One of the most important features we must seek on the land, where we shall grow walnuts, must be being free of irrigation problem. We must make our planning in advance for the irrigation of the saplings and conditions of irrigable land must be maintained after the plantation of saplings. We must know that we shall need water in our land, where we shall plant walnut saplings, for the growth of saplings and for the fruit quality in future, starting from spring and particularly in summer season.

Annual water need of a fully productive walnut tree is about average 1100 – 1300 mm levels.

Water requirement of walnut trees starts at the end of spring, and continued until the end of the harvesting period. Within this period, additional irrigation is needed due to the deficiency of rains within many regions of our country.

If we review the irrigation activities separately in terms of the saplings and fully productive trees:

Irrigation of Walnut Sapling;

a. The facts that the sapling pits opened during plantation have a suitable depth (a depth of 50-60 cm and a width of -40-50 cm in a normal soil structure) and obtaining the soil to be filled in the sapling pit by mixing the surface soil with either well burnt animal manure or leonardite are important in terms of a successful irrigation in the first years.

b. Irrigation of walnut starts with the sap to be given during the plantation of sapling so as to reach to the roots and saturate them (30-50 Lt).

c. If the saplings are planted in winter season, then sap must also be given, but additional irrigation must not be made, unless needed. The humidity of the soil caused by the rains is sufficient.

d. When the spring comes and the rains decrease, the water requirement of the walnut sapling shall increase and additional irrigation shall be needed. The fact that how and when our sapling shall need water is a matter related with the ability of the soil to keep water. Increase of the temperatures shall also increase the water need of the sapling.

e. Plantation must be carried out without taking measures in terms of irrigation, in case of plantations of tubed walnut saplings in summer seasons.

Matters to be observed when determining the water requirement of the sapling;

* You must determine the duration (minutes) and amount (litre) of the irrigation you shall make, by determining the depth (cm) that the water, which we recommend as 15-20 litres in each irrigation during the sapling period, reaches.

* You must observe that how many days the irrigation you make keeps the soil of the sapling humid, and adjust the irrigation frequency accordingly.

* In general, we recommend 15-20 lt of sapling irrigation in every 10 days, 7 days depending on the temperature and rain, and in every 3-5 days on very hot days.

* Water stress to be experienced due to failing to make irrigation may slow down the growth of root, body, and branches during sapling period, and may cause the sapling to dry out.

* Although less irrigation shall have damage on the sapling, irrigations to be made frequently (1-2) shall have negative effects of the growth of the sapling.

* As it is specified above, the fact that the humidity remains in your soil is your main indicators in terms of the amount and frequency of irrigation. You must make your irrigation planning according to the observations you shall make.

* In general, the intervals of sapling irrigation must be continued by reducing until 15 September. If drying is present in root regions of the sapling soil, thus in a depth of 15-20 cm, in our hot regions, then an additional irrigation may be made.

Irrigation of Fully Productive Walnut Trees;

a. It starts particularly from the end of the spring, when the rains are decreased, and continues until the end of the harvesting period in a walnut garden, where fruits are produced. Fall and winter irrigations may be needed, in case of very drought years.

b. failing to make sufficient irrigation causes small fruit formation, shrinking walnut kernel, and sun burnt, fading out of kernel, and staining. These reduce the quality of the walnut fruit.

c. Irrigation must be commenced in the week after the walnut tree blooms.

d. Walnut trees must not be left without water absolutely in the period of fruit formation and kernel filling, which includes June, July, and August and sufficient irrigation must be carried out.

e. Irrigation must be made 15 days before harvesting in order to pull out the fruit from its branch easily in harvesting period.

f. Irrigation must be made immediately after harvesting, and then irrigation must be ceased.

g. It is very important to lead the water to all roots of the walnut tree. For this, an irrigation system shall be established so as to lead water to the capillary roots, which are spread in the projection of the tree intensely.

Special Points to be Taken into Consideration;

a. Particularly in the regions, where early fall frosts are effective, irrigation must be ceased from the mid of September regarding the saplings, and from the end of August regarding the trees. In case water is given, then the tree cannot be prepared for winter dormancy, and the edges of the young offshoots are damaged in early frosts. And this causes low yield in the following year.

b. Irrigation activities carried out before the tree comes up in the regions, where late spring frosts occur, cause late coming up of the walnut tree, and beneficial results may be obtained in terms of being affected negatively from the frosts.

c. When establishing drip irrigation system, attention must be paid to avoid the contact of water with the body and accumulation of it close to the body. This may cause particularly fungus-like diseases.

We recommend carrying out the irrigation activity with drip irrigation method both in sapling period and in large tree period.