Aloe Pests & Diseases

Dealing with Aloe Pests and Diseases

Fungal diseases:

Rust

It is highly recommended to cut off all affected leaves and burn them before commencing spraying with any of the recommended products. For home use you can spray with Funginex (Triforine) or Bravo720 (Chlorothalonil) and alternate with Virikop (Copper Oxychloride).always add a good wetting agent like G49. Dithane WG (Mancozeb) is an excellent preventative product but it is not curative. Always add a good wetting agent like G49 when using these products. The softer more environmentally friendly alternative is Neudorff’s Copper Soap, this is however only suitable as a preventative, it is not curative. An extremely effective treatment for rust is Hydrogen peroxide, use as a full cover spray , 6% (20 volume) used undiluted is recommended with the addition of some wetting agent.  Commercially Bellis (pyraclostrobin & boscalid ) with a good wetter/sticker is used to cure rust on Aloes; it is extremely effective but only available in large containers at a high price, alternate with Defender (Difenoconazole).

Black Spot

This is a complex problem caused by more than one fungus, some plants are more susceptible than others, and soil PH and lack of nutrients can also affect susceptibility. If a plant is extremely susceptible it is recommended you destroy it and replace with a more resistant variety. The best product for home use is Chronos (Prochloraz) but excellent alternatives are Bravo720 (Chlorothalonil) and Fungi-Nil 500WP (Captan), alternate with Virikop (Copper Oxychloride). Dithane WG (Mancozeb) is an excellent preventative product but it is not a curative, always add a good wetting agent like G49 when using these products. The softer more environmentally friendly fungicide alternative is Neudorff’s Copper Soap; this is however only suitable as a preventative, it is not curative. Commercially Bellis (pyraclostrobin & boscalid) and Octave (Prochloraz) are alternated and used with a wetter/sticker added to the mix.

Root Rot

Most problematic with seedlings or hyper arid Aloes, overwatering or sowing seed too thickly will give rise to ideal conditions for fungi and bacteria to develop. Virikop (Copper Oxychloride) alternated with dilute Jeyes fluid solution applied as a soil drench is very effective control for this although it also kills all the good soil fungi and bacteria as well. Commercially a mix of Benomyl (Benzimidazole) and Previcur (L-Propamocarb) or Xanbac (Dichlorofen) is often used. Beneficial fungi that protect the roots can be used, e.g. Trichotec or Trichoplus which are different species of beneficial Trichoderma spp. fungi, you generally only have to use it once as the fungi colonize the root zone and remain living there, multiplying and protecting against harmful fungi and bacteria. Do not use Virikop, Jeyes fluid etc. in conjunction with products like Trichotec.

Pests:

General insects:

 This includes Snout Beetle, various beetles, grasshoppers, caterpillars, Aphids, mealy bug, eight-back bug and scale. For home use alternating applications of Seizer (Bifenthrin) and Kohinor (Imidacloprid) with a good wetting agent like G49 (when spraying, not drenching) is effective for controlling most insects most of the time. Kohinor is best applied by drenching, not spraying. For a severe scale infestation one can use a mix of Garden Ripcord (Cypermethrin) or Seizer (Bifenthrin) or Malasol (Mercaptothion) and Oleum (Narrow fraction mineral oil). Once the scale is dead it generally does not fall off and has to be rubbed off with a cloth or soft brush. Less toxic more environmentally friendly alternatives to deal with insects are Efekto’s Spinosad and Biogrow’s Pyrol , Bioneem and Neudosan Commercially various products are used such as Bandit (Imidacloprid), Dimethoate and other products too dangerous for home use.

Aloe Cancer / Aloe Mites:

The mites live in the Aloe tissue and on the leaf surface in the crown so controlling them is often harder than with other mites. The mites cause the plant to produce unsightly deformations, known as galls/Cancer on the plant. Home use products are generally not systemic like some of the commercial remedies so the home gardener/collector must be extra vigilant and deal with Aloe cancer immediately as it occurs, if the problem is ignored and the mites get into all your Aloes it will become a difficult task to eradicate them. Karbaspray (Carbaryl), Milbeknock (Milbemectin) and Samba (Amitraz) do control these mites effectively if used properly. Karbaspray and Samba are only contact products so are best used as a preventative spray and as full cover spray immediately after cutting out galls , this is vital to ensure mites don’t spread. Natural insecticides like Biogrow’s Pyrol , Bioneem and Neudosan can be used as a preventative spray and to stop mites spreading from one Aloe to another in your collection, they generally break down very quickly though and more frequent spraying may be required. An extremely important aspect of dealing with Aloe mites is to alternate miticides from different chemical classes or else the mites become resistant to the chemicals extremely quickly! Hydrogen peroxide 12% (40 volume ) undiluted with wetting agent added can also be useful as part of a treatment program for Aloe cancer. It is always best to physically remove (cut out) the deformities/growths caused by the mite before spraying, be sure to use a good wetting agent like G49 when spraying for mites. Burn these growths, don’t leave them lying around your garden and don’t put them in your compost heap! Even if one succeeds in killing the mites without removing the galls which is extremely difficult with home use products the galls will persist for many months and are very unsightly. Commercially products like Dimethoate , Parsec (Amitraz) , Makhromectin (Abamectin – as a curative not preventative) + Gallic oil and Floramite with a good wetter/sticker are used to control mites as well as other products too dangerous for home use.