Root tubers are a method of vegetativeplants propagation in. Vegetative reproduction is reproduction without interbreeding. Vegetative reproduction is divided into 2, namely natural vegetative and artificial vegetative. Root tubers are enlarged roots containing food reserves. If this tuber is planted together with the base of the stem, shoots will grow. One example of a vegetative plant is cassava. Cassava or often called cassava, contains nutrients that are good for the body. In cassava there are carbohydrates, protein, fiber, minerals (including potassium, magnesium, phosphorus, and calcium), vitamins (vitamin C and vitamin A), and water.
In vegetatively propagated plants, fibrous roots grow from a straight base. Yams develop from thickening of the root fibers. Cassava plants have several growth phases as follows:
Initial Growth Phase:
a. 5–7 Days After Planting (HST): adventitious roots appear on the base surface of the cuttings. Smooth roots grow from shoots below the soil surface;
b. 10–12 days after planting (DAT): new shoots and young leaves grow;
c. 15 Days After Planting (DAT): all eyes on the cuttings have sprouted.
Initial Phase of Leaf Growth and Roots:
- 15-30 Days After Planting (DAS): formation of leaves and tubers, growth depends on food reserves in planting material (cuttings);
- 30 Days After Planting (HST): enlarged leaves function to carry out photosynthesis and use photosynthetic products (photosynthate) for plant growth;
- 30–40 days after planting (DAT): tubers begin to form. Root fibers and tubers are formed during the first 3 months, and is the right time to fertilize
Stem and Leaf Growth Phase:
- 3–6 months: maximum growth of stems and leaves;
- 4–5 months: maximum photosynthetic period, photosynthate is mainly for the development of leaves and tubers. This period is the 10 most active vegetative growth. Disruption due to pests / diseases, nutrients and water during this period resulted in yield losses
Carbohydrate to Bulbs Translocation Phase:
- 6–9 months: the period of tuber development;
- The highest dry matter accumulation rate in tubers;
- The leaf aging process begins so that the leaves begin to fall.
Dormancy phase (9–10 months):
Leaf formation decreases, most leaves fall and the growth of above-ground plant parts stops. The translocation of sugar and its conversion to starch in the tubers continues until harvest.
The growth of cassava plants was slow in the first three months then increased rapidly in the next two months, and after that it decreased again. The rate of accumulation of N, P, and K is also slow in the first two months and a maximum in the third and fourth months, then very slowly in the last two months (Litbang Pertanian, 2017).
The following is a method for cultivating cassava plants :
1. Preparing seeds. The first
method of cultivating cassava plants is to prepare seeds in the form of lower to middle stem cuttings. The selected seeds come from parent plants aged 10 to 12 months, with a diameter of about 2.5 cm.
2. Preparing the Planting Media
Prepare the planting media by measuring the pH level of the soil using litmus paper, pH meter, and pH tester. The next method of cultivating cassava plants is to clear the land from weeds and plowing. When the soil has been worked on, sprinkle calcite or captan (CaCOlime3)at a dose of 1 to 2.5 tonnes / ha. The function of liming itself is to increase the pH level in acidic soils or peat soils.
3. Planting Seeds
method for planting seeds is to sharpen the lower end of the stem cuttings, then plant them to a depth of 5 to 10 cm. For soil that is watery or moist, just stick it not too deep.
4. Maintenance
How to maintain cassava plants consists of the following stages:
a) Embroidering
Check the dead or growing abnormal stem cuttings. pull out the seeds that fail, then replace them with the remaining seeds you have. Apart from being pulled out, the failed seeds can also be embroidered with embroidery seeds in the morning or evening. The right time for planting is during the first week or second week after planting the initial seedlings.
b) Weed Removing
All weeds or weeds must be removed to keep cassava cultivation running well.
c) Loosening of Soil
Soil that was loosened before planting the seeds must have changed afterwards. Therefore, monitor the condition of the soil and maintain its quality by loosening the soil, which you can do on the same day as removing weeds.
d) Pruning of Shoots
Cassava plants that have 2 to 3 branches must be cut. The goal is to prevent the shoots from growing too big and taking up space. The pruning function is also useful for saving seedlings for the next planting period. So, you don’t need to buy more seeds.
e) Fertilization
- Organic Fertilizer
Several types of organic fertilizers that can be used are compost, green manure and manure. The use of organic matter continuously can reduce nitrogen and carbon reserves in the soil.
Following are the functions of organic fertilizers:
- Strengthens nutrients in sandy soils.
- Able to improve soil structure.
- Improve soil pores and also drainage.
- Increase water absorption in soil.
- Activating nutrients in the soil so that they can be used by plants.
2) Inorganic Fertilizers This
type of inorganic fertilizers comes from chemical fertilizers, such as NPK, KCL, TSP and Urea. We can also add dolomite lime if there is a history of upas fungus attack with a dose of 3 tons for 1 hectare of cassava land. The dose given to cassava plants depends on the fertility level of the soil. Organic fertilizers are given at a dose of 15–20 tonnes / ha of cassava land and 200–500 kg / ha for inorganic fertilizers. While the use of dolomite lime is tailored to the needs. The following is the dose of inorganic fertilizer per hectare given to cassava plants:
Type of Inorganic Fertilizer | Dosage (Kg / Ha) |
NPK Phonska | 120-300 |
NPK Urea | 80-200 |
KCL | 50-125 |
TSP | 30-75 |
Urea | 120-300 |
5. Watering
When cultivating cassava, soil conditions must be in the right humidity level. Not too dry, but also not too wet. During the initial planting period of up to 5 months, soil conditions must always be moist. Furthermore, a good way of watering cassava plants is by irrigating with a puddle system which is done every two weeks. So, don’t pour water directly over the cassava plants.
6. Spraying of Pesticides The
use of pesticides in the cultivation method of cassava plants only needs to be done in moderation. For example, bacterial leaf spot, bacterial leaf spot, brown leaf spot, or concentric leaf spot. Please note, excessive use of pesticides will kill organisms that are good for plant growth. Spraying is carried out in the morning (after the dew is gone) or in the afternoon.
7. Eradicating Pests The
types of pests commonly found in the cultivation of cassava plants are uret pests and red mites. Ureth pests are in the roots of cassava plants, which then damage the roots of the stems and tubers so that the cassava plants die before harvest. To fix this, clean the remaining organic matter at the beginning of the planting period or by mixing insecticide liquid (sevin) at the soil tillage stage (before the seeds are planted). Meanwhile, red mite pests attack the lower surface of the leaves, making the leaves dry. To prevent this is to choose quality initial seeds. As well as spraying large amounts of water.
8. Harvesting
The cultivation method for cassava plants that has been applied for 6 to 12 months of planting can be harvested. For early varieties of cassava, the plants can be harvested at the age of 6 to 8 months. Meanwhile, Deep cassava varieties can be harvested when they reach the age of 9 to 12 months. How to harvest is only by pulling out the stems and cassava tubers with a hoe or ground fork. Sort cassava tubers between clean and fresh ones, with those with defects or black spots.