Efficacy of Armicarb (potassium bicarbonate) against scab and sooty blotch on apples.

A novel formulation of potassium bicarbon-ate (Armicarb) was evaluated in 2004 and 2005 as agent against apple scab and sooty blotch in several field trials. Armicarb controlled scab equally well as the reference treatments sulphur and copper. Armi-carb showed also excellent activity against sooty blotch. However, potential side-effects such as lenti-cell spot development need further investigation. At present, potassium bicarbonate is considered by the Swiss registration authorities as non-toxic to humans and in consequence, no residue levels have been specified. Armicarb has very interesting properties as a plant protection agent and its composition and risk profile are expected to fulfil the IFOAM standards for acceptance of novel plant protection agents to a very large extent

Welche Bodenzusätze helfen bei der Lösung von Problemen mit Feldaufgang in Spinat?

Damping-off of spinach, caused by soil-borne pathogens, is one of the most serious problems in organic spinach production. To overcome these problems soil amendments based on specific strains of micro-organisms or based on organic material are proposed. In pot experiments under controlled conditions 14 microbial strains and six organic soil amendments were tested on their ability to suppress soil borne diseases and to improve plant stand establishment. In a subsequent field experiment with the best treatments, soil amendments with compost showed the best effect while products based on single strains of micro-organisms failed to improve plant stand establishment. It is concluded that under high disease pressure a diverse population of microorganisms as it can be found in compost may more effectively suppress soil borne diseases than single strains of micro-organisms

Saatgut-Testmethoden für Falschen Mehltau an Feldsalat

Peronospora valerianellae is one of the most important pathogens of corn salad. It is seedborne and besides seed treatments there is no possibility to control the disease. The wash-off-test and the grow-out-test are currently in use to test seed lots for the presence of the pathogen. Despite these test methods, there are still seed lots that show infected plants during production of corn salad. This indicates that a low infection rate of a seed lot (< 0.25% - 1%) may lead to serious problems in grower’s production units. To allow an improved identification of seed lots with low infection rate, a specific PCR-based detection method for P. valerianellae was developed. Three test methods were compared for their efficacy to detect contaminated seed lots. Six out of seven seed lots not showing contamination in the standard grow-out test were identified as contaminated. With an extended grow-out test, it was possible to confirm these results from the PCR-test. The PCR based test for P.valerianellae on seed offers the possibility to detect the pathogen below the actual detection limits

Prüfung von Saatgutbehandlungen an Karotten

To grow carrots in organic quality for storage is often difficult due to seed- and soilborne diseases. In a series of experiments, seed treatments were evaluated to improve seed health, field stand establishment and yield of carrots under field conditions on farmer’s fields within their production system. In standard germination tests in the laboratory, positive effects of the treatments were observable. However, in subsequent field experiments, none of the tested seed treatments improved crop establishment or yield. These results indicate that the quality of organic carrot seeds is generally sufficient and improvements with farm-made seed treatments are difficult to obtain. Further improvement in organic production of carrots may be achieved by seed treatments, such as physical methods or biocontrol organisms, applied by specialised companies, prior to marketing of these seeds

Biostrategie gegen Feuerbrand

Der Bioobstbau ist gewappnet gegen den Feuerbrand – auch ohne das Antibiotikum-Präparat Streptomycin, das im Biolandbau nicht zugelassen ist. Für das laufende Jahr ist mit einem hohen Infektionsdruck zu rechnen, denn der Erreger ist nach dem hohen Befall im letzten Jahr fast überall zu finden. Wird eine breit angelegte Strategie sorgfältig umgesetzt, ist die Lage in den Griff zu kriegen