scholarly journals Analysis of Grain Production in Rice Plant : III. Studies of the effects of various nitrogenous nutrient levels and light conditions on the factors constituting field photosynthetic ability and dry matter productivity in paddy rice

1959 ◽  
Vol 28 (2) ◽  
pp. 175-178 ◽  
Author(s):  
Tomoshiro TAKEDA ◽  
Atsuhiko KUMURA
1951 ◽  
Vol 41 (3) ◽  
pp. 271-281 ◽  
Author(s):  
E. S. Bunting ◽  
G. E. Blackman

Between 1942 and 1950, some thirty field experiments have been carried out in the southern half of England to assess the potential value, either for grain or forage production, of seventeen openpollinated flint or dent maizes together with twentynine single or double hybrids of American or Canadian origin.Early-maturing flint varieties will consistently ripen grain, but before mechanical threshing or storage, the cobs require drying. Sibthorp, a mass selection made from an unknown German variety, is the earliest and most productive flint maize so far tested, and in the experiments has yielded as much as 39 cwt. of grain per acre with an average of 24 cwt. The earliest American hybrids, i.e. those with a U.S.A. rating of 80 days from sowing to maturity, give very high yields of grain in favourable seasons. Within the group Wisconsin 240–275, a yield level equal to or exceeding 50 cwt./acre has on occasion been recorded. On the other hand, in the most unfavourable years, such hybrids just failed to produce ripe cobs.Attempts to maintain sixty-five parent inlines of the earliest hybrids have largely failed. However, many of the parent single crosses have matured, and the production on a field scale of the double-cross seed of both Wisconsin 240 and 255 has been carried out.Spacing experiments indicate that for optimum grain production a density of 6 plants/sq.yd. is required for both flint varieties and the earliest hybrids. A spatial arrangement of individual plants is to be preferred to that of groups or hills.American hybrids, in the class of ‘90 days’ to maturity, will in all but the most unfavourable seasons reach the ‘early-dent’ stage of the grain before the incidence of autumn frosts. Yields of dry matter of plants harvested in this phase have ranged from 30 to 85 cwt. of dry matter per acre. In these trials, the plant density was standardized at 4 plants/sq.yd. and higher densities may be demanded for optimal yields.The ratio of the ‘ear’ (that is, the cob, immature grain and enclosing leaf sheaths) to the total shoot weight at harvest varies greatly with the variety or hybrid. With White Horsetooth, the usual variety grown for fodder in England, no cobs are formed before the plants are killed by frost, while with the early hybrids, the ear may be half the weight of the whole shoot.The earliest variety Sibthorp from an early May sowing takes approximately 70–80 days to reach full anthesis, while ‘80-day’ American hybrids are a week later. From sowing to full maturity the period in England is from 140 to 160 days, thus compared to conditions in Minnesota the period is nearly twice as long. Because of the much slower rate of development and because of the humidity of English autumns, it is concluded that until the date of maturity can be advanced some 14 days, grain production on a field scale is not yet feasible. On the other hand, many of the American hybrids are well fitted to the production of silage. The greatest drawback to the introduction of such hybrids is the liability of the seed and seedlings to be attacked by rooks.


2015 ◽  
Vol 66 (4) ◽  
pp. 308 ◽  
Author(s):  
Alison. J. Frischke ◽  
James R. Hunt ◽  
Dannielle K. McMillan ◽  
Claire J. Browne

In the Mallee region of north-western Victoria, Australia, there is very little grazing of crops that are intended for grain production. The success of dual-purpose crops in other regions in south-eastern Australia with higher and more evenly distributed rainfall has driven interest in assessing the performance of dual-purpose cereals in the region. Five experiments were established in five consecutive years (2009–13) in the southern Mallee to measure the forage production and grain yield and quality response in wheat and barley to grazing by sheep or mechanical defoliation. The first three experiments focused on spring cultivars sown from late April to June, and the last two on winter cultivars planted from late February to early March. Cereal crops provided early and nutritious feed for livestock, with earlier sowing increasing the amount of dry matter available for winter grazing, and barley consistently produced more dry matter at the time of grazing or defoliation than wheat. However, the grain-production response of cereals to grazing or defoliation was variable and unpredictable. Effects on yield varied from –0.7 to +0.6 t/ha, with most site × year × cultivar combinations neutral (23) or negative (14), and few positive (2). Changes in grain protein were generally consistent with yield dilution effects. Defoliation increased the percentage of screenings (grains passing a 2-mm sieve) in three of five experiments. Given the risk of reduced grain yield and quality found in this study, and the importance of grain income in determining farm profitability in the region, it is unlikely that dual-purpose use of current cereal cultivars will become widespread under existing grazing management guidelines for dual-purpose crops (i.e. that cereal crops can be safely grazed once anchored, until Zadoks growth stage Z30, without grain yield penalty). It was demonstrated that early-sown winter wheat cultivars could produce more dry matter for grazing (0.4–0.5 t/ha) than later sown spring wheat and barley cultivars popular in the region (0.03–0.21 t/ha), and development of regionally adapted winter cultivars may facilitate adoption of dual-purpose cereals on mixed farms.


2012 ◽  
Vol 81 (1) ◽  
pp. 33-38
Author(s):  
Masami Furuhata ◽  
Tadashi Chosa ◽  
Akihiro Ohsumi ◽  
Osamu Matsumura

1970 ◽  
Vol 75 (3) ◽  
pp. 547-552 ◽  
Author(s):  
G. L. Terman ◽  
S. E. Allen

SUMMARYA greenhouse pot experiment was conducted with paddy rice (Oryza sativa L. var. ‘Nato’) grown on Mountview silt loam at its initial low P level and on this soil receiving preplant unlabelled P applications (medium and high soil P levels). Labelled granular CSP (concentrated superphosphate) alone, a 2/1 mixture of CSP and DCP (dicalcium phosphate) and a 1/2 CSP-DCP mixture were evaluated.Dry-matter yields and tillering increased markedly with amount of applied P on the low P soil, and slightly on the medium P soil; there was no response on the high P soil. Response decreased with decrease in water solubility of the applied P at the low and medium soil P levels. Total uptake of P by rice showed similar trends, except that uptake increased significantly with amount of P applied at the medium soil P level.Percentages of plant P from the labelled fertilizer and uptake of fertilizer P increased in all situations with amount of applied P, decreased with decrease in water solubility of the applied P, and decreased with increase in soil P level. Uptake of soil P increased markedly with increase in soil P level. Soil labelling was much less satisfactory than fertilizer labelling for evaluating the effectiveness of P in different fertilizers.A solution of labelled CSP was applied in a second experiment at time of transplanting and 3 or 6 weeks later. On the low P soil, yields, P uptake and tillering increased with rate of applied P but decreased with later date of application. On the medium P soil, yields, tillering and uptake of P by the grain were rather similar among treatments. Uptake of P in the foliage and mature straw, however, increased with later date of application. These results indicate that late-applied P is readily absorbed by rice but is not effective for increasing yields.


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