Sugarcane Case Study

Sugarcane is one of the world’s major food-producing C4 crops, providing about 75 % of sugar produced in the world for human consumption (Souza et al. 2008). World sugarcane production is close to 1.9 billion tonnes per annum and is concentrated in tropical regions, particularly developing nations in Latin America, Africa and Asia. India is the second largest producer of sugar after Brazil with a global share of 17% in 2014-15. Over five million farmers are involved in the cultivation of sugarcane in tropical and subtropical India, the two distinct agro-climatic regions of the crop in the country. The area under sugarcane was 5.03 million hectare with production and productivity of 356.56 Mt and 70.8 t/ha, respectively during 2014-2015.
In
Most of the field crops germinate in about 3 – 4 days after their sowing and produce sufficient foliage to cover the land surface in about 3 – 4 weeks. If the weeds are kept under check up to about 3 weeks or checked in the third week, there will be no further weed problem until the harvest of the crop. But in the case of sugarcane, it takes about 40 days for completing germination and another 60 days to attain satisfactory ground cover by foliage. During this initial 100 days period, much of the soil, space and sunlight are left unutilized by the crop. Taking advantage of the situation, weeds grow luxuriantly especially under tropical frequently irrigated conditions. The major yield determinant character in sugarcane is the number of millable canes (NMC) per unit area at harvest. This is largely determined by adequate number of germinants and production and survival of early tillers. Wider spacing between rows and frequent irrigations favor the growth of competitive weeds causing shade effect at lower nodal portions affecting tillering as well as early growth resulting in low
Weeds compete with sugarcane to a much greater extent than with other short season row crops, because of the wider row spacing and slow initial growth phase. Generally if the competition due to weed is not checked in time, before the ‘close in’ of cane leaves, the growth of cane plants will be seriously affected and the crop will suffer heavily in yield losses. Studies have shown that if weeds are not controlled satisfactorily in the initial stages, the loss in cane yield could be anything between 17.5 t/ha (Srinivasan et. al., 1981) and 23.7 t/ha (Parihar and Mukerji, 1969). The initial period of 90 days is considered critical and during this period, the sugarcane field should be kept weed free to overcome the ill effects of weeds. In the plant crop, the three week period from 4th to 6th week after planting is considered most critical. This is the stage when the shoot roots develop and take over the functions of the sett roots. During this period a weed free environment is very much essential for the better establishment and growth of the sugarcane