Construction and shaping and pruning Technology of double-arm scaffolding for Pear trees in mountainous area

Construction and shaping and pruning Technology of double-arm scaffolding for Pear trees in mountainous area

Dehua County, Fujian Province, located in the middle of Fujian Province, belongs to the mid-subtropical monsoon area, cold in winter and cool in summer. It is an adaptive area for early-maturing pears in the south of low latitude and high altitude. 2467hm2 has been planted with an annual output of 296 thousand tons and an annual output value of more than 1. 300 million yuan, which has become a new bright spot of farmers' income. In recent years, with the gradual increase of labor costs and the aging of rural labor force, pear scaffolding cultivation has become a new experimental and popularized cultivation model. Many pear orchards in Dehua County are built in hilly and mountainous areas with complex topography and large slope, and there is a lack of suitable scaffolding cultivation mode and shaping and pruning methods. Therefore, the author cooperates with the Fruit Tree and Tea Research Institute of Hubei Academy of Agricultural Sciences. The research on double-arm scaffolding cultivation of mountain pear trees was carried out in the pear orchard of Qunfang Agricultural Professional Cooperative in Dehua County, and good results were obtained.

1 advantages and effects

Pear trellis cultivation can overcome the problems of traditional vertical cultivation, such as too high tree body, inconvenient manual operation, difficult mechanical cultivation, complex shaping and pruning technology, low degree of standardization, three-dimensional results, great difficulty in branch group renewal, great difference in fruit size and quality, poor wind resistance, serious pre-harvest fruit drop and many other problems, which have been widely used in Japan, Korea, Taiwan and other pear producing areas. At present, pear scaffolding cultivation at home and abroad is concentrated in pear producing areas with gentle and open terrain and convenient scaffolding. The scaffolding type is mainly horizontal scaffolding (also known as horizontal grid). The main push tree has four main branches "ten" type and three main branches "rib" type. this kind of scaffolding pear orchard is relatively standard, neat and beautiful, and the effect is good, but it requires high fertilizer and water conditions, management technology level and pear seedling quality. The shaping and pruning is complex, the technology is difficult, the crown takes a long time to form, the production is late, and the effect is slow. In recent years, Japan, South Korea and other pear areas have explored improved tree shapes such as one main branch "keel" type and two main branch "flat arm" type, in order to adapt to the changes of rural labor transfer and aging, but there are limitations in the promotion of pear orchards in hilly and mountainous areas. For this reason, on the basis of introducing and absorbing the experience of shaping and pruning of scaffolding cultivation in pear producing areas such as Japan and South Korea, and according to the actual situation that pear orchards in Dehua County are mostly hillside land, the pear tree double-arm scaffolding model of the Institute of Fruit and Tea Research of Hubei Academy of Agricultural Sciences was improved and innovated, and the original multi-row joint-span scaffolding (grid) was changed into single-row single-family scaffolding (figure 1).

Fig. 1 anterograde tree structure of two arms

Through years of practice, it is found that the tree structure of these improved scaffolding cultivation patterns is simple, the two main branches extend in reverse direction, the fruiting branches on them will not cross, the lighting conditions are good, and they have the function of excellent fruit and wind proof. it is convenient for standardized management and mechanized operations, such as flower and fruit thinning, artificial pollination, bagging, pruning, spraying, fruit picking and so on, especially simple shaping and pruning technology (foolish) and labor-saving. It can be operated by the middle-aged and elderly. This model can make full use of ventilation and light transmission conditions to carry out three-dimensional planting and breeding of "pear-melon" and "pear-chicken". The branches of this cultivation method are horizontally distributed on the surface of the shed, and the fruit can be picked with a large space under the shelf. it is convenient to carry out sightseeing activities such as flower appreciation, fruit tasting and fruit picking, which improves the economic, social and ecological benefits, and provides a powerful basis for solving the technical bottlenecks such as scaffolding and shaping in hills and mountains.

2 scaffolding construction

The main materials of scaffolding are cement column, triangular steel, steel wire and so on. After planting, the scaffolding was built in the winter of the first year or the spring of the second year, and the scaffolding was single-family, that is, a single scaffolding was built on the terrace of the pear orchard in Shunshan. The square cement column of 10cm × 9cm × 270cm was used to punch holes at the 190cm, 220cm and 270cm of the square column. The 220cm of the square column was equipped with triangular steel crossbar of long 240cm, and the triangular steel crossbar drilled five threading holes on the shelf surface with an interval of about 60cm (figure 2).

Fig. 2 positive view of pillar and crossbar frame

The buried depth of the cement column is 50cm, the height of the aboveground part is 220cm, the height of the top of the column is the same, and the distance between the pillars is 400 ~ 500cm. The top of the cement pillar is tied up with a steel wire rope at both ends, and the oblique angle is about 45 °. The underground depth of the anchor is below 80cm. Flat shed frame surface height 170cm, from the middle to both sides pull 5 parallel steel wire with a distance of about 60cm, wire diameter 5 ~ 6mm steel wire, through the crossbar, with a wire tensioner to tighten the connection of the anchor exposed to the ground, and fastened with flange bolts. The 30cm in the middle of the shelf surface (i.e. the main branch positioning line piercing hole) stretches the main branch positioning line to fix the main branch, while the 50cm (raising the inducer wire perforation hole) upward in the middle of the shelf surface is used for the elongated branch culture and the uniaxial long-releasing fruiting branch group culture. The main branch positioning line, raising the lead wire and the shelf surface form a two-wire one-sided rack type [2] (figure 3). After the main line is all pulled up, then pull the positioning line and the lead line.

Fig. 3 single-row single-family scaffolding type

3 shaping and pruning

In the first year, grafted seedlings or sitting seedlings with developed, sturdy and disease-free roots were selected and planted after defoliation in winter to before sprouting in spring. The grafted seedlings left 1 ~ 2 full and strong buds at 5 ~ 10cm above the marriage interface, and the sitting seedlings kept a single bud and single shoot upright. When the seedlings sprouted new shoots 30cm, the bamboo poles with more than 250cm length were vertically inserted near the seedling trunk, and the new shoots were tied to the bamboo poles. After that, the new shoots were kept upright according to the growth situation. In winter, full buds on both sides were selected to dry at 120 ~ 130cm. If the stem height is not fixed, the full buds should be cut short in the middle, and the new shoots should be induced by an erect branch, and then dry again in the following winter.

Fig. 4 positive view of pear tree scaffolding with two arms

In the second year, when the new shoot length 60cm, the branches were pulled out at a base angle of 45 °and fixed to the positioning line of the main branch, and the other shoots were supported to more than 80 °with buds and were put on the shelf one after another. After the new shoot exceeds the positioning line of the main branch, the shed line and attraction line are used to induce the new shoot vertically, and if it is too long, the bamboo pole can be used to assist the induction. When cutting in winter, put down the upright shoot induced by the growing season, fix it on the scaffolding line, remove the competitive branch of the main branch extension branch, select the sturdy lateral bud short section of the main branch extension branch, lead it vertically to the induction line, and wipe off all the buds on the back of the main branch in order to reduce the elongation of the upper branch the following year (figure 4).

In the third year, the sprouting tillers in the 20cm at the base of the main branch were wiped out in time in the growing season, the overgrown branches on the main branches were left on the side, the auxiliary branches were treated with looped branches, and the extended branches were tied upright by the induction line to maintain the growth potential. At the same time, in the fruiting branch group under the culture rack, each main branch selected a lateral robust branch (the branch was produced near the 30cm or 60cm at the main branch, and no branch could be treated by sprouting). The reverse branch extended and flattened with the other main branch, and the reverse branch was selected with a short bud at 60cm, leaving a bud about 20cm from the branch point of the reverse branch, and the rest buds were erased. The new shoots of dorsal buds and cutting buds were raised and induced to form two long branches above 150cm with balanced growth potential, which were slowly placed into flowers and diagonally pulled onto the shelf to form an "F" shape uniaxial long fruiting branch group, which filled the upper shelf space of the trunk. The "F" on the two main branches extends left and right in the direction of the fruiting branch group. By the winter of the third year, the cultivation of tree structure was basically completed (figure 5).

Fig. 5 scaffolding pear tree top view with two arms forward

The 4th year and the peak period: in this period, the shaping and pruning mainly adopts the uniaxial extension of the main branch, elevates and induces the elongated branch, and maintains the growth advantage; secondly, it cultivates the uniaxial fruiting branch group near the shelf point of the main branch and the shelf surface, the method is to select the lateral long branch and strong bud short cut, let the shearing branch extend outward, and form the uniaxial long and extended fruiting branch group year by year. Or select lateral or dorsal weak branches and then vertical induction to promote the strong shoots above 150cm, slowly put into flowering and then flatten the fruit, forming a uniaxial long-spreading fruiting branch group.

Fruit of pear trees in scaffolding