Evaluation of fluopyram for the control of Ditylenchus dipsaci in sugar beet.

Fluopyram, a succinate dehydrogenase inhibitor fungicide, has shown potential in controlling Meloidogyne incognita and Rotylenchus reniformis in tomato. The effectiveness of this compound for the control of Ditylenchus dipsaci in sugar beet was evaluated. In this study, laboratory, growth chamber, glasshouse, and field experiments were conducted. In a motility bioassay, the EC50 value was determined with 3.00 µg/ml a.i. after 72 h exposure to fluopyram. The growth chamber experiment did not show any effects on D. dipsaci penetration rate; however, field experiments revealed a positive effect of fluopyram applied at planting in reducing D. dipsaci infectivity. The glasshouse experiment confirmed a limited effect of fluopyram on D. dipsaci population development. Under field conditions, despite a reduction of D. dipsaci penetration rates in spring, fluopyram was not effective in reducing the population development until harvest. Consequently, D. dipsaci densities in plant tissue and soil were high at harvest and not different among treatments. However, root-rot symptoms were significantly reduced at harvest. Fluopyram applied at planting showed good potential to reduce root-rot symptoms caused by D. dipsaci in sugar beet. However, for the long-term reduction of nematode populations in soil, further integrated control measures are needed to reduce the risks of substantial yield losses by D. dipsaci.Fluopyram, a succinate dehydrogenase inhibitor fungicide, has shown potential in controlling Meloidogyne incognita and Rotylenchus reniformis in tomato. The effectiveness of this compound for the control of Ditylenchus dipsaci in sugar beet was evaluated. In this study, laboratory, growth chamber, glasshouse, and field experiments were conducted. In a motility bioassay, the EC50 value was determined with 3.00 µg/ml a.i. after 72 h exposure to fluopyram. The growth chamber experiment did not show any effects on D. dipsaci penetration rate; however, field experiments revealed a positive effect of fluopyram applied at planting in reducing D. dipsaci infectivity. The glasshouse experiment confirmed a limited effect of fluopyram on D. dipsaci population development. Under field conditions, despite a reduction of D. dipsaci penetration rates in spring, fluopyram was not effective in reducing the population development until harvest. Consequently, D. dipsaci densities in plant tissue and soil were high at harvest and not different among treatments. However, root-rot symptoms were significantly reduced at harvest. Fluopyram applied at planting showed good potential to reduce root-rot symptoms caused by D. dipsaci in sugar beet. However, for the long-term reduction of nematode populations in soil, further integrated control measures are needed to reduce the risks of substantial yield losses by D. dipsaci.

Quantity and quality of food losses along the Swiss potato supply chain: Stepwise investigation and the influence of quality standards on losses.

This paper presents the results of a stepwise investigation of the quantity and quality of food losses along the Swiss potato supply chain. Quantitative data were collected from field trials, from structured interviews with wholesalers, processors and retailers, and from consumer surveys in combination with a 30-day diary study. The "Swiss trade customs for potatoes" pose the basis for the qualitative evaluation of losses. The influences of technological, institutional (business and economy; legislation and policy), and social drivers on the generation of fresh potato and processed potato products losses were assessed. Losses due to quality standards driven by food safety and consumer preferences for certain aesthetic standards have been evaluated too. Across the entire potato value chain, approximately 53-55% of the initial fresh potato production and 41-46% of the initial processing potato production are finally lost. Losses between organic and non-organic supply chains differ from 2% to 5%. From the total initial fresh potato production, 15-24% gets lost during agricultural production, a further 12-24% at wholesalers, 1-3% at retailers, and 15% at private households. In comparison, 5-11% of the initial production gets lost at wholesalers, a further 14-15% during processing, 0% at retailers, and 2% at private households. Losses during agricultural production do not vary much (13-25%) between fresh and processing potatoes. Approximately half of total potato losses occur because potatoes do not meet quality standards. 25-34% of these quality-driven losses are caused by food safety reasons, and the remainder are caused by consumer preferences or suitability for storage. In total, social drivers (e.g., consumer preferences, behavior, or socio-demographical factors) are responsible for two-thirds to three-fourths of all fresh potato losses and 40-45% of all processing potato losses. Technological drivers cause circa one-third of the total processing potato losses. The majority of the rejected potatoes are used as animal feed (67-90%) in Switzerland. Approximately 30% of all fresh potato losses are disposed while just 4-5% of all processing potato losses are thrown away. The interviewed experts stated that lower quality specifications might cause lower loss rates at the first stages of the supply chain but higher ones at the later stages due to worse storage or processing abilities of potatoes with defects, which also might affect proper tubers.

Potential of acrylamide formation, sugars, and free asparagine in potatoes: a comparison of cultivars and farming systems.

Glucose, fructose, sucrose, free asparagine, and free glutamine were analyzed in 74 potato samples from 17 potato cultivars grown in 2002 at various locations in Switzerland and different farming systems. The potential of these potatoes for acrylamide formation was measured with a standardized heat treatment. These potentials correlated well with the product of the concentrations of reducing sugars and asparagine. Glucose and fructose were found to determine acrylamide formation. The cultivars showed large differences in their potential of acrylamide formation which was primarily related to their sugar contents. Agricultural practice neither influenced sugars and free asparagine nor the potential of acrylamide formation. It is concluded that acrylamide contents in potato products can be substantially reduced primarily by selecting cultivars with low concentrations of reducing sugars.