked and cultivated. All agrichemi­ cals in and intermediate eMI wheat-alfalfa plots were applied before 1 June of each year. Low intensity plots received no fertilizer or herbicide. 2 The Great Lakes Entomologist, Vol. 33, No. 1 [2000], Art. 7 https://scholar.valpo.edu/tgle/vol33/iss1/7 2000 35 THE GREAT LAKES ENTOMOLOGIST Table 1. Planting dates, wheat varieties, seeding rates, and fertilizer and herbicide use in intercropped spring wheat-alfalfa plots under high, intermediate and low crop man­ agement intensities (CMIl, Brookings, SD. Planting Spring wheat Year date variety 1, Fertilizer2; Herbicide:>; liters (Al)lha 1990 26 April 'Guard,' 104 High: 101 High: 1.2 Intermediate: 50 Intermediate; 0.6 Low: 0 Low:
Application of the Kano Model for a Better Understanding of Customer Requirements in Higher Education—A Pilot Study
Various pieces of information and knowledge turn into “know-how” simply by their application in the market. This applies to all spheres of activities. It is therefore important to know and understand the requirements of customers already in the stage of making a product, and to confront these with the possibilities of a producer. In this article we are exploring the possibilities of a better understanding of the requirements of customers and stakeholders in the process of the creation of products in educational services. In particular, we examined seven general requirements: practice orientation, ethical orientation, research orientation, quality resources, innovation orientation, skills orientation, and quality staff. We use the Kano model on a pilot sample of respondents at an institution of higher education. Our results showed that “practice orientation” and “quality resources” are the most stable requirements, while “quality staff” is the least stable. The most linear requirement (the same effect on satisfaction and dissatisfaction) is “innovation orientation”. “Research orientation” belongs to attractive requirements and we also found that in the case of “ethical orientation” there are weak relations between positive and negative responses in our survey. The “skills orientation” proved to be too general, and our research shows that it could be indifferent. It is therefore advisable to specify the investigated skills when investigating requirements on educational services. The main contribution based on the proposed research procedures is an effective linking of customers and producers already from the beginning of constructing a value chain. Investing in sophisticated management approaches when modelling products and processes can thus become a significant source of the competitive advantage of an educational institution. At the same time, it is a contribution to better placing of its graduates in the labor market.