Two field experiments were conducted at the Research Farm of the Environmental Studies and Research
Institute, Menoufiya University, Sadat City, Egypt; during the two winter seasons of 2006/2007 and 2007/2008. The objective of this investigation was to study the effects of two methods of composite of organic and mineral fertilizers mixture through , two systems of fertilizing, i.e., external compost with mineral fertilizers, external compost with bio-fertilizer; internal compost with mineral fertilizers; and internal compost with bio-fertilizer as well as the control; on some characters of potato tubers of
Diamont local cultivar. The obtained results indicated generally that the most important findings were as follows:
- Plant height had the significantly highest value for the external compost with mineral fertilizer.
-The four treatments under study did not vary significantly regarding plant fresh weight being significantly higher than the control.
-Treatments of the external compost with mineral and biofertilizer and internal compost with bio-fertilizer gave highly significantly increment in tuber weight as compared to the control.
-The significantly highest total yield (ton/fed) was achieved by treatment of external compost with mineral and bio-fertilizer.
-Treatments of the external compost with bio-fertilizer and internal compost with bio-fertilizer gave significantly the highest tuber dry matter (%).
- Starch and sugar content of tubers exhibited significantly different values due to the treatment applied and the season of growth.
In conclusion, despite the superiority of the four treatments to the control, the treatment of external
compost with mineral fertilizers was the best in terms of improvement the vegetative and yield properties. This treatment was followed by the treatment of external compost with bio-fertilizer.