While I know I’m behind on my weekly posts, I do a lot of reflection on my commutes back and forth to the farm. At first I used to listen to a lot of NPR, so much so that I would catch repeats of different segments since I was driving very early in the morning and then in the late afternoon. One of the main reasons I was listening though was because it was the first 30 days of the Trump administration and I was in need of some ammunition in direct relation to current events. I know that very few people hold the same beliefs and values as I do so intellectual ammunition is needed when I need to defend and counteract to comments coming from mostly old men like my dad and my old boss. While some would say NPR is very liberal biased- at least they try and interview people from the opposite side. I think it’s always important to understand, study, and analyze those in power and who/what they are controlling.
A few weeks ago, Sarvodaya Farms encountered an enemy… the parasitic nematode! They had some significant root damage on the beets!
While it was sad to pull up the beets and see their roots turn into cyst like beaded curtains (lol side tangent: I feel like Maya would have beaded curtains in her room); what an incredible teaching moment I encountered with Manju. (side tangent: For anyone who is looking to apply for the internship- Manju is an incredible teacher- she verbalizes her thought process in her observations and makes sure that everything she does is a teachable moment- it’s very inspiring and also has taught me so much in how I can be a better teacher. Rishi is an equally amazing teacher- his lessons are literally mind blowing- every Wednesday I leave the farm questioning everything related to life, find myself saying this a lot “dang this makes so much more sense!”)
I had never witnessed nematodes before and now that I’m writing this post I will remember them forever and hopefully can teach someone else around me as I continue and build my farming super powers. What an incredible teaching farm Sarvodaya Farms is!
Back to the enemy. I think when studying any opposition, one good and effective strategy is to study their life. Where did they come from? What are their daily habits? What are their strengths? What are their weaknesses? When it comes to pests I think questions like when do they breed? What kind of environments do they seek out? These questions can then hopefully lead to answers since lets face it Bt isn’t the miracle pest bacterium for all pests. I wouldn’t want nature to work like that anyways.
Here are some things I found out about the life of the nematode:
LIFE/EVOLUTION of Nematodes
- from the diagram you can see it has 6 stages: egg, 4 juvenile stages, and adult. Production of the eggs completes the cycle and nematodes can produce anywhere from 50 to 1,000 eggs
- there are 1 million different kinds of nematodes and are 1 billion years old and are the most numerous multicellular animal in the world.
- In terms of species relation, they are relatives of insects, arachnids, and crustaceans and have soft bodies.
- It is said they were first microbial feeders in the primordial oceans but nematodes have evolved their ability to parasitize animals and plants several times
- They are highly equipped to take on their hosts!
- Nematodes have evolved to fill almost every conceivable niche on earth that contains some amount of moisture. (important to note: maybe drying them out is a potential solution!)
- Nematodes are free living: 40% of them feed on bacteria, fungi, and protozoans, 44% on animals, and 15% on plants.
- In plants, nematodes were first discovered in 1743 on wheat seeds and since then a whole field of nematology has formed.
PLANT PARASITIC NEMATODES
- They are tiny worms 0.25-3 mm long, cylindrical, and taper towards head/tail
- They have no respiratory or circulatory system- they use diffusion to get its nutrients
- They move in snake like movments and at its head have hollow mouth spears to puncture the plant cells and secrete protein/metabolites to paralyze the plant
- They thrive in warm soil temperature: 80-90 degrees and can complete their life cycle in 4 weeks.
- Sarvodaya observation: there were quite a few temperature fluctuations in February/March, hot and cold days. I couldn’t decide if I would need shorts or pants at the farm some days.
- Since their predators are bacteria, fungi, and other nematodes, they live inside the plant tissue and make very little movement
- Temperature extremes and moisture extremes is also a big enemy to nematodes but it seems that they have developed some mechanisms to tolerate bioextremes.
- When females die, they will leave behind 1000s of eggs.
- These parasites really know how to give to the next generation!
HOW TO DETECT
- They attack at the root so it is difficult to see the symptoms above ground but some signs are yellowing, stunted top growth, and more weed growth around since the plant has been weakened.
- I think at the farm they were detected when we harvested beets, but maybe someone noticed it before that, not sure.
- There doesn’t seem to be that magic nematicide like there was with Bt sprays but lots of farmers face nematode issues and therefore there is a lot written about some remedies.
- Tillage: exposing soil to dry and temperature extremes will significantly destroy nematodes and their environments
- One article said that tilling in crustacean shells would also help.
- Interesting! Crustaceans are a species related to nematodes so this must have something to do with taking them down. They say to keep your enemies closer…
- Washing your equipment! This will reduce the probability of spreading nematodes infestation to other parts of the farm
- Crop rotation
- One article recommended rotating with cotton but they didn’t specify where they were doing this
- Other articles recommending rotating with crops that are not closely related to each other
- Asparagus, corn, onions, garlic, and small grains will reduce nematode growth
- Velvet beans and grasses like rye will build nematode resistance
- The Mustard Effect!
- The allelopathic properties of mustard and rapseed have nematode-antagonist energy to them!
- At Sarvodaya, they decided to plant red mustard after taking out all of the beets from that bed
- Soil amendments
- Neem oil cake or neem seed cake- I wasn’t really sure how you make the cake but its like cluster of neem seeds I think
- Bone meal
- Green manure
- Nematophagous fungi is an enemy to nematodes, however current nematicides are highly expensive and haven’t really been tested.
- Although 1 article stated that having perennial crops will increase the growth of nematophagous fungi.
- I also then read in another article that marigold is a good thing to plant to resist against nematodes.
- For Sarvodaya Farms, since part of one bed was infested with nematodes, I think in addition to the red mustards, planting some marigolds would be helpful! As well as thinking about the next crop rotation and avoiding planting anything from the beetroot/amarynth family in that bed and neighboring beds. I never had velvet beans but something legumous sounds like it would be good?
- In my short farming life history, I have never been successful at growing beets– it’s always been the one crop I’ve wanted to grow and also carrots! The beets that have been harvested at Sarvodaya have truly taken my breath away. I hope that one day I’ll be able to grow beets from start to finish. I think I have a leg up in my knowledge now thanks to the people at Sarvodaya. One of their beets weighed in over 3 lbs!
https://attra.ncat.org/attra-pub/viewhtml.php?id=149 (I liked this one the best!- most comprehensive.)