The use of homeopathic remedies for raising crops. Somewhat akin to Rudolf Steiner's Biodynamics. Send me information if you've tried using Sulph 3x on your tomatoes or similar.
Viburnum oppulus C200, dissolve 20 - 30 (I don't see the need for any more than one - DH) in 10 liters of water and spray it on a tree that loses its fruit before they are ripe. It stops this tree doing so, instantly.
About four years ago, a bigger part of a highly affected dying forest in Germany close to Baden - Baden was sprayed with homeopathics and recovered dramatically in contrast to the adjoining forests. All newspapers reported this!
Anyone interested in applying homeopathy to agriculture should learn the basic principles of homeopathy and then do what any researcher would do... do some research. For instance, say you have an interest in mango tree crop management. You know way more than I do about the particulars but the research method can be applied.
The first step is to collect proving data. Select a good number of young mango plants, say 20 or so, to start with. They should be a control group. Next, select another group of young plants and administer a remedy on a regular basis, say each day by dissolving one of the polychrests in water. I go with the polychrests because they have been shown to have good broad effects on us and that's a good reason to try them on plants. It's not a guarantee though. And stay with what everyone has used in the past the most often which is a low potency, say 6 or 12x. The amount you dump on the plant really doesn't matter a whole lot as much as the time intervals you use. The most important thing though is to record the particulars that you decide on.
Then as the days and weeks go by, observe, observe, observe. Write down what is a symptom in many plants, what is a symptom in a few plants, and what is a strong symptom in just one plant. Keep numbers and dates. Take pictures of important symptoms. Collect details and make conclusions later. Publish the findings and let others help you create a repertory of mango tree symptoms. (I can put them on my site if you want). You will know what is normal by your control group. Continue the proving until the plants are as unhealthy as you want if that is the result.
Even better would be to have all the plants randomized so that you didn't know which one was getting a remedy and someone else had the responsibility of giving the dose. But realistically, if you get some interesting data, someone else can repeat the trials or you can do the double blind style proving.
Now that you have the data, you can apply the types of symptoms that you've found and categorized to any plants with similar symptoms and see what the results are. Keep records here too, of course. Now you are being a plant doctor.
I'd love to be able to see some of these ideas in action so if you try it, let me know and I'll post whatever information you give me. I'd also welcome anybody's experiences that have tried something like this or if someone has a better refined idea for the process.