Effects of High Temperature on Growth, Yield and Dry-Matter Production of Rice Grown in the Paddy Field

This study examined the adaptation of lentil (Lens culinaris Medik. cv. Digger) to dryland Mediterranean-type environments of southern Australia and determined the effect of time of sowing on growth, yield, and water use. Phenology, canopy development, radiation absorption, dry matter production and partitioning, seed yield, and water use were measured from a range of sowing times at a number of field locations in south-western Australia in 1994, 1995, and 1996. Contrary to previous results with poorly adapted cultivars, our study showed that lentil is well adapted to low to medium rainfall regions (300-500 mm/year) of south-western Australia and that seed yields greater than 1·0 t/ha and up to 2·5 t/ha can be achieved when sown early. Even in the dry season of 1994 when May-October rainfall was <200 mm, yields of approximately 1·0 t/ha were produced from early sowings. Seed yields were reduced with delayed sowing at rates of 4-29 kg/ha · day. Sowing in late April or early May allowed a longer period for vegetative and reproductive growth, rapid canopy development, greater absorption of photosynthetically active radiation, more water use, and, hence, greater dry matter production, seed yield, and water use efficiency than when sowing was delayed. Early-sown lentils began flowering and filling seeds earlier in the growing season, at a time when vapour pressure deficits and air temperatures were lower, and used more water in the post-flowering period when compared to those treatments where sowing was delayed. The values of water use efficiency for dry matter and grain production, and transpiration efficiency, for early-sown lentil (up to 30 kg/ha · mm, 11 kg/ha · mm, and 20 kg/ha · mm, respectively) were comparable to those reported for cereal and other grain legume crops in similar environments. The development of earlier flowering cultivars than Digger with greater dry matter production together with improved agronomic packages will increase and stabilise lentil yields in low rainfall environments of southern Australia.

Download Full-text

Temperature affects dry matter production and net carbon exchange rate of lower-ploidy Fragaria species and species hybrids

Canadian Journal of Plant Science ◽

10.4141/cjps09144 ◽

2010 ◽

Vol 90 (6) ◽

pp. 885-892 ◽

Cited By ~ 3

Author(s):

R.M. Harbut ◽

J.A. Sullivan ◽

J.T.A. Proctor

Keyword(s):

High Temperature ◽

Exchange Rates ◽

Dry Matter ◽

Dry Weight ◽

Temperature Treatment ◽

Dry Matter Production ◽

Carbon Exchange ◽

Matter Production ◽

Net Carbon Exchange ◽

Fragaria Species

Wild species can contribute to a breeding program through their wide adaptability to a range of habitats. In interspecific crosses it is not known how these species may interact in the hybrids. The dry matter production and net carbon exchange rates (NCER) of four lower-ploidy Fragaria species, four species hybrids (synthetic octoploids, SOs) and two cultivars (Allstar and Jewel) were compared under three day/night temperature regimes, low (15°C/10°C), medium (23°C/18°C) and high (30°C/25°C) in growth cabinets. Light intensity was maintained at 425 µmol m-2 s-1 and day length at 14 h. The wild Fragaria species had the highest NCERs across all temperature regimes. High temperatures had a depressing effect on plant dry weight for most genotypes. However, F. nubicola and SO 8245 produced 15 and 33%, respectively, higher plant dry weight at the high temperature compared with the low temperature treatment. Net carbon exchange rates for most species and synthetic octoploids were not significantly affected by high temperature. However, SO 8212 did not survive the high temperature treatment. The lower ploidy Fragaria species can be used to create synthetic octoploids that can maintain net carbon exchange rates and produce plant dry weights that are comparable with those of Fragaria cultivars. The ecological background of the species did not have a negative impact on the plant dry weight and NCER of the synthetic octoploids. Some of the SOs may be sources for improvement of Fragaria cultivars for dry matter production at higher temperatures.

Download Full-text