Nematodes and other garden problems

Modern vegetable production uses fumigants to clean the soil from many soil diseases, nematodes, and some weeds.  Fumigants are often quite toxic and often applied as a gas into the soil.  The soil may be covered with plastic to hold the fumigant in the soil to better kill the pathogens.  After a period of time the fumigant either dissipates and/or decomposes.  Then the plant is either seeded or transplanted into the soil, often through holes punched into the plastic.  The results are improved plant growth with less disease and often free of damaging nematodes.

Forked carrots caused by nematodes

Nematodes are minute round worms that live in the soil and often infect plant roots causing slow plant growth, forked carrots and other maladies.  They are so small they are usually not visible to people and there are numerous species.  Some common nematodes are cyst, root knot, lesion, dagger, and sting nematodes.  There are a few foliar nematodes and others cause medical problems in humans and other animals.

So, what can you do?  Most home gardeners do nothing and accept the damage.  There is a solution that will give your garden a great advantage.  Members of the brassica family such as mustard, turnip, and radish plants produce natural chemicals that can control or at least limit the damage from nematodes and plant diseases.  The diseases that may be controlled are verticillium, pythium, fusarium, rhizoctonia aphanomyces, and fusarium. 

Mustard plants in flowers

These plants are cool season annuals that can be planted in the fall as a cover crop or in very early spring.  When the mustard plants are chopped up and tilled into the soil, they decompose.  The decomposition releases glucosinolates which act as a biofumigant.  The plants, especially the mustard should be chopped and tilled before or at flowering time so the seeds don’t mature.  Mustard plants can be a weed that easily gets out of control.  Using these plants as a natural fumigant will not inhibit the growth of vegetables and the food grown will be perfectly safe to eat.

Tillage radishes

Turnips and tillage radishes can be planted in the fall and grow very well before freeze up.  (Don’t use the small round radishes)  The long cylindrical radishes grow quickly and produce a taproot that will grow deep into the soil improving the soil characteristics.  The deep root when decomposed creates channels that help handle soil water.  Turnips will grow similar to tillage radishes but don’t grow as deep.  When the turnips and radishes are tilled they also release chemicals that help control nematodes.  Tillage radishes and turnips can be seeded in the fall and generally will grow enough to be effective in improving next year’s garden.  Do remember to chop well and till into the soil.  If you choose to grow them as a cover crop, they do provide animal food and are grazed.  You, also, can eat them if you desire.

The Garden Doc

The Color of Food

Years ago two east coast chicken companies waged a battle over whether raw chicken, you buy in the store, should be white or yellow in color.  Dr. Baldwin at the Virginia State University Research Station in Painter, VA conducted research on growing marigolds for the purpose of feeding the flowers to chickens and the chickens would be yellow in color.  It works.  A medical mystery book from years ago had a story about a person who went to the doctor because he was turning orange.  He drove a lot and ate carrots while driving.  The solution was to quit eating so many carrots.  The orange color in carrots and marigolds is mostly carotene.  Green vegetables may contain many of the following colors but chlorophyll usually masks all the other colors. 

Nutritionists always say to eat a wide variety of fruits and vegetables.  The chemicals that give fruits and vegetables their bright colors are some of the most potent antioxidants people can obtain as well as many being studied for anti cancer treatment and important for other vital parts of the body such as the eyes.  Search some of the colorants below and be prepared to be amazed at why they are being studied.

 

Red Fruits & Vegetables

Lycopene is a bright red carotene commonly found in tomatoes.  Anthocyanins are red purple or blue.  They are flavinoids in purple corn, berries, and eggplants.

Orange & Yellow Fruits & Vegetables

Beta-carotene is red or orange, and commonly found in carrots.  Also called terpenoids.  Flavinoids, also called bioflavinoids are the yellow color in citrus, tea, wine & chocolate.  Quecertin and hesperidin are flavinoids.

           

Green Fruits & Vegetables – Green covers up most other colors even when they are present.  

Cholorphyll is green and changes light into glucose in plants.  It is not known to be that active in human health.  Lutein is yellow but found in green plants where chlorophyll covers the yellow.  Zeaxanthin is red to orange and is one of the xanthophylls and important for eyes.  Beta-carotene – See above

Blue & Purple Fruits & Vegetables

Lutein – See above

Zeaxanthin – See Above

Resveratrol is bright red or brown and found in grapes and other fruits.  May extend life and prevent cancer.

Flavonoids - See above

Anthocyanins – See above

White Fruits and Vegetables

EGCG or Epigallocatechin gallate is clear to yellow and is a potent antioxidant

Red Beets – Betalains are a different class causing the red in beets but can also be yellow.  In some plants they replace the anthocyanins.  Betacyanins are red to yellow and Betaxanthins are yellow to orange.  Betanin is a potent red color.  All are antioxidants.   

The red color from beets is often used to color other foods.  They are considered healthful and have/are being studied for cancer control and other healthy benefits.  There is a subtle side effect from betacyanin in beetroot which may cause red urine and poop in some people who are unable to metabolize betanin. This is called beeturia.  If you ever come home from a party and pass red urine the red punch may have been colored with beet juice.  (I apologize for a little coarseness but these are facts.)

The Garden Doc