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Abstract
Summary
Sugar beet is the second sugar crops in Egypt and all over the world. The Egyptian strategy to overcome the sugar production shortage depends mainly on extending sugar beet production rather than sugarcane. This dictates the needs to plan and conduct successful processing season that should be long enough to secure economic operation of the factories. This work was carried out to examine the use of planting dates, harvest age, and varietal response in terms of yield and quality as a measure for a long successful processing season. This work was carried out at Elhafir Shehab-Eldin region at the northern part of Dakahlia governorate north of Egypt (Latitude 31º 25” N) during 2002-2003 and 2003-2004 seasons.
Three planting rounds were used in this work. Each round was treated as a separate experiment. The first round started on August 11th, the second round started on 5th of September while the third one started at 29th of September. Each planting round experiment was laid out in a completely randomized block design with four replicates. A split-split arrangement was used. Three sowing dates were tested within each round and arranged in the main plots. Three multigerm sugar beet varieties were selected for each round and arranged randomly in the sub plots. The varieties used were unique for each planting round. The first round planting dates and varieties were August 11th, August 24th, and September 5th using the varieties Beta poly, Gloria, and Oscar poly. The dates and varieties for the second round were September 5th, September 18th, and September 29th using the varieties Farida, Top, and Toro, respectively. The third round planting dates and varieties were; September 29th, October 10th, and October 27th, using the varieties Gazelle, Kawimera, and Pleno, respectively. In addition, the harvesting age treatments were assigned to the sub- sub plots. The examined harvesting ages are 6, 7, and 8 months except for the third round as it was not possible to carry out the research activities and measurements of yield and quality at the age of 8 months due to technical constrains in the laboratory. All cultural practices were carried out as recommended for the area.
At harvest a sample of 10 roots was drown from each plot to determine average root weight. Plot root yield was used to estimate root yield per feddan. Samples of roots were taken and submitted to analysis on the same day at beet reception laboratory in Dakahlia Sugar Factory to measure sugar percentage, Potassium, Sodium, and α-amino Nitrogen. Quality index was calculated and used to estimate sugar recovery %, and sugar yield / feddan. Furthermore, farmers’ income in Egyptian pounds (L.E.) was calculated using the methods of farmers’ accounting at the Dakahlia beet sugar company.
All collected data of each planting round experiment was subjected to statistical analysis. Means were compared using LSD at 5% probability level.
The major findings of this work could be summarized as follows:
I- Root weight:
In general terms, it is evident that harvest age is the major factor controlling root weight in all planting rounds. However, varietal differences were evident in early or late planting rounds rather than the common used second planting round where all varieties performed similarly. None of the interactions were significant mainly due to the parallel trend of response observed in all treatment combinations.
II- Root production per feddan:
In general terms, it is evident that the main factors affecting root yield of beet under this experimental work conditions were planting dates and harvest age of the crop within each planting round. The response of varieties was in the same trend under the combinations of planting dates and harvest ages. It is worth mentioning that 2002-2003 season represents an average warm season while the 2003-2004 season was a cooler one. Varietal response varied according to the weather conditions prevailed in each season.
To maintain a flow of roots at the maximum level of yield per feddan throughout the processing season of the beet sugar factory, it is advised to use the combinations of planting round, planting dates, harvest age, harvest date, and varieties in the region of the experiment to be as follows:
1- First Aug 11th (6M) Feb 11th Oscar poly
2- First Aug 11th (7M) March 11th Gloria
3- First Aug 11th (8M) April 11th Gloria
4- First Aug 24th (6M) Feb 24th Gloria
5- First Aug 24th (7M) March 24th Gloria
6- First Aug 24th (8M) April 24th Gloria
7- Second Sept 5th (6M) March 5th Toro
8- Second Sept 5th (7M) April 5th Farida
9- Second Sept 5th (8M) May 5th Toro
10- Second Sept 18th (6M) March 18th Top
11- Second Sept 18th (7M) April 18th Toro
12- Second Sept 18th (8M) May 18th Top
13- Second Sept 29th (6M) March 29th Toro
14- Second Sept 29th (7M) April 29th Toro
15- Second Sept 29th (8M) May 29th Top
16- Third Oct 10th (7M) May 10th Kawimera
III- Quality traits:
All of the measured quality traits including; sucrose%, Potassium, Sodium, α-Amino Nitrogen contents, Quality index %, and Sugar recovery% followed the same pattern within all examined planting rounds. Over all the three examined planting rounds, planting dates and harvesting ages and their interactions were the main factors affecting sucrose contents. Major effects were observed for harvest age. Varietal response followed mainly the same pattern.
IV- Sugar yield per feddan:
Overall planting rounds, it was clear that planting dates, harvest age, and their interactions are the major factors controlling of sugar yield. Varietal effects are valid only in late planting round. To master the production process, it is proposed to follow the next pattern within planting rounds of planting date, harvesting age, harvest date, and varieties within the region of experimentation in order to achieve the best stable flow of sugar production throughout the processing season.
1- First Aug 11th (6M) Feb 11th Gloria
2- First Aug 11th (7M) March 11th Gloria
3- First Aug 11th (8M) April 11th Gloria
4- First Aug 24th (6M) Feb 24th Gloria
5- First Aug 24th (7M) March 24th Gloria
6- First Aug 24th (8M) April 24th Gloria
7- First Sept 5th (6M) March 5th Gloria
8- First Sept 5th (7M) April 5th Oscar poly
9- First Sept 5th (8M) May 5th Gloria
10- Second Sept 18th (6M) March 18th Toro
11- Second Sept 18th (7M) April 18th Toro
12- Second Sept 18th (8M) May 18th Toro
13- Third Oct 10th (7M) May 10th Kawimera
14- Third Oct 27th (7M) May 27th Pleno
15- Third Sept 29th (6M) March 29th Pleno
16- Third Sept 29th (7M) April 29th Pleno
V- Farmers income:
Over the three tested planting rounds, and in accordance with the policy of pricing of the beet sugar companies, farmers’ income is affected significantly by planting dates, harvest age and their interaction. Achieving similar maximum return, however, is not possible under all planting rounds.
In conclusion, this work suggests that special studies should be conducted in the farming area for each beet sugar factory in order to define the sequence of planting and harvesting for the different varieties used in the farming system. This is essential to secure constant flow of row material to the factories, optimal sugar production, and to maximize farmers’ income throughout the processing season. This is also of great importance particularly as new varieties are introduced annually into the farming system.