8 1 NATURAL PESTICIDES – 8.9 - BIOLOGICAL CONTROL OF PESTS

 

ORGANIC FARMING COURSE AGRO-ECONOMY

8 1 NATURAL PESTICIDES – 8.9 - BIOLOGICAL CONTROL OF PESTS 

 

Biological control is the use of natural enemies to manage populations of pests (such as ladybird beetles, predatory gall midges, hoverfly larvae against aphids and psyllids) and diseases. This implies that we are dealing with living systems, which are complex and vary from place to place and from time to time. 

 

TEXT in the picture:

Population maxima, Number of pests , number of predators

Population dynamics of pests and predators: the y-axis shows the size of the pest and predator populations, the x-axis their development in time

 

KOZI YA KILIMO HAI KILIMO-UCHUMI                                                                           

8.1 DAWA ASILI ZA WADUDU - 8.9 - UDHIBITI WA WADUDU WA KIBIOLOJI

Udhibiti wa kibayolojia ni matumizi ya maadui asilia kudhibiti idadi ya wadudu (kama vile mbawakawa, wadudu waharibifu, mabuu ya hoverfly dhidi ya aphids na psyllids) na magonjwa. Hii ina maana kwamba tunashughulika na mifumo ya maisha, ambayo ni tata na inatofautiana kutoka mahali hadi mahali na mara kwa mara.

TEXT kwenye picha:

Idadi ya watu maxima, Idadi ya wadudu, idadi ya wanyama wanaokula wenzao

Mienendo ya idadi ya wadudu na wanyama wanaowinda wanyama wengine: mhimili wa y unaonyesha saizi ya wadudu na wanyama wanaowinda wanyama wengine, mhimili wa x maendeleo yao kwa wakati.

FIGURE 8-9- POPULATION DYNAMICS OF PESTS AND PREDATORS

 

8 1 NATURAL PESTICIDES – 8.10 - RELEASING NATURAL ENEMIES

 

ORGANIC FARMING COURSE AGRO-ECONOMY

8 1 NATURAL PESTICIDES – 8.10 - RELEASING NATURAL ENEMIES

If populations of natural enemies present in the field are too small to sufficiently control pests, they can be reared in a laboratory or rearing unit. The reared natural enemies are released in the crop to boost field populations and keep pest populations down. There are two approaches to biological control through the release of natural enemies:

•     Preventive release of the natural enemies at the beginning of each season. This is used when the natural enemies could not persist from one cropping season to another due to unfavourable climate or the absence of the pest. Populations of the natural enemy then establish and grow during the season.

•     Releasing natural enemies when pest populations start to cause damage to crops (Figure 8-9). Pathogens are usually used in that way, because they cannot persist and spread in the crop environment without the presence of a host (“pest”). They are also often inexpensive to produce.

 

TEXT in the picture:

•     releasing beneficial insects

•     cards with trichogramma eggs: against maize fruitborer

•     using antaginic microbes

•     BACTERIA: Bazillus thuringensis àagainst catarpillars, beetles, mosquito etc.

•     VIRUSES: NPV àagainst catarpillar

•     FUNGI: Beauveria bassiana àagainst corn boreres

•     NEMATODES: Steinernema carpocapsae -à against cutworms

KOZI YA KILIMO HAI KILIMO-UCHUMI

8 1 DAWA ASILI ZA WAdudu – 8.10 - KUWAACHA MAADUI WA ASILI

Ikiwa idadi ya maadui wa asili waliopo shambani ni ndogo sana kudhibiti wadudu vya kutosha, wanaweza kukuzwa katika maabara au kitengo cha ufugaji. Maadui asilia waliolelewa hutolewa katika zao ili kuongeza idadi ya wadudu na kupunguza idadi ya wadudu. Kuna njia mbili za udhibiti wa kibaolojia kupitia kutolewa kwa maadui asilia:

• Kinga ya kutolewa kwa maadui wa asili mwanzoni mwa kila msimu. Hii inatumika wakati maadui wa asili hawakuweza kuendelea kutoka msimu mmoja wa mazao hadi mwingine kutokana na hali mbaya ya hewa au kutokuwepo kwa wadudu. Idadi ya adui wa asili huanzisha na kukua wakati wa msimu.

• Kuwaachilia maadui wa asili wakati idadi ya wadudu inapoanza kusababisha uharibifu wa mazao (Mchoro 8-9). Pathogens kawaida hutumiwa kwa njia hiyo, kwa sababu hawawezi kuendelea na kuenea katika mazingira ya mazao bila kuwepo kwa mwenyeji ("wadudu"). Pia mara nyingi ni gharama nafuu kuzalisha.

TEXT kwenye picha:

• kutoa wadudu wenye manufaa

• kadi zenye mayai ya trichogramma: dhidi ya mzaa matunda wa mahindi

• kutumia vijidudu vya antaginic

• BACTERIA: Bazillus thuringensis dhidi ya catarpillar, mende, mbu n.k.

• VIRUSI: NPV dhidi ya catarpillar

• FANGASI: Beauveria bassiana dhidi ya vipekecha-mahindi

• NEMATODES: Steinernema carpocapsae - dhidi ya minyoo

 

8 1 NATURAL PESTICIDES - 8.11 - BIOCONTROL OF PLANT DISEASES BY NON-PATHOGENIC FUNGI

 

ORGANIC FARMING COURSE AGRO-ECONOMY

8 1 NATURAL PESTICIDES - 8.11 - BIOCONTROL OF PLANT DISEASES BY NON-PATHOGENIC FUNGI

Natural enemies that kill or suppress pests or diseases are often fungi or bacteria. They are called antagonists or referred to as microbial insecticides or bio-pesticides. Some commonly used antagonistic microbes are:

Ø Bacteria such as Bacillus thuringiensis (Bt). Bt has been available as a commercial microbial insecticide since the 1960s. Different types of Bt are available for the control of caterpillars and beetles in vegetables and other agricultural crops, and for mosquito and black fly control. The bestknown biocontrol agent used in field crops is the bacteria Bacillus thuringiensis var. kurstaki and Bacillus thuringiensis. var. aizawai against diverse lepidopteran pests, and the Bacillus thuringiensis var israeliensis against mosquitoes. Bacillus thuringiensis var kurstaki is produced in local factories in different African countries (e.g. South Africa, Kenya and Mozambique) and can be used against different pests (African armyworm, African bollworm, bean armyworm, beet armyworm, cabbage webworm, cabbage moth, cabbage looper, cotton leafworm, diamondback moth, giant looper, green looper, spiny bollworm, spotted bollworm, pod borers, tomato looper).

Ø Viruses such as NPV (nuclearpolyhedrosis virus), effective for control of several cater-pillar pest species. Every insect species, however, requires a specific NPV-species. An example: The armyworm Spodoptera exigua is a major problem in shallot production in Indonesia. Since experiments showed that SeNPV (NPV specific for S. exigua) provided better control than insecticides, farmers have adopted this control method. Many farmers in West-Sumatra are now producing NPV on-farm. 

Ø Fungi that kill insects, such as Beauveria bassiana. Different strains of this fungus are commercially available. For example: strain Bb 147 is used for control of corn borers (Ostrinia nubilalis and O. furnacaiis) in maize, strain GHA is used against whitefly, thrips, aphids and mealybugs in vegetables and ornamentals. Several species of fungi can occur naturally in ecosystems. For example, aphids can be killed by a green or white coloured fungus during humid weather.

Ø Fungi that work against plant-pathogens. Some examples include: Trichoderma sp., widely used in Asia for prevention of soil-borne diseases such as damping-off and root rots in vegetables (Figure 8-10). Some Trichogramma species against the African bollworm are bred in some laboratories in Africa against lepidopteran pests and aphids.  A successful introduction of the neotropical parasitoid Apoanagyrus lopezi against the cassava mealybug (Phenacoccus manihoti) caused a satisfactory reduction of P. manihoti in most farmers’ fields in Africa. This is one of the success stories of classical biocontrol.

Ø Entomopathogenic nematodes against different weevil species (e.g. Steinernema carpocapsae, Heterorhabditis bacteriophora) and to control soil insects like cutworms (Agrotis spp.) in vegetables

 

TEXT in the picture:

 Biocontrol by Trichoderma harzianum

The fungi species Trichoderma harzianum is known to parasite important plant disease like damping off (Rhizoctonia solani)

Trichoderma species can affect plant diseases by antibiosis and competition

 In addition, Trichoderma works as a growth stimulant and improves yields and product quality 

Some products are available in Africa n countries.

 

KOZI YA KILIMO HAI KILIMO-UCHUMI

8 1 DAWA ASILI 8.11 - UDHIBITI WA UGONJWA WA MIMEA KWA KUPITIA FANGASI WASIO NA MADAWA

 

Maadui asilia wanaoua au kukandamiza wadudu au magonjwa mara nyingi ni fangasi au bakteria. Wanaitwa wapinzani au wanajulikana kama viua wadudu wadogo au viua wadudu. Baadhi ya vijidudu pinzani vinavyotumika sana ni:

 Bakteria kama vile Bacillus thuringiensis (Bt). Bt imekuwa ikipatikana kama dawa ya kibiashara ya kuua wadudu tangu miaka ya 1960. Aina tofauti za Bt zinapatikana kwa udhibiti wa viwavi na mende katika mboga na mazao mengine ya kilimo, na kwa udhibiti wa mbu na nzi weusi. Wakala wa udhibiti wa kibayolojia anayejulikana sana katika mazao ya shambani ni bakteria Bacillus thuringiensis var. kurstaki na Bacillus thuringiensis. var. aizawai dhidi ya wadudu mbalimbali wa lepidoptera, na Bacillus thuringiensis var israeliensis dhidi ya mbu. Bacillus thuringiensis var kurstaki huzalishwa katika viwanda vya ndani katika nchi mbalimbali za Afrika (k.m. Afrika Kusini, Kenya na Msumbiji) na inaweza kutumika dhidi ya wadudu mbalimbali (African armyworm, African bollworm, bean armyworm, beet armyworm, kabichi webworm, nondo ya kabichi, looper ya kabichi. , mdudu wa majani ya pamba, nondo wa diamondback, kitanzi kikubwa, kitanzi cha kijani kibichi, funza wa spiny, funza wenye madoadoa, vipekecha ganda, kitanzi cha nyanya).

 Virusi kama vile NPV (nuclearpolyhedrosis virus), yenye ufanisi katika udhibiti wa spishi kadhaa za wadudu waharibifu. Kila aina ya wadudu, hata hivyo, inahitaji spishi maalum ya NPV. Mfano: Minyoo aina ya Sodoptera exigua ni tatizo kubwa katika uzalishaji wa shaloti nchini Indonesia. Kwa kuwa majaribio yalionyesha kuwa SeNPV (NPV mahususi kwa S. exigua) ilitoa udhibiti bora zaidi kuliko viua wadudu, wakulima wametumia mbinu hii ya kudhibiti. Wakulima wengi katika Sumatra Magharibi sasa wanazalisha NPV shambani.

 Kuvu wanaoua wadudu, kama vile Beauveria bassiana. Aina tofauti za Kuvu hii zinapatikana kibiashara. Kwa mfano: aina ya Bb 147 inatumika kudhibiti vipekecha mahindi (Ostrinia nubilalis na O. furnacaiis) kwenye mahindi, aina ya GHA inatumika dhidi ya nzi weupe, vithrips, aphids na mealybugs kwenye mboga na mapambo. Aina kadhaa za fangasi zinaweza kutokea kwa asili katika mfumo wa ikolojia. Kwa mfano, aphid inaweza kuuawa na Kuvu ya rangi ya kijani au nyeupe wakati wa hali ya hewa ya unyevu.

 Kuvu wanaofanya kazi dhidi ya vimelea vya magonjwa ya mimea. Baadhi ya mifano ni pamoja na: Trichoderma sp., inayotumika sana katika Asia kwa ajili ya kuzuia magonjwa yanayoenezwa na udongo kama vile unyevunyevu na kuoza kwa mizizi kwenye mboga (Mchoro 8-10). Baadhi ya spishi za Trichogramma dhidi ya funza wa Kiafrika huzalishwa katika baadhi ya maabara barani Afrika dhidi ya wadudu waharibifu wa lepidoptera na aphids. Kuanzishwa kwa mafanikio kwa vimelea vya neotropiki Apoanagyrus lopezi dhidi ya mealybug ya muhogo (Phenacoccus manihoti) kulisababisha upungufu wa kuridhisha wa P. manihoti katika mashamba mengi ya wakulima barani Afrika. Hii ni moja ya hadithi za mafanikio za udhibiti wa kibayolojia wa kitambo.



Nematode entomopathogenic dhidi ya spishi tofauti za wadudu (k.m. Steinernema carpocapsae, Heterorhabditis bacteriophora) na kudhibiti wadudu wa udongo kama minyoo (Agrotis spp.) kwenye mboga.

TEXT katika picha: Biocontrol by Trichoderma harzianum

• Kuvu aina ya Trichoderma harzianum inajulikana kwa vimelea vya magonjwa muhimu ya mimea kama vile kunyonya maji (Rhizoctonia solani)

• Spishi za Trichoderma zinaweza kuathiri magonjwa ya mimea kwa antibiosis na ushindani

• Zaidi ya hayo, Trichoderma hufanya kazi kama kichocheo cha ukuaji na kuboresha mavuno na ubora wa bidhaa

• Baadhi ya bidhaa zinapatikana katika nchi za Afrikan

8 1 NATURAL PESTICIDES – 8.12 – BOTANICALS

 ORGANIC FARMING COURSE AGRO-ECONOMY

8 1 NATURAL PESTICIDES – 8.12 – BOTANICALS

 

Some plants contain components that are toxic to insects. When extracted from the plants and applied on infested crops, these components are called botanical pesticides or botanicals. The use of plant extracts to control pests is not new. Rotenone (Derris sp.), nicotine (tobacco), and pyrethrins (Chrysanthemum sp.) have been used widely both in small-scale subsistence farming as well as in commercial agriculture.

Most botanical pesticides are contact, respiratory, or stomach poisons. Therefore, they are not very selective, but target a broad range of insects. This means that even beneficial organisms can be affected. Yet the toxicity of botanical pesticides is usually not very high and their negative effects on beneficial organisms can be significantly reduced by selective application. Furthermore, botanical pesticides are generally highly bio-degradable, so that they become inactive within hours or a few days. This reduces again the negative impact on beneficial organisms, and they are relatively environmentally safe compared to chemical pesticides:

The impact of chemical pesticides on natural enemies: the y-axis shows the sizes of the pest and predator populations, the x-axis their development in time

FIGURE 8-12 - THE IMPACT OF CHEMICAL PESTICIDES ON NATURAL ENEMIES

KOZI YA KILIMO HAI KILIMO-UCHUMI

8 1 DAWA ASILI ZA WAdudu – 8.12 -BOTANICALS

Mimea mingine ina vipengele ambavyo ni sumu kwa wadudu. Inapotolewa kutoka kwa mimea na kutumika kwenye mazao yaliyoshambuliwa, vipengele hivi huitwa dawa za mimea au mimea. Matumizi ya dondoo za mimea kudhibiti wadudu sio jambo geni. Rotenone (Derris sp.), nikotini (tumbaku), na pyrethrins (Chrysanthemum sp.) zimetumika sana katika ukulima mdogo na pia katika kilimo cha biashara.

Dawa nyingi za dawa za mimea ni za kugusa, kupumua, au sumu ya tumbo. Kwa hiyo, sio kuchagua sana, lakini hulenga aina mbalimbali za wadudu. Hii ina maana kwamba hata viumbe vyenye manufaa vinaweza kuathiriwa. Hata hivyo sumu ya viuatilifu vya mimea kwa kawaida sio juu sana na athari zake mbaya kwa viumbe vyenye manufaa zinaweza kupunguzwa kwa kiasi kikubwa kwa matumizi ya kuchagua. Zaidi ya hayo, dawa za kuulia wadudu za mimea kwa ujumla zinaweza kuharibika kwa kiasi kikubwa, hivyo basi hazifanyi kazi ndani ya saa au siku chache. Hii inapunguza tena athari mbaya kwa viumbe vyenye faida, na ni salama kwa mazingira ikilinganishwa na dawa za kemikali:

Sasa inashughulikia masomo yote 500 yenye mazao, mitishamba na maelezo ya matunda katika Kiingereza na Maswali

Athari za viuatilifu vya kemikali kwa maadui asilia: mhimili y huonyesha saizi ya wadudu na wanyama wanaowinda wanyama wengine, mhimili wa x maendeleo yao kwa wakati.

KIELELEZO 8-12 - ATHARI ZA VIUMBE VYA KEMIKALI KWA MAADUI WA ASILI.

 

                      

8 1 NATURAL PESTICIDES – 8.13 - NEEM SOLUTION

 

 

ORGANIC FARMING COURSE AGRO-ECONOMY

8 1 NATURAL PESTICIDES – 8.13 - NEEM SOLUTION 

 

The preparation and use of botanicals require some know-how, but not much material and infrastructures. It’s a common practice under many traditional agricultural systems. Some commonly used botanicals are:

 NEEM: Neem derived from the neem tree (Azadiracta indica) of arid tropical regions, contains several insecticidal compounds. The main active ingredient is azadiractin, which both deters and kills many species of caterpillars, thrips and whitefly. Both seeds and leaves can be used to prepare the neem solution. Neem seeds contain a higher amount of neem oil, but leaves are available all year. A neem solution loses its effectiveness within about 8 hours after preparation, and when exposed to direct sunlight. It is most effective to apply neem in the evening, directly after preparation, under humid conditions or when the plants and insects are damp. There exist different recipes for the preparation of a neem solution. 

Recommendation to farmers about preparation of neem pesticides: In Ghana, Africa, neem seed kernel extract was tested on cabbage in Farmer trainings and had a very good repelling effect on diamondback moth (Plutella xylostella). Here is their recipe: Pound 30 g neem kernels (that is the seed of which the seed coat has been removed) and mix it in 1 L of water. Leave it overnight. The next morning, filter the solution through a fine cloth and use it immediately for spraying. It should not be further diluted.

Neem cake (ground neem seed or neem kernel powder) has also a considerable potential as a fertilizer and at the same time it will hinder nematode attacks of the crop roots (e.g. tomato). Put neem cake in the planting pit (200g per m2) and mix it with substrate. The neem cake will repel and even kill nematodes and other root pests. Insecticidal agents (azadirachtin) will be translocated to above-ground parts of the plant and help to get rid of pests there.

 

The impact of chemical pesticides on natural enemies: the y-axis shows the sizes of the pest and predator populations, the x-axis their development in time

 

TEXT in the picture:

·         A. Handful of seeds to a coarse powder or bruise 2 kg of leaves. To make a concentrate.

·         B. Infuse them 25 minutes in hot water or overnight in cold water.

·         C. Working under shade filter the concentrate into a half-filled tank.

Stir in a little soap powder and top up the tank with clean cold water.

·         D. Spray the crop in the late afternoon because neem breakdown in the sunlight.

 

FIGURE 8-13 - PREPARATION OF A NEEM SOLUTION

 

KOZI YA KILIMO HAI KILIMO-UCHUMI

8 1 WADUDU – 8.13 - DAWA ASILI: SULUHISHO LA NEEM

 

Utayarishaji na matumizi ya mimea huhitaji ujuzi fulani, lakini sio nyenzo nyingi na miundombinu. Ni mazoezi ya kawaida chini ya mifumo mingi ya jadi ya kilimo. Baadhi ya mimea inayotumika sana ni:

 NEEM: Mwarobaini unaotokana na mwarobaini (Azadiracta indica) wa maeneo kame ya tropiki, una viambata kadhaa vya kuua wadudu. Kiambatanisho kikuu kinachofanya kazi ni azadiractin, ambayo huzuia na kuua aina nyingi za viwavi, thrips na whitefly. Mbegu na majani yote yanaweza kutumika kuandaa suluhisho la mwarobaini. Mbegu za mwarobaini zina kiasi kikubwa cha mafuta ya mwarobaini, lakini majani yanapatikana mwaka mzima. Myeyusho wa mwarobaini hupoteza ufanisi wake ndani ya takribani saa 8 baada ya kutayarishwa, na unapoangaziwa na jua moja kwa moja. Ni bora zaidi kupaka mwarobaini jioni, moja kwa moja baada ya maandalizi, chini ya hali ya unyevu au wakati mimea na wadudu ni unyevu. Kuna mapishi tofauti ya kuandaa suluhisho la mwarobaini.

Pendekezo kwa wakulima kuhusu utayarishaji wa viuatilifu vya mwarobaini: Nchini Ghana, Afrika, dondoo ya mbegu ya mwarobaini ilijaribiwa kwenye kabichi katika mafunzo ya Wakulima na ilikuwa na athari nzuri sana ya kuzuia nondo ya diamondback (Plutella xylostella). Hiki ndicho kichocheo chao: Ponda 30 g ya mbegu za mwarobaini (hiyo ni mbegu ambayo koti lake la mbegu limeondolewa) na uchanganye katika lita 1 ya maji. Wacha usiku kucha. Asubuhi iliyofuata, chuja suluhisho kupitia kitambaa laini na uitumie mara moja kwa kunyunyizia dawa. Haipaswi kuwa diluted zaidi.

Keki ya mwarobaini (mbegu ya mwarobaini iliyosagwa au unga wa mwarobaini) pia ina uwezo mkubwa kama mbolea na wakati huo huo itazuia mashambulizi ya nematode kwenye mizizi ya mazao (k.m. nyanya). Weka keki ya mwarobaini kwenye shimo la kupandia (200g kwa kila m2) na uchanganye na mkatetaka. Keki ya mwarobaini itafukuza na hata kuua viwavi na wadudu wengine wa mizizi. Dawa za kuua wadudu (azadirachtin) zitahamishwa hadi sehemu za juu za ardhi za mmea na kusaidia kuondoa wadudu huko.

 

Athari za viuatilifu vya kemikali kwa maadui asilia: mhimili y huonyesha saizi ya wadudu na wanyama wanaowinda wanyama wengine, mhimili wa x maendeleo yao kwa wakati.

TEXT kwenye picha:

• A. Kiganja cha mbegu ziwe unga mbichi au ponda kilo 2 za majani. Kufanya umakini.

• B. Watie kwa dakika 25 kwenye maji ya moto au usiku kucha kwenye maji baridi.

• C. Kufanya kazi chini ya kivuli chuja mkusanyiko kwenye tanki iliyojaa nusu.

Koroga poda kidogo ya sabuni na ujaze tanki na maji safi ya baridi.

• D. Nyunyiza mimea majira ya alasiri kwa sababu mwarobaini kukatika kwenye mwanga wa jua.

KIELELEZO 8-13 - MAANDALIZI YA SULUHISHO LA NEEM

 

8 1 NATURAL PETICIDES – 8.17 - OTHER PRACTICES FOR DISEASE CONTROL

 

  

ORGANIC FARMING COURSE AGRO-ECONOMY

8 1 NATURAL PETICIDES – 8.17 - OTHER PRACTICES FOR DISEASE CONTROL  

 

Ø  Sulphur is mostly used against plant diseases like powdery mildew, downy mildew and other diseases. The key to its efficacy is that it prevents spore germination. For this reason, it must be applied prior to disease development for effective results. Sulphur can be applied as a dust or in liquid form. It is not compatible with other pesticides. Lime-sulphur is formed when lime is added to sulphur to help it penetrate plant tissue. It is more effective than elemental sulphur at lower concentrations. However, the odour of rotten eggs usually discourages its use over extensive fields.

Ø  Bordeaux mixture (Copper sulphate and lime) has been successfully used for over 150 years, on fruits, vegetables and ornamentals. Unlike sulphur, Bordeaux mixture is both fungicidal and bactericidal. As such, it can be effectively used against diseases such as leaf spots caused by bacteria or fungi, powdery mildew, downy mildew and various anthracnose pathogens. The ability of Bordeaux mixture to persist through rains and to adhere to plants is one reason it has been so effective. Bordeaux mixture contains copper sulphate, which is acidic, and neutralized by lime (calcium hydroxide), which is alkaline. 

Recommendations to farmers on preparation of Bordeaux mixture: Bordeaux mixture comes in several formulations. One of the most popular, effective and least phytotoxic formulations for general use is the following formulation: Mix 90 g of blue copper sulphate with 4,5 L of water (in a non-metallic container). In another non-metallic container, mix 125 grams of slaked lime with 4.5 litres of water. Stir both, mix both solutions, and stir again. This formulation was developed in recognition of the fact that copper, like sulphur, is phytotoxic and that the level of toxicity is related to the age of plant tissue being treated. Application of Bordeaux during hot weather (above 29,5° C or 1,5° C) may cause yellowing and leaf drop. Additionally, leaf burn can occur if it rains soon after a Bordeaux application. Care should be taken when applying this fungicide to young, tender leaves of fruit trees. Do not apply Bordeaux mixture to corn or sorghum, which are described as copper-sensitive plants. There are other, very common and cheap copper formulations available: copper hydroxide and copper oxychloride. They are accepted in organic farming provided that the number of applications is strictly followed and a proper soil amendment is observed to prevent copper accumulation in the soil. 

Ø  Acidic clays have a fungicidal effect due to aluminium oxide or aluminium sulphate as active agents. They are used as an alternative to copper products but, are often less efficient.

Ø  Milk has also been used against blights, mildew, mosaic viruses and other fungal and viral diseases. Spraying every 10 days with a mixture of 1 L of milk to 10 to 15 L of water is effective.

Ø  Baking soda has been used to control mildew and rust diseases on plants. Spray with a mixture of 100 g of baking or washing soda with 50 g of soft soap. Dilute with 2 L of water. Spray only once and leave as long gaps as possible (several months). Do not use during hot weather and test the mixture on a few leaves because of possible phytotoxic effects.

Many plant extracts are known to have fungicidal effects. Onion and garlic are effective against many diseases such as mildew and fungal and bacterial diseases. Mexican and African marigold act as a crop “strengthened” to help potatoes, beans, tomatoes and peas resist fungal diseases such as mildew. The leaves of pawpaw (Carica papaya) and sweet basil have a general fungicidal effect. Many other plant species are known to have fungicidal effects. Traditional knowledge might be of help to amend the range of plant extracts in each region.

 

KOZI YA KILIMO HAI KILIMO-UCHUMI

8 0 WADUDU – 8.17 - TABIA NYINGINE ZA KUDHIBITI MAGONJWA

 Sulfuri hutumika zaidi dhidi ya magonjwa ya mimea kama vile ukungu, ukungu na magonjwa mengine. Ufunguo wa ufanisi wake ni kuzuia kuota kwa spore. Kwa sababu hii, lazima itumike kabla ya maendeleo ya ugonjwa kwa matokeo ya ufanisi. Sulfuri inaweza kutumika kama vumbi au katika hali ya kioevu. Haiendani na dawa zingine za wadudu. Chokaa-sulphur huundwa wakati chokaa kinaongezwa kwenye sulfuri ili kusaidia kupenya tishu za mimea. Ni bora zaidi kuliko sulfuri ya msingi k

atika viwango vya chini. Hata hivyo, harufu ya mayai yaliyooza kwa kawaida huzuia matumizi yake juu ya mashamba makubwa.

 Mchanganyiko wa Bordeaux (Copper sulphate na chokaa) umetumika kwa mafanikio kwa zaidi ya miaka 150, kwenye matunda, mboga mboga na mapambo. Tofauti na salfa, mchanganyiko wa Bordeaux ni wa kuua na kuua bakteria. Kwa hivyo, inaweza kutumika kwa ufanisi dhidi ya magonjwa kama vile madoa ya majani yanayosababishwa na bakteria au fangasi, ukungu wa unga, ukungu na vimelea mbalimbali vya magonjwa ya anthracnose. Uwezo wa mchanganyiko wa Bordeaux kuendelea kupitia mvua na kuambatana na mimea ni sababu moja umekuwa mzuri sana. Mchanganyiko wa Bordeaux una sulphate ya shaba, ambayo ni tindikali, na haipatikani na chokaa (hidroksidi ya kalsiamu), ambayo ni ya alkali.

Mapendekezo kwa wakulima juu ya utayarishaji wa mchanganyiko wa Bordeaux: Mchanganyiko wa Bordeaux huja katika uundaji kadhaa. Mojawapo ya uundaji maarufu zaidi, wenye ufanisi na mdogo wa phytotoxic kwa matumizi ya jumla ni uundaji ufuatao: Changanya 90 g ya sulphate ya shaba ya bluu na 4,5 L za maji (katika chombo kisicho na metali). Katika chombo kingine kisicho na metali, changanya gramu 125 za chokaa kilichopigwa na lita 4.5 za maji. Koroga zote mbili, changanya suluhu zote mbili, na ukoroge tena. Muundo huu ulitengenezwa kwa kutambua ukweli kwamba shaba, kama salfa, ina sumu ya fitoksi na kwamba kiwango cha sumu kinahusiana na umri wa tishu za mmea kutibiwa. Uwekaji wa Bordeaux wakati wa joto (zaidi ya 85° F au 30° C) unaweza kusababisha manjano na kushuka kwa majani. Zaidi ya hayo, kuchomwa kwa majani kunaweza kutokea ikiwa mvua inanyesha mara baada ya maombi ya Bordeaux. Uangalifu unapaswa kuchukuliwa wakati wa kutumia dawa hii ya kuvu kwa majani machanga na laini ya miti ya matunda. Usitumie mchanganyiko wa Bordeaux kwenye mahindi au mtama, ambayo inaelezwa kuwa mimea inayoguswa na shaba. Kuna uundaji mwingine, wa kawaida sana na wa bei nafuu wa shaba unaopatikana: hidroksidi ya shaba na oksikloridi ya shaba. Zinakubalika katika kilimo-hai mradi tu idadi ya maombi inafuatwa kikamilifu na marekebisho sahihi ya udongo yanazingatiwa ili kuzuia mkusanyiko wa shaba kwenye udongo.

 Udongo wenye asidi huwa na athari ya kuua ukungu kutokana na oksidi ya alumini au salfa ya alumini kama mawakala hai. Zinatumika kama mbadala kwa bidhaa za shaba lakini, mara nyingi hazifanyi kazi vizuri.

 Maziwa pia yametumika dhidi ya ukungu, ukungu, virusi vya mosaic na magonjwa mengine ya fangasi na virusi. Kunyunyizia kila siku 10 kwa mchanganyiko wa lita 1 ya maziwa hadi lita 10 hadi 15 za maji ni nzuri.

 Soda ya kuoka imetumika kudhibiti magonjwa ya ukungu na kutu kwenye mimea. Nyunyiza na mchanganyiko wa 100 g ya kuoka au kuosha soda na 50 g ya sabuni laini. Punguza na 2 L ya maji. Nyunyizia dawa mara moja tu na uache mapengo marefu iwezekanavyo (miezi kadhaa). Usitumie wakati wa hali ya hewa ya joto na jaribu mchanganyiko kwenye majani machache kwa sababu ya athari zinazowezekana za phytotoxic.

Extracts nyingi za mimea zinajulikana kuwa na athari za fungicidal. Vitunguu na kitunguu saumu ni bora dhidi ya magonjwa mengi kama vile ukungu na magonjwa ya fangasi na bakteria. Marigold ya Mexico na Afrika hufanya kama zao "iliyoimarishwa" kusaidia viazi, maharagwe, nyanya na mbaazi kupinga magonjwa ya ukungu kama vile ukungu. Majani ya papai (Carica papai) na basil tamu yana athari ya jumla ya kuvu. Aina nyingine nyingi za mimea zinajulikana kuwa na athari za fungicidal. Maarifa ya kimapokeo yanaweza kusaidia kurekebisha aina mbalimbali za dondoo za mimea katika kila eneo.

 

8 1 NATURAL PESTICIDES – 8.15 - A LOT OF MORE NATURAL PESTICIDES

 

ORGANIC LESSONS COURSE AGRO-ECONOMY

8 1 NATURAL PESTICIDES – 8.15 - A LOT OF MORE NATURAL PESTICIDES

 

There are many other extracts of plants known to have insecticidal effects like

tobacco (Nicotiana tabacum), yellow root (Xanthorhiza simplicissima),

fish bean (Tephrosia vogelii), violet tree (Securidaca longepedunculata), and

nasturtium (Nasturtium trapaeolum) which are traditionally used to control pests in Africa.  Anise, chillies, chives, garlic, coriander, nasturtium, spearmint and marigold

 

There are plants known to have a repellent effect on different pest insects (aphids, moths, root flies, etc.) and can be grown as intercrop or at the border of crop fields:

Marigold is especially known to deter root nematodes, while neem cake is known to deter mice.

 

TEXT in the picture:

Trap cropping (push – pull strategy) in Maize for pest stalk borer.

Trap plant (napier gras)

 Rebellant plant (desmodium)

Trap plant

The trap plant is more attractive to the pest either alternative food source or egg laying site than the main crop.

Repellent crop produces an odour that “pushes” away pests.

 

FIGURE 8-15 - TRAP CROPPING - TRAP INTERCROPPING

 

MASOMO HAI KOZI YA KILIMO-UCHUMI

8 1 DAWA ASILI ZA WADUDU – 8.15 - NYINGI ZAIDI YA DAWA ZA ASILI

 

Kuna dondoo zingine nyingi za mimea inayojulikana kuwa na athari za wadudu kama

tumbaku (Nicotiana tabacum), mizizi ya manjano (Xanthorhiza simplicissima),

maharagwe ya samaki (Tephrosia vogelii), mti wa urujuani (Securidaca longepedunculata), na

nasturtium (Nasturtium trapaeolum) ambayo kwa jadi hutumika kudhibiti wadudu waharibifu barani Afrika. Anise, pilipili, chives, vitunguu, coriander, nasturtium, spearmint na marigold.

Kuna mimea inayojulikana kuwa na athari ya kufukuza wadudu mbalimbali waharibifu (aphid, nondo, nzi wa mizizi, n.k.) na inaweza kukuzwa kama mseto au kwenye mpaka wa mashamba ya mazao:

Marigold inajulikana sana kuzuia nematode za mizizi, wakati keki ya mwarobaini inajulikana kuwazuia panya.

TEXT kwenye picha:

Upandaji wa mtego ( mkakati wa kusukuma - kuvuta) katika Mahindi kwa vipekecha shina wa wadudu.

Kiwanda cha mtego (napier gras)

Mmea ulioasi (desmodium)

Mtego wa kupanda

Mmea wa kutega huvutia zaidi wadudu ama chanzo mbadala cha chakula au mahali pa kutagia mayai kuliko zao kuu.

Mazao ya mbu hutoa harufu ambayo "husukuma" wadudu.

KIELELEZO 8-15 - KUPANDA KWA MITEGO - KUPATA MTEGO