Studies on the Selection Methods for Sugarcane Breeding
V. On the effects of mosaic disease on the various characteristics of sugarcane variety
1976 Volume 19 Issue 2 Pages 81-91
Details
1976 Volume 19 Issue 2 Pages 81-91
The purpose of the present investigation was to elucidate the effects of mosaic disease infection on various characters of sugarcane. Field test was of a split plot design and the two treatments (healthy or 100% infected seed with mosaic disease) for thirteen varieties were replicated two times on spring planting and the followed ratooning crop. The results were as follows:
1) Numbers of shoot in the diseased plants were decreased apparently in June and September but obsecurely in July. The progress showed as similar tendancy on both crops, because of repression of shoot.
2) Leaf length and area per blade decreased significantly but there was no change on leaf width.
3) Mosaic disease caused a severe reduction in yield of available sugar or millable cane but did not affect sugar content (C. C. S.) . The rate of available sugar in the diseased compared to healthy controls were 87%, 92% and millable cane yield were 87%, 89% on the spring planting and ratooning, respectively.
4) The loss of millable cane yield originated from the decreases of both number of cane and stalk weight as the two yield components. The decrease of stalk weight resulted from the reduction of stalk length but no difference was to be seen in stalk diameter. The reduction of stalk length was due to decrease of number of node and slightly internode length.
5) The characters of milling juice quality, namely Brix, pollarization, purity and fiber content did not differ from the healthy controls in substance. C. C. S., Brix and pollarization on ratooning increased slightly by infection, since numbers of growing stalk decreased and were exposed to the sufficient sunlight as a result.
6) There were remarkable varietal differences on the loss of the cane yield infected with mosaic disease. The yield loss of some varieties reached as much as nearly 30%, on the other hand some were not much change.
7) The following problems were pointed out on developing the breeding program of mosaic resistance; to clarify varietal difference of natural spreed of mosaic in field condition, to classify and identify mosaic strains existing under the cane belts and to compare varietal reaction to the identified mosaic strains.
