Current European weed control methods and strategies against annual and perennial weeds in organic farming

Review of physical and cultural weed control methods for organic farmin

Current achievements and future directions of physical weed control in Europe

This paper reviews major results achieved with physical weed control methods and strategies especially adapted for horticultural and agricultural crops. Mechanical methods, such as weed harrowing and inter-row hoeing, have provided promising results in cereals, pulse and oil seed rape, particularly when they are part of a strategy that also involves cultural methods such as fertiliser placement or crop seed vigour. In row crops, intra-row weeds constitute a major challenge, and research has mainly aimed at replacing laborious hand weeding with mechanization. A number of investigations have focussed on optimising the use of thermal and mechanical methods against intra-row weeds. And new methods are now under investigation such as robotic weeding for row crops with abundant spacing between individual plants and band-steaming for row crops developing dense crop stands

INTERGRATING PHYSICAL AND CULTURAL METHODS OF WEED CONTROL – EXAMPLES FROM EUROPEAN RESEARCH

The most recent advances in European research on non-chemical weed control methods and strategies for horticultural and agricultural crops are presented

Uncovered Interest Parity in a Partially Dollarized Developing Country: Does UIP Hold in Bolivia? (And If Not, Why Not?)

According to the Uncovered Interest Parity (UIP) condition, interest rate differentials compensate for expected exchange rate changes, equalizing the expected returns from holding assets which only differ in terms of currency denomination. In the previous literature, there are many tests of UIP for industrialized countries, and, more recently, some tests for emerging economies. However, due to data availability problems, poorer developing countries have not been studied. This paper tests UIP in a partially dollarized economy, Bolivia, where bank accounts only differ in terms of currency denomination (U.S. dollars or bolivianos). I find that UIP does not hold in Bolivia, but that the deviations are smaller than in most other studies of developed and emerging economies. Moreover, several factors seem to contribute to the deviations from UIP. The so-called peso problem could possibly account for the observed data, but there is also evidence of a time-varying risk premium, as well as deviations from rational expectations.Uncovered interest parity; UIP; partial dollarization; time-varying risk premium; peso problem; rational expectations

Mechanical weed control in transplanted sugar beet

Results from two years experiments with mechanical weed control in transplanted organic sugar beet

Mechanical control of Cirsium arvense in organic farming

Infestation with Cirsium arvense in organic cropping is an increasing problem in many parts of Europe. A very expansive root system and the ability to form new aerial shoots from root buds facilitate formation of dense patches only a few years after establishment. In the present study, repeated mowing during the first part of the growing season used in combination with a competitive crop is suggested as a control strategy, aiming at diminishing the regenerative capacity of C. arvense. In general, the results from our two experiments showed a linear relationship between the number of mowing passes and the aboveground biomass of C. arvense in the subsequent year. A comparison of the two regression lines within each experiment showed that in both experiments there was no difference between the regression coefficients, whereas the intercepts differed significantly from each other, suggesting that the presence of a competitive crop, here a grass/white clover mixture, is likely to suppress the growth of C. arvense significantly. Hence, our results support the hypothesis that a continuous depletion of carbohydrates from the root system, caused by mowing and/or the use of a competitive crop, will diminish the regrowth capacity of the plant

The importance of crop competition in physical and cultural weed control strategies

The prentation focussed on the importance of crop competition in physical and cultural weed control strategie

Economic Aspects of Physical Intra-Row Weed Control in Seeded Onions

The paper presents a model to calculate the costs for weed control in organic row crops. The model makes it possible to analyse the economic consequences of different weed control strategies in row crops. Particularly the time needed for hand-weeding had a strong impact on the costs

Band-steaming for intra-row weed control

Steaming the soil prior to crop sowing has the potential of eliminating weed seedling emergence completely. Thus, steaming might be a perspective technique for intra-row weed control in non-herbicidal row crops of high value, where manual weeding can be very laborious. This paper presents some preliminary results with the effects of steaming on weed seedling emergence. The work is part of a joint project involving both biological and technical aspects of steaming. The overall objective is to develop an applicable technique for applying steam in bands corresponding to the intra-row area of a row crop. Band-steaming is expected to use much less energy as compared to current steaming techniques for arable usage

Visit to Australia and New Zealand

The report summarises experiences from a study tour to Australia and New Zealand where numerous organic farms and research stations were visited by the Danish scientist Bo Melande