Selection Of Local And Introduced Apricot Varieties

The purpose of this article is to select from the existing collection orchards of apricot such varieties that are resistant to natural and climatic conditions and possess valuable biological and economic characteristics, as well as to select and introduce promising high-yielding varieties.


INTRODUCTION
Apricot is an ancient fruit tree, whose homeland is Armenia, but later it turned out that it is Chinese.At the same time, it was confirmed that the homeland of the apricot is also Central Asia, as wild ones are still found here.Apricot is one of the most widely grown grainy fruits in Uzbekistan.The importance of apricots is determined by the fact that they can be eaten raw and processed.Fresh apricots contain 8.4-19.0% sugar, 0.3-1.7% malic acid and a small amount of tartaric acid, 0.1-1.6% pectin, as well as vitamins A and C, oxalic acid, and in dried form contains 80% or more sugar.The core of most apricots grown in Uzbekistan is sweet and eaten like almonds. It contains 45-58% fat and about 28-30% protein [6]. In terms of drought and heat resistance, apricot varieties are second only to almonds.In summer, it grows well in July when the average temperature is above 300C and the maximum temperature rises to 45-470˚C. [2].
According to the authors, who studied the drought resistance of leaves on the layers of branches, that adaptation of dry soil to the leaves of the lower layers of branches was much higher than the leaves of the upper layers.This is explained by a decrease in the speed of water movement and transpiration in the leaves of the lower layer, as soon as water deficit begins.As a result of observations, the researchers came to the conclusion that the plant, with a lack of water, begins to reduce its consumption and, as a result, becomes more resistant to drought [3].
Seasonal changes in climatic conditions studied by scientists have revealed morphophysiological changes in plants during the annual cycle during long evolution.Cold resistance, yield, fruit yield and characteristics of varieties depend on their adaptability to environmental conditions [7].
According to the author, when studying the physiological state of tempering and frost resistance of plants, the cold resistance of plants rises to a high level during tempering in autumn and early winter.In this case, the accumulation of sugar is characteristic of the first phase of tempering, which begins with the cessation of growth processes.The second phase of tempering begins at a temperature of 2-5˚C, during which time the plants develop frost resistance [8].
The dramatically changing temperatures that kill many flower buds affect in different ways even the same varieties and this depends on meteorological factors, growing conditions and the genotypic characteristics of the variety.Thus, due to the genotypic characteristics of the variety, it is detectedthe sharp temperature for apricot buds -1.1 -5.6˚C, for flowers -0.6 -2.8˚C, and for newborns -0.7-2.2˚C [9].
According to Romanian scientists, the resistance of apricot buds to low temperatures depends on its level of rising. It is observed to completely damage the fruiting buds when temperatures dropped in prolonged exposureto -25˚C in December-January.Apricot tree varieties were not damaged even at a temperature of -28˚С, but damage was detected when this cold temperature was observed for 3-4 hours [1].
Lack of moisture in the soil slows or stops the growth of fruit plants, resulting in subsequent wilting of leaves and early shedding.The next year, the growth quality of the crop and the number of main fruits decreases, and the quality deteriorates[4].

THE PURPOSE OF THE RESEARCH
Selection of local and introduced varieties of apricot in the soil and climatic conditions of the Kashkadarya region and the introduction of selected promising varieties into production.

RESEARCH METHODS
Field and laboratory experiments and the results of scientific research were carried out according to generally accepted methods in fruit growing.

RESEARCH RESULTS
The American Journal of Agriculture and Boimedical Engineering (ISSN -2689-1018) It was observed that by orderly trimming and shaping, the trees made full use of the scattered light relative to the light falling directly on them.This is because it passes through all the branches of the tree and the sun's rays fall on the main part of the leaves.On top of this, it was found that diffused light has a more positive effect on direct light, a larger positive effect on leaf size, color, fruit quality, and good tree growth. In addition, it was shown that how long daylight lasts has a great importance.
As the tree grew older, its demand for water increased, and the root system of fruit trees grew less deeply into the soil, causing less damage to young trees and seedlings from drought.Therefore, when there is little rainfall in the fall and the soil moisture dries out, it is necessary to irrigate the land in winter. The high drought resistance of the Subkhoni Zarya variety is mainly explained by the fact that it is able to retain sufficient moisture even in adverse natural conditions.The number of leaves of the studied apricot varieties, leaf level, water content in the leaves were determined and shown in the table 2 During observations and scientific expeditions, it was observed that the onset of phenological phases in apricot varieties on trees growing in mountainous areas varies from 10 days to 23-27 days, respectively, depending on the biological characteristics of the varieties compared to varieties grown in desert areas.
These phenological phases were identified in the studied apricot varieties and of these varieties grown in mountainous and foothill areas.

OCLC -1121105746
In conclusion, it can be said that among the introduced apricot varieties Monica Blanca and Shalakh in early spring 2017, due to early flowering, short-term frosts caused 65-70% of damage to the flowers, which led to a decrease in yield.Due to the fact that most varieties of the collection Nadjimi, Subkhoni Zarya, Yubiley Navoi, Isfarak Badamsky have a flowering period of 3-11 days, that is, 10-15% later than Monica Blanca and Shalakh, these varieties did not suffer from short-term frosts.
In terms of drought tolerance, Nadjimi and Subkhoni Zarya varieties are more drought and cold tolerant than Monica Blanca and Shalakh varieties due to the small size of the crown and leaves and low water content in the fruit.