Tolerance to weed harrowing in spring barley genotypes

Controlling weeds in spring cereals grown under organic conditions is mostly done by post emergence weed harrowing, where spring tines of the weed harrow control weeds by uprooting and/or covering small weeds plants with soil. In situations with relatively large weed plants and relatively small crop plants, there are increased risks for crop damages by soil coverage or other mechanical damages of the crop leaves. These damages are increasing with increasing weed control intensity, and are resulting in reduced crop growth immediately after weed harrowing. There are risks that the reduced growth reduces final crop yield too. However, there is some evidence that there are varietal differences in the tolerance to weed harrowing. The aim of this study was to estimate the damages by weed harrowing in four pure genotypes and three two- or one three-component mixtures of spring barley, and to analyze if there were differences in tolerance to weed harrowing between the genotypes and mixtures. Results from a two-year field study showed that there were varietal differences in the tolerance to mechanical weed control in the immediate effect as well as the short term effect, however there were marked differences in the immediate and short term effect between the two years. Regarding the long term effect of weed harrowing on yield, there were no significant differences in 2003 but in 2004, Brazil and the three component mixture suffered significantly from weed harrowing while Modena, Otira and Modena+Orthega mixture, seems to benefit from weed harrowing. The reason for these differences is probably due to differences in growth habit at the time for weed harrowing

Multi-session group scenarios for speech interface design

When developing adaptive speech-based multilingual interaction systems, we need representative data on the user's behaviour. In this paper we focus on a data collection method pertaining to adaptation in the user's interaction with the system. We describe a multi-session group scenario for Wizard of Oz studies with two novel features: firstly, instead of doing solo sessions with a static mailbox, our test users communicated with each other in a group of six, and secondly, the communication took place over several sessions in a period of five to eight days. The paper discusses our data collection studies using the method, concentrating on the usefulness of the method in terms of naturalness of the interaction and long-term developments

An exploratory Study of IR Interaction for User Interface Design

Information seeking is an dynamic and interactive process. Factors like users' information needs, individual differences, goals and tasks, knowledge and cognitive abilities etc. influence the information seeking process, and need to be identified and supported in the user interface design. We adopt a user-centered approach to establish a link between research within the IR interaction perspective and the methods in HCI on how to evaluate information seeking interaction in a hypertext IR system (Dienst). Our purpose with this exploratory study is to identify, describe and acquire knowledge of characteristics of the user population, and finally, to make suggestions for supporting users in user interface design. For the evaluation task, we have applied HCI evaluation techniques to our IR evaluation to make a connection between the traditional IR evaluation and HCI evaluation, combining different qualitative and quantitative data collection and analyzing methods, implemented in an experimental real-world online WWW setting. This methodology combined online (WWW-based) questionnaires and database log statistics. Preliminary results revealed several "hidden" realities: a mismatch between what people said they wanted to do as opposed to what they actually did. We also observed that people initially expected a specific function, but when using the system, they did not use it. Finally, we established some group differences concerning variables like previous experience searching information in hypertext systems, IR knowledge and browsing/searching strategies

Beregning af konkurrenceindeks (KI)

Dokumentet indeholder en beskrivelse af hvordan konkurrenceindekset beregnes i vinterhvede og vårbyg

Forskelle i bygsorters tolerance overfor ukrudtsharvning

dette dokument beskriver resultater fra 2 års forsøg med ukrudtsharvning af 4 sorter og 2 eller 3 komponentblandinger af disse sorter

A mobile fitness companion

The paper introduces a Mobile Companion prototype, which helps users to plan and keep track of their exercise activities via an interface based mainly on speech input and output. The Mobile Companion runs on a PDA and is based on a stand-alone, speaker-independent solution, making it fairly unique among mobile spoken dialogue systems, where the common solution is to run the ASR on a separate server or to restrict the speech input to some specific set of users. The prototype uses a GPS receiver to collect position, distance and speed data while the user is exercising, and allows the data to be compared to previous exercises. It communicates over the mobile network with a stationary system, placed in the user’s home. This allows plans for exercise activities to be downloaded from the stationary to the mobile system, and exercise result data to be uploaded once an exercise has been completed

Tolerance of four spring barley (Hordeum vulgare L.) varieties to weed harrowing

We investigated the tolerance to weed harrowing of four spring barley varieties and examined the possible interactions between varietal weed suppressive ability and two nutrient levels. Tolerance was defined as the combined effect of crop resistance (ability to resist soil covering) and crop recovery (the ability to recover in terms of yield). The weed harrowing strategy was a combination of one pre- and one post-emergence weed harrowing. In terms of yield, the four varieties responded significantly differently to weed harrowing and the response depended on nutrient level. At the lower nutrient level, weed harrowing caused an increase in yield of 4.4 hkg ha-1 for a strong competitor (cv. Otira), while there was no effect on yield at the higher nutrient level. For a weaker competitor (cv. Brazil), weed harrowing caused no change in yield at the lower nutrient level, whereas yield decreased by 6.0 hkg ha-1 at the higher nutrient level. There were marked differences between the weed suppressive ability of the four varieties when not harrowed, with less pronounced but significant differences when harrowed. Weed harrowing did not change the weed suppressive ability of a variety. Varieties that are tall at post-emergence harrowing and have increased density after pre-emergence harrowing, are the ones that benefit most from weed harrowing