- The soil
Walnut trees are very picky when it comes to soil. In general these trees prefer deep fields with good drainage. The trees are very resistant to lime and love alkaline soil. Walnuts are also very sensitive to salt in both the soil and the water. A higher ratio of salt means a decrease in productivity. Any clay or sand which limits the roots of the tree may also limit the development and size of the tree.
- The climate
Different species require different climates. Especially freezing cold weather in the spring may impose a high risk on walnut trees. Other changes in the weather such as summer heat, mist, rain and wind may also have an effect.
One of the most important factors limiting the produce of walnuts are the cold weather in spring and fall. Especially walnut trees which grow leaves at a very late stage have a shorter vegetation period and may incur damage in the early fall. Very low temperatures in the winter may also impose risks (temperatures lower than-25ºC). The same goes for warm climates. When the temperatures rise above 38ºC the tree might incur burns. Therefore it is very important to take into account the overall temperatures throughout the year. If you are looking to buy walnut wholesale, you should take these growth factors into account, since they may affect the ultimate product.
- Setup of the plantation
When setting up a walnut plantation expert advice should be sought. Especially when choosing a species to plant, it is very important that the right choice is made. Technical and biological advice is crucial in this regard. Productivity, quality, resistance against cold weather and diseases, climate and harvesting seasons are to be taken into account. When a farmer is considering wholesale trade he should make sure that the walnuts do comply with certain prerequisites.
Since walnuts require pollination from different species as well, it is important that other types of plants are present on the plantation. Roughly 2,5-5% of the plants should be made available for pollination. The amount of walnut trees to be planted is also very important. The area of the plantation should be into account as well as the spaces between the trees.
Walnut trees should be pruned differently and more often than other fruit trees. You can’t prune walnut trees yearly, since that may lead to a decrease in productivity. When the plantation is first set up only the buds should be pruned. Only in the third year you can start shaping the tree. Branches which have dry ends should be cut away.
Walnuts require potassium and nitrogen the most and little phosphor. Before planting the tree the amount of fertilizer should be around 10-50 kg per one tenth of a hectare. After the first year the trees can be given ammonium nitrate or ammonium sulfate based on the PH-value of the soil.
When 1/3rd of the organic walnuts’ green exterior is cracked, it’s time to start harvesting. Thereinafter the green shell is separated and the walnuts are left to dry. Of course it is better to leave the walnut on the tree as long as possible. Harvesting starts in August, depending on the climate and mostly ends in October. This stage may vary depending on the species. Before harvesting the trees should be irrigated and harvesting should start when it’s cooler. The harvesting process is very important in preserving the vitamins of the walnuts and the quality.
If the walnuts are going to be sold without their hard shell, they are transported to a place where their shells are cracked and the walnuts are packaged. This increases the prices of the nuts of course. It is very important that the walnuts are kept humid before cracking. This way, it is easier to separate the nut from the shell.
- Diseases and damage
One of the most frequently seen diseases in organic nuts is gnomonia leptostyla. This disease may affect leaves, the nuts and the buds. You may see some spots on the walnuts or even big stains. In order to prevent this disease from affecting the trees copper-based preparations may be used on the trees.
Another risk which are walnuts imposed to are the parasites inside it called cydia pomonella. The larvae of this parasite may damage the walnut from the inside. Eventually this may cause the walnuts to fall of the tree.
When the green shells of the walnuts are separated and the walnuts are cleaned, they are dried in special ovens and thereinafter they can be stored for a year. Fresh walnuts have a shelf life of 6 months. After these 6 months the walnuts will blacken and get a very bitter taste. Walnut wholesalers will be able to inform you about the shelf lives of different walnuts. In this case there are many walnut products on the market such as walnut extra light halves or walnuts light broken.