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In the field of agriculture, where precise and instantaneous measurements of the moisture contents of grains are required this paper shows a new method for measuring the moisture contents by using microwaves of 9·4 GHz, with unhulled and unground grains; the moisture content can be measured continuously if necessary. Moreover, the measurement can be carried out quite independently of the varieties of grains as well as the moisture distribution in the grain that has been dried by hot air. The accuracy is high, the errors being less than ±0·5% in the measurements for both rice and wheat, the moisture contents of which were in the range of 10 to 30% on wet basis.

Results are given of studies conducted to evaluate the protective values of malathion and pyrethrum grain protectants against damage to corn in Louisiana caused by stored grain insects, especially the rice weevil, Sitophilus oryzae (L.). Both shelled and snapped corn were used in the studies. Malathion gave some protection to stored corn from progressive insect damage during storage; however, satisfactory protection was not obtained at any dosage level tested. Malathion was more effective than pyrethrum. Greater protection was obtained in shelled corn than was possible in snapped corn. Failure in Louisiana to protect corn in storage from insect damage with malathion or pyrethrum is very likely due to the high initial infestation incurred in the field and favorable conditions of temperature, relative humidity, and grain moisture for insect development during much of the storage period.

The paper describes experiments and observations on the damage done by mites to stored grain, and methods of assessing the damage. It is confirmed that mites cannot penetrate grains if the grain-coat is intact; but usually less than 10% of the grains are so intact. In laboratory experiments, mites consumed up to 3% by weight of the grain before dying out; they were able to destroy the germ completely, but consumed very little of the remainder; the maximum rate of consumption observed over a 5-week period was 0-29% of grain weight per week; when added to grain at 75% relative humidity in the proportion of 1% by weight, mites consumed 1% of the grain in 27 days at 21d C, or in 37 days at 10-15d C. Although mites consumed the grain more rapidly at higher temperatures or humidities, they survived longer at lower temperatures or humidities, and finally did more damage. Mites consumed wheat germ flakes more rapidly than grain, and finally reduced its weight by 74-85%. A system of symbols to represent degrees of damage to grain by mites, assessed visually, is presented, and approximate values for the equivalent weight losses are given. The relationship between the product, no. of mites per 100 ex. grain × time in weeks, and the degree of damage to grain, was calculated from experimental data; the damage done per unit of this density × time product was 2-2-5 times higher at 25 than at 5-9d C, and about 1-4 times higher at 70 than at 90% relative humidity. The mean density × time value corresponding to 1% loss of grain weight was 526,000 at 250 C, and 1,765,000 at 5-9d C. Data from granary investigations show the degree of damage associated with various levels of population density and grain moisture. In infested storages, the amount of embryo material destroyed ranged from less than 1% of the total (bulk grain) to about 15% (grain in bags). Mites may cause a rise in the temperature or moisture-content of grain, or an increase in the growth of microorganisms; but there is no evidence to suggest that serious damage from these causes is likely except that dense infestations can cause heating.

Corn losses occurring before and during the harvesting season were determined. These losses were (1) preharvest losses, (2) gathering losses and (3) snapping roll, separating and cleaning losses. Five varieties of grain, with two varieties planted on two different dates, were harvested with a grain combine with a corn head attachment. For most varieties the losses increased rapidly as the grain moisture dropped below 25%. Eighty-five to 95% of all losses were ear drop losses before or during the harvesting operation. Large differences in these losses existed among varieties. The results indicated that poor ear attachment (weak ear shank) was a major factor causing very high ear losses for some varieties at kernel moisture below 25%.

The various processes concerned with heat and moisture transfer in deep beds of grain have been classified. It was found that at high air humidities and grain moisture contents the existing thin layer drying theory is inadequate. Despite the shortcoming of the existing theory, a system of equations and a numerical step by step solution for predicting moisture and temperature changes has been presented in a previous paper, and slight improvements have been suggested. For the special case of heat transfer in an isomoisture bed (no heat transfer) a conventional analytical solution is available. Present experimental driers are only really suitable for operating at relatively high temperatures. In order to obtain data for the properties of grain necessary to predict moisture and temperature changes, and also to investigate the slow drying and cooling of deep beds, it is proposed that an experimental closed system unit capable of handling beds of grain up to 4 ft deep be developed.

This paper considers the prediction of grain moisture and temperature changes at any point in a bed and at any time when drying is being carried out at a relatively rapid rate. A system of equations for predicting these changes is presented, methods of determining the relevant physical properties considered, and a step by step solution by means of a digital computer given. The computed results are in reasonable agreement with experimental observation.

A study of the properties of bulk grain, the heat production of insects and their rates of breeding shows that the cooling of grain in bulk by aeration should control granivorous insects. The grain temperature needs to be lowered to 17–22°, depending on the species of insect. Deterioration of the grain, particularly of its viability, must be avoided, before, during and after cooling by aeration; safe combinations are given for grain moisture content, storage temperature and storage time. Laboratory-scale aeration experiments indicate that barley will not absorb moisture unduly if aerated with untreated air when the atmospheric relative humidity does not exceed 75% in autumn or 80% in winter. An example of the successful cooling of large bulks of malting barley by aeration with fans in commercial stores is described. Aeration for 56–94 h. at the rate of 0.16 cu. ft./m. of air per bushel of grain, in one to three stages, cooled 240,000 bushels (6000 tons) of malting barley in five fairly shallow stores within 3 months of the start of loading. Grain was cooled most quickly along the shortest distances between the aeration duct and the surface of a bulk. On the basis of a review of weather information for 12 years the British Isles were divided into three regions, good, satisfactory and doubtful for aeration. The barley stores described were in the good region. Design of aeration systems for British weather conditions is discussed, including automatic control of aeration. It is concluded that in British conditions cooling by in-store aeration is a reliable, labour-saving, economic method of avoiding the trouble caused by granivorous insects in stores of cereal grains. It should also enable some economies in the amount of drying or of cooling in dryers to be made. Of the cooling methods considered, in-store aeration is the most economical method of cooling the grain.

Two field experiments were conducted near Guelph, Ontario in both 1969 and 1970 with the objectives of (i) studying the relationship between grain moisture percentage and black layer development and (ii) examining the effect of environment on the length of the interval from planting or silking to black layer formation in corn (Zea mays L.). The first experiment involved 10 adapted commercial hybrids planted in early May at a plant population of 70,000 plants/ha. The second study concerned three commercial hybrids that were planted at a plant population of 55,000 plants/ha on each of four dates in 1969 (May 14 and 23, and June 5 and 13) and four dates in 1970 (May 6 and 20, and June 1 and 8). For both experiments records or measurements were taken of the date of 50% silking, 50% black layer, grain moisture percentage at 50% black layer, and final yield. Weather records were used to compute the number of accumulated heat units, by either the Ontario Corn Heat Unit (OCHU) or the 10- to 30-C Growing Degree Day (GDDHU) systems, from planting or midsilking to 50% black layer. Among adapted hybrids planted in May percent grain moisture at black layer varied from 30 to 37. For two hybrids planted on June 13, 1969 and June 8, 1970, black layers developed “prematurely” at a grain moisture of 39 to 42%. This premature black layer formation was an apparent consequence of cool weather during the week prior to black layer development. Delayed planting resulted in a decrease in number of days from planting to midsilking, and an increase in number of days from mid-silking to maturity (50% black black layer). Delayed planting resulted in an increased number of accumulated heat units from planting to midsilking, and a decreased heat unit accumulation from midsilking to maturity, by either the OCHU or GDDHU system. As a result, the number of accumulated heat units from planting to maturity was only slightly reduced by delayed planting date. The two systems were of comparable precision and were superior to number-of-days per se in characterizing the length of the interval from planting to midsilking, but not from midsilking to maturity. Because of its ease of detection, black layer development can serve as a useful end-point for characterizing corn hybrids as to their relative maturity and their adaptability to various localities. Present results suggest that there are significant problems, however, in the wide-scale use of black layer development for this purpose.

Histological studies showed that in good puffing varieties of paddy the aleurone layer was thin and weak at the specific points of bursting while the clearance between the husk and kernel was large and the grain was easily shelled. In the poor puffing varieties the aleurone was uniformly thicker along the peripheral section while clearance between husk and grain was smaller and the grains were relatively more difficult to shell. Optimum maturity of grains at an average grain moisture of 20-24% was essential for getting max. puffing. Delayed harvesting caused sun checks and reduced overall puffing expansion. Sun checks caused by severe drying in the sun produced a similar effect. High grain density was associated with better puffing.

Malathion was applied to grain sorghum from 6 hybrids at the rate of 1.0 pint of 57% emulsifiable concentrate per 1000 bushels. Little hybrid effect on malathion degradation was found during 12 months’ storage at 80°F and 60% relative humidity. Grain moisture content and storage temperature significantly affected residue retention, but foreign material had no effect on the rate of malathion disappearance.

Malathion applied at 2 p.p.m. to wheat of 13.5% moisture content caused 99% mortality of the rusty grain beetle, Laemophloeus ferrugineus (Steph.) at 8 months after treatment; the wheat was stored in airtight containers at 48° F. A dosage of 16 p.p.m. was required for comparable control in wheat of 15.5% moisture content but this dosage was ineffective in wheat of 18% moisture content at 5 months after treatment. Repellency tests in wheat of 12, 15 and 17% moisture content treated at 4 or 8 p.p.m. the test insects being placed in adjoining untreated wheat, showed that adults of L. ferrugineus but not of sitophitus granarius (L.) were repelled from wheat of 12% moisture content treated at 4 p.p.m.: mortalities of both species ranged from 84.8 to 100.0% in treated wheats. Reproduction of L. ferrugineus was reduced more than that of S. granarius in unevenly treated wheat. There was no adverse effete on the milling or baking quality of wheat treated with malathion at 4 or 8 p.p.m.

In growth and digestibility experiments, rolled barleys of 14·2, 18·0 and 21·5% moisture content (the two latter barleys having had a propionic acid-based preservative added) were fed to bacon pigs with either the protein, vitamin and mineral supplements mixed to form a complete diet or added to the barley in the feeding trough without mixing. There were no significant differences between these two methods of feeding in terms of digestibility, growth rate and conversion efficiency. The diets based on the 18·0 and 21·5% moisture barleys contained higher percentages of larger sized particles than the other diet, but gave significantly better growth rates and efficiencies of conversion and thicker backfat deposits. The results from the digestibility experiments did not show that these results were necessarily caused by differences in digestibility.

Airtight storage as a means of preventing deterioration of damp grain was studied both on a laboratory scale and in 10-ton bins, at grain moisture contents from 17 to 24%. Except when containers leaked, there was no development of mould, and the grain was bright and free-flowing, even after prolonged storage, at high moisture content. The grain remained mould-free after a bin was opened several times and small quantities of grain run out in cool weather. Such grain, removed from hermetic conditions and stored in sacks in an unheated building, showed no mould development for several weeks. With prolonged hermetic storage or at high moisture content the grain developed a sour-sweet smell and taste which when extreme were not entirely removed by subsequent airing or drying. There was no spontaneous heating; the grain in the 10-ton bins reflected the mean temperature of the surroundings. The oxygen in the intergranular air was reduced to a low level and replaced by carbon dioxide within a few days or weeks, according to the moisture content and temperature of the grain. At moisture contents of 16% and above, appreciable positive pressure developed inside the containers. The carbon dioxide concentration rose to 90–95% at grain moistures of 22–24%, 70–75% at 19%, 50% at 18%, and 35–40% at about 17% moisture content. The change from aerobic to anaerobic activity was marked by a reduction in the rate of production of carbon dioxide. With grain of less than 14% moisture content, the rate of respiration was slow, the carbon dioxide concentration being only about 2% after 18 months' storage. As long as oxygen remained, the apparent respiratory quotient was consistently between 0.6 and 0.7, whatever the moisture content of the grain. This work formed part of the programme of work of the Pest Infestation Laboratory.

In this paper, a method for measuring the moisture content of grain was presented based on single chip microcomputer and capacitive sensor. The working principle of measuring moisture content is introduced and a concentric cylinder type of capacitive sensor is designed, the signal processing circuits of system are described in details. System is tested in practice and discussions are made on the various factors affecting the capacitive measuring of grain moisture based on the practical experiments, experiment results showed that the system has high measuring accuracy and good controlling capacity.

High moisture corn was sterilized with ethylene oxide gas and stored for 8 weeks. At 0, 1, 2, 4, 6 and 8 week storage periods the moisture content was checked with the USD A ait-oven method and three electronic moisture meters. The moisture meters gave increasingly erroneous readings with storage time. There was no mold development in the treated corn, but the change in dielectric properties make this type of sterilization unsuitable for preparing samples of high moisture corn for moisture meter inspection.

The effects of N nutrition and leaf clipping after mid-silk on maize were examined. N increased yield components and defoliation reduced weight of ears, grains, total dry matter aboveground, harvest index and grain moisture. Crude protein increased, especially with complete clipping.

The correlation between hybrid corn (Zea mays L.) grain yield and percentage grain moisture at harvest was measured in Ontario performance trial data. Positive correlations were detected in mid- to full-season areas.Key words: Zea mays L., hybrid corn, grain yield, grain moisture, maturity, correlation

Residue data were obtained at five intervals over a 30-day period from wheat, maize and sorghum containing eight levels of moisture, following 10 p.p.m. applications of phoxim-methyl emulsion spray. High-moisture content reduces the effectiveness and persistence of phoxim-methyl in stored grain. Degradations differed significantly (P = 0.05) at each moisture level. After 30 days of storage, 10, 3 and 22.9% of the initial residue deposit remained on the 20% moisture sorghum, wheat and maize, respectively. The highest residue deposits remained in the 6% grain moisture levels. After 30 days of storage, 71, 63 and 68% of the initial residue deposit remained on sorghum, wheat and maize, respectively

Full-sib selection is one method of intrapopulation improvement used in maize (Zea mays L.). This study was conducted to evaluate the progress from 10 cycles of full-sib recurrent selection in the Nebraska Krug open-pollinated maize population. A 2-yr full-sib selection cycle was applied to the Krug population beginning in 1966. The selection criterion was a multiplicative selection index consisting of yield (adjusted to 155 g kg-1 moisture), proportion of standing plants, and proportion of plants without dropped ears. Based on field evaluations across none seasons, the selection index increased 0.17 Mg ha-1 cycle-1 (4.4% cycle-1), yield increased 0.07 Mg ha-1 cycle-1 (1.2% cycle-1), the proportion of standing plants increased 2.8% cycle-1, and the proportion of plants without dropped ears increased 0.1% cycle-1. Grain moisture at harvest decreased 3.0 g kg-1 cycle-1 (0.3% cycle-1). Changes in plant traits other than those involved in the selection index were also measured. The multiplicative selection index was successful in increasing the yield on standing plants when applied to a full-sib breeding system. Data indicate that yield on standing plants has continued to increase through the tenth cycle of selection.

Research was performed to determine the effects of variations in grain moisture content, temperature, and dockage content on penetration of HCN through a gain mass. Grain sorghum samples with moisture contents of 11%, 13%, and 15% were fumigated at temperature of 65°, 80° and 95° F. Interstitial air samples and grain samples were taken for cyanide residue analyses at sampling level of 3-, 9-, and 15-ft distances from the point of introduction of the gas. Air samples were taken at 4, 8, and 24 hr and grain samples 4 and 24hr after the introduction of the fumigant. All the main variables caused significant difference in gas concentrations in the air and grain residues. Analyses of samples obtained 4, 8, and 24 hr after introduction of the gas disclosed that cyanide concentrations in the interstitial air and residues on the grain decreased as grain moisture content was increased. These were lower under high temperature conditions. The presence of dockage had an effect similar to that of high moisture in that it reduced the cyanide concentration in the interstitial air and the residue on the fumigated grain sorghum.

The rice weevil ( Sitophilus oryza (L.)) is known to infest standing corn in the field in Louisiana. It was not known at what maximum grain-moisture level oviposition followed by complete development occurred. Studies conducted over a 2-year period showed oviposition may occur at a grain moisture of 65%. Eggs laid at this stage of corn maturity required 9 days for incubation. Complete development from egg to emergence of the adult required 42 days, and occurred between a grain moisture change from 65% to approximately 25%.

O objetivo deste trabalho foi analisar o efeito da distribuição espacial do teor de água dos grãos e da produtividade do feijoeiro sobre as perdas e a qualidade do produto durante o processo de arranquio, recolhimento, trilha e separação em uma recolhedora-trilhadora. O trabalho foi realizado em uma área de 35 ha sob pivô central. Foi determinado o teor de água dos grãos no arranquio e no recolhimento, a produtividade total e líquida da lavoura, a velocidade de trabalho da máquina, a quantidade de grãos perdidos no arranquio, no recolhimento e na trilha e separação e a porcentagem de matéria estranha e própria do feijoeiro presente no produto. As perdas de grãos e a qualidade do produto colhido apresentaram elevada variação de seus valores na área, indicando a necessidade de regulagem específica da recolhedora-trilhadora em cada caso durante a colheita, em função do teor de água e da produtividade. The objective of this work was to analyze the effect of grain moisture and crop yield spatial distribution on grain losses and quality during bean uprooting, collecting, threshing and separating process on a retirement-threshing machine. The work was performed in a 35 ha area under a central pivot irrigation system. Grain moisture on the uprooting and collecting process, the crop yield, the machine work speed, the grain losses during uprooting, collecting, threshing and separating process and the material-other-than-grain were measured. Grain losses and product quality displayed high variation over the area, showing the need for a specific regulation of the retirement-threshing machine on each case during the harvest, in function of the grain moisture and crop yield.

methods include these three phases, they vary in types of progenies evaluated (i.e., inbred, full-sib, half-sib, Recurrent selection methods have been effectively used by maize etc.); number of progenies evaluated; number of se(Zea mays L.) breeders to improve the performance of maize populations for quantitatively inherited traits. Although theoretical compari- lected families (i.e., 5, 10, 20, 30, etc.); parental control; sons of such methods can be easily made, direct comparisons of the and the type of progenies intermated. It is this flexibility efficiencies of methods are time consuming and laborious. Because in the different types of methods and different parameof these limitations, empirical data comparing multiple recurrent se- ters that has led to the utilization of a wide range of lection methods in the same base population are lacking for maize. recurrent selection methods for population improveOur study was designed to compare the response to selection for ment with an equally wide range of responses. Even seven different methods (six intra- and one inter-population) in the with the diversity of recurrent selection methods, two BS11 maize population. A minimum of four cycles of selection were goals remain common throughout, increasing the mean conducted for each of the following methods: mass, modified ear-toperformance of the population and maintaining the gerow, half-sib with inbred tester, full-sib, S1-progeny, S2-progeny, and netic variability in the population to facilitate long-term reciprocal full-sib selection. Selections for all programs except mass and reciprocal full-sib were based on an index composed of grain selection. The focus of our study was to improve the yield, grain moisture, stalk lodging, and root lodging. Each trait in mean performance of a single population with respect the selection index was weighted according to its heritability. The to four important agronomic traits via seven different populations per se, populations selfed, and testcrosses of the popula- recurrent selection methods. tions to the Cycle 0 population and to inbred B79 were evaluated in Grain yield has historically been the most important our study. Response to selection was measured for grain yield, grain trait and the trait most frequently used for selection moisture, stalk lodging, and root lodging along with other agronomic in maize population improvement. Recurrent selection traits. All selection methods were successful in significantly improving methods have not been widely adopted by maize breedthe population per se performance for grain yield. S2-progeny selection ers, although they have been effective for increasing

Changes in grain moisture, germination and vigour of three wheat cultivars packed in paper bags and stored for one year under four different conditions of environmental temperature and relative humidity (RH) were investigated. During the first ninety days of storage significant reduction in grain moisture content of 4, 2.5 and 0.9 %, respectively, under 40 °C, 25 °C and 4 °C and RH of 45 % occurred.Subsequently grain moisture remained constant until the end of storage. Seeds of examined cultivars lost their germination ability and vigour only under elevated storage temperatures. Germination and vigour loss after one year of storage differed between cultivars being higher for seeds kept under 40°C, RH = 45 % (35-85 % and 55-94 %, respectively), than under 25°C, RH = 45 % (10-20 % and 15-22 %, respectively). Obtained data indicate significant influence of storage conditions on moisture content, germination and vigour changes during storage of wheat seeds, as well as varietal dependence of seed viability.

We studied effect of sample size of S 1 progenies of two synthetic populations of maize, 326PO1 and 316PO02, one the estimation of mean value and genetic and phenotypic variability for grain yield and grain moisture. Three sample sizes were formed at random, containing 50S 1 , 100S 1 and 200S 1 progenies per population. Progenies in one sample were randomly assigned in sets. Each set contained 25 progenies arranged in two replicates per set. Progenies were tested during 1995 in field experiments at three locations. Sample size of S 1 progenies had no significant effect on the estimation of genetic and phenotypic variability for grain yield and grain moisture in the examined synthetic populations in the analysis over environments, and had significant effect within environments. In the estimate of mean value of investigated traits sample size had significant effect, over and within environments. Sample of 100S 1 progenies studied in more than one environment is sufficient for reliable estimate of mean value and variability of grain yield and grain moisture in synthetic populations of maize.

TIMELY harvesting of navy beans is essential for low threshing loss, freedom from impact damage to the bean and good quality. Stepwise regression techniques were used to develop threshing loss and damage models from field data. Threshing loss depended upon pod moisture content and showed varietal differences. Damage, including split and checked beans as well as total dam-age, depended upon combine cylinder speed and grain moisture content. Careful adjustment of the combine during harvest is required to mini-mize both threshing loss and damage to the crop.

Experiments 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.

THE previously developed method to measure sound pressure level of wheat was used for corn, milo, and soybeans. For all grains tested, sound level increased with lower grain moisture, larger grain flow rate, and smaller microphone-grain distance. The slope of the dB-MC line was highest for soybeans, lowest for milo, and intermediate for corn and wheat.

SUMMARY margins sustained the highest levels of duck damage. (3) Crop damage was measured along transects, using an empirical weight-length table, and compared with the feeding pressure exerted by the number of birds present as grain losses caused by disease, insects, sparrows and greenfinches were difficult to distinguish from duck damage. (4) Estimates of feeding pressure suggested that levels of duck damage were overestimated using transect measurements. Grain consumption by ducks was compar- able to the amount of grain spilt during harvesting. (5) The number of ducks which fed on ripening barley was influenced by the proximity to water, moisture content of the grain, and the number of days the crop was available. (6) Plant height, grain moisture content, amount of spilt grain, density and area of the barley crop were directly associated with levels of duck damage.

(…) Number of ears plant −1 in the cycles per se increased by 2.4 and 3.3% cycle −1 in 1985 and 1986, respectively. Corresponding increases in grain yield plant −1 were 2.0 and 3.0% cycle −1 , and increases in grain yield ha −1 were 2.0 and 2.8% cycle −1 . Grain moisture, flowering dates, and the period between silk emergence and anthesis decreased with selection for cycles per se. Testcross responses were approximately one-half those of cycles per se for ears plant −1 and either measure of grain yield. Grain moisture did not change with selection, and days to flowering increased by 1 to 2 d in the testcrosses. (…)