Effects of Soil Temperature Regimes on Growth Characteristics, Nutrition, and Grain Yield of IR22 Rice1
- A. K. Bhattacharyya and
- S. K. DeDatta2
The effects of soil and water temepratures of 15, 25 and 35 C on the growth, nutrition, and grain yield of rice (Oryza saliva L.) were studied at three stages of growth in the greenhouse. The dwarf variety IR22 was used as the test plant. Plants grown at greenhouse temperature were used as the control.
Low temperatures at the early vegetative stage retarded the growth of shoots and roots. Compared with the control, higher soil temperatures accelerated the growth and development of the plants. A temperature of 15 C delayed panicle initiation by 17 days and extended the time required for complete heading. Crop maturity was proportionately delayed. Soil temperatures during the early vegetative growth stage had little effect on the concentration of N, P, K and Si in plant tissues. Grain yields were unaffected by the temperature treatments at this stage.
The plants were highly sensitive to cool soil and water temperatures during panicle development. Low soil temperature caused the death of lower leaves and chlorosis of the upper leaves, and both vegetative growth and dry matter production were retarded. Heading was also delayed at the low temperature and it took longer for all the panicles to emerge. Furthermore, fewer spikelets were formed and injury to some of them was observed. Dry matter production was highest at 25 and 35 C during panicle development. Grain yields were significantly decreased by a soil temperature at 15 C during this period.
Plant growth and grain yields were least affected by low soil and water temperatures during the period from heading to crop maturity.Please view the pdf by using the Full Text (PDF) link under 'View' to the left.
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