AGRICULTURE DEPARTMENT

REPORT ON THE 6^th LARGE SCALE COMMERCIAL CHEMICAL RIPENER APPLICATION ON SUGARCANE IN KINYARA

SEPTEMBER 2006

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6^th Commercial Chemical Ripener Spraying

The sixth commercial chemical ripener application was carried out in Kinyara Sugar on14^th June 2006. The results of the spraying are presented below.

1.0 Background:

Cane quality is generally low during and immediately after the rainy seasons. Fusilade super (Fluazifop-p-buty) has proved to be effective in improving pol in cane at the peak of the rain seasons i.e. April – May and September – October. Five successful semi-commercial cane ripening application trials using Fusilade super were conducted at Kinyara Sugar Works Limited between 1997 and 2005. Results from these trials showed increased sugar yields. Table below shows the results of these trials.

Table 1.

Sugar yield increment following ripener application:

1997 - 2005

Year	Sugar yield increase (ts/ha)
Oct. 1997	0.50
Nov. 1998	0.10
May 2000	0.41
Oct. 2002	1.23
Oct. 2005	0.27

The considerable variation in the previous sugar yields of treated cane was largely attributed to weather, differences in varietal yields, ratoon number and growth rate and soil. Having successfully carried out five ripener applications, there is need to confirm further the extent of improvement in sugar content of any other cane ripened. Consequently a large scale commercial ripener application trial was carried out on 14^th June 2006, to evaluate further the effectiveness of Fusilade super in cane ripening.

1.2 Objective:

To evaluate the effect of Fusilade super on the juice quality and sugar yield of the four main commercial varieties – Co945, Co617, Co684 and NCo376.

1.3 Rate of chemical applied:

i) Fusilade super – 0.5 Litres applied in spray volume of 30L/ha with stickers.

ii) 1 part of ISO to 3 parts of Fusilade super- to spray in Buly 5 and 9.

iii) 25 ml of Agral 90 in 100 litres of solution- to spray in the remaining selected fields.

1.4 Fields sprayed with ripener on 14^th June 2006:

Eight fields of Co945, three fields of Co617, three fields of Co684 and three fields of NCo376 (Ref: Table 2) were all sprayed on 14^th June.

Control strips were left in Buly5 (Co617), Muso26 (NCo376), Kyag13 (NCo376), Kiry15 (Co945), Kiry34 (Co617), Kako11 (Co945) and Ruku16 (Co945). All the selected fields (17) had no or little lodged cane at the time of spraying.

Table 2.

Fields sprayed with Chemical Ripener on 14^th June 2006.

Fields	Variety	Crop class	Area (ha)	Age at spray	Age at harvest	Weeks from spray to harvest	Weather condition at spraying and condition after
**Buly5**	Co617	R3	11.5	13.5	14.7	5	Fine weather throughout the spray period.
Buly9	Co945	R3	24.3	14.4	15.6	5
Muso26	NCo376	R1	5.5	13.9	15.1	5
Muso27	NCo376	R1	8.7	13.9	15.1	5
Kyag12	Co684	R4	9.8	14.2	15.4	5
Kyag13	NCo376	R4	14.4	14.2	15.4	5
Kiry34	Co617	R2	20.2	13.9	15.3	6
Kiry15	Co945	R1	12.9	13.7	15.1	6
Kiry18	Co945	R1	11.2	13.7	15.1	6
Kiry35	Co617	R2	15.2	13.7	15.1	6
Kiry37	Co945	R1	9.5	13.7	15.3	7
Muso43	Co945	R1	14.7	13.5	15.1	7
Kako11	Co945	R1	13.7	13.5	15.1	7
Ruku16	Co945	R1	16.7	13.2	14.8	7
Ruku17	Co684	R1	13.0	13.2	15.1	8
Ruku18	Co684	R1	10.3	13.2	15.1	8
Total			211.6	-	-	-	-

2.0 Results:

2.1 Weather during the period of the Trials.

The weekly rainfall (mm), mean daily temperature (°c) and daily sunshine hours are shown in Table 3 below.

Table 3.

Weather during the trial

Weeks after spraying	Rainfall (mm)	Mean daily temperature (°c)			Mean daily sunshine (Hrs)
		Maximum	Minimum	Range
15 – 21 June	31.7	28.8	17.1	11.7	8.8
22 – 28 June	23.3	28.9	16.2	12.7	7.1
29 - 05 July	0.2	29.7	16.1	13.6	9.1
06 – 12 July	31.0	27.2	17.8	9.4	4.9
13 – 19 July	39.5	30.2	17.0	13.2	8.4
20 – 26 July	55.7	26.3	16.8	9.5	4.6
27 – 02 Aug	7.6	27.5	17.7	9.8	5.5
03 – 09 Aug	53.8	25.5	17.3	7.7	2.5
Mean/Total	242.8	28.01	17.0	11.0	6.4

The total rainfall recorded over the eight weeks after ripener application was 242.8 mm (Ref: Table 3). Weekly maximum temperature varied between 25.5°c in week 7 to 30.2°c in week 5 (Ref: Table3). Temperature range varied between 7.7 °c in week seven to 13.6 °c in week three (Ref: Table 3). Sunshine hours (2.5 to 8.8 hrs per day) were relatively low for natural ripening especially in weeks 4, 6, 7 and 8, which is the peak bracket for chemical ripening (Ref: Table 3). This therefore, could have more favoured chemical cane ripening than natural ripening.

2.2. Growth.

Weekly growth measurements were taken on five selected stalks at five random sites in the treated and untreated (control) strips in seven selected fields in par. 1.4 viz; Buly5, Kiry15, 34, Kako11, Ruku16, Kyag13 and Muso26. The measurements were taken from a marked basal internode to the top visible dewlap (TVD) from the first to the sixth week after treatment application.

Table 3.

Mean cane height increment (mm/day) in treated and untreated parts of the cane fields for the period 0 to 6 weeks after spraying.

Field	Height in increment (mm/day)		Observed field condition at harvest
	Treated	Untreated
Buly5	2.2	3.0	In all fields sprayed, there was non-uniform spraying. Strips of what should have been sprayed areas were not sprayed.
Muso26	0.9	1.1
Kyag13	1.2	1.5
Kiry15	1.1	1.4
Kiry34	1.0	1.1
Kako11	1.6	2.4
Ruku16	0.8	1.5
Mean	1.3	2.0

Figure 1.

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Although there was considerable amount of rainfall (total 242.8mm) over the weeks under trial, no marked difference was observed in height increment in both treated and untreated plots (Ref: Table 3, Fig 1). There is considerable similarity in height increment in treated and untreated cane which may be the result of non-uniform spraying, weak recovery and growth in ratoons sprayed following the long drought of November 2005 to March 2006.

2.3. Observation of the performance of Fusilade Super as a ripener on the separate addition of Agral 90(wetter) and Invert Suspension Oil (ISO).

Both Agral 90 and ISO used separately with Fusilade Super appear to influence the performance of Fusilade Super as a ripener. An addition of Agral 90 to Fusilade Super initiates abscission (early central shoot wilting), about one week after spray application. In the case of ISO/ Fusilade combination there was delayed appearance of central shoot wilting. This was observed 10- 14 days after spray application. Thereafter changes in cane for both treatment combinations were very similar with leaves wilting starting from top, progressively moving down to the lower older leaves and the colour of leaves changing from pale green to khaki as the leaves progressively die out. By the fifth week however, clear differences were visible at the upper tender internodes of canes which received the two separate treatments. Canes sprayed with Agral 90/Fusilade combination had discoloured (brownish) constriction in the upper tender internodes, while those sprayed with ISO/Fusilade combination had a distinct black ring (abscission layer) in the upper tender internodes.

2.4 Cane quality as from Agronomy laboratory.

The sprayed and unsprayed strips were sampled after spraying at weekly intervals to determine the Brix % juice, pol % juice, juice purity, fibre % cane, pol % cane and estimated rendement (erp % cane). Ref: Table 4.

Table 4.

Average Cane Quality for sprayed and unsprayed strips

Weeks after spraying	Sprayed					Unsprayed
	Pol % cane	Fibre % cane	Erp % cane	Brix % juice	Pol % juice	Pol % cane	Fibre % cane	Erp % cane	Brix % juice	Pol % juice
1	11.56	11.86	10.54	16.82	13.18	13.14	12.35	11.86	17.26	12.42
2	12.24	12.28	10.00	17.16	14.42	12.22	13.46	9.99	17.34	14.22
3	12.86	12.84	10.40	17.94	14.92	12.18	14.16	9.85	17.84	14.40
4	13.22	13.80	10.94	18.24	15.48	12.28	13.82	10.16	17.40	14.40
5	13.80	14.56	11.29	18.30	15.72	13.44	14.68	11.00	15.28	15.90
6	12.60	13.65	10.42	17.88	14.70	11.95	13.65	9.89	17.45	14.10
Mean	12.71	13.17	10.60	17.72	14.74	12.54	13.69	10.46	17.10	14.24

Erp % Cane = Estimated recoverable pol % cane

= Pol % Cane x (ME/100) x (BHR/100)

ME = Mill Extraction

= 100-(fx45)/100 f= Fibre % Cane

BHR = Boiler House Recovery

= 0.96 x (J-M) / (100-M) x (100/J) x 100

Where M= Final molasses purity, J = First Expressed juice purity.

The Pol % cane, Fibre % cane, Brix % juice and Pol % juice were figures obtained and calculated from Agronomy laboratory analyses over the weeks under trials. Whilst the ME and BHR were obtained from weekly factory reports.

There were no significant gains in pol% cane and erp % cane of treated and non treated canes recorded from Agronomy laboratory analyses. A 0.17 % and 0.14 % increase in pol % cane and erp% cane were recorded in treated and untreated cane respectively (Ref: Table 4). Other quality parameters measured showed equally low gains in treated cane against untreated (Ref: Table 4).

2.5 The Cane Quality data as recorded from the factory:

Cane quality data from Factory Laboratory was obtained for cane samples taken from treated and untreated strips. To avoid the disruption of milling process by using whole field samples, only relatively small samples of both treated and untreated cane were delivered to factory.

On average, samples which could be milled within one hour or so were used. To get these, 15 haulage units were loaded with treated cane and sent to factory in a convoy. These delivered tonnage ranging from 154 to 207 from each selected treated field. For untreated cane tonnage varied between 23.6 tonnes in Buly5 *** to 121.7 tonnes in Ruku16. Overall, milling of both treated and untreated cane took a quarter an hour to two hours with minimal disruption in the overall factory milling process. Milling of control followed immediately after milling the treated cane with a small time gap. The balance of treated cane not taken as sample was milled together with the rest of other canes from other fields and OG areas. Separate milling of NCo376 sample was rejected by factory due to its baggase retention of excess moisture resulting into poor burning and failure to raise adequate steam. The variety had to be milled mixed with others.

The data from factory are presented in Table 5 below.

Table 5.

Treated Fields:

Field	Weeks after spray	Variety	Fej Bx	Fej pol	Fej pty	Est. rend	Pol% cane	Fibre% cane	Est. tc/ts	Me %	BHR	KTM	Jave ratio
**Buly5	5	Co617	17.83	15.65	87.77	10.30	12.03	21.73	9.71	92.23	89.42	34.90	76.84
Kiry34	6	Co617	18.72	16.48	88.03	10.86	11.60	20.08	9.21	93.16	87.91	37.76	70.38
Kiry15	6	Co945	19.40	17.28	89.07	11.46	11.83	19.18	8.72	93.08	87.91	37.61	68.47
Kako11	7	Co945	19.50	17.62	89.36	11.77	13.73	19.75	8.50	93.88	87.15	63.55	77.91
Ruku16	7	Co945	18.94	17.22	90.92	11.54	12.53	20.19	8.67	93.77	87.46	39.57	72.78
Mean			18.88	16.85	89.03	11.19	12.34	20.19	8.94	93.22	87.71	42.71	73.28

NOTE**Buly5 numbers are duplicates. Requested Kinyara Sugar verify the chart entries.

Untreated Fields:

Field	Weeks after spray	Variety	Fej Bx	Fej pol	Fej pty	Est. rend	Pol% cane	Fibre% cane	Est. tc/ts	Me %	BHR	KTM	Jave ratio
**Buly5	5	Co617	17.83	15.65	87.77	10.30	11.30	20.39	9.71	92.23	89.42	34.90	72.18
Kiry34	6	Co617	19.24	17.13	89.03	11.36	11.50	20.81	8.80	92.84	87.91	37.76	67.15
Kiry15	6	Co945	18.11	16.12	89.01	10.67	11.19	19.13	9.37	92.70	87.91	37.61	69.44
Kako11	7	Co945	16.52	14.31	86.62	9.35	10.44	19.73	10.70	91.95	87.15	63.55	73.93
Ruku16	7	Co945	17.74	15.60	87.94	10.28	10.33	20.16	9.73	92.44	87.46	39.57	66.23
Mean			17.89	15.76	88.07	10.39	10.95	20.04	9.62	92.43	87.71	42.68	69.79

NOTE**

Buly5 numbers are duplicates. Requested Kinyara Sugar verify the chart entries.

Although data from the Agronomy laboratory showed minimal gains in cane quality parameters, factory data showed considerable gains in pol % cane and estimated rendement.

There was a 0.8 % gain in estimated factory rendement of treated cane over untreated. Pol % cane had 1.39 % gain over the untreated. Overall, all factory data for treated cane were higher than those for untreated cane (Ref: Table 5). Kill to mill in week 7 was almost double those of other weeks largely because of the employees strike in that week. Boiler house recovery and mill extraction were high and similar for both parameters (Ref: Table 5). Java ratio of treated cane was 3.5 % higher than that of untreated cane (Ref: Table 5).

2.6 Cane and sugar yields of the ripened fields:

The cane sugar yields of the sprayed and unsprayed strips of the ripener treated fields are shown in Table 6 below.

NOTE**Buly5 numbers are duplicates. Requested Kinyara Sugar verify the chart entries.

Table 6.

Cane and sugar yields of sprayed and unsprayed fields

Duplicated numbers in ISO TREATMENT.

*** See report in Paragraph 2.5.2 (23.6 Tonnes in field)

Multiply Rendement of 0.103 x 23.6 ton equals 2.43 tons Sugar ***

TOTAL CANE IN BULY 5 is 23.6 Tons ?????

Buly 5 has control tract in the field of 11 Ha

Field	Variety	Crop class	Yield (tc/ha)	Rendement		Sugar yield (ts/ha)
				Treated	Untreated	Treated	Untreated
**Buly5	Co617	R3	60.5	10.30	10.30 **	6.23	6.23 ***
Kako11	Co945	R1	72.9	11.77	9.35	8.58	6.82
Kiry15	Co945	R1	83.8	11.46	10.65	9.60	8.92
Kiry34	Co617	R2	56.4	10.86	11.36	6.13	6.41
Ruku16	Co945	R1	83.3	11.54	10.28	9.61	8.56
Mean	-	-	71.4	11.19	10.39	8.03	7.39

Est. sugar yield ha = (yield/ha x Rend)/100

*** ISO SUGAR CALCULATION***

(23.6 x 0.103)/100 = 0.024 Tons Sugar/Ha ?

Considerable variation in yield was noted in both treated and untreated portions of the fields. This is attributed to differences in varietal yields, non uniformity of soils and non-uniformity in spraying

.

The mean yield recorded across all crop classes was 71.4 tc/ha (Ref: Table 6). The mean rendement of treated and untreated cane were 8.03 tc/ha and 7.3 tc/ha respectively representing an overall increase of 8.7 % over the untreated fields (Ref: Table 6).

2.7 Discussions:

There was considerable growth rate similarity recorded between the treated (mean 2.1 mm/day) and the untreated (mean 2.0mm/day), Ref: Table 3 and Fig.1. Relatively low day temperatures (mean 28.0°) coupled with moderate sunshine hours (mean 6.4 hrs/day) and warm night temperatures (mean 17.0 °c) may have resulted into high night respiratory rates effecting growth in both treated and untreated cane.

A 0.64 ts/ha increment in sugar yield of the treated cane over the untreated showed further that Fusilade super had improved the sugar yield in treated cane visa-a-avis untreated cane. It thus confirmed that the gain in pol was due to ripener application applied this time of the year when pol % cane is expectedly low. The effectiveness of the chemical was however affected by non-uniform application in virtually all fields treated. The small samples of untreated cane milled may have also had some effect on the final results especially where data in the factory is collected on hourly and/or weekly basis.

Clearly, better response to ripener was obtained from fields with high yields – Kako11, Kiry15 and Ruku16. Better response was also obtained from fields with variety Co945 which is represented by Kako11, Kiry15 and Ruku16. Higher ratoon order (R3, R4) should be avoided in ripening because of the generally low yields. Future ripening will focus on high yielding fields and more Co945 carrying fields to maximise sugar yields.

The gain in sugar yields in the treated over the untreated fields was moderate (0.64 ts/ha) during this period of ripener application. Moderate sunshine hours (mean 6.4 hours/day), temperatures (mean 22.5°c) and temperature range (mean 11.0 °c) and low cane yields, were factors responsible for moderate sugar yields obtained from ripened fields despite the heavy rainfall (total 242.8mm) obtained over the ripener period. During this period, the conditions fairly favoured chemical ripening hence the moderate sugar yield obtained.

3.0. Economic consideration:

The costs incurred during the chemical ripener application on 14^th June 2006 are shown in Table 6 below.

Unit Cost of ripener application operation covering 211.56ha Table 6.

Details	Unit cost (Ug. Shs)
Positioning of the aircraft @Ug shs. 4,273,500	20,200
Aircraft spray costs @ Ug.sh. (12US$ per ha)	22,200
Air Navigation + landing fees, Bank charges	2,011
Fusilade Super Costs @ Ug.sh. 37,540	18,770
Avgas Cost per litre 1845 Ug.sh (1litre sprays 1 ha)	1,845
Labour (G13) 10 @ Ug. Shs. 4,241	200
(2 Supervisors @ Ug. Shs.)	272
(6 flagmen @ Ug. Shs.4241	120
Cost/ha	65,619

What is the Cost of Agral ?

What is the Cost of ISO ?

Appendix 1 shows the total costs involved in the exercise and estimated gain or loss accruing from the ripener undertaking in June 2006.

Report date 29 September 2006.

Dr. Mugalula and members of this report have been requested to verify questioned data in Table 5 & 6 as well as well as Paragraph 2.5.2 and significance of statement in paragraph 2.3.1.

Effective this date, 17 January 2010, Dr. Mugalula and members of this report have not replied.

Dr. Andrew Mugalula Mr. Tom Ejoku Mr. John Uyer

Estate Agronomist, Agronomy Monitoring Superintendent Agronomy Research Superintendent

Kinyara Sugar Works Ltd Kinyara Sugar Works Ltd Kinyara Sugar Works Ltd

Tel: 077 699462 Tel: 078 668438 Tel: 078 457783

MugalulaA@Kinyara.co.ug AgricAgroSupts@Kinyara.co.ug AgricAgroSupts@Kinyara.co.ug

Ms. Elizabeth Nazziwa Mr. Alex Otut Ms. Solome Namutebi

Agronomy Research Supervisor Agronomy Monitoring Supervisor Outgrower Agronomy Supervisor

Kinyara Sugar Works Ltd Kinyara Sugar Works Ltd Kinyara Sugar Works Ltd

Tel: 078 398681 Tel: 078 022597 Tel: 078 702071

AgricAgroSupts@Kinyara.co.ug AgricAgroSupts@Kinyara.co.ug AgricAgroSupts@Kinyara.co.ug