FACTORS AFFECTING GROWTH

FACTORS AFFECTING GROWTH

Since the beginning of plant growth has been dependent on the environment, and the greater the degree of dependence that followed the age. The success of the growth of a plant is controlled by several growth factors. Poerwowidodo (1992b) suggested that the growth of a plant is influenced by genetic factors and environmental factors.

Environment is a unit of whole state and the influence of the outside of the control of life and the development of a plant. These factors will affect growth together, although in a particular situation, one factor or several factors more prominent than the influence of other factors.

Soil and climate are the two main elements environment. Depth understanding of these two elements is the key to the success of forest plantation development.

Good plant growth relies on a balanced combination of environmental factors and profitable. If one factor is not balanced with other factors of these factors can suppress or sometimes stop the growth (Buckman and Brady, 1982).

The state of the soil and climate as an essential element of environmental factors affecting plant growth has the diversity of a place to another in support of growth. This diversity is closely related to the properties of the soil and the climate itself so there should be in-depth description of the properties of both factors.

1. Land

Silvicultural interest in the land is derived from the three functions in the growth of the tree that is: as a source of minerals (nutrients), the supply of moisture and physically or mechanical support. Soil productivity is a function of the characteristics of the soil and climate. Soil properties are divided into physical and chemical categories.

According to Valentine (1986), physiographic land and soil properties more significant influence on the productivity of the tree. Physiographic have indirect effects on the forest environment, particularly because of its influence on the climate and soil factors. Physiographic factor is altitude, slope, aspect and sometimes the ground conditions.

Topography where teak plantation areas in Muna generally flat to gently sloping elevation 20 meters above sea level, but in South Kendari there are a few places rather bumpy light with a height of less than 200 meters above sea level. While Teak in Java can live at an altitude of 0-800 meters above sea level and in particular in Cepu 31 masl (Soerianegara and Indrawan, 1978; Wahyono, 1986)

Among the physical properties of the soil is the most important water-holding capacity is available, relating to the solum and the depth of the root zone, soil texture and content of the rock. Indicators on the condition of drainage is also important, for example, the presence of spotting, the depth of the ground water level, the permeability of the bottom layer, which is associated with ease of rooting and water movement. Wahyono (1986) reported that soil depth for Teak on Muna about 90 cm.
Binding ability of a type of soil and provide water and nutrients for plant growth is affected by the texture, structure and soil organic matter content. In general, Teak will grow normally when textured loam soil with crumb or loose soil structure (Sumarna, 2004).

Soil water content greatly affects the growth of plants because water is the biggest part in the preparation and allocation of photosynthate, maintain cell rigidity, maintaining body temperature plants, as a solvent material that will fotosintat compiled through physiological reactions in the body plant. Water is also a solvent of nutrients in the soil so as to facilitate uptake by plant roots, solve and reduce rock thereby increasing the availability of nutrients for plants.

Poerwowidodo (1992b) states, that the water content in the soil less will lead to a reduction in cell division and elongation that ultimately will affect plant growth. The role of indirect soil moisture for plant growth is through its influence on soil microorganisms that play a role in outlining the many minerals that are more likely absorbed by plant roots. The optimum water content in the soil that can support maximum plant growth is at field capacity point, since in this condition the soil aeration pretty good and activity of soil microorganisms running smoothly.

The existence of microorganisms in the soil also has a very important role on the growth of forest plants. Decomposition of organic matter into humus may not be able to take place without the presence of microorganisms decomposers. The formation of humus in the soil is expected to improve and enhance soil fertility, which in turn will influence both the growth of plants (Paloloang, 1994).

According to Soerianegara and Indrawan, 1978; Krishnapillay 2005, quality teak plant growth depends on the structure, porosity, drainage and ability to hold water in the soil. Teak is the best growth was obtained in soil with good drainage and fertile, especially with volcanic substrates originating from volcanic activity and metamorphic or alluvial soil.

Soerianegara and Indrawan (1978); Sumarna (2004) argues, that Teak can grow on various types of soil and soil tolerant thin. However, more suitable Teak grows in Mediterranean soil types that contain lime, such as are found on the island of Muna and Bojonegoro, East Java (Wahyono, 1986; Anonymous, 2006c). Reddish Brown Mediteran special soil in Wonorejo, East Java Teak obtained the highest plant growth at the same age (19 years) than the Red Latosol in Pati, Central Java and Red Yellow Podzolic Complex (PMK), Yellow Podzolic and Regosol in Cikampek, West Java (Martini and Suriamihardja, 1982), as shown in Table 1.

Table 1. Teak Plant Growth in Different Types of Soil

Soil Type	Height (m)	Diameter (cm)
Reddish Brown Mediteran	17.63	27.17
Red Latosol	16.39	22.50
PMK complex, Yellow Podzolic and Regosol	16.70	24.94

Source: Martini and Suriamihardja (1982)

There are variations in the growth of Teak from a tread to tread more influenced by the soil-forming parent materials. Krishnapillay (2005), stated that the growth of Teak better on the ground made of limestone and alluvial parent than flakes. Stem diameter and height of teak trees on the soil parent material flakes and laterite lower than the parent material limestone soil and alluvial (Table 2).

Table 2. Plant Growth Teak on Material Parent

Parent Material	Planting Year	Spacing (m)	Height (m)	Diameter (cm)
Limestone	1965	2.4 x 2.4	31.38	35.44
Alluvial	1966	2.4 x 2.4	31.34	34.60
Flakes Lateritic	1966	2.4 x 2.4	18.12	26.20
Flakes	1965	2.4 x 3.0	17.24	23.50
Flakes	1962	2.4 x 2.4	18.44	24.28
Lateritic	1963	2.4 x 3.0	20.24	25.44

Source: Krishnapillay (2005)

According to Paloloang (1994), the other properties of the soil also affects the growth of plants is the composition of soil air. Oxygen is an element that is absolutely necessary to do the respiration of plants, while carbon dioxide needed for photosynthesis. Respiration in the roots depends on the amount of oxygen available in the earth element. If low oxygen pressure, respiration roots will be reduced, and vice versa. Root respiration is closely related to the absorption of nutrients by plants. Anaerobic soil conditions, such as flooded soils (poor drainage) will disturb the balance of oxygen and carbon dioxide, and this will adversely affect the activity of plant roots. Air circulation is necessary to control the oxygen and carbon dioxide that plant roots activities are not disrupted. Resilience types of Teak to oxygen deprivation ranged 0-10 days (Soerianegara and Indrawan, 1978).

Nutrients is an absolute necessity for plants to grow and develop properly because since the beginning of its growth has been dependent on the role of a nutrient. The availability of sufficient nutrients and by providing opportunities for the survival of plants. There are at least 13 essential nutrients obtained from the plant in the soil, macro elements are N, P, K, Mg, Ca, S and the elements Fe, Mn, Cu, Zn, B, Mo, and Cl as micro elements. One of the macro elements that are important to Teak is Ca because Ca deficiency can hinder growth (Kaosa et al., 1981 in Krishnapillay, 2005).

Soil acidity is one of the chemical properties of the soil are the most important because it can affect nutrient uptake and growth in two ways: 1) direct influence of H + ions, 2) indirect effect, ie via an influence on the availability of nutrients and the presence of elements that are toxic. Teak plants require optimal pH of 6.5 to 7.5. At the pH value is too low Al, Fe and Mn become soluble in an amount enough to cause poisoning suffer Teak, whereas at very high pH values ​​bicarbonate ions will be found in large quantities so as to interfere with the normal absorption of other elements and are very detrimental to optimum growth Teak (Krishnapillay, 2005).