FAO has a paper out on organic agriculture, as part of the International Conference on Organic Agriculture and Food Security, going on in Rome as I type. Here’s a quote:
The strongest feature of organic agriculture is its reliance on fossil-fuel independent and locally-available production assets; working with natural processes increases cost-effectiveness and resilience of agro-ecosystems to climatic stress. By managing biodiversity in time (rotations) and space (mixed cropping), organic farmers use their labour and environmental services to intensify production in a sustainable way.
Those are some of the strengths, and very significant they are too. An often-quoted weakness of organic agriculture, however, is that yields are often lower than what you’d expect from “conventional” agriculture. But why? Well, according to a recent study using wheat as a model, part of the reason is that the varieties used are poorly adapted to the particular conditions of organic agriculture: “increasing yield in organic systems through breeding will require direct selection within organic systems rather than indirect selection in conventional systems… With crop cultivars bred in and adapted to the unique conditions inherent in organic systems, organic agriculture will be better able to realize its full potential as a high-yielding alternative to conventional agriculture.”
And one of the reasons that there has been so little breeding within organic systems (apart from some bio-dynamic breeders) in Europe is that the resulting seeds might not be eligible for registration and hence could not be put on the market. So what’s the point? What’s more the new legislation (about which I promise to write again soon) would not help either.
From this consumer’s perspective the strongest feature of organic agriculture is the lower use of biocides (“lower” because I believe there are important exceptions such as the use of copper based products in viticulture; I would advice against drinking “organic” wine). My impression of the FAO report (after a quick scan) is that their list of the strongest features about organic farming reflects wishful thinking rather than fact.
Anyway, breeding varieties for organic farming systems would naturally put more emphasis on resistance to pests and disease, and on nutrient use efficiency, in addition to yield, quality, etc. This surely makes it harder, and more interesting, to do than breeding for conventional systems.
But I am not sure that, for the cited study on wheat, the (Luigi’s) conclusion that the conventional varieties are poorly adapted to organic systems is warranted. The authors found a variety x production system interactions. That is, the best performing variety in an organic system was different from the best performing variety in an conventional system. Yet, in three out of five locations, organic yield was not different from conventional yield. In these locations there was enough rain to grown an organic manure crop before the wheat crop. In the other two locations the nitrogen supply to the organic wheat crop was very low.
If the objective is to raise organic wheat yield in these areas where it is much lower than conventional yield, I forward that an “organic breeding program” would not do. A quantum leap would be needed, perhaps nitrogen fixation via genetic modification (a taboo in organic circles).
Well, that’s what comes of simplifying perhaps a bit too much, perhaps. Since we’re talking about meta-narratives, here’s another one. Landraces do better (whatever that may mean) than modern varieties under organic conditions because those conditions more closely resemble those under which they have been developed by generations of farmers than those under which modern varieties are typically selected. The idea of an organic-adapted GMO would bust that, and is delicious.
“Organic conditions”? In many cases organic conditions means high-soil-fertility-intensive-agriculture. It relies on short-straw cereals and early maturing veggies as much as other approaches to living from the land. Sure, pest and disease tolerance is more important, and perhaps farmers and consumers have more appreciation for quality beyond size, color and weihgt. But I would not equate organic conditions with those of pre-modern agriculture. (but what is that, and where, and when?). Generalization is difficult. The problem with these meta-narratives may be that they neglect diversity. Conventional vs. organic. Landrace vs. modern. We cannot discuss the world without simplifying. But we should not simplify it too much.
I need some latest issues or topics related to do PhD thesis research work on the late blight of potatoes in organic agriculture.
thanks
I suggest you contact researchers in this topic, for example The Rodale Institute or Elm Farm Research Centre. IFOAM may also be able to help.
Number 1 is varietal resistance. There is large literature about breeding for “durable” resistance (and avoiding “major” or “R” genes (or not)).
There are many management options that probably deserve further research. You can diminish infection through dilution (mixtures). See Karen Garrett’s publications.
Avoid early infection from cull piles etc. There has also been some work looking into the effect of high nitrogen, perhaps via micro-climate (more leaves; more humidity; more blight). E.g. this paper
by Henry Juarez and colleagues.
Here is an interesting treatise on the production of potatoes in the USA (northwest). Published in 1870. It might have some interesting “organic” tips and tricks. A scanned book from the marvelous Core Historical Literature of Agriculture collection at Cornell University.