The demography of the rice weevil, Sitophilus oryzae (L.) (Coleoptera: Curculionidae), submodels of age-specific survivorship and fecundity

1983 ◽  
Vol 73 (2) ◽  
pp. 333-334 ◽  
Author(s):  
B. C. Longstaff ◽  
D. E. Evans
Keyword(s):  
Moisture Content ◽  
Environmental Conditions ◽  
Sitophilus Oryzae ◽  
Continuous Functions ◽  
Rice Weevil ◽  
Potential Usefulness ◽  
Published Data ◽  
Grain Moisture ◽  
Wide Range ◽  
Grain Temperature

AbstractExperiments are described in which age-specific survivorship and fecundity of Sitophilus oryzae (L.) were determined over a wide range of environmental conditions (15·0-32·3°C and 11–14 % grain moisture content). The data derived from these experiments, together with some previously published data, were used to develop mathematical submodels for these processes. The models are continuous functions of time, grain moisture content and grain temperature. Rates of increase per week and per generation were calculated for the range of environmental conditions used. The results are discussed in relation to previously published work, and the potential usefulness of the submodels is discussed briefly.

Reaction norm and stability of short-season maize hybrids as affected by environment

2020 ◽  
Author(s):  
В. Сотченко ◽  
А. Горбачёва ◽  
А. Панфилов ◽  
Н. Казакова ◽  
И. Ветошкина
Keyword(s):  
Moisture Content ◽  
Grain Yield ◽  
Reaction Norm ◽  
Yield Potential ◽  
South Urals ◽  
The South ◽  
Maize Hybrids ◽  
Grain Moisture ◽  
Wide Range ◽  
Short Season

Полевые опыты проведены в 20162018 годах на опытных полях ВНИИ кукурузы в п. Пятигорский Предгорного района Ставропольского края и в Институте агроэкологии филиале Южно-Уральского ГАУ в с. Миасское Красноармейского района Челябинской области. Цель исследований изучить потенциал урожая раннеспелых гибридов кукурузы и уборочную влажность зерна в разных климатических зонах, выявить гибриды, гарантирующие стабильно высокий урожай зерна в условиях Южного Урала. Одной из важнейших экологических особенностей кукурузы является её широкая норма реакции на изменение условий среды, показателем проявления которой выступает пластичность и стабильность. Было проведено изучение основных хозяйственно ценных показателей девяти раннеспелых гибридов кукурузы трёх селекционных учреждений РФ при оптимальном сроке посева в двух географических точках (Северо-Кавказском и Уральском регионах РФ). Анализ нормы и стабильности реакции гибридов кукурузы по урожаю зерна на условия вегетации позволил отнести все изучаемые гибриды к среднепластичным. Значение нормы линейной реакции (r 0,71) свидетельствует об усилении отзывчивости гибридов на улучшение условий среды. Низкостабильными оказались только два гибрида: Машук 150 МВ и Ладожский 148 СВ. Остальные гибриды относятся к высокостабильной группе. Экологическая стабильность реакции слабо связана с урожаем зерна (r 0,26). Высокоурожайными на Южном Урале оказались гибриды кукурузы Уральский 150 и Обский 140 СВ. Гибрид кукурузы очень раннего срока цветения Кубанский 101 СВ был самым низкоурожайным и низкорослым в обоих пунктах. Лучший гибрид кукурузы для условий Южного Урала Уральский 150: при среднем урожае зерна за 3 года 6,5 т/га его уборочная влажность составила 31,7. Field trials took place in 20162018. The aim to select the best short-season maize hybrids for the South Urals and evaluate their yield potential as well as grain moisture content at harvest under different environmental conditions. Maize has a wide range of responses to environment defining its plasticity and stability. Economically important traits of nine short season maize hybrids obtained from three Breeding Institutions were analyzed in the North Caucasus and Ural regions of Russia under optimal seeding date. Hybrid yields showed medium variation as a response to growth conditions. Linear reaction norm model (r 0.71) represented sensitivity increase to improved conditions. Mashuk 150 MV and Ladozhskiy 148 SV hybrids were the most sensitive to environmental changes. Other hybrids had similar performance across different environments. Low trait variation under different conditions affected grain yield insignificantly (r 0.26). Uralskiy 150 and Obskiy 140 SV had high productivity in the South Urals. Extra short-season Kubanskiy 101 SV hybrid showed the lowest productivity and height at both locations. Uralskiy 150 hybrid was the most productive in the South Urals: for 3 years its grain yield amounted to 6.5 t ha-1, grain moisture content at harvest 31.7.

Susceptibility of Twelve Genotypes of Triticale to the Rice Weevil (Coleoptera: Curculionidae) and the Lesser Grain Borer (Coleoptera: Bostrichidae)2

1991 ◽  
Vol 26 (3) ◽  
pp. 339-344 ◽  
Author(s):  
J. E. Baker ◽  
F. H. Arthur ◽  
P. L. Bruckner
Keyword(s):  
Moisture Content ◽  
Growth Parameters ◽  
Oryza Sativa L ◽  
Sitophilus Oryzae ◽  
Brown Rice ◽  
Rice Weevil ◽  
Rhyzopertha Dominica ◽  
Progeny Production ◽  
Lesser Grain Borer ◽  
Total Progeny

Population development by the rice weevil, Sitophilus oryzae (L.) and feeding damage caused by the lesser grain borer, Rhyzopertha dominica (F.), were assessed on twelve triticale (X Triticosecale Wittmack) genotypes maintained at 25°C and at 11.7 or 14.2% moisture content. Among genotypes at 14.2% moisture content, total progeny production by the rice weevil ranged from 7.1 (GA82014) to 8.8 (87AB13541) weevils per female-day; mean time to adult emergence ranged from 35.5 (GA82014) to 36.9 days (87AB13541 and CT4699); and rate of emergence (a measure of the slope of the cumulative emergence curve at the average emergence day) ranged from 0.59 (87AB 13541) to 0.72 (‘Morrison’). Although there were some statistical differences among these population growth parameters on different triticale genotypes, all genotypes were at least as susceptible as the long grain brown rice (Oryza sativa L.) and soft red winter wheat (Triticum aestivum L., cultivar ‘Florida 302’) controls tested concurrently. Development time of rice weevils was significantly delayed and total progeny production after 65 days was reduced about 17-fold on triticale genotypes at 11.7% moisture content. About 3-fold more frass was produced by lesser grain borers feeding for 7 days at 25°C on triticale genotypes at 14.2% moisture content compared to that obtained on genotypes at 11.7% moisture content. Significantly more feeding and frass production by lesser grain borers occurred on triticale and wheat than occurred on rice.

scholarly journals Processes of Heat and Mass Transfer During Grain Mass Storage in Metal Silos of Large Capacity

2021 ◽  
Author(s):  
Ivan Kechkin ◽  
Vladimir Ermolaev ◽  
Marina Belyaeva ◽  
Valentina Tarakanova ◽  
Elena Gurkovskaya ◽  
...  
Keyword(s):  
Mass Transfer ◽  
Moisture Content ◽  
Heat And Mass Transfer ◽  
Rate Of Change ◽  
Mass Storage ◽  
Large Capacity ◽  
Wheat Grains ◽  
Grain Moisture ◽  
Temperature And Humidity ◽  
Grain Temperature

This study showed that there were some changes in the temperature and humidity parameters of wheat grains during the storage year. The grain moisture content in both the near-wall and central parts of the metal silo largely did not change, remaining at a level of 10-11%. Moisture values were recorded monthly, and grain temperature was recorded in accordance with seasonal changes, thus, the range of temperature changes was from 20 to 32°С at a minimum outdoor temperature of 5°С. The moisture content of the grain in the surface layer increased by 0.4-1.2% and the final moisture content of the grain was 11.6%. Experiments on grain temperature and humidity changes with active ventilation in large-capacity metal silos have shown that the rate of change (decrease) in temperature depends on the specific air flow rate, and the difference in air and grain temperature. Experimental storage showed that a grain with the moisture content up to 13.6% can be stored for up to nine months without deterioration in quality. A longer shelf life is possible for wheat grains with a moisture content of up to 12%. This article pays special attention to the processes occurring in the under-roof space of large-capacity metal silos and suggests methods for solving this problem. Keywords: long-term storage, active ventilation, metal silos, heat and mass transfer processes

Modelling and Simulation Moisture Transfer in Wheat Stored in a Simulated Sealed Pit

2008 ◽  
Vol 4 (3) ◽  
Author(s):  
Mohamed A. Ismail ◽  
Michael P. Douglass ◽  
Brian C. Stenning
Keyword(s):  
Finite Difference ◽  
Moisture Content ◽  
Input Data ◽  
Moisture Transfer ◽  
Storage Period ◽  
Moisture Distribution ◽  
Wall Material ◽  
Moisture Contents ◽  
Grain Moisture ◽  
Grain Temperature

A mathematical model, coupled to another one which was used to calculate the conductive heat transfer, was developed to predict the change of moisture distribution with time in the radial and axial directions in a simulated sealed cylindrical pit storing wheat. The finite difference method was used in the model to calculate the diffusive moisture transfer. The model predicts the grain moisture contents in the pit during the storage period using input data of initial grain temperature, initial grain moisture content, storage time and number of spatial elements in both radial and axial directions. Other input data include the finite difference spatial increment in both directions, the finite time increment, temperatures of soil surrounding the pit and the physical properties of grain, pit wall material and surrounding soil. To validate the model, predicted moisture contents were compared with measured data for wheat of Apollo variety being stored in a simulated sealed pit for a period of 70 days. The wheat was stored in a cylindrical mild steel tank with 0.6 m in both diameter and height. The initial uniform grain temperature was 15 °C and the initial uniform grain moisture content was 12.45% (w.b.). Both measured and predicted moisture contents show that the major change in wheat moisture content took place during the first week of the storage and an establishment of steady state under the storage conditions of the pit is unattainable i.e. moisture diffusion is a very slow process. At the end of the storage period, the grain moisture contents were increased by an average of 1.62% (w.b.) and the grain temperatures were decreased by an average of 2.63°C at the top layer of the pit. For the bottom layer of the pit, the grain moisture contents were decreased by an average of 0.50% (w.b.) and the grain temperatures increased by an average of 7.04°C. The diffusive moisture transfer model predicted the grain moisture contents with a standard error of estimate between measured and predicted of 0.18 -0.75% and of 0.18-0.74% (w.b.) using Chung's equation and modified Henderson's equation, respectively. There was no difference between the two sorption equations (Chung's and modified Henderson's equations) used in predicting grain moisture contents.

scholarly journals Toxicity of diatomaceous earth on seed weevil, Sitophilus oryzae L. and its effect on agro-morphological characters of maize seeds

2021 ◽  
Vol 13 (4) ◽  
pp. 1180-1186
Author(s):  
S. Aisvarya ◽  
M. Kalyanasundaram ◽  
M. Kannan ◽  
A. Lakshmanan ◽  
T. Srinivasan
Keyword(s):  
Diatomaceous Earth ◽  
Sitophilus Oryzae ◽  
Morphological Characters ◽  
Rice Weevil ◽  
Management Tool ◽  
Contact Toxicity ◽  
Pest Species ◽  
Promising Alternative ◽  
Maize Seeds ◽  
Wide Range

Sitophilus oryzae L. (Curculionidae; Coleoptera) is considered to be a serious internal feeder of stored cereals. The use of insecticides results in the development of resistance among the pests and residues in the produce. Diatomaceous Earth (DE) is from a natural source, environment-friendly, safe to humans and natural enemies. In addition, it is highly effective against a wide range of stored pest species and has no toxic residues on the treated seeds. The promising alternative to synthetic insecticides is the application of DE in storage pest management under physical control. With this background, the present study was aimed to find the efficacy of DE against rice weevil, S. oryzae L. and their effect on the agro-morphological characters of maize (Zea mays L.) seeds. Contact toxicity bioassays were carried out with different concentrations of DE against S. oryzae. The results of the bioassay studies revealed LD50 at the concentration of 1.27 mg/100 gm of maize seeds. Further, 100 per cent mortality was achieved at the dose of 15 mg/100 gm of maize seeds within six days of exposure. The effect of DE on the germination provided a significant increase in germinability of maize seeds (LD50= 94%, LD95= 98% and control= 96%). DE at the concentration of LD95 had a beneficial effect on the seedling parameters, especially germination% (98%) and seedling length (53.02 cm) of maize. The present study concluded that DE could be effectively utilised as an alternative management tool to chemical insecticides in the management of rice weevil under storage conditions.

Technologies for lupine hulling

2020 ◽  
Author(s):  
В.М. Косолапов ◽  
С.И. Тютюнов ◽  
А.Э. Ставцев ◽  
С.В. Зверев
Keyword(s):  
Moisture Content ◽  
Water Content ◽  
Flow Rate ◽  
Environmental Conditions ◽  
Fine Fraction ◽  
Air Flow Rate ◽  
High Fiber ◽  
Sieve Size ◽  
Grain Moisture

При обрушении зерна белого люпина используют технологические схемы, позволяющие получать крупку из ядра. Порядок выполнения операций оказывает существенное влияние на результаты процесса обрушения зерна. Режим дробления не изменяли, что привело к получению недоруша (без изменения влажности партии зерна) в размере 6%. На количество недоруша оказывают влияние интенсивность применения агрохимических средств в технологиях возделывании белого люпина, а также почвенно-климатические условия и влажность зерна во время обрушения. Хорошие результаты показала простейшая схема с измельчением на центробежной дробилке с последующей пневмосепарацией, которая позволяет получать до 70% крупки с повышенным содержанием белка и низким содержанием клетчатки, что важно при производстве комбикорма в птицеводстве и свиноводстве. Одновременно при этом производят мучку с пониженным (около 20%) содержанием белка и повышенным содержанием клетчатки (около 10%), что делает возможным её использование в рационах КРС. Определено, что смена технологических режимов работы оборудования сказывается на качестве обрушения зерна белого люпина, т.к. снижение скорости удара при дроблении (при постоянстве остальных режимов процесса обрушения) приводит к росту доли крупки (снижению относов и мучки), но при этом увеличивается содержание недоруша. Повышение скорости потока воздуха при пневмосепарировании снижает долю крупки, поскольку большая часть её мелкой фракци попадает в относы, а качество крупки возрастает, т.к. в относы попадают крупные частицы оболочек и зародыш. Уменьшения размера сита до #2,1 мм приводит к перераспределению фракций в относах. В оболочках, которые в основном составляют сход с этого сита, могут появиться частицы ядра. После просеивания относов и выделения оболочек, доля которых может составлять до 20%, остаётся мучка. Мучка несмотря на повышенное содержание клетчатки может содержать в мелких фракциях до 30% белка. Hulling is a process of separating the grain from its hulls. Hulling steps significanlty affect the final result. Crusing mode stayed unchanged leading to 6% of unhulled grain (no variation in grain water content). Application of chemicals, environmental conditions and grain moisture content influenced the proportion of unhulled grain obtained. Good results were obtained when using centrifugal crusher. After the chaffing 70% of crushed grain showed high protein and low fiber contents, which was importain for poultry and pigs feeding. At the same time being poor in protein (around 20%) and rich in fiber (around 10%) the produced bran could be used in cattle diet. Variation in the parameters of the processing equipment affected the quality of crushed grain. Reduced crusing speed increased both hulled and unhulled grain fraction, decreasing hull and bran contents. Increasing air flow rate reduced the fraction of crushed grain but improved its quality since most of the grain fine fraction got separated together with large husk and corcle particles. Decreasing sieve size induced the redistribution of separated fractions. Some husks were separated together with grain particles. The hull proportion could reach up to 20% without the bran. Despite the high fiber content, the bran can contain up to 30% of protein.

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