Harvest herbaceous plants

Perennial vegetables such as globe artichokes and rhubarb crop much more quickly if grown from divisions or "offsets" taken from a mature plant (see also Herbaceous Plants, p.J93) rather than seed. Asparagus should not be harvested until plants are in their third year, so one-year-old plants, known as crowns, are usually planted (see above, far right). Jerusalem artichokes are grown from tubers, like potatoes, and seakale from sections of fleshy root known as "thongs."... 

Ramie is a bast fiber obtained from the perennial herbaceous plant, Boehmeria nivea. It is mainly grown in China, India, Japan, Korea, and Philippines. Ramie plants are one of the fast-growing plants and can be harvested within an interval of a few months. Three crops of this plant can be harvested every year. Sisal is a hard fiber extracted from the leaves of the sisal plant Agave sisalana). The length of sisal fiber is between 1.0 and 1.5 m and the diameter is about 100-300 tm. 

Jibutilon theophrasti is a herbaceous annual plant produciag a jute-like fiber. The plant is native to the People s RepubHc of China and is commercially grown ia China and the former USSR. Because of its association with jute ia mixtures and export, it is also called China jute. The plant grows to a height of 3—6 m with a stem diameter of 6—16 mm. After harvesting by hand and defoHation, bundles of the stems are water retted and the fiber is extracted by methods similar to those for jute. The fiber is used for twiae and ropes. 

To any energy planter, the most meaningful measure of solar energy conversion to biomass is the number of kilograms of dry matter produced per hectare per year (or tons per acre per year). While photosynthetic processes per se remain an important factor, equally important are all other processes and constraints of plant growth and development which come into play as photosynthate is elaborated to harvestable biomass. Each of these factors finds expression in the energy planter s gross yield of biomass. Annual dry matter yields in the order of 22,500 kg/ha (10 tons/acre) are common for a few species but the majority of herbaceous land plants probably yield less than 4500 kg/ha (2 tons/acre). 

There are two principal limitations of the sickle-bar mower as a harvest implement for herbaceous biomass crops (a) It is designed to operate in relatively low-density stands of plants, and (b), its cutting process is confined... 

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