|
Organic Farming
Package of practices
Maintenance of buffer zone
In order to cultivate turmeric organically a buffer zone of 25 to 50 feet shall
be maintained if the nighbouting farms are non-organic. The produce from this zone
shall not be treated as organic. Turmeric being an annual crop, the conversion period
required will be two years, Turmeric can be cultivated organically as an intercrop
with other crops provided organic methods of cultivation is followed for all the
companion crops.
Sources of planting material
Carefully preserved seed rhizomes free from pests and diseases which are collected
from organically cultivated farms should be used for planting. However, to begin
with seed material from high yielding local varieties may be used in the absence
of organically produced seeds. A seed rate of 2500 kg rhizomes is required for planting
one hectare.
Preparation of land and planting
While preparing the land, minimum tillage operations may be adopted. Beds of 15
cm height, 1 m width and of convenient length may be prepared giving at least 50
cm spacing between beds. Solarisation of such beds is beneficial in checking the
multiplication of pests and diseases causing organisms. The polythene sheets used
for soil solarisation should be kept away safely after the work is completed.
At the time of planting apply 25 g powdered neem cake and mix well with the soil
in each pit taken at a spacing of 20-25 cm within and between rows. Seed rhizomes
may be put in shallow pits and covered with well rotten cattle manure or compost
mixed with Trichoderma (10 g compost inoculated with Trichoderma). Turmeric
can be planted during April-May with the receipt of pre monsoon showers.
Cultural practices
Mulching the turmeric beds with green leaves is an essential operation to enhance
germination of seed rhizomes and to prevent washing off of soil due to heavy rain.
This also helps to add organic matter to the soil and conserve moisture during the
later part of the cropping season. Judicious mix of leguminous leaves with high
nitrogen content and leaves rich in phosphorous like acalypha weed and leaves rich
in potassium like calatropis can be used according to availability. The first mulching
is to be done at the time of planting with green leaves @ 10-12 tonnes per ha. It
is to be repeated again @ 5 tonnes/ha at 50th day after planting. Cow dung slurry
may be poured on the bed after each mulching to enhance microbial activity and nutrient
availability. Weeding may be carried out depending on the intensity of weed growth.
Such materials may be used for mulching. Proper drainage channels are to be provided
in the inter-rows to drain off stagnant water.
Manuring
Application of well rotten cow dung or own compost from own form @ 5-6 t/ha may
be made as a basal dose while planting rhizomes in the pits. In addition, application
of neem cake @ 2 tonnes/ ha is also desirable.
Plant protection
Pests
Regular field surveillance and adoption of phytosanitary measures are required for
pest management. If shoot borer incidence is noticed, such shoots may be cut open
and pick out larvae and destroy them. Spray neem oil 0.5% at fortnightly intervals
if necessary.
Diseases
No major disease is noticed in the crop. Leaf spot and leaf blotch can be controlled
by restricted use of Bordeaux mixture 1%. Application of Trichoderma at the time
of planting can check the incidence of rhizome rot.
Harvesting and post harvest operations
Turmeric is to be harvested at correct maturity. Depending upon the variety, the
crop becomes ready for harvest in 7-9 months, medium varieties in 8-9 months and
late varieties after 9 months.
Usually the land is ploughed and the rhizomes are gathered by hand picking or the
clumps are carefully lifted with a spade. Harvested rhizomes are cleaned of mud
and other extraneous matter adhering to them. The average yield per hectare comes
to 20-25 tonnes of green turmeric.
Fingers are separated from mother rhizomes. Mother rhizomes are usually kept as
seed material. The fresh turmeric is cured for obtaining dry turmeric. Curing involves
boiling of rhizomes in fresh water and the drying in the sun.
No chemical should be used for processing. The cleaned rhizomes are boiled in copper
or galvanized iron or earthen vessels, with water just enough to soak them. Boil
till the fingers/mother rhizomes become soft. The cooked turmeric is taken out of
the pan by lifting the thoughs and draining the water into pan itself. The same
hot water in the pan can be used for boiling next set of raw turmeric which is already
filled in troughs. The cooking of turmeric is to be done within 2-3 days after harvest.
Rhizomes may also be cooked using baskets with perforated bottom and sides. The
mother rhizomes and the fingers are cured separately.
The cooked fingers/mother rhizomes are dried in the sun by spreading in 5-7 cm thick
layers on bamboo mats or cement floor. A thinner layer is not desirable as the colour
of the dried product may be adversely affected. During night time, the material
should be heaped or covered. It may take 10-15 days for the rhizomes to become completely
dry. Artificial drying using cross-flow hot air at a maximum temperature of 60°C
is also found to give satisfactory product. In the case of sliced turmeric, artificial
drying has clear advantages in giving brighter coloured product than sun drying
which tends to suffer due to surface bleaching. The recovery of dry product varies
from 20-30% depending upon the variety and the location where the crop is grown.
Dried turmeric has a poor appearance and rough dull colour outside the surface with
scales and root bits. Smoothening and polishing the outer surface by manual or mechanical
rubbing improve the appearance.
Manual polishing consists of rubbing the dried turmeric fingers on a hard surface.
The improved method is by using hand-operated barrel or drum mounted on a central
axis, the sides of which are made of expanded metal mesh. When the drum filled with
turmeric is rotated, polishing is effected by abrasion of the surface against the
mesh as well as by mutual rubbing against each other as they roll inside the drum.
The turmeric is also polished in power-operated drums. The yield of polished turmeric
from the raw material varies 15-25%.
The colour of the turmeric always attracts the buyers. In order to impart attractive
yellow colour, turmeric suspension in water is added to the polishing drum in the
last 10 minutes. When the rhizomes are uniformly coated with suspension they may
be dried in the sun.
Rhizomes for seed purpose are generally stored after heaping under shade of tree
or in well ventilated shade and covered with turmeric leaves. Sometimes the heap
is plastered with earth mixed with cow dung. The seed rhizomes can also be stored
in pits with sawdust. The pits can be covered with wooden planks with one or two
holes for aeration.
|