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rherbfarm

Basil reaction to over fertilization

rherbfarm
16 years ago

Can anyone tell me how genoveese basil will react to too much nitrogen. I am attempting to become a basil grower with over 20,000 plants in 40 150' raised beds. My soil is poor and rocky and tested very very low in nitrogen.I have added 9, 3.8 cu ft of peat moss and epsoma organic plant tome to soil at a rate of 50 lbs per bed. Retested and still very low on Nitrogen. Have added 1/2 reccommended amount of UREA to beds and plants looked much better. two weeks later added the other half of dose. Now two more weeks have gone by and plants look like they our turing yellowish green on top leaves. My question please is this a sign of to much UREA or not enough? . Also I have many plants with lots of holes on leaves. I had a problem with cut worms early in the year and did nothing to get rid of them. They seem to stop as plants grew. is the holes the same bug?

if anyone has any experiance with these problems I would appreciate your analysis. Thanks again

Comments (8)

  • ksrogers
    16 years ago

    The holes are probably from those litte green caterpillers that like to chew at night. Oak trees have been severely damaged and my peach and apple trees also have lots of little holes. The leaves, even though only a little has been chewed, should be fine. If you do see new damages, spray with Bt, and also neem oil.

    For Urea additions, your pushing the soil way too fast and because your using the raw chemicals, you can expect all kinds of bad things to happen. New yellowing leaves are a sure sign of a very low primary ingredient. If you raise the nitrogen too much, you reduce iron, phosphorous, and potash. All of these ammendments should have been done well before anything was planted. I usually adjust soil in the fall, then again just before I till the garden the next spring. My ammendments are lime, humate, fish meal, seaweed meal, and a general purpose low level, long lasting garden fertilizer, as well as iron sulfate. You don't want quick and sudden changes, as these can quickly kill plants. For the long term things like corn gluten (acts as a germination preventer) which slowly breaks down into nitrogen. Cotton seed meal is another long term nitrogen additive. Once the plants have been exposed to harsh, strong, and sudden changes, you may get very stunted plants. Compost can be added as well as well composted manure. Removing as much of the gravel and rocks also helps to build soil tilth. Things like worm castings, and dried blood meal are also good low dose, long lasting sources of nitrogen. Also, if you have not checked soil pH, that is also very important. When I had my soil tested, everything was good, except iron, which was extremely low. Now that its been ammended several times, my plants seem to do much better and don't suddenly die. Foliar fertilizer sprays are also great to use on plants that are not eaten as leaf herbs. The sprays are done in early morning and applied to all leaf surfaces. Not sure what planting zone your in, so I can't tell whether you will have a big crop or not. Unfortunately, what your doing is getting to the extreme, so give things weeks to break down and absorb, before making any more drastic changes. Sometimes a home versions of a soil tests may incorrectly indicate the wrong conditions.

  • rherbfarm
    Original Author
    16 years ago

    Thanks for the feedback, to clarify I added the peat and organic fertilizer before I planted. I also check the ph and it was 6.0 I am in Upstate NY and Planted seedlings weekly (4 beds p/week) since last week of May/07. The first beds plants range from 10-17" tall. I also have topped all plants to encourage branching out. My Basil is Genoveese. in March/07 and on most beds I had broadcast some daikon radish seeds(that I had laying around)that grew until I preped the beds as stated above. The radish plants,peat and fertilizer were all tilled into the soil before I planted basil. Thanks again for your feedback I really appreciate all

  • ksrogers
    16 years ago

    Why the radish?? If anything, you would do well to plant winter rye in early fall, then till it under in spring. Its natral nitrogen will give a long slow release for the next growing season. Good luck! Another high nitrogen plant is hairy vetch. Planting and growing both through winter, will raise the nitrogen level to a dangerous state where it can actually burn seeds, so it needs a few weeks after a few tills.

  • rherbfarm
    Original Author
    16 years ago

    I just had 10lbs of radish seed from a project 5 years ago.
    This is the first year for me in this project and the opportunity to start last fall wasnt there. I thought it is better than doing nothing. My soil is major poor and the radish will tolerate the cold and give me something to till into the beds when I prep for the basil. Thanks for the suggestions for this fall. I need a ph of 5.5 - 6.5 for my basil beds are your suggestions appropriate for that ph. Thank You again

  • ksrogers
    16 years ago

    To help in the long term to lower a high pH would be a garden sulfur. This product slowly breaks down and will take at least 6 months to lower soil pH. Use sparingly. I use it about every 3-4 years in my blueberry patch, which needs a pH down below 4.5 all the time. Avoid using fast acting items like aluminium sulfate. No lime is usually needed, because most garden soil has a pH of about 6.5 anyway, unless its in an area were there is a lot of hard water, calcium, marble, or sand, that tend to raise the pH. Be sure to get a good soil tester too. If you can find some nearby sources of composted manure, regular garden compost, and even dead leaves and grass clippings, they work very well. I have a compopst pile at the back of my property. In early fall its up over 5 foot tall. The next spring, it breaks down to less than 3 feet. Because of acid rain, I apply a little lime to it, which will regulate its pH to give more friendly bacteria a chance to thrive in. As mentioned elsewhere, my soil is very low in iron. If I were to just apply iron sulfate, the pH would be very low and not good for most plants that like normal pH soils. Thats the main reason I also apply some lime as well. For the fall prepping, I suggest that you plant winter rye grass. It should show up as spiral blades of grass. Very soft and tender, in spring it gets easily tilled under. That should give you nitrogen well beyond what is needed for basil. If you allow the rye to form seed stalks, it will replant itself. Some do this just to reduce weed seeds and have on going rye as a crop that is beneficial to all garden soil.

  • barrie2m_(6a, central PA)
    16 years ago

    The off-color yellowing is probably due to either cool nights, prolonged wet soil or other strssing condition on the plants. Nitrogen excess is not tolerated well by basil but usually expresses itself by brittle curled leaves and stunted growth. Since your pH is low you might have below normal Calcium and/or Magnesium levels.

    How did you determine that your soil N was low? Most soil test labs do not test for nitrogen since it is such a mobile element,ie. it leaches out of the soil relatively quickly. I always use a modest amount of nitrogen fertilizer in a blend form such as 10-20-20. Urea (46-0-0)is just too easy to overuse and should be avoided for basil.

    Holes in the leaves can be caused by a number of pests so look closer for a cause. Slugs, catepillers, small beetles and japanese beetles are likely suspects.

    Your soil pH is plenty low. Definately don't add sulfur unless it is as gypsum (calcium sulfate). Basil may tolerate a wider pH range but the lower levels may indicate a nutrient deficiency as I mentioned earlier.

  • rherbfarm
    Original Author
    16 years ago

    "How did you determine that your soil N was low? "

    I use a test kit that test for N,P,K and PH seperately. Recently we have had several high 40 degree nights. I also notice during this time that on cloudy days the basil tops look yellowish and when the sun is strong it dosn't.

    I am going to have my soil tested by a lab thanks for the imput

    "For the fall prepping, I suggest that you plant winter rye grass."

    My soil now gets very hard and compacted on the top inch or so will the rye grass help with this condition. It seems this soil has little organic matter in it.

    Thanks again for your input much appreciative

    rhf

  • ksrogers
    16 years ago

    Work in chopped up leaves, and grass clippings. Yes, the soil will loosen some if you plant the rye grass. It needs no digging to plant the seeds, and will germinate when temps are higher than 50 degrees for a while. Winter rye root system is small, and tender. Tilling lightly, then deeply, in early spring will help to break up the hard soil. Adding some sand, as well as other compost will also help to get it to loosen some. If its hard clay, adding gypsom will also help. Many commercial farmers plant winter rye as a cover crop, and there are a few others, as mentioned, hairy vetch, clover and even a few others. For a loose soil, you do need plenty of organic matter. My nextdoor neighbor and I have an agreement, he cuts the lawn with is regular mower, and takes up all the grass clippings I make when I use my garden tractor with no catch bag. I also have a big gas powered mulcher that can suck up a lot of dead leaves and many acorns. This mulch gets dumped into a compost heap at the back corner of my yard, and the neighbor only needs to lift his waste stuff over a 5 foot tall chain link fence. I turn over and treat the compost every year. Its moved side to side and I dig out whats on the bottom and apply that to the garden prior to tilling. Also, I add the ammendments like iron, lime, seaweed and fish meal, just before tilling. My tiller is a Tryobuilt 7 hp machine. After all the garden is tilled, I have to drive over it with my tractor to help press it down a little. After that, I have a 300 pound steel drag mat that is pulled behind the tractor to furher level my soil. The final application is a black plastic fabric mulch cloth that helps block the weeds. I cut small round holes for the transplants, or thin slots for the seeds I plant.

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