Search

Copyright of Weed Research is the property of Wiley-Blackwell and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The article presents a study regarding the fusarium wilt of cucumbers in Great Britain. Isolation of the species of Fusarium from cucumbers with wilt or root rot symptoms is being done in various countries, and to provide wilt control on infested nurseries, Cucurbita ficifolia has been recommended and used as a rootstock in Netherlands. The study shows that grafting does not offer great advantages as a technique, but can be of great importance on nurseries where fusarium wilt has become established.

This article presents observations on diapause in Tetranychus urticae that infest cucumbers in commercial glasshouses. In some houses small numbers of mites were recovered, but in general the results suggest that plant condition did influence entry into diapause. Although temperature and photoperiod were favorable for diapause, relatively few mites were trapped in the heavily infested houses where the plants remained vigorous. These results show that dispausing mites may continue to emerge and start new infestations over a relatively long period of time.

This article cites a study that examines the efficiency of commercial high volume spraying with acaricides on glasshouse cucumbers. Fluorescent tracers have been used to asses the efficiency of high volume spraying with acaricides on cucumbers under glass. There are big differences between nurseries but a large proportion of leaves may often have very poor deposits. Cover is least efficient on leaves between the arch and the glass where considerable shading occurs causing patchy and very light deposits. Preliminary observations on the correlation between traced spray deposits and mite control indicate that heavy deposits of petroleum oil are needed to give a good control of active stages of Tetranychus urticae.

This article cites a series of experiments on the use of acaricides in controlling tetranychus urticae in commercial cucumber glasshouses in the Lea Valley, England. The treatments were applied to plots of five or six plants and were replicated in most of the trials. The findings showed that tetradifon gave consistently good results. Two new pesticides, binapacryl and thioquinox gave good results but were phytotoxic. Dicofol also gave variable results and there was evidence of resistance to the material in one of the trials. Throughout the trials the phytotoxic effects of several of the agents being tested has been one of the most important limiting factors in their application on cucumbers.

This article cites a study that examined the damage to glasshouse lettuce due to Pratylenchus (P.) penetrans. The lesion nematode P. penetrans was associated with stunting and reduced production of glasshouse lettuce crops on several smallholdings in Cambridgeshire, England in 1972. Short-duration pot experiments in which oxamyl was used to control the nematodes showed that damage in untreated soil began soon after lettuces were transplanted. P. penetrans was probably the cause of the poor growth both in untreated soil in pots and in the commercial crops.

This article looks at the two plant diseases and pests. Root-knot eelworm was recorded on several crops in eastern England. Meloidogyne artiellia has been described from oats and other crops but not from the grasses. In 1952, females of a Meloidognye species differing in some respects from the described species were found in small galls on the roots of Lolium multiflorumLam. undersown in an oat crop near Swansea, Wales. The Rose Line Pattern is considered to be a form of Rose Mosaic. Clearly defined wavy yellow bands were present on the young red leaves, sometimes conforming to an oak-leaf pattern. Quite often the line marking was confined to a strip across the distal end of the leaf.