Introduction

• Sugarcane harvesting should be so timed that the cane attains peak maturity and maximum yield level under the given growing conditions.
• The method of harvest should be such that maximum of the cane produced is harvested to the ground level and all extraneous matters such as tops, trash, roots etc. are excluded to the extent possible.
• When the crop matures the leaves turn pale and start yellowing or drying.In many varieties such symptoms may not be seen. If irrigation water is applied, crop may appear lush green.
• Mature canes when tapped give a sort of metallic sound. When a mature cane is cut in a slanting way and held against the sun, we can observe sugar crystals glistening.

• Sugarcane harvesting should be timed so that the cane attains peak maturity and maximum yield level under the given growing conditions.
• The method of harvest should be such that maximum of cane produced is harvested to the ground level and all extraneous matters such as tops, trash, roots etc. are excluded to the extent possible.
• When the crop matures the leaves turn pale and start yellowing or drying.In many varieties such symptoms may not be seen. If irrigation water is applied, crop may appear lush green.
• Mature canes when tapped give a sort of metallic sound. When a mature cane is cut in a slanting way and held against the sun, we can observe sugar crystals glistening.
• Stalking of harvested cane under shade with trash cover could minimize the loss in weight and accumulation of reducing sugars significantly.

• Harvesting is done manually using various types of hand knives or hand axes. Harvesting requires skilled labourers as improper harvest of cane leads to loss of cane yield (thus sugar), poor juice quality and problems in milling due to extraneous matter.
• Proper harvesting 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 internodes are eliminated and proper cleaning of the cane i.e. removing the extraneous matters such as leaves, trash, roots etc.
• Harvesting labour is becoming scarce and costly, particularly in the tropical India. The Indian Institute of Sugarcane Research, Lucknow has developed a tractor front mounted harvester which gives an out turn of 2.5 ha per day of 8 hours.

• Important sugarcane quality parameters are the juice Brix, pol or sucrose and purity.

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

• Juice sucrose per cent is the actual cane sugar present in the juice. Juice sucrose percent is determined using a polarimeter. Hence it is also referred to as pol percent.
• For all practical purposes pol % and sucrose % are synonyms. To determine sucrose percent in juice, an instrument called 'Sucrolyser' is available.

Purity Coefficient: Purity coefficient or simply purity refers to the percentage of sucrose in the total solids in the juice.

Sucrose (Pol) Purity = ------------------- x 100 Brix

• A higher purity indicates the presence of higher sucrose content out of the total solids. A cane crop is considered fit for harvest if it has attained a minimum of 16 per cent sucrose with 85 per cent purity.

• The reducing sugars (RS) refers to the percentage of other sugars (fructose, glucose) in the juice. A lower RS value indicates that much of the sugars have been converted into sucrose.

• The CCS % refers to the total recoverable sugar per cent in the cane. This is calculated by the following formula:

CCS % = 1.022 S - 0.292 B

where S is sucrose % in juice and B is Brix in juice.

• HR Brix readings can be separately taken from the top and bottom. A narrow range indicates ripeness of the canes, while a wide difference indicates that the cane is yet to ripen. If the bottom portion is having lower Brix than the top, it indicates that the cane is over-aged and reversion of sugar is taking place.