More leeway for chemical products thanks to organic fungicide CULTIVATION AND TECHNOLOGY the two untreated hectares separately from the others, because the skin quality simply cannot compare with the other table potatoes.’ Not expensive to use The crop farmers apply the Proradix Agro to the crop with a Mafex disk atomiser. They spray when they prepare the planting stock for planting. ‘The dosage of the bacterium application is 60 grams per hectare and costs 100 euros, which is not at all expensive. I can tell you that, for a product such as Amistar, you need 3 litres per hectare and that costs 180 euros.’ To supply a product with a good skin quality is especially important for father and son Schelling if they wish to continue to produce table potatoes. ‘We don’t receive a bonus or anything like that when we deliver Folvas with a good skin quality. However, if the skin quality is not good, you simply cannot sell them as table potatoes’, Bert and Leo Schelling explain. ‘We have stored the yield of the two untreated hectares separately from the others, because the skin quality simply cannot compare with the other table potatoes.’ And the two crop growers are just as careful with storing their produce as they are with growing their table potatoes. For this purpose, they built a state-of-the art storage facility in 2003 with mechanical cooling. All 1,500 tons of Folva table potatoes are stored here in boxes. The storage equipment is fully computer-controlled. For ventilation they use an extraction system, which has good results according to the Schellings. ‘The tubers remain firm for a long period of time and the skin is also protected against moisture and Silver scurf.’ Father and son Schelling lifted the Folvas during the months of September in dry weather conditions. This has not resulted in any adverse consequences for the internal quality of the crop. ‘We lifted with a drawn two-row Grimme with cascade lifting mat. Thanks to this mat we were able to retain adequate soil in the initial stage right up to the feed belt, which is why he is glad that he now has a really valuable lot of table potatoes in storage of which both he and the buyer can be totally satisfied. ● Leo Hanse ADD MONCEREEN TO SEED POTATO CROP Proradix Agro is an organic fungicide. In the Netherlands it may be used in the cultivation of potatoes. The sale and distribution is in the hands of Koppert Biological Systems in Berkel and Rodenrijs. The product contains the Pseudomonas sp. bacterium. This is a bacterium that is able to activate the plant’s own defence mechanism. These defence mechanisms ensure that the pathogens in the soil have little or no chance to infect the plant. Tests have shown that the bacterium can resist diseases such as Rhizoctonia and common scab. This increased resistance also seems to produce better and more regular plant growth, resulting in a higher yield per kilogram and a more uniform grade. The latter was also evident in the acceptance test, which Innoventis in Slootdorp carried out four years ago. The conclusion shows ‘that the potatoes were more uniformly shaped.’ At the same time, the treated potatoes showed fewer deformities. This acceptance test included parallel plots with untreated potatoes and a plot where potatoes had been treated with Moncereen and Mantrac. As far as Rhizoctonia is concerned, it appeared that Moncereen had a stronger effect than Proradix Agro. For the cultivation of consumption potatoes, this doesn’t pose a problem, according to Hendrik de Vries, director of Innoventis, but it is not strong enough for the cultivation of seed potatoes. ‘If you want to use the organic product for seed potatoes, it is sensible to add Moncereen in cases of heavy Rhizoctonia pressure. This is shown by testing that was carried out in Slootdorp last season’, is De Vries’ reaction. Potato World 2010 • number 2 27 Pagina 26
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