RESPONSES OF SOME SUGARCANE VARIETIES TO STANDARD AND COMBINATION RIPENER TREATMENTS
The effects on sucrose yield of varying the time interval between Ethrel and Fusilade Super applications in a com­ bination treatment were tested on variety NC0376. Results suggested that Ethrel applied 12 weeks, and Fusilade Super applied eight weeks before harvesting were the most bene­ ficial. Other varieties which responded to a combination treatment were N19, N12 and N22. Varieties N14, N19, N17, N12, N22 and NC0376 grown under irrigation all re­ sponded to one of the ripener treatments, and their responses to Ethrel and Fusilade Super are discussed. There were no significant gains in sucrose yield of CP66/1043 in response to the ripeners although sucrose content was increased.
EFFECTS OF FUSILADE SUPER AND ETHEPHON AS SINGLE AND TANDEM TREATMENTS ON FOUR SUGARCANE VARIETIES
The responses of four varieties to the single sprayings of ethephon and Fusilade Super and to these chemicals applied in tandem were compared in the plant and three ratoon crops. The tandem treatment was best on N19 and N22 while Fusilade Super was the most effective ripener for N12 and CP6611043. The conditions under which the tandem treatment would be the most effective could not be elucidated. Ethephon was only effective in one crop of N19 and N12. Current cost to benefit ratios of 4.1 and 4.9 were estimated but could exceed 10 when matching varieties with the most appropriate treatment and ideal conditions for chemical ripening.
PRECISION FARMING APPROACHES TO SMALL-FARM AGRICULTRUE
Precision farming implies a management strategy to increase productivity and economic returns with a reduced impact on the environment. It is based on the application of information technology to a description of variability in the field, variable-rate operations and the decisionmaking system. There are three technology levels and three strategies in the development of precision farming. Precision farming practices can be used on small farms as well as big ones, and they play a core role in rural development programs which are integrated with industry. A real-time soil spectrophotometer was developed to describe soil variability in farmers' fields, to be used in precision farming.