Fruit trees make up calcium plants to grow diseases
The sapwood is light brown with a grey or pink tinge and is not sharply differentiated from the heartwood, which is light grey-brown with a pink tinge. Some trees develop a corewood, which is streaked with orange and red lines.
DENSITY
The timber is a Medium Hardwood with a density of 640-880 kg/m3 air dry.
Untreated specimens of merpauh measuring 50 mm x 50 mm x 600 mm achieved an average service life of 1.5 years at the testing ground at the Forest Research Institute Malaysia (FRIM). This placed the timber under the non durable category. The timber is readily attacked by insects and fungi, especially staining fungi, which discolour both the sapwood and heartwood.
Based on trials carried out on two species of merpauh, it was found that the treatability of the timber varies considerably, from very easy to average.
Texture is moderately coarse but even, with interlocked grain.
The timber falls into Strength Group B (Engku, 1988b) or SG 4 (MS 544:Part 2:2001).
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When there is no obvious symptom in the upper part of the apple in the early stage of calcium deficiency, the root growth has been affected, the root tip growth of the root has stopped, and the cortex continues to thicken, and many new roots grow at the proximal apex. In severe cases, the roots die, typical symptoms It is a short, thick and multi-branched root group that grows near the dead roots. Symptoms of the upper part, when the new shoot grows several inches or more than one foot long, the top bud stops growing, the top young leaves appear chlorotic spots, the tip and the leaf edge curl downward, and the chlorotic part becomes dark brown after 1-2 days. Forms dead spots and continues to expand to the lower leaves. Fruit calcium deficiency is prone to bitter pox disease and spotted sputum symptoms start from the waist and lower part, the subcutaneous pulp begins to develop lesions, and gradually appear round and concave color spots on the fruit surface (green or yellow fruit surface becomes thick green, red The fruit surface darkens red), and the cut pulp can be seen in the 5-8 mm deep pulp under the peel. Many sponge-like brown spots with a size of 2 to 5 mm appear. The flesh gradually shrinks and the epidermis is necrotic, showing a brown spot. The fruit of the red jade variety is mostly brown round spots on the fruit surface with the lenticels as the center. The edges are clear and slightly concave, but not deep into the flesh, only the layers of cells under the epidermis are discolored. Some orchards in the apple producing areas of northern Fujian have reduced the commercial rate by more than 20% and the loss of more than 500-600 yuan in some years due to physiological diseases caused by calcium deficiency.
2. The main reason for the occurrence of calcium deficiency in fruit trees:
1 soil available calcium supply is insufficient In general soil, the effective calcium content is very small, only tens to hundreds of milligrams per kilogram. The loess soil in the apple producing areas such as the Loess Plateau and the North China Plain in the north is rich in calcium. There is not much calcium available in the soil. Moreover, the organic matter content in these soils is more than 1%, and it is difficult to convert the ineffective calcium into effective calcium.
2 Calcium is absorbed and transported in plants. Calcium is transported in the plant with calcium in the form of calcium ions through the xylem. Since calcium reduces the permeability of the cell wall, this makes calcium more slowly into individual cells.
3 Calcium distribution in various organs Unbalanced calcium transport and distribution in plants is closely related to transpiration. The transpiration of strong organs, such as leaves, gives more calcium. The transpiration of the fruit is weak, so there is very little calcium in the fruit.
4 Different organs compete for calcium. The peak of calcium absorption by apple young fruit is the same period as the new shoot. Due to the large number of leaves on the new shoots, the transpiration is strong, and the competition for calcium is strong. Most of the calcium that enters the tree is absorbed by the new shoots, resulting in little calcium entering the fruit.
3. What is the situation? Apple is prone to calcium deficiency and rainy weather or dry weather, soil water shortage, and reduce the water content of the tree, which will induce calcium deficiency in fruits. After fruit bagging, the transpiration of young fruit is inhibited and calcium deficiency is easy. The densely planted branches and the densely planted fields with poor wind and light are prone to calcium deficiency in the inner and lower parts. Therefore, special attention should be paid to calcium supplementation in dense planting and bagging gardens in the rainy and dry years. In addition, the thin organic garden with low soil organic content has not applied organic fertilizer for a long time, and the soil has low effective calcium content, and it cannot be replenished. It is also necessary to timely supplement calcium.
4. The peak period of calcium absorption in the fruit of calcium supplementation is the new shoot. According to the study, from 3-6 weeks after the flowering of apples to early July, 90% of the calcium required for the fruit has entered the young fruit. Calcium supplementation for apples should be carried out in this period. Three weeks after flowering, spray 3-4 times of calcium, 7-10 days apart, 8-10 weeks before fruit harvest, should also supplement l-2 times of calcium, because the relative concentration of calcium decreased as the fruit expanded. The bagging garden must focus on making several more calcium before bagging.
5. How to supplement calcium with calcium supplementation should adopt the method of foliar spray fertilizer, and the effect of applying calcium fertilizer on soil is very poor. During the fruit growth and development period, foliar application of calcium lactate 500-600 times liquid for 4-6 times can effectively increase the content of free calcium and pectate acid calcium in the peel, promote the stability of the pericarp cells and increase the fruit firmness. It can increase the photosynthesis intensity, prevent sunburn, crack fruit, reduce respiratory consumption, increase nutrient accumulation, enhance stress resistance, promote smooth skin, early coloration and improve storability.
When the leaf surface is supplemented with calcium, the back of the leaf and the fruit should be sprayed, preferably before 9-10 am or after 4 pm.
NATURAL DURABILITY
PRESERVATIVE TREATMENT
TEXTURE
STRENGTH PROPERTIES