Hi 
- ORIGIN
The origin of the cultivated pear trees in Europe goes back to very remote times, probably between 1,000 and 2,000 years BC. It is native to the regions of Eastern Europe and western Asia.Deriva apparently from the selection of wild pear (Pyrus communis var. Pyraster) breeds hybridized with several other European or Asian species: Pyrus nivalis Jacq., P. pyrifolia (Burn) f.) Nakai, P. spinosa Forssk., etc.
The Greeks and the Romans knew the cultivation of the pear tree and it was the latter that introduced its cultivation in the Ebro Basin.
- TAXONOMY AND MORPHOLOGY
-Family: Rosaceae.
-Species: Pyrus communis L.
-Planta: pyramidal tree, rounded in its youth, then oval, which reaches up to 20 meters high and on average lives 65 years. Tall trunk, thick, cracked bark, gray, often lenticular plates stand out. The branches are inserted forming an acute angle with the trunk (45º), smooth bark, first green and then gray-violaceous, with numerous lenticels. When they are young they are thorny, then helpless and fragile.
- Root system: deep root, with the central axis very developed, therefore allows a good anchorage and is resistant to drought.
- Leaves: oval, finely dentate or entire, coriaceous, glabrous or rarely tomentose, somewhat glossy on the upper surface, with petiole equal in length to the lamina or shorter; at first they are somewhat hairy, but they end up being hairless and have the crenate-serrated or almost entire margin.
-Flores: they have long cabillos and form umbelliform corymbs at the end of the branches; They are of good size, with an inferior ovary and white or pinkish-white; the chalice is formed by 5 sepals lanceolate, narrowed in point; the petals usually measure 12-15 mm and are obovate and free.
-Fruto: in pomo, narrowed in the base; This can be rounded or attenuated and prolonged in the peduncle. Sepals marcescentes in the umbilicated apex. With five cells, each with 1-2 seeds of smooth outer cover or something mucilaginous. The skin of the fruit is more or less smooth, green, which turns brownish or yellowish when ripe. Hard pulp, very acidic or astringent first, at the soft maturity, with sclerous cells scattered.
- ECONOMIC IMPORTANCE AND GEOGRAPHICAL DISTRIBUTION
China and Spain are the countries in which it is expected that exports will increase, since both benefit from higher demand, and as a result have increased their own crops.
Chinese exports have been increasing considerably in recent years. In about ten years, China has gone from not exporting anything to 141,000 tons, and becoming the world's leading producer of pears. Among the reasons for this increase is the good quality of their crops.
The stagnation and regression that in some countries presents the production of pears is due largely to phytopathological problems, but also to the lack of quality with which the final product reaches the consumer, since most pears do not have an external aspect attractive. Since it is the taste along with a pleasant texture what motivates the purchase of most varieties.
- EDAFOCLIMATIC REQUIREMENTS
It thrives well in temperate and somewhat humid climates, being more resistant to cold than to heat. Extreme summers dry the fruits and prevent them from growing. Although the most suitable climate is characterized by winters with enough winter cold, few late frosts and springs and sunny summers with not very high temperatures, although the existing varietal range allows its cultivation in diverse climates within the temperate zone.
During flowering it is affected by dew, mist, humidity and late frosts. In hot regions only summer varieties will give good results.
Do not forget the necessary winter rest of the tree and the very different demands of this one with respect to the different varieties.
It flowers at 7ºC and it resists temperatures of -18ºC to -20ºC and up to -40ºC in full winter rest. Prefers the airy situations of the great plains. The pear trees require about 900 to 1000 hours of cold, below 7.2ºC during the winter to leave their rest.
It is a demanding fruit on the ground. It only thrives well in the silty-clayey, healthy and permeable earths. It requires homogeneous and deep soils, neither too dry nor too humid. It damages the stagnant humidity in the ground. In sandy soils it can withstand an excess of humidity in winter, on condition that it can evacuate this excess quickly. Soils that are too dry in summer do not allow it to develop normally, forming sclerous masses in the pulp of the fruit.
The ideal soils for planting pear over quince are those whose pH is between 6.5 and 7.5, active lime less than 7%, fertile, with a minimum depth of 50 cm and without salinity. If it is planted with a free pattern, the pH can reach 8.2-8.3 and the lime activates 11-12%.
- PROPAGATION
The multiplication is done by seed and by grafting, although the seed is used to obtain new varieties or graft patterns. The graft is done to the bud by watching over the following patterns:
-Franco: as an advantage, its resistance to limestone should be highlighted (up to 15%, which is not supported by the quince). The Frankish patterns of the pear tree are heterogeneous trees (when coming from seed) and of great development, thus making difficult certain particularities of the crop such as pruning and harvesting; it also influences the slow entry into production. The root system of the Frankish standards is of great power, pivoting and very deep, which determines a good anchoring, resistance to asphyxiation in humid soils and tolerance to drought.
The Frankish patterns used in different parts of the world do not all come from Pyrus communis seed, but are obtained from other species or subspecies of Pyrus that have previously been tested.
-Pyrus betulaefolia: native to the central and northern regions of China. A line or clone of great homogeneity and adaptation to fresh dry land has been selected and multiplied. It is resistant to the limestone and the lanigerous aphid and prints the plant with great precocity, but has not given the results that were expected of it.
-Membrillero: is used as a pear pattern due to the great homogeneity of the populations. They have a moderate and dwarfed growth, which gives great precocity in obtaining fruiting. Its root system is composed of roots less thick and deep, so it vegetates very well on surface soils, very fresh and, in general, in all irrigations, even in very humid soils, provided that the limestone is not excessive (8% lime). active maximum), as chlorosis or yellowing of the leaves and consequent rickets occur.
The quince trees are tolerant to the lanigerous aphid, but susceptible to drought and fire blight. Its longevity is quite reduced, considering it in general no more than 30 years.
On this pattern two types have been distinguished:
-Membreillero de Angers: they are of little vigor, great precocity and high productivity. Its root system is shallow, so it suffers considerably when there is a drought. It is very sensitive to calcareous soils and spreads easily by layering and staking.
-Membrillero de Provence: they are in general very heterogeneous. The root system is less superficial, therefore better supports drought. It has greater affinity with the varieties to which it induces greater vigor and easily multiplies by layering.
The sensitivity of the ferric chlorosis of the pear-tree grafted on the quince tree and the incompatibility with it of some important varieties make this pattern, the most interesting for fruit quality and tree management, not always employed, having to resort to frank patterns that due to the great vigor induced and slower entry into production can only be advised in varieties of moderate vigor and rapid entry into production.
- PARTICULARITIES OF CULTIVATION
7.1. Plantation
The plantation frames are very variable, depending on the patterns used, as well as the different formations. Therefore, the distances between trees can range between 0.30 m for the vertical cord grafted on quince and 12 m, for free forms on franc.
If a quince is used as a pattern, plantations with poles and wires are usually trained to improve the anchoring and facilitate the formation of the trees. Sometimes it is also done with free pattern for this reason.
To avoid excessive density and the consequent shading, special management procedures are necessary after planting and considerable pruning must be done, both lateral and in the upper part.
7.2. Subscriber
Fertility should be medium or even somewhat low, to avoid excess vigor and depth greater than 50 cm.
Using decomposed manure of medium composition, it should be applied every year 0,700 kg / m2 and making the fertilizer every three years, 2,100 kg / m2. It is advisable, however, to alternate manure with chemical fertilizers.
