Analysis of the Application of the Trellis Cultivation Model in Pear Orchard Renovation

Korla fragrant pear is one of the specialty fruits of the Aksu region. In 2003, due to a rare continuous low temperature in spring, 621 hectares of fragrant pear trees were killed by freezing, and due to natural factors such as wind damage and fruit drop during the flowering period, the fruiting area of fragrant pear decreased by 1933 hectares, with direct losses reaching 115 million yuan. The traditional frost prevention measures previously used in pear orchards, such as smoking and windbreak barriers, could not withstand sudden severe weather, making it particularly urgent to solve the frost and wind damage problems facing fragrant pear.

The trellis cultivation model is a pear orchard management model in which cement posts are erected around the perimeter of the pear orchard and grids of 0.5-1.5 sq m are evenly stretched above the orchard, with all branches of the pear trees tied to the wire. Since all fruiting branches are tied to the wire, the trellis surface is neat, ventilation and light penetration are effective, branch opening angles are large, flower buds and fruiting branch groups are easy to form, and wind resistance is strong, making pruning and harvesting easy. In recent years, it has been widely applied in pear orchard renovation in inland areas, and its wind damage prevention efficacy has been fully affirmed.

The Korla fragrant pear variety is not resistant to wind damage, and sudden low temperatures affecting flower bud differentiation are the main physiological disasters causing large-scale yield reduction of fragrant pear in recent years. Moreover, fragrant pear has strong branching ability and high requirements for harvesting. Adopting the trellis cultivation model to change the traditional management model and renovate existing fragrant pear orchards is a relatively optimal management model.

I. Targets of the Trellis Cultivation Model in Pear Orchard Renovation

It mainly targets old, low-yielding pear orchards severely affected by wind and frost damage. On the original basis, trellis facilities with different grid sizes are added for pear orchard renovation, so that the entire orchard trellis surface is neat, branch opening angles are large, fruiting branch groups are increased, summer and winter pruning and autumn harvesting are easy, and wind and frost damage are reduced, thereby achieving the goal of substantially increasing fragrant pear yield and raising farmers' income.

II. Investment Estimate for the Trellis Cultivation Model

Since this project is a renovation on the basis of existing pear orchards, apart from the cement posts, wire, and technicians' travel expenses needed to build the trellis, there is no other capital investment.

1. Investment for old orchards over 35 years: 2150 yuan/667 sq m

Old orchards over 35 years, due to the large number of branches, are constructed with 1.5 sq m grids.

① Investment in cement posts

68 posts/667 sq m x 25 yuan/post = 1700 yuan.

② Investment in wire

150 kg/667 sq m x 3 yuan/kg = 450 yuan.

2. Investment for low-yielding orchards: 2630 yuan/667 sq m

Low-yielding orchards are often caused by extensive pruning, too many water shoots, and few fruiting branch groups, resulting in low fragrant pear yield, so 1.2 sq m grids are used for construction.

① Investment in cement posts

86 posts/667 sq m x 25 yuan/post = 2150 yuan.

② Investment in wire

160 kg/667 sq m x 3 yuan/kg = 480 yuan.

3. Investment for orchards prone to wind and frost damage

Newly built orchards, due to weak construction of windbreak shelterbelt networks, are prone to wind and frost damage. For pear orchards prone to wind and frost damage, 1.0 sq m grids are used for construction, so that as many branches as possible are trained onto the trellis, reducing wind damage and facilitating the application of frost prevention measures.

① Investment in cement posts: 0.31 ten thousand yuan

100 posts/667 sq m x 25 yuan/post = 2500 yuan.

② Investment in wire

200 kg/667 sq m x 3 yuan/kg = 600 yuan.

III. Expected Benefit Analysis

At present, the yield of fragrant pear orchards under 6 years old in the Korla region is 500 kg/667 sq m, the yield of 8-10 year old fragrant pear orchards is 1.5-2 tons/667 sq m, the yield of 11-20 year old fragrant pear orchards stabilizes at 2-2.5 tons/667 sq m, and the yield of fragrant pear orchards over 20 years old stabilizes at 2 tons/667 sq m, after which the yield declines year by year.

With the trellis cultivation model, since all branches are tied onto the trellis, it is conducive to flower bud formation and increases fruiting branch groups. Taking orchards under 6 years old with a three-main-branch tree shape as an example, under the general cultivation model, each main branch has 30 fruiting mother branches, each mother branch has 6-8 fruiting spurs, and the yield per 667 sq m is 504 kg; under the trellis cultivation model, with the number of mother branches unchanged, 5 more fruiting spurs are added per 667 sq m. Calculated by the same method, the yield per 667 sq m can be increased by 360 kg. At the unified market purchase price of 3 yuan per kg, the income per 667 sq m can be increased by 1080 yuan. It can thus be seen that adopting the trellis cultivation model can significantly improve the current situation of a single fragrant pear cultivation model and weak resistance to wind and frost damage; at the same time, because trellis cultivation can reduce the difficulty of summer and autumn pruning and harvesting of fragrant pear, it can also raise labor productivity and substantially reduce labor costs.