Oriza Sativa Research Articles

Agricultural BMPs for Phosphorus Reduction in South Florida

Four sets of eight or twelve 0.7 ha plots, designed for soil and hydraulic uniformity, were used to screen potential Best Management Practices (BMPs) for reducing total phosphorus (TP) concentrations and loadings in the Everglades Agricultural Area (EAA) of south Florida. The four production systems and their alternatives (treatments) studied were: (1) sugarcane (interspecific hybrids of Saccharum sp.) versus drained fallow plots; (2) fast versus slow drainage rates for sugarcane; (3) rice (Oriza sativa L.) in rotation following radishes to serve as a P filter crop versus traditional flooding fallow; and (4) banding phosphorus (P) fertilizer at 50% of the soil-test recommendation rate for cabbage (Brassica oleracea L.) versus full-rate broadcast applications. The study showed that there were no differences in P concentrations in drainage water between sugarcane and drained fallow fields. Annual P loading to the plots in rainfall and irrigation water (0.63 kg TP ha1) exceeded the P loading of drainage waters (0.52 kg TP ha1 for sugarcane and 0.59 kg TP ha1 for drained fallow plots). Slow drained sugarcane plots exhibited significantly higher TP concentrations than the fast drained plots. However, TP loads were significantly higher (0.97 kg ha1) for fast drained plots than for the slow drained plots (0.67 kg ha1). Rice as a P filter crop following radishes reduced TP concentrations and loadings. Finally, banding P fertilizer at a reduced rate for cabbage reduced TP concentrations compared to those for broadcasted P at the full recommended level. Total phosphorus loadings in drainage water were 1.17 kg ha1 for banded and 1.38 kg ha1 for broadcast treatments. A total of 1.30 kg TP ha1 entered the plots in rainfall and irrigation water. All treatment TP loadings leaving the plots in drainage water were close in magnitude to TP loadings to the plots, even under heavy fertilization. This indicates that the EAA system is currently a net assimilator of P.

Defensive secretion of rice bug,Leptocorisa oratorius fabricius, (Hemiptera: Coreidae): A unique chemical combination and its toxic, repellent, and alarm properties

Defensive secretion produced by adult males and females ofLeptocorisa oratorius, Fabricius (Hemiptera: Coreidae) living on the host plant,Oriza sativa, was analyzed by a combined gas chromatography-mass spectroscopy technique. Both male and female secretions consisted of two major components: (E)-2-octenal andn-octyl acetate, 76% and 16% (w/w), respectively. The remaining 8% were trace compounds, some of which were identified as hexyl acetate, 3-octenal, 1-octanol, and (Z)-3-octenyl acetate. In a survey among 38 coreid defensive secretions, (E)-2-octenal andn-octyl acetate were found to occur rarely in addition to coreid-specific compounds, while their combination as primary constituents was found to be unique. Toxicity and repellency of this secretion were evaluated using two household pests,Anoplolepis longipes andSitotroga cerealella, as test insects, and lethal concentration (LC50) values of 0.24 ppm and 0.14 ppm, respectively, and repellencies of 63% and 58%, respectively, were obtained. Comparing the above values with those of a pentatomid bug,Coridius janus, evaluated under the same conditions, it was apparent that this secretion has potential as a repellent to enemies ofL. oratorius but not as a toxicant to attack them. Bioassay on the alarm activity of this secretion revealed that it elicits alarm responses, alerting and dispersing aggregated male and femaleL. oratorius: this is followed by "self-coating" activities. In addition, some unique behaviors were also noted among alarmedL. oratorius.

Chemical composition and biodegradability of crop residues colonized by white‐rot fungi

AbstractTwo experiments were conducted to study the degradation of rice (Oriza sativa L) straw and maize (Zea maize L) stover by selected white‐rot fungi, using loss of organic matter, disappearance of cell wall constituents, and in‐vitro dry matter digestibility (IVDMD) as indices of rumen microbial degradation. Four white‐rot fungi—Cyrathus stercoreus, Dichomitus squalens and two strains (cellulase‐less mutant and a wild type) of Phanerochaete chrysosporium—were selected for the first experiment. After 30 days of solid state fermentation. C stercoreus increased IVDMD of both substrates from 373 g kg−1 (rice) and 393 g kg−1 (corn) to approximately 540 g kg−1 by selectively degrading hemicellulose as opposed to cellulose. The highest IVDMD was obtained with a minimal loss of dry matter (33 g kg−1). In contrast, both strains (wild and mutant) of P chrysosporium degraded cellulose and hemicellulose indiscriminately, and thus lowered the IVDMD to 276. 257 as opposed to 373 for rice straw and 301. 307 as opposed to 393 g kg−1 for maize stover. All the fungi showed a preference for degrading maize stover compared with rice straw, although the materials were similar in cellulose and lignin concentration. No direct correlation was found between lignin degradation and the improvement of substrate IVDMD of either substrate.The objective of the second experiment was to determine the rate and extent of digestibility of rice straw colonized by C stercoreus during two incubation periods (15 and 30 days). Dry matter disappearance (DMD) was determined by ruminal incubation of the substrate contained in nylon bags. The 30‐day incubation period was superior (1.3 ×) to that of the 15‐day period in improving in‐situ DMD. Treatment of rice straw for 30 days not only improved the extent of dry matter digestibility (616 as opposed to 389 g kg−1), but also increased (1.5 ×) the rate of disappearance of substrate.

Effects of Weeds on Fecundity and Survival of Leptocorisa oratorius (Hemiptera: Alydidae)

Leptocorisa oratorius (F.) adults preferred Echinochloa cruz-galli (L.) over rice, Oriza sativa L., var. IR 36, for resting sites, whereas rice was preferred over Eleusine indica (L.), Echinochloa colona (L.), Brachiaria mutica (Forsk.), Paspalum conjugatum Berg., P. paspalodes L., and Digitaria ciliaris (Retz.). L. oratorius oviposited on all plant species, but those confined for 8 d on flowering rice laid more eggs than those confined on weeds. Females began oviposition 2 wk after molting, and fecundity was consistent for 5 wk. Nymphs completed their development only on E. cruz-galli , E. colona , D. ciliaris , or rice after panicle emergence. Results indicate that weed control is an important factor in L. oratorius management programs.

Studies on the selective mechanism of pretilachlor. II. Absorption, translocation, and metabolism of pretilachlor.

Involvement of pretilachlor (2-chloro-2′, 6′-diethyl-N-[2-propoxyethyl]-acetanilide) selectivity in its absorption, translocation, and metabolism was investigated in 4 gramineous species, rice (Oriza sativa L. cv. nihonbare), corn (Zea mays L. cv. honeybantam), barnyardgrass (Echinochloa oryzicola VASING.), and finger millet(Eluesine coracana GAERTN.), and two perennials Sagittaria pygmaea MIQ., and Cyperus serotinus ROTTB.. Growth retardation by pretilachlor was more severe in barnyardgrass and finger millet than in corn and rice. Sagittaria pygmaea MIQ. revealed greater tolerance than Cyperus serotinus ROTTB. Seed treatments showed higher susceptibility to pretilachlor than 3 week old seedling treatments in gramineous species but the reverse was true in perennial weeds.Higher absorption of 14C-pretilachlor was observed in rice and barnyardgrass than in corn and finger millet, regardless of seedling ages. Both young and mature seedlings of Sagittaria pygmaea MIQ. and Cyperus serotinus ROTTB. absorbed very little 14C-pretilachlor, compared with gramineous species. 14C-pretilachlor absorbed by roots was translocated easily to shoots and distributed in all parts of the plants.Absorbed 14C-pretilachlor changed into a water-soluble compound (s) in plants within 2 hours after treatments at 76-82% and about 60% in tolerant and susceptible sepcies, respectively. Metabolic activity was greater in the tolerant corn and rice than in the susceptible barnyardgrass and finger millet in both seedling ages, suggesting that the herbicide may be metabolized into a nontoxic water-soluble compound, the glutathione conjugate of pretilachlor, by glutathione S-transferase (GST) and that pretilaclor selectivity may be related to this activity in gramineous species. Perennial weeds also showed high activity to metabolize pretilachlor into water-soluble compound (s), even though their low GST activities.

Laboratory and field studies of a natural attractant of the rice pest,Leptocorisaacuta (Hemiptera, Coreidae)

Abstract Rice plant, Oriza sativa L was found to produce a volatile attractant for Leptocorisa acuta (Thumb), one of the most important pests of rice. Laboratory bioassay using an olfactometer showed that both sexes of Leptocorisa are attracted to steam distillates of rice grain in its milk stage. Steam distillates of blooming stage and the matured grains did not attract the pest. Field trails carried out with active samples as baits, attracted both sexes of Leptocorisa quite successfully.

Fate of Thiobencarb and Molinate in Rice Fields

AbstractThe fate of thiobencarb (S‐[4‐chlorobenzyl] N,N‐diethylthiolcarbamate) and molinate (S‐ethyl hexahydro‐1 H‐azepine‐1‐carbothioate) in air, water, soil, and vegetation of rice (Oriza sativa L.) fields was documented for 32 d following application. Analysis of variance was used to determine if holding periods facilitated herbicide dissipation in water prior to release to drainage canals. Maximum thiobencarb concentrations in air, water, soil, and vegetation were 1.4 µg/m3, 576 µg/L, 3860 µg/kg, and 1750 µg/kg, respectively. During the 6‐d holding period, thiobencarb concentrations in water did not decline significantly, indicating that this period was not sufficient to facilitate dissipation. The mass balance budget indicated that thiobencarb was predominantly distributed between water (34%) and soil (43%) and <1% was located in air and vegetation. Maximum molinate concentrations in air, water, soil, and vegetation were 48 µg/m3, 3430 µg/L, 2210 µg/kg, and 918 µg/kg, respectively. Molinate concentrations in water declined significantly during the holding period, indicating that this water‐management practice facilitated dissipation of molinate. The mass balance budget indicated that as much as 81% of the molinate applied was dissolved in water followed by soil (10%), air (9%), and vegetation (<1%). Partitioning of these herbicides in the field was closely related to their physico‐chemical properties.

Effect of Environmental Temperature During Development of Rice Plants on Some Properties of Endosperm Starch

AbstractStarch granules were isolated from polished grains of rice plants (Oriza sativa L.) grown under controlled temperature conditions. Distribution of isoamylase‐debranched starch materials and unit chain‐length of amylopectin were examined by gel‐filtration on columns. Higher environment temperature decreases amylose concentration in endosperm starches of Japanese rice cultivars. The amylose concentration in the endosperm starch is determined by the environment temperature 5 – 15 days after heading. Interestingly, the higher environment temperature seemed to increase the amount of long B chains and decrease that of short chains of amylopectin. The effect of environment temperature on pasting characteristics of starch by DSC, starch‐granule digestibility by amylases and X‐ray diffractograms of starch was also investigated.

Fertilizer Zinc Efficiency in Flooded Calcareous Soils

AbstractEffect of Zn sources and methods of application on rice (Oriza sativa var. Giza 159) was studied in relation to organic matter application and to N source. In addition to laboratory investigations, a pot experiment was conducted with 65Zn‐labelled soil (Vertic Torrifluvents) and two field experiments with labelled and nonlabelled Zn fertilizers.Zinc oxide (ZnO) was superior to ZnSO4 in increasing grain yield and Zn content of flooded rice and in maintaining higher Zn concentration in the soil solution. With different methods of ZnSO4 application, rice yield and Zn uptake were in the order: applied to surface water 2 weeks after transplanting ≫ mixed with soil = surface applied to soil. The corresponding percentages of plant Zn derived from fertilizer and of Zn utilization from the applied fertilizer were 11.2, 8.46, and 6.26%; and 2.9, 1.4, and 1.0%, respectively. Effectiveness of organic matter in increasing yield and Zn content was greater when applied 2 weeks before transplanting than when applied at transplanting, as it decreased soil solution Zn during the first 2 weeks of anaerobic decomposition. The organic matter induced a temporary reduction in Zn content early in the season, but a good correlation was obtained between grain yield and Y leaf Zn at the midtillering and panicle initiation stages.With combined Zn and organic matter application, urea as a N source resulted in higher yielding and Zn content than (NH4)2SO4. Specific activity measurements showed that under nonflooded conditions rice was largely dependent on the Zn labile pool, while flooded rice was able to derive Zn from an additional source. Results generally indicate that formation of sphalerite (ZnS) may play a major role in controlling Zn solubility in flooded calcareous soils.

Study of the unsaponifiable matter of Oriza sativa husk oil.

The phospholipids were precipitated from Oriza sativa husk oil by acetone and saponified. The unsaponifiable matter was fractionated with different solvents and each fraction was examined by paper chromatography, where upon a single spot showing a brilliant yellow fluorescence under ultraviolet light was obtained which corresponded to the mobility of 11, deoxy corticosterone. The unsaponifiable matter was treated with alcohol. The soluble portion was identified as β–sitosterol whereas insoluble portion was separated chromatographically over alumina using different solvent systems. The first fraction obtained from petroleum ether eluated was identified as 11, deoxy corticosterone. The second and third fractions collected from petroleum ether : benzene (5 : 1) and benzene yielded ferulic acid and co–prostane respectively.

The Study of Phospholipids in the Oil of the Husk of Oriza sativa

The Study of Phospholipids in the Oil of the Husk of Oriza sativa

Oxygen Diffusion in the Soil‐Plant System II. Respiration Rate, Permeability, and Porosity of Consecutive Excised Segments of Maize and Rice Roots1

AbstractRespiration rates were determined at 4.4, 20.8 and 30% oxygen concentration for consecutive excised segments of maize (Zea mays L.) and rice (Oriza sativa L.) roots. From these data, the maximum respiration rate, the oxygen concentration at which respiration was half of the maximum rate, and the root permeability to oxygen were derived for each position along the root, up to 10 cm from the root tip for maize and 6 cm for rice. The gas‐filled porosity of these segments was measured by the pycnometer method.The root tip segment is characterized by the highest maximum respiration rate, highest permeability, and lowest porosity. Both respiration rate and permeability decrease with distance from the root tip, whereas porosity increases to a maximum of 10% for maize and 33% for rice. The oxygen concentration at which respiration is half of the maximum rate is about 8% for maize and about 16% for rice at each position along the root.

Predicting Nitrogen Availability to Rice: II. Assessing Available Nitrogen in Silt Loams With Different Previous Year Crop History

Soil test methods that measure NH44-N in silt loams before and after incubation under waterlogged conditions were evaluated as predictors of N availability to ‘Nato’ rice (Oriza sativa L.) grown in the greenhouse. Eighteen soils for each of five previous year crop histories were utilized. All so ls were from crop rotations containing rice. Coefficients of determination (r2) for the regression of N uptake by rice on NH4+-N after 6 days incubation of soil from the different crop histories increased in the order of cotton (Gossypium hirsutum L.) < rice < lespedeza (Lespedeza striata Thumb.) < soybean (Glycine max L.) < reservoir (irrigation water storage or fish production), and ranged from .12 to .77. Exchangeable Ca was inversely related to N uptake and accounted for significant percentages of variation in uptake on all soils except those from reservoirs. Exchangeable Ca was not related to NH4+-N production during incubation. For all previous year crop histories NH4 -N in soil after 6 days incubation was a better single predictor of N uptake by rice than soil organic matter values. Initial NH4+-N content of reservoir soils was about 5 times greater than in soils of other crop histories. The amount in these silt loam soils from reservoirs (55 kg N/ha) was about half that found in previous studies for reservoir soils of clay texture. Multiple regression analyses indicated that including initial NH4+-N together with NH4+-N production during incubation improved the prediction of N uptake over NH4 -N production values alone. Including exchangeable Ca together with initial NH4+-N and NH4+-N production values improved the prediction on all soils except those from reservoirs.

Eliminação de fósforo por sementes e raízes de plantas de arroz (Oriza sativa L., var. Batatais) (Nota prévia)

Os autores obtiveram sementes de arroz (Oriza sativa, L. var. Batatais) contendo p32 agitando-as com uma solução que possuía P marcado ou cultivado plantas em presença de P radioativo. As sementes foram semeadas em volume reduzido de silica ou de silica e solo sendo as plantas cultivdas durante 18 dias e depois colhidas. Foram feitos extratos nítricos perclóricos de: silica, misturas sílica-terra, plantas e sementes. Os resultados mostraram haver reliminação de P pelas sementes e/ou pelas plantas e sugerem a possibilidade de fixação do mesmo pelo solo.

Cassia tora Linn. Leaf Meal as a Component in Poultry Rations

CASSIA TORA LINN. is a leguminous plant of the tropics, that grows ubiquitous during the monsoon. The use of Cassia tora Linn, seed in the rations of cattle (Kehar and Murty, 1950) and poultry (Murty and Iyer, 1957) was reported to have no adverse effects on the digestibility of the proximate principles and the retention of nitrogen and minerals. The silage of these green plants with paddy (Oriza sativa) straw was found to form a maintenance ration for cattle (Kehar and Murty, 1957). Hughes and Eyles (1953) indicated the use of leaf proteins as a feeding stuff in the rations of laying hens did not cause any adverse effects on the health of the birds or a fall in egg production. Hence it was thought desirable to investigate the possibility of using Cassia tora Linn. leaf meal in poultry rations. The digestibility of a standard poultry mash substituted with different …