It is an organization of technical workers and others directly interested in the technical aspect of the South African Sugar Industry. It operates under the auspices of the Sugar Association of South Africa, but is governed under its constitution by a Council elected by its members.
SUMMARY OF AGRICULTURAL DATA
SUGARCANE CROP 1967/68 AND 1968/69
The Miller-cum-Plantcr group currently leads the sector with the highest sugarcane yield per hectare under sugarcane and averaged 24.8 and 20.4 tonnes of sugarcane per hectare under sugarcane respectively across seasons. The grower then receives tons of sucrose per hectare per month and tons of sugar cane per centimeter of rainfall for each field each month.
A SULPHUR DEFICIENCY IN SUGARCANE
Sucrose yields per acre in the three high sulfur treatments were approximately 2.5 times that of the control treatments. Odendaal: Were the treatments applied to the soil surface or were they incorporated into the soil?
OBSERVATIONS ON FROST DAMAGE AT NAKAMBALA ESTATE
32 Proceedings of The South African Sugar Technologists' Association - June 1969 Although some of these lalas had a tendency to break. The effect of frost damage on some of the non-sugar constituents of sugarcane.
FIRST RATOON RESULTS OF TWO IRRIGATION EXPERIMENTS AT PONGOLA
It is clear that the soil profile for the 28-day cycle was not saturated at the beginning of the planting period below a depth of 4 ft. A month of complete suspension of irrigation after gradual drying was not long enough to allow depletion of soil moisture in the surface layers.
SOME NOTES ON SOIL CONSERVATION PRACTICES AT TONGAAT
Soil erodibility: what qualities should be applied to structures; deep recent sand that has not been preserved; During the life of the crop, structures become filled with silt and soil deposits after storms.
THE EFFECT OF DIFFERENT METHODS OF FURROW IRRIGATION ON WATER APPLICATION
Application in the mid-row treatments was suboptimal, especially in the narrow V-shaped furrow of the I N treatment (1.7 inches). This is probably because the groundwater table contributed a significant amount of water in the row treatments.
RECLAMATION OF TWO SALT-AFFECTED SOILS IN ZULULAND
Another possibility is the fungicidal effect of the sulfur which can suppress soil pathogens in the rhizosphere3. In general, the sulfur appears to have effected a more rapid improvement in the soil physical conditions.
THE USE OF LAND CHARACTERISTICS IN CROP SCIENCE WITH PARTICULAR REFERENCE TO THE
SOUTH AFRICAN SUGAR INDUSTRY
It is therefore logical that a statement of these data should be made in a manual of sugarcane production in terms of the climate types and soil ranges. Furthermore, a statement of the climate and soil classes themselves would logically precede the presentation of capability and treatment data in a manual.
THE ELIMINATION OF THE VIRUS DISEASE, STREAK, BY THERMOTHERAPY AND TISSUE CULTURING
Despite this, none of the specimens, when developed, were free of the symptoms of streak disease. True differentiation and the production of the initial vascular bundles follows, as illustrated in Fig.
THE EFFECT OF A SYSTEMIC INSECTICIDE
ON THE SPREAD OF MOSAIC AND ON CERTAIN SUGARCANE INSECTS
During examination of the cane in this experiment for the presence of mosaic it was noted that many of the leaves contained insect eggs, usually inserted into the midrib. The incidence of mosaicism decreased linearly as distance from the source of infection and vectors increased, with this effect noted over a surprisingly short distance.
THE DEVELOPMENT OF POPULATIONS OF NUMICIA VIRIDIS MUIR IN SUGARCANE FIELDS
It is interesting that a decline in numbers between nymphs and adults of the same generation was most common and most noticeable during the period from August to November. At two of the sites the cane was sampled not only on the perimeter but at 25-yard intervals into the field up to 100 yards. The purpose of the experiment was to find out (1) whether there was a predominance of one sex; (2) whether females only fly at a certain stage of egg maturity; (3) whether there were differences in numbers, sex ratio or state of maturity at different distances from the old cane (from which the adults were presumed to have come, as there was no other older cane or green grass in the immediate vicinity) .
SMUT SUSCEPTIBILITY TESTING OF SUGARCANE VARIETIES IN RHODESIA
No significant difference between N:Co.376 and N:Co.310 was revealed in the percentage of soot-infected feces or in the number of lashes produced. A comparison of the number of soot whips recorded in N:Co.310 and N:Co.3'76 shows the higher sensitivity of the former variety. In the first inoculation experiment, N:Co.376 turned out to be more sensitive to soot than N:Co.310.
MECHANISATION SYMPOSIUM
HISTORICAL REVIEW OF SUGARCANE MECHANISATION IN AUSTRALIA
The next planned step in the general mechanization of the crop, after the success of the loading operation, was the development, to a successful commercial stage, of the full-stalk harvester. The need to crush cane quickly due to faster deterioration of cut cane compared to whole stem material. Crop mechanization, both cutting and loading, has progressed at a high rate in Queensland.
LABOUR VERSUS MECHANISATION
COMPETITION OR CO-OPERATION
Data for the 1965/66 crop have indicated that approx. 50% of the cane harvested during the season was burned (Du Toit and Murdoch)2. This total of 4.575 million man-days employed over a crushing season of 220 days indicates that 20,800 workers would have been needed instead of the postulated 32,000, a reduction of 35%. Had all these growers used herbicides at the average scale encountered in a farm management sample survey, the labor requirement would have been 1.79 million man-days or 6,500 workers for the season, a 35% reduction.
THE RESULTS ACHIEVED BY INTRODUCING A HIGH CAPACITY LOADER ON A LARGE
MILLER-CUM-PLANTER ESTATE
The estimated use of the side loader was taken at 6 hours per day and the grab loader at It can be seen that the production for a given bonus is greater for the grab loader than for the side loader. The profile of the push/pile is very important for the successful operation of the machines.
THE FUTURE OF MECHANISATION IN SOUTH AFRICA
In light of the above, it is possible to set certain goals, both in the short and long term, with regard to labor use and mechanization of sugarcane harvesting. King: Although the number is decreasing, most of the cane is still carried on rails, ie. this reduces foreign matter in the cane and does not impair the efficiency of the cutter.
THE INTRODUCTION OF MIRID EGG PREDATORS (TYTTHUS spp.) INTO SOUTH AFRICA
Individuals caged with eggs of Perkinsiella insignis are feeding on them and surviving. In South Africa both insects were reared in insectaria on eggs of Peregrinus maidis (Ashm.) as an alternative host. Wise: Apparently intended to release some of these bugs in the warmer months.
THE EFFECTS ON RATOON CANE OF SUB-SOILING IN A NUMBER OF SOILS IN THE SUGARBELT
Results of the physical analysis of a Glenrosa soil one month after subsoil (average of 6 replicates). It is estimated that the effect of the underground fire by cutting roots, and the disturbance of the root/. It is not very difficult, but it depends on the condition of the cane and on unbiased sampling.
INJURY TO SUGARCANE BY 2,4-D FORMULATIONS
126 Proceedings of The South African Sugar Technologists' Association — June 1969. susceptible as N:Co.310, and that there were no real differences between commercial products of the same formulation. least damage done was again evident in the case of N:Co.376. Under the conditions prevailing for Experiment II, no differences were noted for any of the post-emergence applications. Differences in the susceptibility of varieties to damage were observed and of the varieties tested, N:Co.376 was more susceptible than N:Co.382 and N:Co.310.
TESTING BAND FERTILIZER DISTRIBUTORS
This is due to the faster movement of the teeth through the material in the hopper, causing greater disruption of the particles. Because the 'pockets' between the teeth are now filled more completely, the moving properties of the machine improve. Jennings: The application for determining the maximum angle for minimum recirculation (Mamrec) would be interesting.
EXPERIENCES WITH THE DARNALL ELECTRIC MASSECUITE HEATER
Hulett (in chair): The main disadvantage of the Darnall heater was its unreliability. With a continuous centrifuge, the massakuite can be superheated above the saturation temperature just before solidification, so that the molten sugar in the vicinity of the crystal does not have time to diffuse through the molasses. Robinson: One of the problems at Darnall was that a tight massager sometimes broke the electric heater insulators, and this could have been avoided by preheating the massager.
SOME IMPROVEMENTS IN THE DESIGN AND OPERATION OF COAL FIRED BOILERS
- Superheater tube chokages aud failure
- Coal grading and selection
- Economiser tube chokages and flyash arresters Considerable difficulty had been experienced at
- The use of accumulators
This caused a variation in the porosity or permeability of the coal on the grate with resulting draft problems. This economiser was an addition to the boiler and not part of the original installation. 172 Proceedings of The South African Sugar Technologists' Association — June 1969 to be satisfactory the other two were changed i.
PROCESS PLANT INSTALLATIONS AT SOUTH AFRICAN SUGAR FACTORIES
But at Sezela there are two pressure supply rollers for every three rollers, which are not in the T.R.V. Buchanan: Feed rollers are being ignored just as they were in the Mutual Milling Control Project. At the same time, he was able to find out how much of the installed equipment was being used.
THE MUTUAL CLARIFICATION PROJECT PROGRESS REPORT No. I
Hourly catch samples of lime juice, strained juice, and syrup should be taken to the laboratory and cooled to room temperature before pH is measured. Centrifuge a portion of the filter feed (sludge before adding bagasse) and filter and determine the Brix in the clear supernatant. 194 Proceedings of the Association of Sugar Technologists of South Africa - June 1969 10% potassium iodide solution (freshly prepared).
ASPECTS OF FLOTATION CLARIFICATION OF MIXED JUICE
Even the flotation of the juice normally expelled and heated to boiling point was completely satisfactory. Some of the floating flotsam was carried down and dispersed again, finally finding its way into the clear juice. However, a small amount of very fine precipitate always remained in the clear juice of the laboratory scrubber.
CLARIFICATION TRIALS AT DARNALL
P. JENNINGS
Due to differences in pol and moisture content of sugars from different weeks, data relating to raw sugar samples were related to incomplete solids. In Table V, the arithmetic means of the individual raw sugar analyzes were expressed as the percentage of incomplete solids in the composites for the corresponding week. In Table VII, the standard deviations of the analytical results for individual raw sugars were expressed as a percentage of the arithmetic mean.
