Coffee Seedling Technology: the production Management method of Coffee Seedling stage and the distance between Coffee planting plants

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Production capacity

Coffee production capacity, usually using a conversion factor, converts the kilograms of berries picked from a coffee tree or a batch into the kilograms of raw beans. This conversion coefficient, also known as "bean yield", should be calculated according to different coffee gene types. The average bean yield of varieties in Arabica population is 18%-20%, Canefra is 20%-25%, and Arabusta is 10%-15%. According to the different gene types of coffee, the performance of coffee production varies greatly, and the difference between the lowest yield and the highest yield is as much as 2-4 times. Superior planting conditions can reduce the capacity gap between different populations. Through observation, it is concluded that the yield of coffee plantations with a planting period of more than 4-5 years is usually sufficient to assess long-term income potential. However, the occurrence of gene types with too much fruit is difficult to predict and is not very stable throughout the life cycle of coffee plants. This is a typical common problem of Kaddura and many Kadim lines under Brazilian cultivation conditions.

3.3.1.2

Vigor

The vitality of young wild plants can be obtained by measuring the diameter of the main stem of the plant, or by measuring the growth rate of the diameter of the main stem in the first and second years. This characteristic is a very effective yield index, for example, Canefa tree with a correlation genetic coefficient of 0.70 to 0.93 has been found in C ô te d'Ivoire and put into practical research. The vigor of adult trees is mainly obtained by the measurement of plant height and / or crown diameter, which are closely related to coffee yield. However, it is not necessary to choose plants with strong vitality for cultivation. The "productivity activity coefficient" (also known as "fruit yield rate") has been used in the seed selection of Canefra in order to reduce the plant distance and increase the yield.

3.3.1.3

Visual Breeders Evaluation system

In some coffee-producing countries, a practical scoring system is used to evaluate the capacity of a single coffee tree. The scores covered the actual yield, expected yield in the coming year, plant vitality and plant shape. In Brazil, grain uses a 10-point scale, which is scored in the first three production years of the variety experiment, which has a good correlation with the subsequent yield of 15-20 years. The scoring system can be used by coffee breeders to pre-select a large number of germplasm, such as separating F1 and F2 populations, without observing the yield and plant vitality for a long time.

3.3.1.4

Growth habit

Nowadays, people are more and more fond of dwarf coffee trees because they can be planted with high density and are beneficial to berry picking. Dwarf plants are usually related to current genes, which will mean that heterozygous dwarf plants will produce isolated seedlings. The selection of dwarf plants can be carried out in the nursery stage. In coffee plantations, mixed cultivation of tall and low varieties is not recommended, as there is unequal competition for nutrient intake.

3.3.1.5

Yield stability

In order to evaluate the stability of production capacity under different planting environments, the experiment of planting the same variety at multiple sites was conducted. Therefore, planting variety recommendations should be different even in different regions of the same country. For example, Cameron determined the difference in growth conditions between the western and eastern regions of the country by using different clonal seed selection techniques for Canephora breeding.

3.3.2

Disease resistance ability

3.3.2.1

Fungal diseases

Under field conditions, the resistance to leaf rust (CLR,Hernileia vastatrix) can be evaluated by subjective observation. The 5-point scoring system is usually used to grade the sensitivity (S) and disease resistance (R) of coffee plants to bacteria. The resistance and level of coffee plantation to leaf rust will directly affect the yield, and the incidence of high-yielding plants is very high. In order to evaluate the resistance of coffee trees to fungal diseases under control, we used two simple experiments: in vitro leaf or leaf disc inoculation.

In order to resist CBD patients caused by Colletotrichurn kahawae, the proportion of black fruit can be estimated, or the degree of fruit drop disease can be measured during infection. In laboratory experiments, Hypocotyl inoculation can be used for early screening and confirmation of disease resistance of coffee mother plants in the field. The berries separated by the latter also have commercial value. For more information about CLR/CBD disease resistance testing, readers can refer to the relevant chapters of this book devoted to fighting fungal diseases.

The importance of fighting other coffee diseases such as this cannot be ignored and should be observed in plantations and nurseries during the epidemic, it is recommended that a five-point scale be used to classify the disease according to the incidence of the disease (% of the infected organs) or the severity of the disease (% of the tissues damaged by the disease).

According to the genetic diversity of Arabica species, various disease resistance can be observed, such as Fusarium wilt (Fusariurn spp), bacterial wilt (Pseudornonas syringae), brown spot (Cercospora cofeicola) and recently discovered American leaf rust (Mycena citricolor). The Canefra strain is also resistant to Fusarium, leaf anthracnose (Colletotrichurn spp.) and pink (Corticiurn spp.). The resistance of coffee plants can only be observed in an environment conducive to disease breeding. For example, black eye spots are mainly caused by uneven nutrition, uneven yield, and uneven shading in coffee trees. In this case, plants with too much fruit are more likely to be infected. This situation has occurred in some Kadim species in some producing countries.

Selection and breeding of Coffee

3.1

Summary

3.1.1

Main content

In order to produce high-yield and high-quality coffee, it is very important to select the variety. Coffee breeding, that is, the creation and research and development of new varieties, has developed a series of high-yield varieties for farmers, which are not only suitable for different farming systems, but also show their enhanced resistance to leaf rust and coffee berry beetles.

In the next 10 to 15 years, in order to enhance the resistance to different nematode species and other insects, especially coffee striped moth and coffee berry beetle, through the use of artificial hybrid varieties of Arabica and Robusta, it is also possible to improve the quality attributes of influence cup testing (especially for Robusta), and further progress is expected.

The future progress of coffee breeding depends not only on the genetic diversity among the populations to be bred, but also on the efficiency of identifying effective genetic variants and incorporating them into new and improved varieties. Precisely because coffee is a perennial crop, seedling projects take several years to produce results, so long-term commitments in terms of financial and human resources are needed.

In many major coffee-producing countries, the share of funds and human resources allocated to coffee breeding and scientific research has been suppressed by the low price of the coffee market in recent years. What is important, however, is that today, most of the coffee in the world coffee market comes from coffee plantations where varieties are selected by artificial hybridization-an argument that is particularly true for Arabica coffee but not for Robusta. In the current situation of low coffee prices, only the farmers who grow high-yielding improved varieties can generate revenue, so the improved varieties contribute a lot. To a large extent, the future survival of the coffee industry depends on the continuous research and development of new and improved varieties. Only in this way can we overcome the changing environment and the new problems that restrict production capacity.

Recently, coffee breeding techniques and characteristics of existing coffee varieties have been reviewed in detail in papers and articles written by Carvalho, Van der Vossen, Charrier, Berthaud and Wrigley. Kushalappa and Eskes wrote an article on the progress of research on seedling breeding against leaf rust. The classification of coffee species, including the description of several current commercial varieties of Coffee, has been introduced in the previous chapters and summarized the classification of coffee in the major producing areas of the world.

The purpose of this chapter is to provide background information for agronomists to understand the breeding techniques of coffee and the stages of developing and cultivating high-yield varieties.

3.1.2

Characteristics of Coffee species related to breeding

The two major coffee-growing species are Arabica and Robusta, and there are significant botanical differences between the two. Arabica species are tetraploid inbred species, which are propagated by self-pollination. On the other hand, Robusta is diploid and strictly cross-pollinated, which is due to the self-incompatible allele. Therefore, the source of each coffee seed is pollinated with neighboring coffee plants. In addition to the above differences, interspecific hybridization between the two species is possible, although the plants grown from interspecific hybridization are not so fat.

The cultivated variety (Cultivar) is a variety with relatively fixed genetic genes (variety). For Arabica species, most Arabica subspecies are combined with genotypes (homozygous); they represent a genotype that is propagated by self-pollination (internationally famous varieties such as Mundo Novo, Catimor and Caturra). Varieties crossed between different varieties are generally known as "F1" hybrids. In the process of raising seedlings, "Line" is considered to be the advanced offspring obtained through continuous successful self-pollination, but they are not necessarily synthesized by the same gene type. "pure line" (pureline) is synthesized by the same gene type.

The selection between species lines requires population isolation, and its purpose is to obtain varieties with fixed synthesis of the same kind of genes, and become inter-line selection or inter-family selection. The populations derived from F1 hybrids by self-pollination become F2 hybrids, F3 hybrids are derived from F2, and so on. F6 or more fortified hybrid populations can be considered as fixed varieties.

As for Robusta, varieties that have already been developed under this species are done through cloning and screening or the offspring of hybrids (hybrids between cloned varieties). The Robusta hybrid variety is propagated in the breeding garden of double or polyclonal varieties. Cloned varieties are propagated by undercutting.

END