The soil should also be relatively loose, not compacted. The less energy the plant devotes to forcing its way through hard soil the more remains for producing a quality carrot.
Carrots that are grown together in crowded spaces, bumping against one another as they grow may also become deformed as well as stunted. Be sure to adequately space your carrots to allow room for growth at their expected full mature stature, spacing is generally listed on the seed packet for the particular cultivar you are growing..
Assuming your soil is not compacted, there is minimal obstructions in the soil and your plants are adequately spaced other reasons for deformed carrots are biological in nature, insects, disease and the dreaded nematode.
Root knot nematodes cause a slightly different deformity in carrots than that caused by compaction and overcrowding. Carrots effected by nematodes appear hairy with galls and swellings on the main feeder root as well as the hairy capillary roots. In addition nematodes generally affect a larger portion of the crop than just a few random carrots.
Chemical treatments for nematodes by small scale back yard gardeners is not advisable. Not only are the chemicals involved toxic they are also costly. Costly to your pocket book and the environment. Beneficial nematodes are the best treatment. They are predatory nematodes that will devour the ones that are attacking your plants.
Aster yellows or Phytoplasma aster is caused by a bacteria that over winters in perennial weeds and is spread by Leaf Hoppers
. It affects many different plant species in the vegetable garden it can ruin not only carrots but lettuce, onions, parsley and celery as well. One of the symptoms is deformed roots and hairy capillary roots.
The disease also reduces the size and quality of the roots. The carrots are malformed and develop many hairy secondary roots. Infected roots are tough, off-flavor and lighter in color. There is no control for asters yellows once a plant becomes infected. Therefore, growers must prevent the disease by controlling leaf hoppers.
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