Harvesting and Storage

Ripening of sugarcane and harvesting

  • Unlike in other crops maturity in sugarcane cannot be judged by physical appearance since, the economic product is sugarcane.
  • When concentration of this sucrose exceeds 16 per cent and juice purity increases over 85 percent, the cane crop is said to be mature.
  • Cane maturity can be determined approximately by taking the crop age as criteria and crop appearance.
  • However these methods are not so correct because crop maturity greatly influenced by planting time, crop management practices and weather conditions.

Juice Brix

  • Juice Brix refers to the total solids present in the juice expressed in percentage.
  • Brix includes sugars as well as non sugar.

  • Brix is measured using a brix hydrometer and then necessary corrections with reference to temperature are made and true Brix is obtained.

  • Brix can be measured in the field itself in the standing crop using a 'Hand Refractometer'.

Juice Sucrose percent

  • Juice sucrose percent is the actual cane sugar percent in the juice.
  • Juice sucrose percent is determined by using a plarimeter.
  • That is why sucrose percent is also referred as Por percent.
  • Now-a-days to determine sucrose percent in juice, an instrument called "Suerolyser" is available.

  • A cane crop is considered fit for harvest if it has attained a minimum of 16percent sucrose with 85percent purity

Factors affecting Juice quality

    1.  Variety
    2.  Weather conditions particularly during ripening phase.
    3.  Soil type
    4.  Level and time of manuring
    5.  Quality and quantity of irrigation water.
    6.  Planting time
    7.  Age at harvest
    8.  Pest and disease incidence
    9.  Salinity
    10.  Water logging etc.
    11.  Lodging
    12.  Late tillering

  • Keeping inview the above factors proper steps have to be taken to maintain better quality.

Cane yield

Cane yield = stalk number x single cane weight

stalk number depends on

    1.  Germination %
    2.  Tillering capacity
    3.  Percent cane formed shoots and their retention till harvest.

Stalk weight depends on

    1.  Lenght of cane
    2.  Diameter of the cane

  • Harvesting should be aimed to realise maximum number of millable canes produced with least possible losses.

Harvesting tools

  • Manual harvesting of cane by using hand knives or hand axes in very common in India.
  • Usually in all these tools, the cutting blades is heavier than the handle so that cane cutting is easier and efficient.
  • Harvesting requires skilled labourers otherwise these may be loss in cane yield and thus sugar yield.
  • Proper harvesting there fore should ensure :
  • Ground level harvest so that the bottom sugar rich internodes are harvested which add to yield and sugar.
  • De-topping at appropriate level so that the top immature nodes are eliminated.
  • Proper cleaning of cane viz., removing the extraneous matter such as leaves, trash, roots etc.

Mechanical harvesting

  • Now-a-days labour shortage is acute.
  • Timely supply in required quantities of harvested and cleaned cane is highly essential inorder to avoid mill stoppage.
  • Most of the new mills are of high harvesting capacity and many old mills expanding their crushing capacities made the problem much more acute
  • In the coming years the labour problem is likely to deteroiate further. Keeping all their in view mechanization of cane harvest is inevitable.

Problems in machine-used-harvesting in India

  • Small holdings with irregular fields
  • Diverse cropping patterns followed
  • Cultivation practices which have been developed for bullock power and manual harvest.
  • Poor farmers who cannot afford costly machines types of mechanical harvesters.

Types of mechanical harvesters

  • There are essentially two types of harvesters of cane. They are Chopper harvesters and wholestick harvesters.
  • The chopper harvesters harvest the cane, chop them and then load.
  • Usually the trash and other extraneous matter will be higher in these types, for lodged canes chopper types are useful.
  • Wholestick harvesters are good for erect non-lodged canes.
  • These machines are able to detop the cane at required hight and cut the whole sticks.
  • In order to obtain efficient harvesting by using machinery an important requirement is the change to wider row spacing of around 1.5 meters to facilitate easy movement of machinery.
  • One major apprehension among the farmers in likely yield reduction when the spacing is widened from the present row spacing of 75-90cm.
  • However, experiments conducter at different locations indicating that there is no yield loss if appropriate management practices are adopted.
  • The only problem is smaller fields.
  • For economic utilization of machinery a row length of atleast 200meters or more is required. So that turn-around time is reduced.
  • Another prblem is all fields are not of the same level.
  • In general, the quality of machine harvester cane is poor as compared to manually harvested ones because to have harvester cane is the cleanest possible one devoid of leaves, trash, and etc.
  • The cane also will be well bundled and loaded neatly.
  • However, we may have to device means to over come these problems to the extent possible.


Sugar recovery management

  • Sugar recovery for the past ten years indicate considerable variation ranging from 9.7% to 10.3%.
  • The fluctuations in the recovery levels could be noticed between the states, within the season and between the seasons.
  • Under the existing agroclimatic situations and available technologies on hand there is every possibility to reach a level of 12.0 per cent in the tropical belt and 10.5 per cent in sub tropical belt.
  • However, to attain these levels of sugar recovery needs thorough examination of the present situation, present short falls and appropriate measures to be taken to care them is necessary.

Causes for lower and ununiform recoveries

    1.  Quality of cane
    2.  Mill efficiency.

  • Among the two, the fluctuations in mill efficiency are very narrow, controllable and stabilized, but the only major problem is the quality of cane.

Causes for low recovery in the beginning of the crushing season

    1.  Unfavaorable pre-harvest weather conditions
    2.  Immature/under - aged cane
    3.  Inappropriate variety
    4.  Un scientific cane drawal.

Causes for lower recovery at the end of the season

    1.  Unfavourable weather conditions
    2.  Over - aged cane
    3.  Delay in harvest of flowered cane
    4.  Damaged, dry and dead canes
    5.  Longer/extended crushing duration.

Other causes for lower recoveries

    1.  Late and excess manuring of nitorgenous fertilizers
    2.  Lack of basal phosphatic fertilizer and inadequate potassic fertilizer application
    3.  Inadequate crop management
    4.  Unfavourable growing conditions like salinity, alkalinity, water logging etc.

Causes for season to season variations in recovery

    1.  Changes in weather
    2.  Changes in varietal composition
    3.  Changes in crop management
    4.  Changes in cane harvest management
    5.  Changes in crushing duration
    6.  Changes in nill performance.

Steps to achieve and sustain uniformly higher sugar recoveries

Varieties and varietal scheduling

(a) Staggered planting
(b) Use of early maturing/high sugared varieties
(c) Autumn planting

Crop management

(a) Crop nutrition
(b) Irrigation in relation to sugar recovery
(c) Avoiding lodging, bud sprouting and aerial rooting
(d) Newer planting techniques to obtain quality cane
(e) Healthy seed programme

Harvest management

(a) Age of harvest
(b) Maturity survey based harvest
(c) Close harvest
(d) Avoiding extraneous matter
(e) Quick transport of the harvested cane
(f) Use of cane ripeners.