Harvest time

No matter how many years a farmer has been cultivating crops, he will always feel the excitement of harvest time; the moment when it all comes together and he can see how his efforts have paid off. A full two weeks after pulling the potato haulms of their Sylvana crop the Plomp family have picked a dry moment to lift their seed tubers. After a growing period of 103 days their Sylvanas are fully mature. Sylvana can be classed as medium early, and it has the added advantage of being an early bulker that gives good marketable yields early on in the season. Particularly under Libyan conditions this characteristic can prove to be useful for consumption growers who need to harvest their crop earlier than usual due to drastic weather conditions.

 

Harvest time

 

Man & Machine

To lift their seed tubers the Plomp family are using a complete harvester, manufactured by Grimme; the machine not only lifts the potatoes, but also separates them from soil, haulms and stones, if any. As a result of Mr. Plomp's effective soil preparation the ridges in his field contain very few clods.

When using complete harvesters such as these, proper soil preparation, exact planting and sufficient hilling are absolute prerequisites. Fully mechanised harvesting is only possible with a level seed bed in place, and straight and even ridges. Otherwise the harvester would cause more harm than good, with tuber damage posing the greatest risk. This is all the more crucial as only sound tubers with good, undamaged skin can be stored succesfully.

But as in most work environments the all-important factor is the skill of the persons involved. In order not to bruise the potatoes, the operator has to drive with just enough speed to keep the potatoes rolling gently over the webs, taking care not to bump them about. And any experienced farmer will spend more time looking back over his shoulder to focus on the ridges behind him where the action is, rather than looking to the ridges in front that he knows only too well.
 

Man & Machine

 

From tipper to hopper

After the potatoes have been lifted and separated, they are conveyed directly into an accompanying trailer. The tubers are then transported into the storage of the Plomp family, where they are tipped very gently onto a hopper, which serves as a buffer and removes any remaining soil from the crop. The hopper then guides the potatoes onto a conveyor belt where any irregularities such as stones can be picked out. During this whole process the Plomp family ensure that drop heights are reduced  properly to avoid internal bruising and mechanical damage. The tubers then proceed onto another conveyor belt that carefully lowers them into a storage box using an automatic box filler. Yet again great care is taken not to bruise the potatoes.
 

From tipper to hopper

 

Sylvana 2012!

Ladies and gentlemen, we proudly present... Sylvana, harvest 2012! For now we can only offer you a short glimpse, as the potatoes will be stored until they are graded. Grading cannot take place before their skin has thickened sufficiently so that the grader will not damage them. Although the tubers still need to be graded, we can safely say that this year's harvest excels in uniformity. The skin quality is also very promising, as the tubers are exceptionally low on common scab.

The ventilation system inside the storage will first dry the tubers using outside air. Ventilation is essential to keep the surface of the potatoes dry and remove excess heat and carbon dioxide. It will also supply the oxygen that the potatoes need to breathe. As ventilation also causes the potatoes to lose water, Mr. Plomp takes care to keep the ventilation hours as low as possible, ventilating sufficiently to keep the potatoes in good shape, but at the same time limiting weight loss due to evaporation. To limit sprout growth and delay the aging of his tubers Mr. Plomp uses diffuse light in his storage.

As the Sylvanas will be exported in the coming months, they will be cooled after they have dried sufficiently, depending on outside temperatures. This will improve their growth vigour, and ensure that the tubers will sprout and emerge quickly at planting time.

Because Sylvana has a strong dormancy, it can be stored very well. For Libyan farmers growing for consumption, this creates various marketing possibilities. Not only can they deliver a more regular supply to the market and stand better chances of obtaining higher market prices, good storability is also a condition for export.

 

Sylvana 2012

 

Photos courtesy Ad van Luyk and HZPC