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.
COMMERCIAL EXPERIENCE WITH CHEMICAL SUGARCANE RIPENERS AT SIMUNYE SUGAR ESTATE IN SWAZILAND
The results of five years of commercially ripening sugar­ cane, mainly variety NCo 376, are presented and discussed. The ripeners were Ethrel (ethephon), Polado (glyphosate) and Fusilade Super (tluazifop-butyl). Extensive assessments confirmed the consistency and effectiveness of Ethrel in ripening variety NCo 376, with positive responses in all years, from May to October, averaging0,7 units of pol % cane and 1,0t pol ha-I. Polado was used mainly on late harvested cane, increasing pol % cane and t pol ha: by about 0,6 and 0,4 units respectively. Fusilade Super gave disappointing re­ sults at the recommended rate ofO,3 Qha", but at 0,42 Qha" it has apparently outperformed Polado, though not Ethrel. Combining both Ethrel and Fusilade, the so-called 'piggy­ back' treatment, produced excellent results on variety NCo 376 in 1986, increasing pol % cane, t pol ha" and pu­ rity % cane by 1,3, 1,4 and 2,0 units respectively. These results indicate that each ripener acts independently and that the individual benefits are additive.
On the fractionation of β-lactoglobulin and α-lactalbumin
Abstract Existing methods for the preparation of α-lactalbumin and β-lactoglobulin are examined critically. It is proposed that the most satisfactory method for the preparation of the whey protein fraction from bovine milk is (NH 4 ) 2 SO 4 fractionation. A number of new gentle procedures for the fractionation of the whey proteins are compared with some existing methods. The distribution of total protein at various stages is determined by total Kjeldahl nitrogen and the kind of protein by starch-gel electrophoresis. The effect of variables, such as pH, salt concentration and temperature on the separation of α-lactalbumin and serum albumin from β-lactoglobulin is studied. Differences in the behavior ( e.g. solubility) of genetic variants of β-lactoglobulin are noted. The solubility of each of the major whey proteins, under similar conditions to those used in the fractionation, is compared with its solubility in the whey protein mixture. The understanding gained of factors important in the fractionation is used in recommending new procedures for α-lactalbumin and β-lactoglobulin isolation.