Production, harvesting, processing

Grower interest in kenaf arises primarily from its potential as a commercial fiber crop. Since the entire top growth is harvested, it returns little crop residue back to the soil. While kenaf certainly has merit as an alternative crop, there is nothing inherently “sustainable” about it.

High biological efficiency

Kenaf is a seasonal crop harvested at least once a year. Moreover, kenaf is a tall and fast-growing annual growing to a height of 12-18 feet in a 150- day growing season. The average dry stem plant production of kenaf/jute ranges from 20-40 ton/ha/year. Recently, it is reported that new kenaf variety has been developed with a yield of 12 ton/acre. Whereas, the production of the fastest wood plant is only 8-12 ton/ha/year and the forest trees need at least 10-14 years from plantation to harvest. Because the biological efficiency of kenaf is much higher than the perennial wood plants, using kenaf as raw materials will reduce the cost for pulp and paper industry as compared with using woodpulp.

Wide ecological adaptability

Kenaf can be grown on a wide range of soil types, and has good tolerance to salinity, water stress and water logging. Agronomic, they have some advantages in respect to susceptibility to climatic extremes, and to pests and diseases.
Also, kenaf can be grown year-round in the tropics, and as summer crops in sub-tropical and temperate areas.

Sustainable agricultural practices

Experiments have shown that only a modest amount of fertilizer, a preemergence herbicide, a small amount of post-emergency herbicide is required for kenaf cultivation. Furthermore, because kenaf is grown for the fibrous stalk, and not the fruit or flower of the plant, insecticides are not required. On the
other hand, this crop can produce five to ten tons of dry matter per acre with about one ton of dry matter returned to the soil in the form of leaves as well as about three tons of roots in the soil. Thus, a large amount of organic materials is replaced into the soil while producing a substantial amount of cellulose.
Cultivation of kenaf will not result in high level of agrochemical residue. By contrast, it enriches the soil fertility.

Harvest and post-harvest techniques

The evaluation of field equipment for harvesting kenaf continues to be an important aspect of commercialization. It has been demonstrated that standard forage cutting, chopping and baling equipment can be used for harvesting kenaf as either a forage or fiber crop. Kenaf can be baled into small square or large round bales. Sugar cane harvesters, with and without modification, have also been successfully used to harvest kenaf. In cotton growing regions, cotton modules have been used for field-side storage of chopped kenaf. Kenaf can also be pelleted for use as a fiber or forage crop.
Pelletizing kenaf increased its density by at least 390 percent, therefore, reducing both transportation and storage costs. It may be economically advantageous to use available commercial harvesting and processing equipment rather than investing in the development and production of kenaf specific equipment. Appropriate harvesting and pelletizing equipment is readily available throughout the United States. Mobile in the field harvester/separators are being developed, which will cut and then separate the bast and core fibers in the field. When harvesting kenaf for fiber use, the moisture content and the equipment availability are important considerations. Kenaf can be harvested for fiber when it is dead, due to a killing frost or herbicides, or when it is still growing. The dry standing kenaf can be cut and then chopped, baled or transported as full
length stalks. If the kenaf drying and defoliation process is dependent on a killing frost, the harvesting date will vary on the area of the state where the crop is growing and the time required for the kenaf to dry unless artificial drying is used. Much of the land which could be planted to kenaf does not lend itself to late harvest because of weather conditions and soil type. Actively growing kenaf can be cut and then allowed to dry in the field. 0nce dried, the kenaf can then be chopped, baled or transported as full length stalks. The availability of in the field harvester/separators will add to the harvesting options.

Seed production and marketing

Because of the African origin of kenaf, the kenaf seeds usually require an additional 60-90 days of frost free conditions to reach the physiological maturity for germination, which makes the seed production and supply of kenaf a difficult part for kenaf cultivation. Furthermore, the quality of the seed produced is closely affected by the climate conditions. To ensure the continuos supply of high quality kenaf seeds, some countries have established off-season nursery. For example, in Hainan, China, high quality kenaf seeds are produced in March. On the other hand, kenaf seed market in producing countries is not well regulated. Farmers have difficult in accessing high quality seeds. Poor quality, even fake seeds sometimes are channeled to the seed market and cause damage to the farmers.

Cultivation kenaf on marginal lands

Since kenaf has a wide range of adaptation to the climate and soils, it is possible to cultivate kenaf in some marginal lands which can not be used for cultivating other agronomic and horticultural crops. This will also sooth the competition for lands between kenaf and other food crops observed, specially in countries with high population and less cultivable lands like China. By contrast, a large area of lands exist with poor soil or other adverse conditions such as, flooding, arid and semiarid, saline, etc. In Indonesia, success has been achieved in cultivating kenaf in low pH pat soils dominating large areas of east Java.

BAYOF sc - NIF: G-17774258 - Ctrs. Nacional II APDO 58 - 17700 LA JONQUERA (Girona) - Espagna
Phonel : +33 8 70 44 82 86 - Fax : +33 4 68 04 84 03 - Cell : +33 6 76 19 59 09 / +33 6 22 27 40 90