Agriculture Reference
In-Depth Information
There are also a number of types of insects, with various common names, that
attack the leaves of tuber crops. The most common of these are the various potato
beetles. Tubers can also be attacked by nematodes, which are microscopic worms,
wire worms, and grubs all of which can injure or completely destroy the tuber.
There are three relatively simple approaches to minimizing disease and insect
pest in tuber crops. First, crops are grown in rotation with other crops such that there
are four or more years between tuber crops on the same piece of land. Second, only
disease-free planting materials, are used. Third, the pH of the soil can be kept low
such as to inhibit the growth of various microorganisms. To protect tuber sections
used as planting material, the open sides are often coated with sulfur. This accomplishes
two things. The sulfur kills bacteria and fungi, and it also causes the soil around the
cutting to become more acid as bacteria oxidize the sulfur to sulfuric acid. Both
effects of sulfur improve the vigor of the tuber plant and increase the amount of
disease-free harvest.
Various general-use insecticides and other pest control agents can be used to control
disease and pest in potatoes. This includes dusting or spraying plants with insecticide to
control potato beetle.
5.5.6 Harvesting
Harvesting tubers can be done manually by digging the individual plants or mechani-
cally using a tractor (Fig. 5.11). Hand harvesting is common in many parts of the world,
particularly where the crop is on a steep hillside. Figures 5.9 and 5.10 show that tubers
are located just under the soil where the tops emerge. Thus it is possible to dig potatoes
without damaging the tubers because their location is easily determined. Once the soil
is loosened, tubers can easily be collected by hand and carried out of the field.
Figure
5.11.
Tractor pulling a potato haravester. Potatoes are removed from the soil, soil sep-
arated from potatoes, and potatoes transferred to wagon for removal from field. (Courtesy of
Spudnik Equipment Company LLC.)
