Protein Content Of Rice Grains Research Articles

Effects of Leaf-Blade Cutting or Panicle Thinning at Full Heading Time on the Protein Content of Rice Grain

Effects of Leaf-Blade Cutting or Panicle Thinning at Full Heading Time on the Protein Content of Rice Grain

Studies on the Influence of Cultural Conditions to Protein Content of Rice Grain

Studies on the Influence of Cultural Conditions to Protein Content of Rice Grain

Protein Content of Rice Grain as Affected by Nitrogen Fertilizer and Some Triazines and Substituted Ureas1

AbstractField experiments were conducted to determine whether varietal differences in protein content exist and to study the use of cultural practices — plant density, time of N application, and application of chemicals —for increasing protein content of rices (Oryza sativa L.).Results demonstrated that a high‐yielding improved line ‘IR480‐5‐9’ has high protein content in the grain. The protein content of brown rice of IR480‐5‐9 varied from 9.5 to 10.2% without application of N. The highest protein of ‘IR480,’ was about 12.5% while that of ‘IR8’ was 9.8%. In another experiment, the protein content of IR480 was 10.2%, while that of ‘IR22’ was 8.6%. Both rices had similar grain yields (7.8 metric tons/ha).In another experiment, the protein content of several rice cultivars was significantly higher when 150 kg/ha N was applied half at planting and half at heading than when all N was applied at planting.Simetryne [2,4‐bis (ethyl amino)‐6‐(methyl thio)‐S‐triazine], at 0.5 kg/ha active ingredient, applied either as granular or liquid formulation at panicle initiation or at heading stage of the rice crop, significantly increased the protein content and protein yield of IR22 compared with the fertilized control. Three chemicals, tenoran [N′‐4 (4‐chlorophenoxy) phenyl‐N,N‐dimethyl urea], CP 17029 [2,4 bis (3 methoxy‐propyl amino)‐6‐(methyl thio)‐Striazine], and benzomarc (N‐benzoyl‐N‐dichloro‐3,4‐phenyl N′‐N′‐dimethyl urea) also increased protein content of rice grain without significantly affecting grain yields and yield components.

Studies on Protein Content in Rice Grain : II. Effects of the fertilization on protein content and protein produtction in paddy grain

To prove the effects of the fertilization on protein content of paddy rice, the present experiments were carried out as follows. (1) Planting density was altered as 5O, 80, 110 or 140 hills/3.3m2, and the levels of basaldressing applied were 0.56, 0.75, 0.94 or 1.13kgN/are. The amounts of phosphatic and potassic fertilizer were normally fertilized. (2) In addition to basal dressing, top dressing of 0.05∼0.25g N/hill were applied on various stage before or after heading stage. (3) Two kinds of N, P and K fertilizer experiment paddy fields were used, the one is the usual field continued 12 years for the experiment and the other is newly opened field for the experiment. The results are summarized as follows. 1. As to associated effects of planting density and nitrogen supply on protein content (%) and protein production (protein % × grain yield), it was observed that the more nitrogenous fertilizer applied and the more spacing was wide, the more protein % in rice grain was increased. Ultimately, protein % depends on nitrogen supply per hill. Protein production also tended to increase in higher levels of nitrogenous fertilizer in any planting density, but it was hardly influenced by planting density in any nitrogen levels. 2. The most effective stage of top dressing of nitrogenous fertilizer on the protein % is the heading stage. Before heading stage the effect was slight. After heading stage, the effective period keep on decently long time but the effect make a slow descent gradually. The more nitrogenous fertilizer applied, as top dressing the more protein % was increased and it was more effect to apply all amount of it at the nearer stage to heading date. Top dressing of 0.25g N/hill at the heading stage increased protein content by 38% compared with non top dessing. 3. As to the protein content in rice grain of each plot in N, P and K fertilizer experiment field, in case of usual paddy field, protein % was most high in N P K plot and was inferior any other plots that were excepted each nutrient element. On the other hand, in case of new paddy field with great P-absorptive coefficient, non-application plots of phosphatic fertilizer increased percent of protein by 20-30%compared with N P K plots, but these plots were accompanied remarkably by the decrease in grain yield, consequently reduced the total protein production per unit area.

Studies on Protein Content in Rice Grain : I. Variation of protein content between rice varieties and the influences of environmental factors on the protein content

In order to clarify protein content variation of the rice varieties and the relation between protein content and environmental factors, some investigations were carried out as follows. To clarify the variation of protein content of rice varieties, 33 varieties of Hokkaido and Tohoku district were planted in the same paddy field for 7 years from 1963 to 1969 and protein content in their rice grains were compared yearly. As to the influences of the environmental factors, rice crops were grown during their ripening stage under high (25-27°C) air temperature, high (30°C) or low (17°C) water temperature, and sunshading, protein content of their rice grains were compared for 2 years of 1968 and 1969. The results are summarized as follows. Protein % in rice grains is respectably differing with rice varieties. In general, earlier ripening varieties tend to show higher % than the later one. Most varieties of Hokkaido belong to the earlier ripening group and showed higher % than most varieties of Tohoku district. In each district, Norin No.20 of Hokkaido and Oirase of Tohoku district were remarkably higher % than the other varieties yearly for 7 years, so it seems that they have somewhat super hereditary natures refering to accumulation of protein. Protein % of the same variety that was planted on the fixed plan differed year by year. This fact shows that protein content is influenced by the weather condition of each year. From the results of some experiments refering to weather environments, it was cleared that protein % of rice grains is increased by high air temperature or high water temperature as well as decreased by low water temperature or sunshading during their ripening stage.