8 0 PESTS – 8.3 - PREVENTION PRACTICES AND MONITORING 6 - 10

 

 ORGANIC FARMING COURSE AGRO-ECONOMY

8 0 PESTS – 8.3 - PREVENTION PRACTICES AND MONITORING 6 - 10

Knowledge about plant health and pest and disease ecology helps the farmer to choose effective preventive crop protection measures. As many factors influence the development of pest and disease, it’s crucial to step in at the most sensitive points. This can be accomplished through the right timing of management practices, a suitable combination of different methods, or the choice of a selective method. Some important preventive crop protection measures are the following ones:

 

1)      Application of suitable soil cultivation methods:

→  Facilitates the decomposition of infected plant parts.

→  Regulates weeds which serve as hosts for pests and diseases.

→  Protects the micro-organisms which regulate soil borne diseases.

2)      Use of good water management:

→   No water logging: causes stress to the plant, which encourages pathogens infections.

→   Avoid water on the foliage, as water borne disease spread with droplets and fungal disease germinate in water.

3)      Conservation and promotion of natural enemies:

→   Provide an ideal habitat for natural enemies to grow and reproduce.

→   Avoid using products which harm natural enemies.

 

4)      Selection of optimum planting time and spacing:

→   Most pests or diseases attack the plant only in a certain life stage; therefore it’s crucial that this vulnerable life stage doesn’t correspond with the period of high pest density and thus that the optimal planting time is chosen.

→   Sufficient distance between the plants reduces the spread of a disease.

→ Good aeration of the plants allows leaves to dry off faster, which hinders pathogen development and infection.

5)       Use of proper sanitation measures:

→   Remove infected plant parts (leaves, fruits) from the ground to prevent the disease from spreading.

→   Eliminate residues of infected plants after harvesting.

 

MONITORING

Regular monitoring of pests, diseases and weeds is the basis for effective management. To be able to manage pests, diseases and weeds, information is needed on the specific pests, diseases and weeds present in the region, village or crop fields and the associated damage they cause.

KOZI YA KILIMO HAI KILIMO-UCHUMI

8 0 WADUDU – 8.3 - TABIA ZA KINGA NA UFUATILIAJI 6 – 10

Ujuzi kuhusu afya ya mimea na ikolojia ya wadudu na magonjwa humsaidia mkulima kuchagua hatua madhubuti za kuzuia mazao. Kwa kuwa mambo mengi huathiri ukuaji wa wadudu na magonjwa, ni muhimu kuingilia kati katika sehemu nyeti zaidi. Hili linaweza kutimizwa kupitia muda sahihi wa mazoea ya usimamizi, mchanganyiko unaofaa wa mbinu tofauti, au uchaguzi wa mbinu iliyochaguliwa. Baadhi ya hatua muhimu za kuzuia mazao ni zifuatazo:

1) Utumiaji wa njia zinazofaa za kilimo cha udongo:

→ Huwezesha kuoza kwa sehemu za mmea zilizoambukizwa.

→ Hudhibiti magugu ambayo hutumika kama mwenyeji wa wadudu na magonjwa.

→ Hulinda viumbe vidogo vinavyodhibiti magonjwa yanayoenezwa na udongo.

2) Matumizi bora ya maji:

→ Hakuna ukataji wa maji: husababisha mkazo kwa mmea, ambayo huhimiza maambukizo ya vimelea.

→ Epuka maji kwenye majani, kwani ugonjwa unaoenezwa na maji huenea kwa matone na ugonjwa wa fangasi huota kwenye maji.

3) Uhifadhi na uendelezaji wa maadui wa asili:

→ Kutoa makazi bora kwa maadui asilia kukua na kuzaliana.

→ Epuka kutumia bidhaa zinazodhuru maadui asilia.

4) Uchaguzi wa wakati mwafaka wa kupanda na nafasi:

→ Wadudu au magonjwa mengi hushambulia mmea katika hatua fulani ya maisha; kwa hivyo ni muhimu kwamba hatua hii ya maisha hatarishi haiwiani na kipindi cha msongamano mkubwa wa wadudu na hivyo kwamba wakati mwafaka wa kupanda uchaguliwe.

→ Umbali wa kutosha kati ya mimea hupunguza kuenea kwa ugonjwa.

→ Uingizaji hewa mzuri wa mimea huruhusu majani kukauka haraka, ambayo huzuia ukuaji wa pathojeni na maambukizi.

5) Matumizi ya hatua sahihi za usafi wa mazingira:

→ Ondoa sehemu za mimea zilizoambukizwa (majani, matunda) kutoka ardhini ili kuzuia ugonjwa usienee.

→ Ondoa mabaki ya mimea iliyoambukizwa baada ya kuvuna.

UFUATILIAJI

Ufuatiliaji wa mara kwa mara wa wadudu, magonjwa na magugu ndio msingi wa usimamizi bora. Ili kuweza kudhibiti wadudu, magonjwa na magugu, taarifa zinahitajika kuhusu wadudu, magonjwa na magugu mahususi waliopo katika mkoa, mashamba ya kijiji au mazao na uharibifu unaohusiana nao.

8 0 PESTS – 8.4 - TYPICAL SIGNE OF DISEASE OF ATTACKS ON CROPPLANTS

 

     ORGANIC FARMING COURSE AGRO-ECONOMY

     8 0 PESTS – 8.4 - TYPICAL SIGNE OF DISEASE OF ATTACKS ON CROPPLANTS

 

   Most crop diseases are caused by fungi, bacteria or viruses. 

•       Fungi cause the great majority, estimated at two-thirds of infectious plant diseases. They include all white and true rusts, smuts, needle casts, leaf curls, mildew, sooty moulds and anthracnose. In addition, they are responsible for most leaf, fruit, and flower spots, cankers, blights, wilts, scabs, and root, stem, fruit, wood rots among many others. Parts of plants or the total crop plant can wither and die.

•       Bacteria cause any of the four following main problems. Some bacteria produce enzymes that breakdown the cell walls of plants anywhere in the plant. This causes parts of the plant to start rotting (known as ‘rot’). Some bacteria produce toxins that are generally damaging to plant tissues, usually causing early death of the plant. Others produce large amounts of very sticky sugars; as they travel through the plant, they block the narrow channels preventing water getting from the plant roots up to the shoots and leaves, again causing rapid death of the plant. Finally, other bacteria produce proteins that mimic plant hormones. These lead to overgrowth of plant tissue and form tumours. 

•       Viruses mostly cause systemic diseases. Generally, leaves show chlorosis or change in colour of leaves and other green parts. Light green or yellow patches of various shades, shapes and sizes appear in affected leaves. These patches may form characteristic mosaic patterns, resulting in general reduction in growth and vigour of the plant.

Careful and continuous monitoring of pest and disease levels during critical times of growth of a crop is the key to successful management. This can be done through regular scouting of the field by the farmer. It helps the farmer to intervene early enough before the pest and/or disease cause significant damage.

TIPS in the picture:  HOW TO MAKE A FRUIT FLY TRAP

1.       Cut a PET bottle

2.       Remove the cap

3.      Insert and glue the reversed upper part of the bottle into the bottom part.

4.      As a bait, use half a cup of vinegar, mixed with water and add 4-6 drops liquid soap

You also can use jam or confiture mixed with water, so that the flies fall in

5.       Hang the bottle in a tree where most fruit flies have been seen,

KOZI YA KILIMO HAI KILIMO-UCHUMI

8 0 WADUDU – 8.4 - ISHARA YA KAWAIDA YA UGONJWA WA MASHAMBULIZI KWA MIMEA

Magonjwa mengi ya mazao husababishwa na fangasi, bakteria au virusi.

• Kuvu husababisha idadi kubwa, inayokadiriwa kuwa theluthi mbili ya magonjwa ya kuambukiza ya mimea. Wao ni pamoja na kutu zote nyeupe na za kweli, smuts, sindano za sindano, curls za majani, koga, molds za sooty na anthracnose. Zaidi ya hayo, wanahusika na madoa mengi ya majani, matunda, na maua, ukungu, ukungu, mnyauko, upele, na mizizi, shina, matunda, kuoza kwa kuni miongoni mwa mengine mengi. Sehemu za mimea au jumla ya mmea wa mazao zinaweza kunyauka na kufa.

• Bakteria husababisha mojawapo ya matatizo makuu manne yafuatayo. Baadhi ya bakteria huzalisha vimeng'enya ambavyo huvunja kuta za seli za mimea mahali popote kwenye mmea. Hii husababisha sehemu za mmea kuanza kuoza (inayojulikana kama ‘kuoza’). Baadhi ya bakteria hutoa sumu ambayo kwa ujumla huharibu tishu za mmea, kwa kawaida husababisha kifo cha mapema cha mmea. Wengine huzalisha kiasi kikubwa cha sukari yenye kunata sana; wanaposafiri kwenye mmea, huziba njia nyembamba zinazozuia maji kutoka kwenye mizizi ya mmea hadi kwenye vikonyo na majani, na kusababisha kifo cha haraka cha mmea. Hatimaye, bakteria nyingine huzalisha protini zinazoiga homoni za mimea. Hizi husababisha kuongezeka kwa tishu za mmea na kuunda tumors.

• Virusi mara nyingi husababisha magonjwa ya kimfumo. Kwa ujumla, majani yanaonyesha chlorosis au mabadiliko ya rangi ya majani na sehemu nyingine za kijani. Vipande vya rangi ya kijani au njano ya vivuli mbalimbali, maumbo na ukubwa huonekana kwenye majani yaliyoathirika. Vipande hivi vinaweza kuunda mifumo ya mosai ya tabia, na kusababisha kupunguzwa kwa jumla kwa ukuaji na nguvu ya mmea.

Ufuatiliaji makini na unaoendelea wa viwango vya wadudu na magonjwa katika nyakati muhimu za ukuaji wa zao ndio ufunguo wa usimamizi wenye mafanikio. Hili linaweza kufanywa kwa kukagua shamba mara kwa mara na mkulima. Humsaidia mkulima kuingilia kati mapema vya kutosha kabla ya wadudu na/au ugonjwa kuleta madhara makubwa.

 VIDOKEZO kwenye picha: JINSI YA KUTENGENEZA MTEGO WA NZI WA MATUNDA

1. Kata chupa ya PET

2. Ondoa kofia

3. Ingiza na gundi sehemu ya juu ya nyuma ya chupa kwenye sehemu ya chini.

4. Kama chambo, tumia nusu kikombe cha siki, iliyochanganywa na maji na kuongeza matone 4-6 ya sabuni ya maji.

Unaweza pia kutumia jam au confiture iliyochanganywa na maji, ili nzi waanguke

5. Tundika chupa kwenye mti ambapo nzi wengi wa matunda wameonekana

8 0 PESTS – 8.5 - TRAPS TO MONITOR INSECT PESTS

 

 ORGANIC FARMING COURSE AGRO-ECONOMY

8 0 PESTS – 8.5 - TRAPS TO MONITOR INSECT PESTS

 

Scouting avoids unnecessary use of natural plant extracts. Limited use of these substances (e.g. pyrethrum, derris and tobacco) and oils is important as they also have negative effects on beneficial insects. If the application of these substances is not regulated, many pest predators and parasiticides may be killed as well. Over application of these substances may also lead to pests developing resistance. Therefore, scouting should be planned and done in an organised way. It is important to get a random sample that will be representative of the overall situation in the crop garden. Therefore, the scout (farmer) needs to observe and record any of the findings for better decision making. 

The most common pattern in pest and disease scouting programs involves walking along a predetermined zigzag or M-shaped route through a field. This pattern is commonly used because it is easy to teach, convenient to use, and ensures that all regions of the field are visited. To monitor insect pests, different traps can also be used (Figure 8-4 & 8-5). The simple idea is to know more about the presence of the insect pests in the field especially the fast moving (mobile) insect pests (e.g. fruit flies, lepidopteran pests). 

Ø Fruit flies can be captured using bait traps. For example, PE-bottles with small holes can be half-filled with water, some cattle urine, fruit flesh or a small dead fish and a drop of detergent or soapy water. These bottles are then hung in trees and checked every three days. 

 

Ø Yellow plastic cards coated with adhesive are also good for trapping aphids and leafhopper. Yellow-orange plastic boards are appropriate for white flies, while blue cards are appropriate for thrips monitoring. 

 

Ø Light traps are especially needed where noctuid’s (e.g. moths, cutworms, African armyworm, and cotton bollworm) are a problem. Within crops attacked by cutworms, visual checks of caterpillars have to be done by dawn.

 

TEXT in the picture:   TRAPS TO MONITOR INSECT PESTS

·         blue / yellow sticky traps à pest insects ; pheromone trap  à pest insects    

·         homemade trap à fruit flies; light trap à noctuid’s

 

KOZI YA KILIMO HAI KILIMO-UCHUMI

8 0 WADUDU – 8.5 - MITEGO YA KUFUATILIA WADUDU WADUDU

Kuchunguza huepuka matumizi yasiyo ya lazima ya dondoo za asili za mimea. Utumiaji mdogo wa dutu hizi (k.m. pareto, derris na tumbaku) na mafuta ni muhimu kwani pia zina athari mbaya kwa wadudu wenye faida. Ikiwa uwekaji wa dutu hizi hautadhibitiwa, wadudu wengi waharibifu na viua wadudu wanaweza kuuawa pia. Utumiaji mwingi wa dutu hizi pia unaweza kusababisha wadudu kukuza upinzani. Kwa hivyo, skauti inapaswa kupangwa na kufanywa kwa njia iliyopangwa. Ni muhimu kupata sampuli ya random ambayo itakuwa mwakilishi wa hali ya jumla katika bustani ya mazao. Kwa hiyo, skauti (mkulima) anahitaji kuchunguza na kurekodi matokeo yoyote kwa ajili ya kufanya maamuzi bora.

Mchoro unaojulikana zaidi katika programu za kupeleleza wadudu na magonjwa huhusisha kutembea kwenye njia ya zigzag iliyoamuliwa mapema au njia yenye umbo la M kupitia shamba. Mchoro huu hutumiwa kwa kawaida kwa sababu ni rahisi kufundisha, rahisi kutumia, na huhakikisha kuwa maeneo yote ya uwanja yametembelewa. Ili kufuatilia wadudu, mitego tofauti pia inaweza kutumika (Mchoro 8-4 & 8-5). Wazo rahisi ni kujua zaidi juu ya uwepo wa wadudu waharibifu shambani hasa wadudu wanaotembea kwa kasi (mkononi) (k.m. nzi wa matunda, wadudu wa lepidopteran).

 Nzi wa matunda wanaweza kunaswa kwa kutumia mitego ya chambo. Kwa mfano, chupa za PE zilizo na mashimo madogo zinaweza kujazwa nusu na maji, mkojo wa ng'ombe, nyama ya matunda au samaki mdogo aliyekufa na tone la sabuni au maji ya sabuni. Chupa hizi zinatundikwa kwenye miti na kukaguliwa kila baada ya siku tatu.

 Kadi za plastiki za manjano zilizopakwa kwa gundi pia ni nzuri kwa kunasa aphids na leafhopper. Bodi za plastiki za manjano-machungwa zinafaa kwa nzi weupe, wakati kadi za bluu zinafaa kwa ufuatiliaji wa thrips.

 Mitego nyepesi inahitajika hasa pale ambapo noctuid (k.m. nondo, minyoo, viwavijeshi wa Kiafrika, na funza wa pamba) ni tatizo. Ndani ya mimea iliyoshambuliwa na minyoo, ukaguzi wa kuona wa viwavi lazima ufanyike alfajiri.

MAANDIKO katika picha: MITEGO YA KUFUATILIA WADUDU WADUDU

• mitego ya kunata ya bluu/njano  wadudu waharibifu; mtego wa pheromone  wadudu waharibifu

• mtego wa kujitengenezea nyumbani  nzi wa matunda; mtego mwepesi  noctuid’s

8 0 PESTS – 8.6 - INDUCE PLANT RESISTANCE

 

ORGANIC FARMING COURSE AGRO-ECONOMY

8 0 PESTS – 8.6 - INDUCE PLANT RESISTANCE

Organic management and control of diseases is based strongly on strengthening the plant with the aim of enhancing its self-defence and thereby preventing the outbreak of the disease. One typical expression of induced resistance is the thickening of cell walls of the plant, which interferes with pathogen entering the cell. Another is the dying of the infested cell walls, which causes the pathogen to die also, and thus reduce its spread.

There are several resistance-inducing substances that can be prepared by the farmers themselves. Some are plant extracts made from efeu (Hedera helix), rhubarb (Rheum rhabarbarum), or giant knotweed (Reynoutria sachalinensis). 

Compost teas and herbal teas are tools that can be made on the farm to enhance crop health and fertility, and to inoculate the leaves and roots with soluble nutrients, beneficial microorganisms, and beneficial metabolites (products that aid in the growth and development of plants).  

Compost extract is a fertilizer, but it also can induce plant resistance. For its preparation, mature compost is mixed with water at a ratio of 1:5 to 1:8 (vol/vol: 1L of compost for every 5 to 8 L of water) and well stirred before it is left to ferment for 3-7 days. One spoonful of molasses can be added per litre of liquid, because this enhances the development of the microorganisms. The fermentation site should be shaded and safe from the rain. After the fermentation period and before the application, the extract is well stirred, then filtered and diluted at a ratio of 1:5 to 1:10.

Plant extracts can be obtained from stinging nettle, horsetail, comfrey, clover, seaweed and others, alone or mixed with marine by-products such as fish waste or fishmeal. Dilutions of 1:10 or 1:5 are used as foliar spray or soil drench.

As a rule, it is recommended to apply compost extracts or teas every 7 to 10 days to prevent diseases from developing and to enhance soil microorganisms.

 

KOZI YA KILIMO HAI KILIMO-UCHUMI

WADUDU 8 0 - 8.6 - HABARI USTAWI WA MIMEA

Usimamizi na udhibiti wa magonjwa kikaboni umejikita katika kuimarisha mmea kwa lengo la kuimarisha ulinzi wake na hivyo kuzuia mlipuko wa ugonjwa huo. Usemi mmoja wa kawaida wa upinzani unaosababishwa ni unene wa kuta za seli za mmea, ambazo huingilia kati pathojeni inayoingia kwenye seli. Mwingine ni kufa kwa kuta za seli zilizoathiriwa, ambayo husababisha pathojeni kufa pia, na hivyo kupunguza kuenea kwake.

Kuna vitu kadhaa vya kushawishi ambavyo vinaweza kutayarishwa na wakulima wenyewe. Baadhi ni dondoo za mimea zilizotengenezwa kutoka efeu (Hedera helix), rhubarb (Rheum rhabarbarum), au knotweed kubwa (Reynoutria sachalinensis).

Chai ya mboji na chai ya mitishamba ni zana zinazoweza kutengenezwa shambani ili kuimarisha afya ya mazao na rutuba, na kuchanja majani na mizizi kwa virutubishi mumunyifu, vijidudu vyenye faida, na metabolites zenye faida (bidhaa zinazosaidia ukuaji na ukuzaji wa mimea) .

Dondoo la mbolea ni mbolea, lakini pia inaweza kusababisha upinzani wa mimea. Kwa ajili ya maandalizi yake, mboji iliyokomaa huchanganywa na maji kwa uwiano wa 1:5 hadi 1:8 (vol/vol/vol: 1L ya mboji kwa kila lita 5 hadi 8 za maji) na kukorogwa vizuri kabla ya kuachwa ichachuke kwa 3- siku 7. Kijiko kimoja cha molasses kinaweza kuongezwa kwa lita moja ya kioevu, kwa sababu hii huongeza maendeleo ya microorganisms. Mahali ya kuchachusha yanapaswa kuwa na kivuli na salama kutokana na mvua. Baada ya kipindi cha fermentation na kabla ya maombi, dondoo huchochewa vizuri, kisha huchujwa na diluted kwa uwiano wa 1: 5 hadi 1:10.

Dondoo za mimea zinaweza kupatikana kutoka kwa nettle, mkia wa farasi, comfrey, clover, mwani na zingine, peke yake au kuchanganywa na bidhaa za baharini kama vile taka za samaki au unga wa samaki. Dilution ya 1:10 au 1:5 hutumiwa kama dawa ya majani au unyevu wa udongo.

Kama kanuni, inashauriwa kutumia dondoo za mbolea au chai kila baada ya siku 7 hadi 10 ili kuzuia magonjwa kutoka kwa maendeleo na kuimarisha microorganisms za udongo.

8 0 PESTS – 8.7 - PROMOTING AND MANAGING NATURAL ENEMIES

 

 ORGANIC FARMING COURSE AGRO-ECONOMY

8 0 PESTS – 8.7 - PROMOTING AND MANAGING NATURAL ENEMIES

 

The natural enemies of pests are other organisms (fungi, bacteria, viruses, insect predators, and insect parasiticides) which kill pest. Therefore, the organic farmer should try to conserve natural enemies already present in the crop environment and enhance their impact. This can be achieved with the following methods:

•       Minimize the application of natural pesticides (chemical pesticides anyway are not per-mitted in organic farming).

•       Allow some pests to live in the field which will serve as food or host for natural enemies.

•       Establish a diverse cropping system (e.g. mixed cropping).

•       Include host plants providing food or shelter for natural enemies (e.g. flowers which adult beneficial insects feed on).

There are many possibilities to enhance floral diversity within and along the boundaries of crop fields:

§  Hedges - Use indigenous shrubs known to attract pest predators and parasitoids by offering nectar, pollen, alternative hosts and/or preys. Most flowering shrub species have this property. However, care should be taken to not use plant species known to be alternative hosts of pests or diseases.

§  Beetle banks - Strips of grass in the neighbourhood of crop fields harbour different natural pest enemy groups like carabids, staphylinid beetles and spiders. In order to lower the risk of weeds and plants known as host plants of crop pests and diseases, one to three native grass species can be sown in strips of 1 to 3 m.

§  Flower strips - Use indigenous flowering plant species known to attract predators and parasitoids by offering nectar, pollen, alternative hosts and/or preys. Most flowering plant species have this property. However, care should be taken not to use alternative hosts of pests or diseases. Three to five native flowering plant species can be sown in well-prepared seed beds, arranged in strips of 1 to 3 m on the boundary of the crop field. After flowering, seeds can be collected to renew the strip or create new ones. 

§  Companion plants - Natural pest enemies can also be attracted by companion plants within a crop. These companion plant species can be the same as used in the flower strips. A few (1 or 2 per 10 m²) flowering companion plants within a crop serve as a ‘service station’ for natural pest enemies.

 

 

KOZI YA KILIMO HAI KILIMO-UCHUMI

8 0 WADUDU – 8.7 - KUKUZA NA KUWASIMAMIA ADUI ASILI

 

Maadui wa asili wa wadudu ni viumbe vingine (fangasi, bakteria, virusi, wadudu wanaokula wadudu, na dawa za kuua wadudu) ambao huua wadudu. Kwa hiyo, mkulima wa kilimo-hai anapaswa kujaribu kuhifadhi maadui wa asili ambao tayari wapo katika mazingira ya mazao na kuongeza athari zao. Hii inaweza kupatikana kwa njia zifuatazo:

• Punguza uwekaji wa viuatilifu asilia (viuatilifu vya kemikali hata hivyo haviruhusiwi katika kilimo hai).

• Ruhusu baadhi ya wadudu kuishi kwenye shamba ambalo litakuwa chakula au mwenyeji wa maadui wa asili.

• Anzisha mfumo wa upandaji miti tofauti (k.m. upandaji miti mchanganyiko).

• Jumuisha mimea mwenyeji inayotoa chakula au makazi kwa maadui wa asili (k.m. maua ambayo wadudu wenye manufaa wazima hula).

Kuna uwezekano mwingi wa kuboresha uanuwai wa maua ndani na kando ya mipaka ya mashamba ya mazao:

 Ua - Tumia vichaka vya kiasili vinavyojulikana kuvutia wadudu waharibifu na vimelea kwa kutoa nekta, chavua, mwenyeji mbadala na/au mawindo. Aina nyingi za vichaka vya maua vina mali hii. Hata hivyo, tahadhari inapaswa kuchukuliwa ili kutotumia aina za mimea zinazojulikana kuwa mwenyeji wa wadudu au magonjwa mbadala.

 Maeneo ya mende - Sehemu za nyasi karibu na mashamba ya mazao huhifadhi makundi mbalimbali ya adui wadudu waharibifu kama vile carabids, mende wa staphylinid na buibui. Ili kupunguza hatari ya magugu na mimea inayojulikana kama mimea mwenyeji wa wadudu na magonjwa ya mazao, spishi moja hadi tatu za nyasi asili zinaweza kupandwa kwenye vipande vya mita 1 hadi 3.

 Vipande vya maua - Tumia spishi za mimea ya kiasili inayotoa maua inayojulikana kuvutia wanyama wanaowinda wanyama wengine na vimelea kwa kutoa nekta, chavua, mwenyeji mbadala na/au mawindo. Aina nyingi za mimea ya maua zina mali hii. Hata hivyo, uangalizi unapaswa kuchukuliwa kutotumia majeshi mbadala ya wadudu au magonjwa. Aina tatu hadi tano za mimea asilia zinazotoa maua zinaweza kupandwa kwenye vitanda vya mbegu vilivyotayarishwa vyema, vikiwa vimepangwa kwa vipande vya mita 1 hadi 3 kwenye mpaka wa shamba la mazao. Baada ya maua, mbegu zinaweza kukusanywa ili kufanya upya ukanda au kuunda mpya.

 Mimea shirikishi - Maadui wa wadudu wa asili wanaweza pia kuvutiwa na mimea shirikishi ndani ya zao. Aina hizi za mimea shirikishi zinaweza kuwa sawa na kutumika katika vipande vya maua. Mimea michache (1 au 2 kwa kila m2 10) inayochanua maua hutumika kama 'kituo cha huduma' kwa maadui wa asili wa wadudu.

8 0 PESTS – 8.8 - MECHANICAL CONTROL OF PESTS

 

  ORGANIC FARMING COURSE AGRO-ECONOMY

 8 0 PESTS – 8.8 - MECHANICAL CONTROL OF PESTS

Mass-trapping of pests is an additional control measure. They often can easily be built with cheap material. Some examples include:

Light traps can be used to catch moths such as armyworms, cutworms, stem borers and other night flying insects. Light traps are more efficient when placed soon after the adult moths start to emerge but before they start laying eggs. However, light traps have the disadvantage of attracting a wide range of insect species. Most of the attracted insects are not pests. In addition, many insects that are attracted to the area around the light traps (sometimes from considerable distances) do not actually fly into the trap. Instead, they remain nearby, actually increasing the total number of insects in the immediate area. 

Colour and water traps can be used to monitor adult thrips. In some cases, thrips can even be reduced by mass trapping with coloured (blue, yellow or white) sticky traps or water traps in the nursery or field. The colour spectrum of the boards is important for the efficacy of the sticky traps. Bright colours attract more thrips than darker ones. Sticky traps with cylindrical surfaces are more efficient that flat surfaces. They are best placed within a meter of crop level. Traps should not be placed near the borders of fields or near shelter belts.

Water traps should be at least 6 cm deep with a surface area of 250 to 500 cm², and preferably round, with the water level about 2 cm below the rim. A few drops of detergent added to the water ensure that thrips sink and do not drift to the edges and escape. Replace or add water regularly. 

Yellow sticky traps can be used to control whiteflies, aphids and leaf mining flies. Yellow plastic gallon containers mounted upside down on sticks coated with transparent car grease or used motor oil, is one such trap. These should be placed in and around the field at about 10 cm above the foliage. Clean and re-oil when traps are covered with flies. Yellow sticky boards have a similar effect. To use, place 2 to 5 yellow sticky cards per 500 m² field area. Replace traps at least once a week. To make your own sticky trap, spread petroleum jelly or used motor oil on yellow painted plywood (size 30 cm x 30 cm). Place traps near the plants but faraway enough to prevent the leaves from sticking to the board. Note that the yellow colour attracts many insect. Note that the yellow colour attracts many insect species, including beneficial insects, so use yellow traps only when necessary.

Fruit bagging prevents fruit flies from laying eggs on the fruits (Figure 8-8). In addition, the bag provides physical protection from mechanical injuries (scars and scratches). Although laborious, it is cheap, safe and gives a more reliable estimate of the projected harvest. Bagging works well with melon, bitter gourd, mango, guava, star fruit, avocadoes and banana (plastic bags used).

 

Recommendations to farmers regarding fruit bagging: Cut old newspapers to fruit size and double the layers, as single layers break apart easily. Fold and sew or staple the sides and bottom of the sheets to make a rectangular bag. Blow in the bag to inflate it. Insert one fruit per bag then close the bag and firmly tie the top end of the bag with sisal string, wire and banana fibre or coconut midrib. Push the bottom of the bag upwards to prevent fruit from touching the bag. For example, start bagging the mango fruit 55 to 60 days from flower bloom or when the fruits are about the size of a chicken egg. When using plastic bags (e.g. with bananas), open the bottom or cut a few small holes to allow moisture to dry up. Moisture trapped in the plastic bags damages and/or promotes fungal and bacterial growth that causes diseased fruits. Plastic also overheats the fruit. Bags made of dried plant leaves are good alternatives to plastic.

 

 

 KOZI YA KILIMO HAI KILIMO-UCHUMI

 8 0 WADUDU – 8.8 - UDHIBITI WA MITAMBO YA WADUDU

Ukamataji wa wadudu kwa wingi ni hatua ya ziada ya kudhibiti. Mara nyingi zinaweza kujengwa kwa urahisi na nyenzo za bei nafuu. Baadhi ya mifano ni pamoja na:

Mitego nyepesi inaweza kutumika kukamata nondo kama vile viwavi jeshi, minyoo, vipekecha shina na wadudu wengine wanaoruka usiku. Mitego nyepesi huwa na ufanisi zaidi inapowekwa mara tu baada ya nondo waliokomaa kuanza kujitokeza lakini kabla ya kuanza kutaga mayai. Hata hivyo, mitego ya mwanga ina hasara ya kuvutia aina mbalimbali za wadudu. Wengi wa wadudu wanaovutia sio wadudu. Kwa kuongeza, wadudu wengi wanaovutiwa na eneo karibu na mitego ya mwanga (wakati mwingine kutoka umbali mkubwa) hawana kweli kuruka kwenye mtego. Badala yake, wanabaki karibu, na kuongeza idadi ya wadudu katika eneo la karibu.

Mitego ya rangi na maji inaweza kutumika kufuatilia thrips ya watu wazima. Katika baadhi ya matukio, thrips inaweza hata kupunguzwa kwa kunasa kwa wingi kwa mitego ya rangi (bluu, njano au nyeupe) yenye kunata au mitego ya maji kwenye kitalu au shamba. Wigo wa rangi ya bodi ni muhimu kwa ufanisi wa mitego ya fimbo. Rangi mkali huvutia thrips zaidi kuliko nyeusi. Mitego ya kunata yenye nyuso za silinda ni bora zaidi kuliko nyuso tambarare. Wao ni bora kuwekwa ndani ya mita ya kiwango cha mazao. Mitego haipaswi kuwekwa karibu na mipaka ya mashamba au karibu na mikanda ya hifadhi.

Mitego ya maji inapaswa kuwa na kina cha angalau 6 cm na eneo la 250 hadi 500 cm2, na ikiwezekana pande zote, na kiwango cha maji karibu 2 cm chini ya ukingo. Matone machache ya sabuni yanayoongezwa kwenye maji huhakikisha kwamba thrips huzama na hazielekei kwenye kingo na kutoroka. Badilisha au kuongeza maji mara kwa mara.

Mitego ya manjano yenye kunata inaweza kutumika kudhibiti inzi weupe, vidukari na nzi wa kuchimba majani. Vyombo vya manjano vya galoni za plastiki vilivyowekwa juu chini juu ya vijiti vilivyopakwa grisi ya gari inayoonekana wazi au mafuta yaliyotumika ya gari, ni mtego mmoja kama huo. Hizi zinapaswa kuwekwa ndani na kuzunguka shamba kwa umbali wa cm 10 juu ya majani. Safisha na utie mafuta tena mitego inapofunikwa na nzi. Bodi za nata za manjano zina athari sawa. Ili kutumia, weka kadi 2 hadi 5 za njano za kunata kwa kila eneo la 500 m2 la uwanja. Badilisha mitego angalau mara moja kwa wiki. Ili kutengeneza mtego wako unaonata, panua jeli ya petroli au mafuta ya gari yaliyotumika kwenye plywood iliyopakwa rangi ya manjano (ukubwa wa sm 30 x 30 cm). Weka mitego karibu na mimea lakini kwa mbali ili kuzuia majani kushikamana na ubao. Kumbuka kwamba rangi ya njano huvutia wadudu wengi. Kumbuka kwamba rangi ya njano huvutia aina nyingi za wadudu, ikiwa ni pamoja na wadudu wenye manufaa, hivyo tumia mitego ya njano tu wakati wa lazima.

Ufungaji wa matunda huzuia nzi wa matunda kutaga mayai kwenye matunda (Mchoro 8-7). Kwa kuongeza, mfuko hutoa ulinzi wa kimwili kutokana na majeraha ya mitambo (makovu na scratches). Ingawa ni ngumu, ni nafuu, salama na inatoa makadirio ya kuaminika zaidi ya makadirio ya mavuno. Bagging hufanya kazi vizuri na tikiti, kibuyu chungu, embe, mapera, tunda la nyota, parachichi na ndizi (mifuko ya plastiki inatumika).

Mapendekezo kwa wakulima kuhusu kuweka mifuko ya matunda: Kata magazeti ya zamani kwa ukubwa wa matunda na tabaka mara mbili, kwani tabaka moja hutengana kwa urahisi. Pindisha na kushona au kuunganisha pande na chini ya karatasi ili kufanya mfuko wa mstatili. Piga kwenye begi ili uiongezee hewa. Weka tunda moja kwa kila mfuko kisha funga mfuko na ufunge kwa uthabiti ncha ya juu ya mfuko kwa uzi wa mkonge, waya na uzi wa ndizi au katikati ya nazi. Sukuma sehemu ya chini ya begi kwenda juu ili kuzuia matunda kugusa mfuko. Kwa mfano, anza kuweka tunda la embe siku 55 hadi 60 kutoka kuchanua maua au wakati matunda yana ukubwa wa yai la kuku. Unapotumia mifuko ya plastiki (k.m. na ndizi), fungua sehemu ya chini au kata matundu machache ili kuruhusu unyevu kukauka. Unyevu ulionaswa kwenye mifuko ya plastiki huharibu na/au kukuza ukuaji wa fangasi na bakteria ambao husababisha matunda yenye magonjwa. Plastiki pia huzidisha matunda. Mifuko iliyofanywa kwa majani ya mimea kavu ni mbadala nzuri kwa plastiki.