Reduced Midseason Pesticide Program for Control of Scab and Plum Curculio in Peach

Abstract

Risks to peach production from scab (caused by Cladosporium carpophilum) and plum curculio (Conotrachelus nenuphar), two key pests in the southeastern United States, are high until 2 months past petal fall and then decreases during midseason. This suggests that reduced-input pesticide strategies may effectively control both pests during the latter period. In this study, we evaluated midseason pesticide applications according to an alternate-row middle (ARM) spray program in which sprays were applied only to every other tree row while reducing tractor speed and keeping application intervals unchanged relative to conventional spraying of both sides of the trees. In a 2-year trial in a research orchard, conventional sprays of fungicide (primarily sulfur) and insecticide (primarily phosmet) were applied at 10- to 14-day intervals until first cover, followed by continued conventional sprays of fungicide and insecticide (standard), conventional sprays of one pesticide together with ARM sprays of the other pesticide, or combined ARM sprays of both pesticides. Schedules with midseason ARM sprays of both pesticides also were evaluated in two commercial orchards in 2 years. In all experiments, plots receiving combined ARM sprays were equivalent to the standard in fruit quality and control of scab and plum curculio. Combined ARM spraying resulted in lower environmental nontarget effects (as estimated by the Environmental Impact Quotient) and reduced application time by 25 to 33% for each midseason spray and 12.5 to 18.5% for the entire period from petal fall to the preharvest interval.

Micronised and non‐micronised sulphur applications control peach scab equally well with negligible differences in fruit quality

“…This observation is in contrast to studies reporting inferior colouration and finish in cv. Blake peaches treated with sulphur‐based programmes compared with captan treated fruit (Scherm & Savelle, 2001; Lan et al , 2003) and to a study by Palmer et al (2003) demonstrating that sulphur applications reduced not only fruit colouration but also leaf photosynthesis of cv. Braeburn apple compared to non‐sulphur treatments.…”

“…Fungicide efficacy studies by others have reported the negative impact of elemental sulphur on fruit quality by reducing colouration (Drake, 1984; Scherm & Savelle, 2001; Lan et al , 2003; Palmer et al , 2003) and increasing fruit russeting (Basak et al , 1983; Sanchez et al , 2001; Steenkamp et al , 1984). In contrast, other studies revealed that elemental sulphur can reduce russeting of apple cv.…”

Weed control, environmental impact and profitability of reduced rates of imazethapyr in combination with dimethenamid in dry beans

“…The EI was designed to provide growers and weed management practitioners with a single number that indicates the magnitude of relative risk. Despite criticism mainly due to simplicity (Dushoff et al 1994), EI has been used effectively by several researchers to compare environmental risk of different pesticides and/or production systems (Fernandez-Cornejo 1998;Edwards-Jones and Howells 2001;Ziegler et al 2002;Bues et al 2003, Lan et al 2003Brimner et al 2005). The EI can be used as a decision tool, along with herbicide efficacy, crop safety, and profit margins to identify the most advantageous weed management strategy in dry beans.…”