Do you want to choose the climate when growing grapes?

I don't know your home environment. I'll give you some data for your reference. The concept of producing area is a place suitable for growing grapes, and it is the best place to grow grapes. From the world, it is generally on the 40-degree north latitude line. For example, Bordeaux in France, California in the United States, Xinjiang in China and Huailai in Hebei are all on this line. 40 degrees north latitude is its suitable cultivation area, and most high-quality grape producing areas in China are also located on this line. Grape cultivation in the world is mainly concentrated in the warm temperate zone of the northern hemisphere, mainly in Europe and southern Central Asia, and also in South Africa.

At the end of 16 and the beginning of 17, grapes were widely planted in Europe, starting from Bordeaux and Burgundy in France in the west, passing through the Mediterranean Sea, Black Sea and Caspian Sea, and reaching California in the United States. For thousands of years, they have been famous for their high-quality grapes. With the popularization of grape planting technology, a large number of grapes are planted in warm temperate regions such as Africa, South America, Australia and New Zealand. Grapes are sold to all corners of the world. There are places in the world that don't produce grapes, but there may be no people who can't eat grapes. In China, Xinjiang has the longest grape cultivation history, and its grape varieties, fruit quality and yield are second to none. In addition to Xinjiang, Hebei Province is currently the second largest grape producing area in China, and the grape production in Liaoning, Shandong and even Southwest China is getting higher and higher. If a bunch of grapes is used to mark the grape producing areas in China, then the line at 40 degrees north latitude must be like a ribbon full of pearls.

Growth condition

Grape planting can be described as a complex labor. If fruit farmers want to have a good harvest and grapes have good quality, they must first choose the best growing environment of vines before transplanting and grafting to meet the growth of grapes.

Processing will certainly affect the quality of wine, but it is the quality of grapes that ultimately determines the quality of grapes. In the history of wine, fruit farmers often look at God's face and pray that he can give grapes the best growth conditions, because they want to make not only wine, but also good wine. In addition, climate, soil and regional conditions are prerequisites for grape growth, so the choice of vineyards is always considered from these three aspects.

area condition

Grapes have strong adaptability to the environment and are easy to grow, but regional cooperation is needed to grow wine grapes with good quality and unique flavor. The change of topography can produce a microclimate different from the general climate.

Slope is not only beneficial to concentrate sunlight, but also has better drainage performance, so it is more suitable for planting vines than flat land with too fertile soil.

In the northern part of the earth, the slopes facing south can absorb more sunlight, so the temperature of the soil is higher. In the southern hemisphere, and vice versa. In hot areas, the hillside with cool climate is also suitable for planting vines.

Altitude also affects temperature. Grapes ripen longer in vineyards with high altitude and cool climate.

Climatic conditions

Generally speaking, vines are suitable for temperate climate, so most vineyards in the world are concentrated in temperate regions between 38 degrees and 53 degrees north and south latitude. There are many climatic factors affecting the growth of grapes, among which sunshine, temperature and moisture are the most important. The growth of grapevines needs sufficient sunshine and water, and has different effects on different grape varieties. Grapes are also affected by weather changes. If there is frost in summer, hail in summer, and the rain doesn't stop at harvest time, all these will ruin a year's harvest.

Quality and composition of soil

The soil quality of vineyards has a very important influence on the characteristics and quality of wine. Generally, vines don't need much nutrients, so barren land is especially suitable for grape planting. Too fertile land makes vines flourish, but it can't produce high-quality grapes. In addition, the drainage and acidity of the soil, the types of minerals contained in the underground soil, and even the color of the topsoil. It also deeply affects the formation of wine quality and characteristics. The common soils in vineyards are granite soil, sedimentary rocks and soil, gravel and pebble fields.

Grape growth process

Germination stage

When the temperature rises to 10℃ in spring, the annual growth cycle of grapes begins: new buds sprout, then the first new leaf appears, and then new buds begin to grow. In May and June, petals begin to form, and then blossom to form young fruits.

Young fruit stage

This period starts from the young fruit and lasts until the end of the discoloration period. During this period, the young fruit expands rapidly and remains green and hard. Sugar began to appear in young fruits. Meanwhile, during this period, the acid content began to increase gradually.

Overripe stage

When berries are ripe, the material exchange between fruits and other parts of plants basically stops. The relative sugar content of fruit can be increased by water evaporation (juice concentration increases), and berries enter the over-ripe stage. Overripening can increase the sugar concentration in fruit juice, which is necessary for brewing wine with high alcohol content and high sugar content.

period of dormancy

It usually takes 90~ 100 days from flowering to fruit ripening. At the end of autumn, as the temperature drops, the grapes begin to shed leaves, and then enter the winter dormancy period.

Discoloration period

The discoloration period is the period when grape berries are colored. During this period, berries no longer swell. Chlorophyll in the peel is decomposed in large quantities, and the white variety becomes pale, loses its green color and is slightly transparent; Pigment began to accumulate in the peel of colored varieties, and gradually turned from green to red and dark blue. Berry content began to decline.

mature period

It takes about 35 to 50 days from the end of the discoloration period to the ripening of berries. During this period, the berries expanded again, gradually reaching the inherent size and color of the variety, and the acid content of the juice decreased rapidly, while the sugar content increased.

Climate is the main index of grape variety zoning.

In France, it has always been thought that only grapes planted in specific soil can produce world famous wines with special flavor. They believe that soil plays an important role in the division of grape growing areas. However, for the vast grape producing areas in the world, this situation of dividing grape regions by soil is not universal and absolute. The factors affecting the quality of grapes and wine are comprehensive. Only in most cases, climate often plays a leading role in the growth of grapes and the quality of wine. Climate has become the most important and active factor among many factors. Meteorological conditions such as illumination, measurement and precipitation are all necessary conditions for grape growth and fruiting, especially in summer and autumn.

1, lighting

Sunlight is the only energy source of grape photosynthesis, and it is the driving force of grape energy and material circulation. 90%-95% of grape yield and quality comes from photosynthesis. The total energy emitted by the sun into space is 3.7× 1033 erg per second. Outside the earth's atmosphere, if the energy radiated by the sun is 100, the energy reflected back to space through the atmosphere is 37%, and the remaining 63% passes through the atmosphere, of which 20% is caused by atmospheric warming and atmospheric movement, and only 43% reaches the ground. If this 43% is totally absorbed by plants, the photosynthetic effective radiation (PAR wavelength is 380-710 nm (1nm1000 micron), that is, 400-760 nm, is among the sunlight components that chlorophyll absorbs and participates in photochemical reactions when green plants are engaged in photosynthesis. When American scientist R. Emerson and others studied photosynthesis in the 1920s, they found that the quantum utilization efficiency of photosynthesis was only 22.4% in the range of photosynthetic effective radiation of 380-7 10 nm. The reason why the quantum efficiency of photosynthesis is so low shows that plants waste a lot of energy when they absorb light energy and convert it into chemical energy. So in fact, the efficiency of converting solar energy from crops is far from 2%.

Under natural conditions, a lot of solar energy is wasted due to light saturation and other reasons. In many cases, the real solar energy consumed by photosynthesis has not reached 1% of the total solar energy. In China, the solar energy utilization rate of general vineyards is only about 0.5%. Modern science has been pursuing the utilization of solar energy, improving the conversion rate, tapping the potential of increasing production and achieving high yield and high quality. Grapes are light-loving crops and have been erected and pruned for thousands of years. So as to obtain more sufficient and reasonable illumination. In recent years, people still create a more suitable microclimate for grapes through the transformation of scaffolding and pruning, so as to improve the photosynthetic efficiency of each grape leaf and achieve the goal of high quality and high yield.

During the grape growing period, sufficient light makes the flower buds differentiate well and the leaves turn green. Hypertrophy The new buds are stout and the fruits are well colored, especially the European grapes that are particularly sensitive to light. Unlike the European and American hybrids such as Kangke, Kataba and Black Hu Xiang, they can be colored normally only in direct sunlight. In the case of scattered light, bright colors can also be formed. Due to the special demand of grapes for light, the lighting conditions in the grape producing areas are relatively good. However, in the southern provinces where there is no sunny day in China, grapes with good quality cannot be planted, or even cultivated, because in the long-term rainy climate, grape leaves are thin and yellow-green, new shoots are long or thin, petioles are elongated, and flower buds are poorly differentiated, which often leads to small ears and falling flowers and fruits. Due to insufficient light, photosynthetic products are few. Grapes are malnourished, the yield of grapes decreases, the quality is inferior, the new shoots are not fully mature, and the wintering is poor, which is prone to freezing injury. Grape's demand for light is not that the stronger the light, the better. In summer, the high temperature at noon is accompanied by strong light. Under strong light, the surface temperature of fruit can reach above 50℃, and sunburn often occurs on grapes. At noon, when the leaves have the best lighting conditions, there will be a "nap phenomenon". What is the "nap phenomenon"? Under natural conditions, there are two types of diurnal variation curves of plant photosynthesis. One is unimodal, with the strongest photosynthesis and the highest photosynthetic rate at noon; The other is bimodal. There is a peak of photosynthesis in the morning and afternoon, and a trough of photosynthesis at noon, which is called "nap", which is called midnight depression in English. Grapes have obvious "siesta" phenomenon, and the loss caused by "siesta" can account for 30-50% or even more of the total photosynthetic products of some plants. Therefore, we must find ways to reduce or eliminate "siesta" so that precious lighting conditions at noon are not wasted.

Napping is an adaptive protective response of plants to strong light, which is influenced by ecological factors (light, soil, temperature, humidity and CO2 concentration), physiological factors and biochemical factors. At present, it can not be completely explained in theory, nor can it be overcome in production practice.

2. Temperature

Temperature (heat) is the most important meteorological factor affecting the growth and fruit of grapes. Grape is a warm temperate plant. Considerable heat is needed. Active accumulated temperature refers to the sum of daily active temperatures of grapes in a certain growth period, which is widely used. It can not only better reflect the relationship between grape development speed and temperature conditions, but also represent the heat resources in a certain area. The average monthly temperature required during the grape growing period (from budding to fruiting) is 10. The active accumulated temperature above C varies from province to province due to different varieties.

When planting grapes and regionalizing varieties, grape varieties should be selected according to the annual effective accumulated temperature in each region. Knowing the effective accumulated temperature in a certain area and the requirements of a certain variety for effective accumulated temperature, we can roughly infer the possibility of economic planting of this variety in a certain area. Since the effective accumulated temperature is the average value for many years, the fluctuation range of this average value may be 200℃-300℃. Therefore, the above data should be considered in specific applications.

Temperature also has an important influence on the growth and fruiting process of grapes. When the temperature reaches 7℃- 10℃ in spring, the grape roots begin to move. Germination begins at 10℃- 12℃. The suitable temperature for grape shoot growth, flowering, fruiting and flower bud differentiation is 25℃-30℃. If the weather is cold during flowering (< 15℃), the grapes can't bloom normally. The suitable temperature for ripening of fresh grapes and dry grapes is 28℃-32℃, and that for wine grapes is 17℃-24℃.

High temperature will do harm to grapes, but the degree is far less than that of low temperature. The harm of low temperature to grapes is a common problem in grape cultivation in the world, and low temperature limits the cultivation area of grapes. Grapes are generally planted in the northern hemisphere between 20-5 1℃ north latitude. The northern boundary of European grape varieties cultivation is the Rhine River basin in Germany. Grapes grow here because the growing period is too short. The temperature is too low and the accumulated temperature is too little. In some years, the vines and fruits of grapes are not mature yet. Therefore, the vineyards here are all facing the sun on the south slope of the north bank of the Rhine River, making full use of the microclimate of the slope and the regulating effect of the Rhine River on the temperature to ensure the ripening of grapes. The southern border of farming extends to India. In the southern hemisphere, grapes are mainly planted at 20-40℃ south latitude. Constraints on the expansion of grape growing areas in Europe to the equator. High temperature, diseases and insufficient low temperature are the causes of grape dormancy. In some parts of India, some European grapes and hybrid grapes can also grow, but there is no real dormancy period. The main limiting factor for the expansion of European grapes to the poles is that the growing season is short, which is not enough to ensure the maturity of fruits and vines and to resist the low temperature in winter.

The harm of low temperature is mainly the severe cold in winter. The cold resistance of Eurasian grapes varies greatly among different varieties, and there are also considerable differences among different tissues and organs. Generally speaking, the cold resistance of American grapes is greater than that of Eurasian grapes. Grape roots have the weakest cold resistance, and most of them are in a 5. C, according to the determination of Shenyang Agricultural University in 1983- 1984, the critical temperatures of root freezing injury of some fresh rootstocks are as follows: Rose fragrance -5.2℃, Kyoho -6.7℃, Kangbaier Zaochang -7.0℃, Harmony -8.0℃ and Freedom -9.0. Gongniang -9.65438 +0℃, Beichun -9.3℃, Pueraria lobata -9.4℃, Binjiang Grape-1.4℃, Peking University-12.6℃. Vitis amurensis× Vitis binjiang hybrid -65438. In order to reduce root freezing injury, it is of great economic value to use Vitis amurensis and Beta as cold-resistant rootstocks to make grapes buried in the ground and planted in colder areas. But cold-resistant rootstocks are not used in most parts of northern China. In some cold years, even in the case of burying soil, the root freeze injury is quite serious. Therefore, it is necessary to do a good job in winter cold protection. It is generally believed that. When the average minimum temperature for many years is between-15℃ and-14℃, grapes can overwinter without mulching, but grapes must be covered in different degrees below-15℃ to overwinter safely. Even so, the soil temperature 50 cm below the surface often reaches -5℃. The winter buds of grapes are weak in cold resistance, followed by mature annual branches, and perennial branches and trunks are the most cold-resistant. The bud eye of Eurasian grape can withstand the low temperature of -20℃- 18℃ in winter, but if the maturity of branches is poor and the dormancy period is short, it is-15. C. When the temperature is-10℃, the flower buds will freeze. When the temperature is-18℃, if the low temperature lasts for 3-5 days, not only the bud eyes will freeze, but also the branches will freeze.

Low temperature in spring is the harm of late frost. The shoots and young leaves begin to freeze at-65438 0℃, and the inflorescence freezes at 0℃. In autumn, in some years in northern China, early frost appears prematurely, and leaves and grape berries will also be frozen, resulting in discoloration of leaves and softening of berries. At this time, the temperature generally drops to -5℃-3℃ (Table 3-9).

Step 3 precipitate

Among the agricultural environmental factors, natural precipitation and seasonal distribution of precipitation strongly affect the growth and development of grapes and the yield and quality of grapes. In some areas, the seasonal variation of precipitation of some cultivated varieties is one of the most important climatic factors for grape variety zoning. Due to different climate types in the world, the seasonal variation of precipitation shows significant differences. The seasonal distribution of precipitation in the Mediterranean climate is characterized by drought in summer and autumn and rainy in winter and spring (Figure 3-3). However, the climate of the main grape growing areas in China is monsoon climate (except Xinjiang). The seasonal distribution of this climate-declining water is characterized by drought in autumn, winter and spring, and rainy in summer, accounting for 45%-65% of the whole year, which is in sharp contrast with the precipitation characteristics of world-famous grape producing areas.

The grape producing areas in China are all controlled by the high temperature and rainy climate in summer, and the rainy weather in the south in spring increases the difficulty of grape cultivation. Due to the seasonal distribution of precipitation in China, it is suitable for crop growth, but unfavorable to grapes (except Xinjiang), so the phenomenon of "water stress" of grapes is very obvious. The so-called "water stress" refers to insufficient or excessive water. Or untimely, it will hinder the growth and development of crops, so that the climatic resources such as light and heat can not give full play to their functions, the production potential can not be fully exerted, the output will drop, and the quality will be inferior. For example, grapes grow in soil with more rain, the roots absorb too much water, the new shoots grow rapidly, the cells swell, the cell walls become thinner, and the tissues become brittle and tender. Meiyu in flowering period affects the process of pollination and fertilization, causing serious flower and fruit drop and disease spread. In quite a few years, the grapes suffered more rainfall at maturity, the sugar accumulation in berries was difficult, the new shoots were flourishing, the leaf curtain was closed and the diseases were serious. The scarcity of rain and snow in winter and spring will have a negative impact on the overwintering and the growth of grapes in the next year. Although the "water stress" caused by drought is not as serious as that caused by rainy weather, it should be paid full attention to in production and solved by irrigation.