Thrips, Mites, Viruses, Mould and other nasty threats to a successful grow

As many grow reviews will testify one of the biggest threats to a successful crop cycle is the problem of viruses spread by Thrips. These are long and slim little devils that can wreak havoc in any growroom, beit one for mother plants or flowering clones. And, as with any insect threat, the best course of action is one of prevention rather than cure. A few simple steps and care in the preparation and nurture of growing plants can make the difference between a successful grow and a devastating infestation.

What you need to know: Thrips love pollen! Consequently in most cases you will find that the greatest abundance of them would be found on flowering male plants. On all plants the place to look for them is in the growing tip. Not only will they leave feeding marks on the plant's leaves but another tell-tale sign of their presence is a sticky residue on the leaf surface. This in turn provides fertile ground for a mold that will rapidly grow on it. Often turning black it is an indicator of major problems. These problems may well be passed down to clones and so plants that have suffered from Thrips in the past should never be used as a mother. Clones from a mother that has suffered from a Thrip carried viral infection may well begin to grow quite happily until a combination of optimum conditions are reached on the plant and in the grow room. Then the virus would present itelf again and potentailly dessimate a crop in one or more different ways, from slight marking of leaves right up to the complete collapse of the plant. This is one reason why mothers grown from seed (as opposed to a clone from an existing mother) offer a safer option as few organisms can survive on the seeds themselves or in the conditions that are best for seed storage.

Keeping the insects out: Silk or similar screen printing material is an acceptable way of covering air intakes into the grow environment. Approximately 190 microns should be reagrded as the maximum hole size that will form an effective barrier to the variety of insects, including Thrips, that can threaten the plants. Obviously such a small mesh size requires a certain amount of compensation in terms of the screen size in order to draw through a sufficient quantity of air

Being alert to invasion: Frequent and proper examination should alert a grower to any potential infestation problem before it gets out of hand. Visual checks on the plants themselves aswell as the strategic placing of sticky cards are the main ways to check for unwanted visitors in a grow room. At the first sign of trouble the appropriate action should be taken.

Insecticide Sprays: Any grower worth their salt will be acutely aware of the need to be careful when spraying a room. Proper use and awareness of the constituent elements of any synthetic sprays is essential. Many are toxic and would consequently cause harmful side-effects in anyone using the resultant crop. For this reason it is always advisable, where possible, to use natural insecticides (such as cinnamon based ones) which have little or no effect on soil or crop quality and safety. The spraying cycle varies according to the type of invader but a good rule of thumb is 3 sprays (each spaced five days apart in the case of Thrips and seven days apart in the case of Spider Mites)

Using predator (friendly) mites: These may well be of use in the flowering room, where no form of spray should be used at all, but there are still pitfalls associated with their use. Firstly, by their very nature, they mostly require lighting conditions that would occur outisde in their natural environment, in other terms - a long day of varying light intensity across the full spectrum. Secondly, they are susceptible to residual traces left by any prior insecticide spraying and so are of little use in a mother room where this may have occured.

Other methods to sustain a healthy grow: There are a few simple steps that can be taken throughout the course of cloning and growth that will help to maintain healthy plants. As stated already, start off with quality seed strains from quality suppliers. Secondly, when taking cuttings from various mothers it is imperative that the cutting knife is sterilised after use on each individual plant. This is for the obvious reason of safeguarding against the spread of any latent infection. Soil or medium quality is another important factor that can affect the quality of a grow. Soil PH should not be allowed to become too acidic. Any drop below 5.8 or so should be treated with a suitable agent such as hydrated lime or potassium nitrate. It may be that an occasional feed of magnesium sulphate is also needed to maintain magnesium levels within the plants. Once every three weeks should be sufficient. In all these cases the concentration of the compound agent should not be too great (EC of 1.8 or less)

Although no grow could ever be guaranteed, even despite your best efforts, following a little simple advice will significantly increase your chances of harvesting a high quality and heavily laden crop.