http://www.ulmer.de/Artikel.dll/nb_0306_doering_Mjk4MjM3.PDF?UID=30784F790BA7A5F300940221881E3C553EA16D4B162BA0BF The application of straw mulch in potatoes is a possible strategy for soil erosion control, virus control and reduction of post-harvest soil nitrate losses. In this study, the effects of mulching on severity of late blight (Phytophthora infestans [MONT.] DE BARY) and black scurf (Rhizoctonia solani KÜHN) were assessed in organically managed field experiments over three years at four sites in Germany. Late blight severity was assessed as percentage of infected leaf area or percentage of leaves with late blight lesions. Black scurf on harvested tubers was assessed on tubers per plot. . In addition, effects of straw mulch on air temperature, relative humidity and evaporation in the potato stand were measured. Straw mulch had no significant effect on late blight severity in most of the experiments, but a trend of late blight reduction through the application of straw mulch was observed in 13 out of 15 experiments. Black scurf was not influenced by straw mulch, with effects being non-significant in 16 out of 17 experiments.
Archive for January, 2008
Aspects of straw mulching in organic potatoes – II. Effects on Potato Virus Y, Leptinotarsa decemlineata and tuber yield
January 31, 2008In a three years series of on-farm field experiments in organically grown potatoes in Germany the influence of straw mulch on the incidence of Potato virus Y (PVY), on the infestation with Colorado potato beetle (CPB, Leptinotarsa decemlineata), and on tuber yield was investigated. The effect of straw mulch on PVY incidence appeared to be dependent on the overall level of PVY infection, which differed between years, locations and varieties. There was a consistent PVY reduction, when the overall level of PVY infection was high. In contrast to this, no consistent trend could be observed, when there was a very low general PVY infection level. Straw mulch did not significantly affect the infestation with Colorado potato beetle in the field experiments, where three levels of straw were applied (nil, moderate amount and high amount). There was a consistent trend with the highest infestation in the nil amounts and the lowest CPB infestation at the highest amount of straw. In five out of six field experiments there was no significant effect of straw mulch on tuber yield.
Soil insecticide for the control of wireworm and PCN in potatoes
January 29, 2008Soil insecticide for the control of wireworm and PCN in potatoes
Mocap 10g (Ethoprophos) is an effective treatment for wireworm in potatoes. It is also effective against PCN, especially on sandy and silt soils. It is best used within a program of IPM that includes risk assessment, rotation, ploughing and good variety choice. A baiting system can be used to detect wireworm populations which is cheap, simple to use and highly effective in arable rotation.
Best practices to potato protection against aphids & Colorado potato beetle
January 28, 2008This document describes the best practices against aphids and Colorado potato beetle.
First, the main points to potato protection against aphids are:
- identification of the aphids: Myzus persicae, Macrosiphum euphorbiae, Aulacorthum solani, Aphis nasturtii;
- spray with the best product at the best moment: it defines a threshold of 20 leaflets with aphids on 40 observed and the best active ingredient is pymetrozine;
- respect benefit insects.
Secondly, the main points to potato protection against Colorado beetle are:
- spray when larvae are like a grain of wheat;
- be careful not to confuse beetle larvae with ladybirds larvae;
- if the aphids and beetles are simultaneously presents, use polyvalent products;
- prefer:
o 300 l/ha volume sprayings.
o Temperature < 20°C
o Hygrometry > 70%
o After irrigation.
The results are based from potato group composed of:
- regioanal ministry services: Services de la protection des végétaux Nord-Pas de calais, Picardie, Champagne-Ardenne ;
- technical institutes: Arvalis-institut du vegetal, Institut Technique de la Pomme de Terre ;
- local advisers: Fredon Nord-Pas de Calais, Picardie, Champagne-Céréales, GEDA 51, CAT 51, ATPPDA, CETA 51 ;
- industrials : Mc Cain, Roquette, Syngenta ;
Résumé français
Depuis 1994, des professionnels de la pomme de terre se sont associés pour une meilleure connaissance des pucerons : reconnaissance des principales espèces, nuisibilité, évaluation des différentes substances actives et détermination des seuils de traitement. Le sujets travaillés évoluent aujourd’hui avec de nouvelles problématiques, notamment la lutte contre le doryphore, ravageurs actuellement en recrudescence.
Crop protection on potatoes in organic production (II-pests)
January 24, 2008This document informs about biology of main pests in potatoes and the solutions in organic productions in France.
pomme-de-terre-ravageurs-itab.pdf
ITAB (Institut Technique de l’Agriculture Biologique / France)
This document informs you on the different measures to protect potato crops mainly against Colorado potato beetle (Leptinotarsa decemlineata), aphids, slugs, wireworms and nematods.
Against Colorado potato beetle, it recommands some preventive measures:
- to change plots year by year
- to limit the soil porosity
- to collect eggs, larvaes and adults
- to spray with pyrethre or bacillus products.
The main risk with the aphids is viruses. So, the producers have to favorise benefit insects against aphids and spray with oily products.
The quality of seedling is very important to prevent the introduction of viruses and nematods and you have to destroy the sick plants.
Against slugs the producers must prepare the soils without balls.
The fight against wireworms is very difficult and you have to make rotations and destroy the eggs with superficial soil work during the summer.
The recommendations are based on field trials from:
- research: Inra Rennes
- applied research (institutes): ITAB, Arvalis Institut du vegetal,
- local advisers : Fredon Nord Pas de Calais, IBB, Aval Douar Beo
Résumé français
La pomme de terre est soumise à de nombreux bio-agresseurs. Cette fiche présente la biologie et les symptômes des principaux ravageurs aériens et telluriques (Doryphore, pucerons vecteurs de virus, nématodes, gastéropodes), ainsi que les moyens de lutte disponibles en agriculture biologique.
Crop protection on potatoes in organic production (I-diseases)
January 17, 2008This document informs about biology of main diseases in potatoes and the solutions in organic productions in France.
PROTECTION PHYTOSANITAIRE EN CULTURE DE POMME DE TERRE BIOLOGIQUE FICHE 1
ITAB (Institut Technique de l’Agriculture Biologique / France)
This document informs you on the different measures to protect potato crops mainly against late blight (Phytophthora infestans), rhizoctonia (Rhizoctonia solani).
He describes the preventive measures:
- to avoid moist areas,
- to plant with low densities,
- to eliminate very invading weeds,
- to isolate potatoes plots,
- to make four years rotation,
- to work firstly into the undamaged plots,
- to verify the quality of the seeds.
He describes also the other diseases and the solutions in organic productions: silver scurf (Helminthosporium solani), black dot (Colletotrichum coccodes) and storage diseases (Fusarium, Erwinia, Streptomyces).
3/
The recommendations are based on field trials from:
- research: Inra Rennes
- applied research (institutes): ITAB, Arvalis Institut du vegetal,
- local advisers : Fredon Nord Pas de Calais, IBB, Aval Douar Beo
Résumé français
La pomme de terre est soumise à de nombreux bio-agresseurs. Cette fiche présente la biologie et les symptômes des principales maladies fongiques et bactériennes, ainsi que les moyens de lutte disponibles en agriculture biologique.
Potato blight fungicides
January 16, 2008tableau-synthese-antimildiou-2007.pdf
This table informs about registrated fungicides in France and gives differents informations : regular informations, preventive and curative activities, efficiency informations, leafwetness.
Validation of a DSS for an integrated protection against late blight
January 15, 2008
These documents informs about the use of a Decision Support System against potato late blight
presentation-mildilis-2007.pdf
The protection against the potato late blight requires in France a lot of fungicides treatments (between 12 and 15 on average). To reduce this number meaningfully without risk, the use of epidemiological models and decision support systems provide a precious help. The objective of the 3 years trials and follow-ups of fields was to create a DSS based on the Ullrich-Schrödter model (with adapted thresholds to the french conditions).
Résumé français
La protection contre le mildiou de la pomme de terre nécessite en France 12 à 15 applications de fongicides en moyenne. Afin de réduire ce nombre sans risque, l’utilisation de modèles épidémiologiques et des systèmes de prévision s’avère précieuse.
L’objectif de 3 années d’essai et de suivi de parcelles était de créer un outil basé sur le modèle Ullrich-Schrödter avec des seuils adaptés aux conditions françaises.
Mildi-LIS®, an on line decision support system for treatment against potato late blight
January 15, 2008This document presents the working order of the DSS Mildi-lis against potato late blight
Mildi-LIS® is an online decision support system that allows a reduction of the number of treatments against late blight potato. It is based on the epidemiological model Premil from ARVALIS – Institut du végétal researches. The institute works since 1998 to adapt the Ullrich Schrödter (Ullrich J. und Schrödter H. 1966) model to French climatic conditions. Premil is validated since 2002 (Gaucher D. and Chambat S. 2002). Up to now, a computer version was available but it did not seem to come up to growers who expected more exchanges with their technician about weather data and the follow-up of their plots.
Résumé français
Mildi-Lis® est un outil d’aide à la décisiob qui permet de réduire le nombre de traitement contre le mildiou de la pomme de terre. Il est basé sur les recherches d’Arvalis- institut du végétal à partir du modèle épidémiologique Premil. L’institut a travaillé depuis 1998 pour adapter le modèle Ullrich Schrödter aux conditions climatiques françaises. Désormais, une version électronique est disponible mais il ne semble pas convenir aux producteurs qui attendent plus d’échanges avec leur technicien sur les données climatiques et le suivi de leurs parcelles.
