This study discusses the methodical problems which occur during the process of generating weed distribution maps in geoinformation systems (GIS). Particular attention will be paid to the question of whether or not the weed sampling data and the weed distribution maps for site-specific weed control are sufficiently representative. Manual or image-processing sampling procedures are applied in ord...

This paper demonstrates the framework and methodology how weed population dynamics can be predicted using rule-base fuzzy logic as applied to GIS spatial image. Parthenium weed (parthenium hysterophorus L.) infestation in the Central Queensland region poses a serious threat to the environment and economic viability of the infected areas. Government agencies have taken steps to control and manag...

IN spite of more than 20 years of investigation by many workers (reviewed by SONNEBORN 1959), kappa-the first-discovered cytoplasmic genetic basis of the killer trait in Paramecium aurelia-still poses intriguing problems. Among them are the correlation of kappa’s visibly distinguishable forms with its diverse properties: abilities to reproduce, to infect, to kill and to confer complete resistan...

Whilst it is agreed that climate change will impact on the long-term interactions between crops and weeds, the results of this impact are far from clear. We suggest that a thorough understanding of weed dominance and weed interactions, depending on crop and weed ecosystems and crop sequences in the ecosystem, will be the key determining factor for successful weed management. Indeed, we claim th...

Weed interference in annual cropping systems can be highly variable from year-to-year, as well as spatially heterogeneous. These factors have confounded efforts to develop simple methods for predicting competitive outcomes early in the growing season. A 2-year study was conducted with maize in competition with four annual weed species (Setaria faberi, Abutilon theophrasti, Chenopodium album and...

Critical period of weed control is the foundation of integrated weed management and, hence, can be considered the first step to design weed control strategy. To determine critical period of weed control of aerobic rice, field trials were conducted during 2010/2011 at Universiti Putra Malaysia. A quantitative series of treatments comprising two components, (a) increasing duration of weed interfe...

In cropping systems, integrated weed management is based on diversification. Rather than relying solely on one or two herbicides, a multiplicity of weed control strategies is employed. Yet, integrated weed management as currently practiced is far from integrated; every weed is still managed the same regardless of location or season. The recent development of precision application technology is ...