**3.2. Methodology**

In [20] no effects were obtained for the higher doses of potassium, although the employment of the dose of 60g K2O plant-1 had been about 40% higher than the dose of 30g K2O plant-1. The authors justified such results due to the high variation coefficient obtained for the anal‐ ysis of harvesting of unripe fruits. For [3], the effects of potassium fertilizations on fruit trees are more conditioned to aspects of quality than quantity, since this element is not in limiting

The results showed that potassium fertilizations provide increases of production of dry mat‐ ter of branches and fruits, where better results were associated with levels of 90 g K20 plant-1, in a stand of 1600 plants per hectare and in soils under conditions of low and medi‐

The apple tree (*Malus domestica*) origin center is the Caucasus region, in the Asian montains and in the East of China. It is supposed that the development of the casual species have been initiated 20.000 years ago. It seems that the Greeks in the classical ancient times had cultivat‐ ed apple tree, in fact in the roman empire the apple tree culture was already widespread. In Brazil, the beginning of the apple tree culture occurred probably in Valinhos municipality,

Apple is among the fourth most consumed fruits in the world. In Brazil it is commercialized during the twelve months of the year and distributed all over the country. Except its con‐ sumed *in natura* it is utilized in puree, jam, dry fruit, concentrated juice and fermented bev‐ erages. The apple tree fruit is rich in peptic substances and cellulose that together with

The apple orchards in Brazil initiated in the end of the 60's and beginning of the 70's. Since this date, Brazil depended on importation to supply the apple market. But trough the gov‐ ernment supporting, now a days, the evolution of the crops was fast, getting to 34 thousand of hectares and a production of about 850 thousand ton, concentrated in the Santa Catarina state. From 1988 Brazil started to export apples reaching self-sufficiency in 1998 when the

Potassium (K) is the most extracted nutrients from the soil by apple fruits. Currently, with the use of new technologies, yield may reach values higher than 100 t ha-1 [22]. Which in‐

The effective fruiting of apple trees is influenced by N, which plays an important effect in floral bud formation and increases the period when the ovule can be fertilized [23]. K in‐

amounts for the development of the plant.

**2.6. Conclusions**

202 Soil Fertility

um fertility in potassium.

state of São Paulo in 1926 [21].

lignin constitute fibers [21].

exportations exceed the importations [21].

**3.1. Potassium fertilization in apple orchards**

creases the nutrients demanded by the apple.

**3. The apple tree**

In [32] made an research with the objective to evaluate the effects of long-term annual addi‐ tions of K to the soil on yield, fruit size, mineral composition and Ca-related disorders of 'Fugi' apples for São Joaquim, Santa Catarina state, Southerm Brazil (28º 17′ S, 49º 55′ W). The experiment was conducted in the growing seasons from 1998 to 2006 in three commer‐ cial orchards of 12, 16 and 19 years old. Clay content and chemical characteristics of the soil from the experiment orchards, at the beginning of the experiment, are presented in Table 6.

The experimental plots comprised five plants, spaced 4.5 m between plants by 6.0 m be‐ tween rows in one orchard and 3.0 by 6.0m in the other two, with the three central plants used as measurement plants. Trees were trained on a central leader system and received the same pruning and thinning practices as recommended for apple commercial orchards.


**Table 6.** Soil testing results before experiment implementation (1998). [32].
