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How Do Nematodes Damage Plants

By Clyde Brown,2014-02-10 02:36
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How Do Nematodes Damage Plants

Gerbera Breeding & Consulting Dr. Yoseph Shoub

    58, Savionim St., Ganey Am 45905, Israel, Tel/Fax: 972-9-7406731

    http://www.gerberaisrael.com E-mail: gerbera1@zahav.net.il

Nematodes a major problem of gerbera culture in India. Tuesday, September 19, 2006

     thReport on visit to India, on behalf of ‘Selecta’ 6 - 14 September 2006

     Let us feed our gerbera plants and stop feeding the nematodes

     Y. S. a gerbera grower

Nematodes are the hidden enemy of intensive agricultural crops.

    Nematodes are plants’ parasites; they are actively present almost in any soil cultivated by men, and

in most cases they damage the root system..

     In India with its long traditional agriculture, the presence of nematodes is being a severe and critical

growing problem.

    And as the gerbera roots system is very sensitive to nematodes, the Indian gerbera growers have to realize that nematodes damage is identified in almost any gerbera soil farm, as well as in gerberas grown in containers.

    Therefore, every gerbera grower should pay attention to it, and if not, the nematodes will limit the development and the establishment of the Indian gerbera industry.

    As plant’s parasite, the nematodes are fed via the root system by damaging the root system. The injuries damage to the roots reduces the ability of the plants to obtain water and nutrients from the soil solution. These facts affecting negatively the growth and the productivity of intensive greenhouse crop as the gerbera, and especially in hot country like India, when gerbera plants need and use a lot of water.

     When nematodes numbers and damage get high, or when environmental stresses occur, only than the aboveground symptoms are discovered by the non experienced growers.

    1/6 9/20/2006

Gerbera Breeding & Consulting Dr. Yoseph Shoub

    58, Savionim St., Ganey Am 45905, Israel, Tel/Fax: 972-9-7406731

    http://www.gerberaisrael.com E-mail: gerbera1@zahav.net.il

    Aboveground nematodes’ symptoms, often resemble nutrient deficiencies or drought stress. The symptoms include: yellowing, wilting, thinning and flowers injuries, therefore the growers tend to describe these symptoms, mistakably, as a result of deficiencies or salinity problems (which certainly exist). Gerbera new plants, planted into fumigated or disinfected soil beds, grow and do well only for certain time, probably for the half first season. Later in the season, when the adventitious roots grow deep into the soil bed and meet the nematodes remainder in deeper soil

    levels, very soon, if not treated on time, the roots will be infected by the nematodes that move upward and attacking the secondary roots system. Fast re-infection by nematodes happened also when sanitary instructions are not taken care properly, and growers are importing and distributing infected-nematodes’ soil into the greenhouses.

     Nematode damage usually occurs in localized areas in the greenhouse, these areas may enlarge over time. Localized areas are: non disinfected spots, constant import of contaminated soil by the growers Shoes, cultivation tools, flower buckets, etc. Obviously, because gerberas are very sensitive to nematodes, keeping all the sanitation regulations for gerbera culture is a must without

    any exceptions, however most of the Indian gerbera growers I have met during my short visit, do

     not follow sanitation rules at all.

    Assuming that sanitation rules, regulations and practices are known to the gerbera growers, I’ll not

    discuss it here this time, but I’ll advice suppliers and consultants to refresh the growers constantly

     with this subject.

Chemical Soil disinfection for gerbera

    1. Condor (Telon) (1,3 Dichloropropene) Kills root knot (galls) and free nematodes spread

     in the soil. To be used only before planting (it is very phytotoxic and corrosive for some

     metals and PVC plastics). Condor can be used via polypropylene and polyethylene plastics 2/6 9/20/2006

Gerbera Breeding & Consulting Dr. Yoseph Shoub

    58, Savionim St., Ganey Am 45905, Israel, Tel/Fax: 972-9-7406731

    http://www.gerberaisrael.com E-mail: gerbera1@zahav.net.il

     irrigation lines, on condition that the irrigation lines are separated from the civil

     drinking lines.

    2. Metam-Sodium (Edigan, Metamor) - Kills only free nematodes.

     To be used only before planting. Edigan can be used via the irrigation system, on condition

     that the irrigation lines are separated from the civil drinking lines.

Pre planting treatments -

    Down here, we describe possible pre - planting treatments (based on Israeli growers’ experience),

    with Condor and Metam-Sodium. The treatments are fore gerbera soil beds, while the damaged old plants are still grown there, without destroying the soil beds:

     A. Use first the Condor for killing and destroying the old plants: 12 Liter in 30,000 liter water /

     1000m, directly to the soil beds as they are.

B. Use again Condor, 30 days after the first treatment, for disinfection: 30 Liter in 20,000 Liter

     water / 1000m.

     Before the performing of this treatment, remove the dead plants and elevate the soil beds,

     and than cover the soil beds with plastic film.

C. Use Edigan, 3 to 4 days after the second Condor treatment: 72 100 Liter in 20,000 Liter water /

     1000m, bellow the plastic film used for treatment B.

    The users have to wait at least 10 days, in case of light - red light soils, after the Edigan

    treatment before planting the new crop, and in the cases of heavy soils, they have to wait

at least 25 days before planting.

THAT'S A MUST!!!!

3/6 9/20/2006

Gerbera Breeding & Consulting Dr. Yoseph Shoub

    58, Savionim St., Ganey Am 45905, Israel, Tel/Fax: 972-9-7406731

    http://www.gerberaisrael.com E-mail: gerbera1@zahav.net.il

     Seasonal treatments during the growing period

D. Nemacur * (Fenamiphos) or Rugby** (Cadusafos) Kill root knot nematodes.

    These chemicals can be used during the growing season every 3 months via the irrigation lines 1 - 3.5

    liter / 1000m, on condition that the irrigation lines are separated from the civil drinking lines.

     Better to start with this treatment with established plants, few months after planting.

    E. Temik* granular ( Aldicarb) Temik is a systemic compound that move inside the plant tissues

through the roots where it is absorbed to the aboveground plant organs.

    Temik is very toxic compound, and only licensed growers are allowed to use it.

     It act as: Nematicide, Insecticide and as Miticide. It can be used few times during the growing season.

    The granules are spread over the plants on the soil beds 5 kg /1000m, and immediately after, the active

    toxic chemical should be washed by sprinkling from the leaves into the ground.

* Nemacur and Temik are products of Bayer (a German chemical company).

** Rugby is a product of F M C (USA)

F. Formalin (Formaldehyde) - Is used in agriculture for seed treatment, soil disinfection, and as an

    Insecticide, Fungicide and Nematicide. Practically, it is used to control contaminated spots in the Greenhouse. However in some Indian gerbera farms it has been used successfully as a general

     disinfection material before planting.

    General remark

    In general, nematodes and other diseases survive for a long time in the plant remains and in the

soil particles, as well as in the greenhouse structures, therefore disinfection of the structures and the

equipments used in the greenhouse is always necessary.

4/6 9/20/2006

Gerbera Breeding & Consulting Dr. Yoseph Shoub

    58, Savionim St., Ganey Am 45905, Israel, Tel/Fax: 972-9-7406731

    http://www.gerberaisrael.com E-mail: gerbera1@zahav.net.il

Summary -

    With an accurate combination use of the above mentioned treatments, the gerbera growers will be

    able to keep the nematodes population in limited figures, but no more than 2 productive years.

    It seems that the Indian grower’s wish, of growing gerberas longer than 2 seasons is not practicable

    and needs an economical accurate re - evaluation. We have to remember that nematodes, salinity,

plants aging and other growing factors, are always exist in our greenhouses.

    Therefore the accumulated results of these growing factors are decreasing of plants growth vigor,

And reduction of flowers qualities and production.

    Yet, awareness and properly care is needed for controlling the problems on time, preferably

immediately on planting day.

    Control means, constant monitoring and discovering the problems when they just start. Thus

    the growers have to gain the experience and the knowledge. I hope that my lectures and

    the above paper will contribute some helpful information for the gerbera industry in India.

Dr. Yoseph Shoub

Solar Disinfection

    Solar disinfection is a process of using heat from the sun to kill nematodes and other pests.

    Considering the fact that gerbera culture in India is widespread in the hot regions, attached here is

    some information regarding the solarization technique, used in some hot countries, and in Israel as

well (but not yet for gerberas).

     The candidate soil should be prepared as for planting, than the soil is covered with a clear plastic

    sheets, the edges of the plastic should be buried in the soil. The plastic cover is left on the soil for at

least 4 to 6 weeks, but do not remove the plastic until planting time.

5/6 9/20/2006

Gerbera Breeding & Consulting Dr. Yoseph Shoub

    58, Savionim St., Ganey Am 45905, Israel, Tel/Fax: 972-9-7406731

    http://www.gerberaisrael.com E-mail: gerbera1@zahav.net.il

How does it works:

    The sunlight goes through the clear plastic and heats the soil underneath. The plastic then holds

the heat, and force it penetrating into the soil. Long-term exposure to high temperature kills

    nematodes, as well as many weeds, fungi, and insects. The solar disinfection level is usually 15 to

    20 centimeters deep. Do not till or mix the soil after solarization, since that may re - infect the soil

with nematodes from the non treated zone below.

    Because solar heat depends on sunlight and heat, solarization works best during the summer months.

    It does not work well in areas that get shade. The benefits of solar disifection may be enhanced by

    using a second layer of plastic. The air gap between the two plastic layers is creating extra insulation.

6/6 9/20/2006

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