Fumigation of the soil

Fumigation of the soil.

During the seminar organized in Warsaw under the Ministry of agriculture of Poland, was under- introduced the results of the project "Sustainable use of chemical fumigants for destroying soil pathogens in rural management" (SustUse Fumigants). The project operated for 3 years (2010-2012) and was implemented in several evropeyskih countries. He had to answer the question of whether to restrict doses of the drugs recommended for the fumigation of soil and how effective this biological methods.

General information on the topic of research is the production of seedlings of wild strawberries gave Dr. Beata Bag from the Institute of Horticulture in Skierniewice. Before fumigation of soil the samples were taken for tests, which indicated a large number of pathogenic organisms is relatively strawberries (Fusarium, verticales, late blight). All isproba- bathrooms methods of chemical fumigation significantly reduced the number of pathogens in the soil, what the greatest effect gave the drug Basamid 97 GR (active ingredient dazomet the normal 40g/sq. m.) and Nemasol 510 SL (active the relevant substance METAM soda 60 ml/sq. m.). The active pair have also reduced the number of pathogens in the soil.

As informed lecturer, very important was the economic aspect of fumigation, which is a uterine plantations of strawberries has shown very good results in comparison with experiments for growing vegetables (peppers, tomatoes) in plastic tunnels. Use Nemasol 510 SL (90 ml/sq. m.) allowed to obtain per hectare to 798 thousand pieces of strawberry seedlings, when the control (soil netactivity) was obtained 418 thousand PCs./ha. the Difference turned out to 380 thousand units/ha. Attention was drawn to the financial question. Destruction of weeds (payment of herbicides, additional hand-weeding and cleaning of old dead plants) carried 2600 PLN per hectare, and fumigation - 10000 PLN./ha. So, fumigation soil preparation Nemasol 510 SL (90 ml/sq. m.) has increased the cost of investment in training plantation liquor to 7400 PLN./ha. This operation led to the increase of gross harvest of 380 thousand pieces/ha, at price of 0,33 PLN/sapling provides income 125 400 PLN./ha. Adminpower eveliene the cost of fumigation and profits in the amount of 118 thousand PLN./ha. If you take away the gross expenditures for agriculture, preparation of seedlings for sale (about 50% of the gross income), the additional profit from fumigation turns 60 thousand PLN./ha, informed Pani Beata.

Based on the results of research conducted on the plantation of strawberries, Dr. Beata Bag made the following conclusions:

chemical fumigation of the soil as well as the active use of steam reduced chislennosti of verticilata, which has a positive impact on the health of the cells and quality of seedlings;

- the effectiveness of fumigants such as Basamid 97 GR and Nemasol 510 SL, used in smaller doses to the destruction of verticilata was also high and showed 80%, which indicates vozmozhnosti reduction of applied doses drugs;

- decontamination of the soil reduced the number of weeds in the plantation, which gives the ability to restrict the use of utilization of herbicides;

- decontamination of the soil positively influenced the size of plants and number of plants - their crop was big in 2-2,5 times;

- As told to Professor Peter Sobiczewski, fumigation of the soil also increased nitrogen availability in the soil and divalent manganese, which gives the possibility of limiting the use of mineral fertilizers.

Table 1

The effect of soil fumigation on the number of seedlings obtained in nurseries strawberries

Choose areas which have not been observed Verticillium regardless of culture. The plot was not supposed to have cases of red and black root rot. To minimize the risk of the development of black rot on roots not engage landing immediately after removing the old strawberry plants.

Planting strawberries immediately after solanaceous or other Verticillium-susceptible crops is also not a good option. This includes tomatoes, potatoes, peppers, eggplant, melon, mint, BlackBerry, chrysanthemum, rose, or related crops. If possible choose a site, which is not grown any of these crops from three to five years. The soil should not show residual effects of herbicides from the previous crop.

This is the first planting of strawberries on the plot?

If the site has no recent history of cultivation of strawberry (over the last five years) were not recorded Verticillium outbreaks in other crops, soil borne infection such as red root rot or wilting verticillatae should not be a problem.

Whether you're a Peratallada plantation?

If strawberries are planted on the same field, required rotation or must be carried out fumigation of the field. Remember that fumigation is not an option for organic production.

In rotation land should be plowed, planted and processed by culture immune to Verticillium for at least two years. Remember that many soil borne infection form a shape conducive to survival for many years, even if strawberry is missing. Therefore, the longer the plot might be in circulation, the better.

A combination of crop rotation with fumigation it is advisable and used by many manufacturers. However, for organic production (where fumigation can't be used), but the rotation often gives an acceptable level of control of soil infection, provided that the site remains long enough in circulation.

Please note that no crop rotation, no soil fumigation does not provide adequate control of red root rot. Therefore, when you encounter this problem, must be used resistant varieties and improved soil drainage.

It is advisable to always use the turnover of varieties resistant to red rot and wilt verticillata.

The main points to determine the feasibility of fumigation.

Fumigation destroys most of the seeds of weeds, pathogens, nematodes and insects in the soil. Fumigants are often applied as liquid form . After applying true fumigants move into the gaseous state, other pesticides applied in the same way can stay mixed with water.

When using soil fumigants, consider the following points:

- the harmful organism that is the target of the fumigation.

Rates of application vary depending on the target application. As a rule, nematodes and soil insects are killed at lower doses than weed seeds and pathogens of fungal and bacterial diseases. Seeds to kill weeds with fumigation hardest. Currently, methyl bromide (CH3Br) is the only drug that gives excellent weed control. But since 2005 the production of these drugs has been stopped due to the damaging effects on the ozone layer.

Figure 1A. Unit for liquid fumigant into the soil by gravity.

Figure 1B. Rod for introducing fumigant into the soil.

- the structure of the soil.

As a microscopic distance between particles of the soil decreases and become less common (as in the case of heavy and tight soils), rates of application of the fumigant should be increased to counter the reduced or delayed dissemination and penetration. On heavy soils frezowanie (wet soil) could increase the pore volume in the soil, enhancing the effect of subsequent fumigation.

- the soil temperature.

For effective fumigation the soil temperature at a depth of 15 cm shall have a temperature not below 10°C. the higher temperature leads to increased evaporation and more intense fumigant movement through the soil.

- the content of organic matter in the soil.

Humus organic matter improves soil structure and generally promotes the spread of the fumigant in the soil. However, a very high content of organic matter in the soil can adsorb or bind fumigant, reducing its effectiveness. Fresh (undecomposed) plant residues can impede the spread of the fumigant in the soil and can serve as a refuge for pests. The organic substance preferably completely decomposed.

- Soil moisture.

Fumigants move through the air contained in the soil, and dissolve in water. They must enter into the soil layer for a contact and the destruction of harmful organisms. Therefore, preferred a moderate level of soil moisture, which helps effective fumigation.

During or immediately after fumigation, the soil surface should be closed to prevent too rapid withdrawal of the fumigant in the air. This can be achieved by rolling , watering or covering with tarpaulin or plastic , depending on the type of fumigation. The fumigant must act within 2..4 days, after which from 4 to 14 days of ventilation (for dispersion of fumigant) must pass between fumigating and planting (depending on the type of fumigant).

Figure 2. Packing (sealing) the soil to prevent evaporation of the drug into the atmosphere.

Figure 3. Solid shield film for retention of the drug.

More preferred interval is 3..4 weeks. For this reason, autumn is usually the best time for fumigation.

However, spring fumigation can be very effective if the soil is warm enough and observed the interval between treatment and planting. Avoid too deep plowing after fumigation, that would not of treated soil is not mixed with the processed. Recommended shallow plowing.

See table 1 for analysis of the characteristics of foreign fumigants.

To obtain good results:

- ideally, the area should be treated and disinfected in September.

- produce plowing to a depth of 20..25 cm, after which seadistuste or treated with a rototiller, therefore, that there were no lumps, coarse particles of soil and stones. This should be done before the end of August or in early September.

- required soil temperature 15..21°C at the depth up to 15 cm.

soil moisture should be 50..75% of plaguemaster soil.

- organic residues (corn stalks, grass, straw, etc.) should be well-rotted.

depending on soil type, temperature and use of the drug, must be aged from two week to two month period between decontamination of soil and planting, to prevent damage to crops. Some drugs require only a 7 day wait.

soil samples for content of nematodes, larvae or other harmful organisms will help to determine the need for fumigation. Post these samples in July.

Table 1. Rates of application and spectrum of action.

^a 0 =no impact; 5 = great impact.

Comments on the methyl bromide: Methyl bromide has been the standard for fumigation of the soil for many years. Largely because of its effectiveness in combating the seed of weeds, as well as in the suppression of other soil pests and diseases. In connection with the problems caused by bromine in the atmosphere, its use for disinfection of the soil is minimized in a number of countries. Significant focus is on the development of a new drug, with the same or even better properties. You have already created other noteworthy drugs, such as methyl yodit. Methyl yodit shows itself as very similar in their effect to methyl bromide the drug. Consult with local offices of plant protection to obtain reliable information on the availability of soil fumigants in your area.