8 1 NATURAL PESTICIDES – 8.16 - PRECAUTIONS TO FARMERS REGARDING USE OF PLANT EXTRACTS

  

ORGANIC FARMING COURSE AGRO-ECONOMY

8 1 NATURAL PESTICIDES – 8.16 - PRECAUTIONS TO FARMERS REGARDING USE OF PLANT EXTRACTS

 

Despite being “natural” and widely used in agricultural systems, some botanicals may be dangerous for humans and they can be very toxic to natural enemies. Nicotine for example, derived from the tobacco plant, is one of the most toxic organic poisons for humans and other warm-blooded animals. Pyrethrins are not poisonous for humans and warm-blooded animals. However, human allergic reactions are common. It can cause rash and breathing the dust can cause headaches and sickness. 

-     Before a new botanical pesticide is applied in a large scale, its effect on the ecosystem should be tested in a small field experiment. Do not just use botanical pesticides as a default option! First understand the ecosystem and how botanicals influence it!

-     Do not have direct skin contact with the crude extract during the process of preparation and application. 

-     Contact with plant extracts should be avoided in the eyes. 

-     Make sure that you place the plant extract out of reach of children during storage.   

-     Wear protective clothing (eyes, mouth, nose and skin) while applying the extract.  –

-     Wash your hands after handling the plant extract.

Besides extractions of plants, there are some other natural pesticides, which are allowed in organic farming. Although some of these products have limited selectivity and are not fully biodegradable, there are situations, when their use is justified. However, in most cases, the desired effect is best reached in combination with preventive crop protection methods. Some examples are:

•       Soft soap solutions: against aphids and other sucking insects.

•       Light mineral oil: against various insect pests (harms natural enemies!).

•       Sulphur: against spider mites (harms natural enemies!). The acaricidal effect of sulphur is best at temperatures above 12° C. However, sulphur has the potential to cause plant injury in dry hot weather (above 32° C). It’s also incompatible with other pesticides. Sulphur should not be used together or after treatments with oil to avoid phytotoxicity.

•       Plant ashes: wood ashes from fireplaces can be efficient against ants, leaf miners, stem borers, termites and potato moths. Ash should be dusted directly on pest colonies and infested plant parts. The ash will dehydrate the soft bodied pests. Wood ashes are often used when storing grains to deter storage pests such as weevils. In addition, ashes are used against soil borne diseases.

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KOZI YA KILIMO HAI KILIMO-UCHUMI

8 1 DAWA ZA ASILI – 8.16 - TAHADHARI KWA WAKULIMA KUHUSU MATUMIZI YA DONDOO ZA MIMEA.

 

Licha ya kuwa "asili" na kutumika sana katika mifumo ya kilimo, baadhi ya mimea inaweza kuwa hatari kwa wanadamu na inaweza kuwa sumu sana kwa maadui wa asili. Nikotini kwa mfano, inayotokana na mmea wa tumbaku, ni mojawapo ya sumu ya kikaboni yenye sumu kwa wanadamu na wanyama wengine wenye damu joto. Pyrethrins sio sumu kwa wanadamu na wanyama wenye damu ya joto. Hata hivyo, athari za mzio wa binadamu ni za kawaida. Inaweza kusababisha upele na kupumua vumbi kunaweza kusababisha maumivu ya kichwa na ugonjwa.

- Kabla ya dawa mpya ya mimea kutumiwa kwa kiwango kikubwa, athari yake kwenye mfumo ikolojia inapaswa kujaribiwa katika jaribio dogo la shamba. Usitumie tu viuatilifu vya mimea kama chaguo-msingi! Kwanza elewa mfumo ikolojia na jinsi mimea inavyoathiri!

- Usiguse ngozi moja kwa moja na dondoo ghafi wakati wa mchakato wa utayarishaji na uwekaji.

- Kuwasiliana na dondoo za mimea kunapaswa kuepukwa machoni.

- Hakikisha kwamba unaweka dondoo la mmea mahali pasipoweza kufikiwa na watoto wakati wa kuhifadhi.

- Vaa nguo za kujikinga (macho, mdomo, pua na ngozi) unapopaka dondoo. -

- Nawa mikono yako baada ya kushika dondoo la mmea.

Kando na uchimbaji wa mimea, kuna dawa zingine za asili zinazoruhusiwa katika kilimo hai. Ingawa baadhi ya bidhaa hizi zina uwezo mdogo wa kuchagua na haziwezi kuharibika kikamilifu, kuna hali wakati matumizi yao yanahesabiwa haki. Hata hivyo, katika hali nyingi, athari inayotaka hupatikana vyema pamoja na mbinu za kuzuia mazao. Baadhi ya mifano ni:

• Suluhisho la sabuni laini: dhidi ya vidukari na wadudu wengine wanaonyonya.

• Mafuta ya madini ya mwanga: dhidi ya wadudu mbalimbali wadudu (hudhuru maadui wa asili!).

• Sulphur: dhidi ya sarafu za buibui (hudhuru maadui wa asili!). Athari ya acaricidal ya sulfuri ni bora kwa joto la zaidi ya 12 ° C. Hata hivyo, sulfuri ina uwezo wa kusababisha uharibifu wa mmea katika hali ya hewa kavu ya joto (zaidi ya 32 ° C). Pia haiendani na dawa zingine za wadudu. Sulfuri haipaswi kutumiwa pamoja au baada ya matibabu na mafuta ili kuepuka phytotoxicity.

• Majivu ya mimea: majivu ya kuni kutoka mahali pa moto yanaweza kuwa bora dhidi ya mchwa, wachimbaji wa majani, vipekecha shina, mchwa na nondo za viazi. Majivu yanapaswa kumwagika moja kwa moja kwenye makundi ya wadudu na sehemu za mimea zilizoathirika. Majivu yatapunguza maji kwa wadudu wenye miili laini. Majivu ya kuni mara nyingi hutumika wakati wa kuhifadhi nafaka ili kuzuia wadudu waharibifu kama vile wadudu waharibifu. Aidha, majivu hutumiwa dhidi ya magonjwa yanayotokana na udongo.