Semper.Fi
Well-Known Member
A very interesting scholar's article on Brix levels and pest/pathogen defense!!!
...." In the past several years a number of products have come on the market claiming to raise plant Brix levels. In addition to the nutritional/taste benefits of “high-Brix” crops one of the reported advantages of raising Brix levels is fewer pests and diseases
(e.g. http://www.goodearthgardenschool.com/gegs/archives/2009/09_June_15_High_Brix_gar dens.pdf).
The objective of this study was to review the scientific evidence regarding high-Brix crops and pest levels. For our review we focused on insect pests. In our review we found no studies that directly studied the impact of manipulating plant Brix level on insect levels. Only one study, published in a non-peer reviewed report, examined the impact of Brix on pest levels in the field, and found no relationship. Similarly, in our evaluation of Brix manipulations on potatoes we have found no consistent relationship between Brix levels and aphid counts. Fundamental to the idea of high-Brix crops is the optimal balance of key nutrients via foliar and soil feeding. We examined the impact of several of these key nutrients on pest pressure and did find that this was an area of active research.
The impact of nitrogen on plant-feeding insects is well known – excess nitrogen leads to increase insect populations. For the other nutrients unfortunately the relationship between nutrient levels and pest incidence is less clear. For example, phosphorous, calcium and magnesium levels have all been shown to either increase or decrease insect feeding as levels of the nutrients are manipulated. Potassium on the other hand seems to have a consistent trend towards lower pest pressure with increasing potassium input. Several studies have proposed that examining individual nutrients is too simplistic and that it is the combined impact of nutrients that affects insect feeding. This type of idea is consistent with the high-Brix concept of optimal mineral balance. We also interviewed two American practioners of high-Brix crops who were able to provide details regarding their specific management programs and anecdotal evidence of the impact of increasing foliar Brix levels on pest pressure.
In summary, while our review did not find any support for the idea that high-Brix crops lead to less pest pressure, we did find that many of the individual nutrients manipulated in “high-Brix” programs have been shown to have impacts on pest levels. Although there is support in the literature that a balance of nutrients is necessary to minimize pest pressure, a Brix-reading on its own is likely too simplistic to fully encompass the complex mechanisms mediating nutrient-plant-insect interactions. Growers are encouraged to conduct their own on-farm trials if using high-Brix products."....
God dammmmmmmmmmm another load of stuff for me to brew over a bit more . . . .
~_
...." In the past several years a number of products have come on the market claiming to raise plant Brix levels. In addition to the nutritional/taste benefits of “high-Brix” crops one of the reported advantages of raising Brix levels is fewer pests and diseases
(e.g. http://www.goodearthgardenschool.com/gegs/archives/2009/09_June_15_High_Brix_gar dens.pdf).
The objective of this study was to review the scientific evidence regarding high-Brix crops and pest levels. For our review we focused on insect pests. In our review we found no studies that directly studied the impact of manipulating plant Brix level on insect levels. Only one study, published in a non-peer reviewed report, examined the impact of Brix on pest levels in the field, and found no relationship. Similarly, in our evaluation of Brix manipulations on potatoes we have found no consistent relationship between Brix levels and aphid counts. Fundamental to the idea of high-Brix crops is the optimal balance of key nutrients via foliar and soil feeding. We examined the impact of several of these key nutrients on pest pressure and did find that this was an area of active research.
The impact of nitrogen on plant-feeding insects is well known – excess nitrogen leads to increase insect populations. For the other nutrients unfortunately the relationship between nutrient levels and pest incidence is less clear. For example, phosphorous, calcium and magnesium levels have all been shown to either increase or decrease insect feeding as levels of the nutrients are manipulated. Potassium on the other hand seems to have a consistent trend towards lower pest pressure with increasing potassium input. Several studies have proposed that examining individual nutrients is too simplistic and that it is the combined impact of nutrients that affects insect feeding. This type of idea is consistent with the high-Brix concept of optimal mineral balance. We also interviewed two American practioners of high-Brix crops who were able to provide details regarding their specific management programs and anecdotal evidence of the impact of increasing foliar Brix levels on pest pressure.
In summary, while our review did not find any support for the idea that high-Brix crops lead to less pest pressure, we did find that many of the individual nutrients manipulated in “high-Brix” programs have been shown to have impacts on pest levels. Although there is support in the literature that a balance of nutrients is necessary to minimize pest pressure, a Brix-reading on its own is likely too simplistic to fully encompass the complex mechanisms mediating nutrient-plant-insect interactions. Growers are encouraged to conduct their own on-farm trials if using high-Brix products."....
God dammmmmmmmmmm another load of stuff for me to brew over a bit more . . . .
~_
