Search Results

You are looking at 1 - 10 of 248 items for :

Clear All

; Rankin and Hockey, 1922 ). Winter (1929) was the first to describe resistance to A. agathonica in red raspberry, conducting a series of experiments showing that aphids in Minnesota were unable to colonize plants of ‘Herbert’ in isolation. Huber and

Free access

aphid-vectored viruses in red raspberry at East Malling, UK. At the Scottish Crop Research Institute (Invergowrie), virus infection rates in plots of resistant cultivars was less than 10% after 3 years, while 100% of susceptible plants became infected

Free access

aphids ( T. aurantii ) are the primary insect pests observed. The purple flower color of Camellia ‘Maozi’ is unique, distinctively different from its parents, which have red (RHS# FF3030) and yellow (RHS# FFFF00) colors, respectively. Floral buds start

Free access

Abstract

Young, excised leaflets of 7 clones of red raspberry (Rubus idaeus L.) indicated potential nonpreference resistance to the aphid vector of raspberry mosaic viruses, Amphorophora agathonica Hottes. More aphids deserted resistant clones than susceptible ‘Latham’ over a 3-day period. Treatment of excised leaflets with 6-benzylamino purine (BA) increased desertion rates as compared to distilled water in resistant clones.

Open Access

Abstract

‘NY 632’ was the most resistant of 21 clones of red raspberry (Rubus idaeus L.) evaluated for resistance to the aphid Aphis rubicola Oestlund in New York over a 3-year period.

Open Access

Abstract

‘Royalty’ is a new purple raspberry cultivar with the high fruit quality of the red raspberry (Rubus idaeus L.) and the vigor and large fruit size associated with the purple raspberry (R. idaeus × R. occidentalis L). The cultivar is hardy and has wide adaptation and good yield potential. It has immunity to Amphorophora agathonica Hottes, the aphid vector of the raspberry mosaic virus complex, and resistance to Aphis rubicola Oestland, the aphid vector of raspberry leaf curl. It also shows resistance to Byturus rubi Barber, the raspberry fruit worm.

Open Access

Insecticide application techniques were evaluated to find the most effective way to spray contact insecticides to control aphids on leaf crops under field conditions. A hydraulic boom sprayer was tested with several nozzle types, nozzle positions, and pressures, and compared with an electrostatic sprayer and a controlled droplet applicator (CDA). Spray deposition in the canopy and drift were evaluated with moisture-sensitive cards. Trials were conducted on collards and red leaf lettuce in 1989, mustard greens in 1990, and turnip greens in 1991. Green peach aphid [Myzus persicae (Sulzer)] was the major species in all trials. Among hydraulic boom treatments in all trials, aphid control was not significantly different when insecticide applied at 60 psi (414 kPa) was delivered by hollow cone, twin flat-fan, or standard flat-fan nozzles mounted directly on the boom. In most trials, hollow cones were more effective when mounted on drop pipes and directed sideways into rows than when mounted on the boom and directed over rows. Hollow cone nozzles used at 150 psi (1035 kpa) vs. 60 psi did not control aphids significantly better, but higher pressure caused significantly more drift. Contact insecticide applied by an electrostatic sprayer controlled aphids somewhat less satisfactorily than by a conventional hydraulic sprayer. Insecticide applied by a CDA controlled aphids the same as by a hydraulic boom sprayer but with slightly less drift. The desired objective of maximum aphid control, good coverage of downward-facing surfaces in the canopy, and minimum drift was most consistently provided by the hydraulic boom sprayer with hollow cone nozzles on drop pipes directed sideways into the canopy using a pressure of 60 psi.

Full access

Abstract

BC 72-1-7, a selection from the British Columbia red raspberry (Rubus idaeus L.) breeding program, is being released as germplasm. It has a unique combination of desirable horticultural characteristics and resistance to several pests which will make it a useful parent. The selection is homozygous for gene Ag1 which confers resistance to Amphorophora agathonica Hottes, the aphid vector of raspberry mosaic virus. It is the 1st genotype described which is homozygous for the characteristic. The use of BC 72-1-7 as a parent makes it unnecessary to screen for aphid reaction, since all its seedlings will be resistant. Other useful characteristics of this selection are varying levels of resistance to several diseases including root rot, most likely caused by Phytophthora erythroseptica Pethb., postharvest fruit rot caused by Rhizopus spp., and probable resistance to pollen transmission of raspberry bushy dwarf virus (RBDV). Useful horticultural characteristics are high yield and bright red, nondarkening fruit color.

Open Access

Postharvest treatments significantly reduced or eradicated pests on various tropical cut flowers and foliage. Immersion in water at 49° C for 10 minutes killed armored scales on bird of paradise leaves, Strelitzia reginae Banks, as well as aphids and mealybugs on red ginger, Alpinia purpurata (Vieill.) K. Schum. Vapor heat treatment for 2 hours at 45.2° C provided quarantine security against armored scales on bird of paradise leaves. A 5 minute dip in fluvalinate combined with insecticidal soap eliminated aphids and significantly reduced mealybugs on red ginger. A 3 minute dip in fluvalinate, a 3 minute dip in chlorpyrifos, or a 3 hour fog with avermectin-B significantly reduced thrips on orchids, Dendrobium spp., without injury to the flowers. No postharvest treatment was both effective and nonphytotoxic on all commodities.

Free access

Abstract

Twenty-two cultivars and three selections of red raspberry were evaluated for resistance to the aphids Amphorophora agathonica and Aphis rubicola in New York. ‘Canby’, ‘Lloyd George’ and ‘NY 632’ were immune to A. agathonica; ‘Washington’ and ‘Mailing Exploit’ demonstrated potentially useful levels of resistance. No immunity to Aphis rubicola was observed, but several cultivars manifest considerable resistance. Resistance to A. agathonica was not correlated with resistance to A. rubicola.

Open Access