The strict control of certain pests is sometimes only necessary if that pest is a vector for certain viruses, and one can tolerate low populations of some pests if they have natural enemies to keep them under control. As organic production is on the increase, this route is an important option.
Many insecticides permissible in organic production are also harmful to the natural enemies of the pests. Spraying such products when there is a low pest population means we would have to continue to spray because the pests’ natural enemies would also be destroyed. Whitefly and aphids are pests that can be easily biologically controlled when their natural enemies are present.
Where yellow leaf curl virus (curly stunt) is present, no whitefly can be tolerated and where tobacco mosaic virus is a hazard, no aphid can be spared. Many of these pests start off in patches that can be thoroughly sprayed with a knapsack, without having to spray the whole area. Red spider mite and russet mite are also candidates for this modus operandus.
Many farmers avoid the use of pyrethroids, which often cause red spider mite to flare up as the beneficial mite species that control the red mites are killed off. spider mite is easily spotted as small yellow dots appear on the leaf surface. When the leaves are turned over the small reddish mites can be seen with the naked eye. In severe infestations the fruit can also be blemished.
Mites are more prevalent in hot, dry conditions and are very partial to tunnel cultures. There are a number of effective systemic products for mite control and organic producers can use sulphur, either as a powder or dust. The application should be done in cool, dry conditions. Bio Cure is another option for organic growers. With both these products wetting of all leaf surfaces is necessary.
Another mite which is more difficult to spot is the russet mite. This is a much smaller creature and not visible to the naked eye. good lens is required to spot these pear-shaped mites. The first symptoms are that the plants look rather lacklustre and have a rusty colour. The mites can be spread by wind and labour working in the tunnels.
In the case of red spider mite, when populations are high, one can feel a slightly painful prick as they bite one’s skin. Both these mites usually need a follow-up spray to take out the population.The sooner these pests are detected, the cheaper and easier they will be the control. – Bill Kerr ([email protected] or call (016) 366 0616). |fw
Times have changed. This might be a well-worn refrain but that doesn’t diminish its validity.
t’s no secret the fresh produce markets’ slice of the fresh produce cake has dwindled from a high of around 90%-plus, 30 or 40 years ago, to a slim 25% of a R27 billion industry. There are many reasons for this, but one of the main ones has been the inability or intransigence of markets to adapt to changing circumstances. In most cases management wanted to make changes, but were blocked by their political masters in the various municipal forums. Political masters who had no clue about markets and clearly didn’t give a damn – as long as the market was bringing in the money, nobody was going to upset the apple cart (forgive the pun!).
For these reasons it’s heartening to see some of our markets have managed to convince their masters it’s important to promote themselves. The big four, Johannesburg, Tshwane, Cape Town and Durban, have all tackled this with varying degrees of gusto. Certainly, the first three have set out to establish themselves as brands in some form or other. It’s also interesting to note that ownership varies among them. Johannesburg is corporatised, wholly owned by the city of Johannesburg. Cape Town is privately owned and the other two still belong to their respective local authorities.
Of a total of 23 markets in South Africa can only think of two more that have tackled the promotion issue – Bloemfontein and Klerksdorp. These markets don’t have the kind of funds the big guys have, but the fact is they’re doing something commendable. Klerksdorp has gone all-out with a complete, all-new branding and marketing strategy. can’t say much more than that at this stage.
The approach of market management has been to include all stakeholders and get buy-in from everybody. This is fundamental and will ensure the success of these undertakings.
There was a time when many markets were out there promoting themselves at farmers’ days, conferences and shows. Market Masters (now called Market Managers) and other senior staff used to make regular visits to both farmers and buyers. look forward to the day when all markets do the same and stand up to show the world they’re indispensable members of the community, and the agricultural economy of our country.That 25% slice of the fresh produce cake needs to grow again. – Mike Cordes ([email protected]). |fw