Browsing Vegetable Report 2004 by Subjects
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Comparative Efficacy of Oberon® (spiromesifen) Against Bemisia Whiteflies in Spring CantaloupesSeveral studies were conducted on spring cantaloupes from 2002-2004 to evaluate a new insecticide, Oberon (spiromesifen) for whitefly control in spring melons. These studies demonstrate that this IGR-like insecticide offers melon growers management alternatives for effectively controlling whiteflies. The results strongly suggest that Oberon has good potential for controlling whiteflies in spring melon crops similar to what can be expected from Courier. Oberon provided 21-28 days of residual control of whiteflies under spring growing conditions when applied early in whitefly population growth. Our studies also indicate that spray timing is important for cost-effective control with both Oberon and Courier. They also suggest that action thresholds based on adult abundance and nymph densities differ for these two compounds depending on whether Admire has been applied at planting.
Is Aphid Management Sustainable in Desert Head Lettuce?New restrictions on insecticides for aphid control presents new challenges for lettuce growers. Dimethoate is soon to be unavailable and the future status of other conventional aphicides is uncertain. However, a number of new active ingredients will soon be available that offer lettuce growers valuable alternatives for aphid management in lettuce. The present dilemma and potential for implementing new chemistries into lettuce IPM programs is discussed in this report.
Whitefly Resistance to Insecticides in Arizona: 2002 and 2003 Results"Whitefly resistance to insecticides is a constant threat to successful management of sticky cotton resulting from inadequate control of Bemisia whiteflies. A three-stage resistance management program was implemented in Arizona cotton following a severe whitefly resistance crisis in 1995. This program has been highly successful for eight years. Success has been fostered by intensive investments into improved whitefly sampling and treatment decisions, coupled with conservation of natural enemies. This latter component has hinged on limited, strategic use of two insect growth regulators in cotton, use of the neonicotinoid insecticide, imidacloprid, in vegetables and melons, and tactical deployment of non-pyrethroid and pyrethroid chemicals. Statewide monitoring of whitefly resistance to insecticides in cotton, melons and greenhouse crops has permitted annual assessments of the status of whitefly resistance management in Arizona. In this paper we summarize susceptibility of whitefly collecions made in cotton in the 2002 and 2003 seasons and discuss longer term trends in resistance development. No major problems regarding field performance of insecticides against whiteflies were observed or reported in 2002 or 2003. However, monitoring confirmed the early stages of evolution of resistance to pyriproxyfen (Knack®) and showed that whiteflies possessing this resistance could be detected in all cotton-producing areas of the state. Susceptibility to buprofezin (Applaud®/Courier®) has not changed significantly since 1997. Mean susceptibility to synergized pyrethroids (e.g., Danitol® + Orthene®) has increased strikingly on a statewide basis since 1995. However, 50 and 25% of cotton fields sampled in 2002 and 2003, respectively, had resistance levels expected to result in inadequate performance of synergized pyrethroid treatments. Whiteflies from throughout Arizona were highly susceptible to imidacloprid (Admire®/Provado®) and two other neonicotinoid insecticides, acetamiprid (Intruder®) and thiamethoxam (Actara®/Centric®/Platinum®)."