Dry Kernel Research Articles

Regulated deficit irrigation in almonds: effects of variations in applied water and stress timing on yield and yield components

The impacts of three different water stress-timing patterns for three levels of seasonal applied water on production were evaluated in mature almond trees [Prunus dulcis (Mill.) Webb cv. Nonpareil] grown under high-evaporative demand conditions in the southern San Joaquin Valley of California. The stress timing patterns involved biasing water deficits to the pre-harvest or post-harvest periods in addition to uniform deficit irrigation for the entire season, referred to as A–C patterns. The three levels of water availability were 55, 70, and 85% of potential seasonal evapotranspiration (ETc) equivalent to 580, 720, and 860 mm of applied water per season, respectively. Treatments were imposed over four seasons. Predawn leaf water potential was used as the stress indicator and approached −4.0 MPa with the A pattern at the lowest applied water level and −3.5 MPa with the B pattern at the same irrigation level. For every level of applied water, kernel weight at harvest was significantly reduced in the A pattern relative to the B and C patterns. At harvest, the most severe reduction in kernel dry weight relative to the control (17%) occurred in 580A, while there were 11% reductions in 580B and 580C. At the 860 mm level, only the A pattern dry kernel weight was less than the control. Moreover, the A patterns for all irrigation levels had lower kernel percentages than for the B and C patterns, indicating the greater sensitivity of kernel growth relative to shell growth in the regulated deficit irrigation (RDI) scenarios that biased the stress toward pre-harvest. The B stress patterns had a strong negative impact on fruit load relative to the A patterns at the 580 and 720 mm levels of applied water. No differences in crop load relative to the control were observed among the A and C regimes for all three levels of applied water. Nut load tended to increase during the experiment with 580A and 720A while it decreased with time with the B patterns for the same irrigation levels. We believe that the lower fruit loads involve stress during flower bud differentiation, which occurs mid-August–September in this cultivar and location, quite late in the season relative to other fruit and nut crops. The most successful stress timing pattern in terms of yield (the integrator of fruit size and load) was C, which avoided the large swings in tree stress observed with A and B. The onset of hull splitting was delayed by the severe pre-harvest stress in 580A while being accelerated by the milder stress of 720A. Spider mite levels were unaffected by the RDI. Canopy size was reduced with the A patterns at all irrigation levels. This occurred without any concomitant reduction in fruit load, resulting in higher fruiting densities (305 and 283 nuts/m2 of orchard floor shaded area in 580A and 720A, respectively, vs. 214 nuts/m2 in the control). Coupling the higher fruiting densities and smaller canopy sizes with higher tree planting densities offers growers the possibility of increasing yields while consuming less water. Maintaining more compact canopies with RDI rather than pruning would also lessen the amount of wood requiring disposal, thereby moderating air quality degradation resulting from burning. It must be emphasized that the scenario we outline—increasing kernel yields while using less water due to stress-related higher fruiting densities—requires that the smaller canopies be maintained by RDI, not pruning.

QTL Influencing Kernel Chemical Composition and Seedling Stand Establishment in Sweet Corn with the shrunken2 and sugary enhancer1 Endosperm Mutations

This study was conducted to identify the chromosomal location and magnitude of effect of quantitative trait loci (QTL) controlling sweet corn (Zea mays L.) stand establishment and investigate the impact of dry kernel characteristics on seedling emergence under field conditions. Genetic and chemical analysis was performed on two F2:3 populations (one homozygous for su1 and segregating for se1, the other homozygous for sh2 endosperm carbohydrate mutations) derived from crosses between parental inbreds that differed in field emergence and kernel chemical composition. A series of restriction fragment-length polymorphism (RFLP) and phenotypic markers distributed throughout the sweet corn genome were used to construct a genetic linkage map for each population. F2:3 families from the two populations were evaluated for seedling emergence and growth rate at four locations. Mature dry kernels of each family were assayed for kernel chemical and physiological parameters. Composite interval analysis revealed significant QTL associations with emergence and kernel chemical and physiological variables. Improved emergence was positively correlated with lower seed leachate conductivity, greater embryo dry weight, and higher kernel starch content. QTL affecting both field emergence and kernel characteristics were detected in both populations. In the su1 se1 population genomic regions significantly influencing emergence across all four environments were found associated with the se1 gene on chromosome 2 and the RFLP loci php200020 on chromosome 7 and umc160 on chromosome 8. In the sh2 population the RFLP loci umc131 on chromosome 2 and bnl9.08 on chromosome 8 were linked to QTL significantly affecting emergence. Since seedling emergence and kernel sugar content have been shown to be negatively correlated, undesirable effects on sweet corn eating quality associated with each emergence QTL is discussed. Segregating QTL linked to RFLP loci in these populations that exert significant effects on the studied traits are candidates for molecular marker-assisted selection to improve sweet corn seed quality.

Twenty‐Four Cycles of Mass Selection for Prolificacy in the Golden Glow Maize Population

Maize (Zea mays L.) has the potential to produce an ear primordium at several nodes, and selection for increased prolificacy often increases grain yield. We have previously demonstrated the effectiveness of mass selection for increasing the number of active ear shoots in the ‘Golden Glow’ maize population. The objective of our research was to evaluate associated changes in ear and plant morphology after 24 cycles of mass selection for prolificacy in Golden Glow. Cycles 0, 6, 12, 18, 23, and 24 were grown in 1997 at two locations (Madison and Arlington, WI) at two planting densities (15 070 and 73 197 plants ha−1). At the lower planting density, the mean number of ears per plant increased from 1.61 at C0 to 4.93 at C24, and the response rate increased over the more recent cycles, mainly from C18 to C24. At C24, tiller number has increased, and lateral branches (terminating in ears) were located at approximately one node higher and two nodes lower on the main stalk compared with the original population. Total node number on the main stalk increased, and the internode length decreased over the 24 cycles, but the opposite occurred for lateral branches. At the lower planting density, ear diameter, ear length, and kernel size decreased by 0.03, 0.10, and 0.01 cm cycle−1, respectively, but total number of kernels per plant and dry kernel weight per plant increased significantly at a rate of 36.69 kernels cycle−1 and 5.60 g cycle−1 over the 24 cycles. Similar trends, but of lesser magnitude, were observed at the higher planting density. The changes in plant morphology observed across cycles of selection for prolificacy represent a general derepression of axillary meristematic growth in both main stalks and lateral branches.

Effects of processed corn silage on its digestibility and production of growing beef replacement heifers

A study was conducted to determine effects of processing whole crop chopped corn prior to ensiling on diet digestibility and growth of beef replacement heifers. Corn silage (CS) was harvested using two identical six-row self-propelled choppers, one of which was adapted with a roller-processing unit. Corn was chopped to either 13.3 mm (unprocessed; UP) or 10.6 mm (processed; PR) theoretical length of cut (TLC) and ensiled in silage bags. Over the 56-day feedlot study, 90 growing British-cross replacement heifers were randomly assigned to UP or PR CS with three pens per treatment. The diet initially consisted on a dry matter (DM) basis of 55.4% UP or PR CS, 22.3% alfalfa hay (AH), 19.6% wheat middling (WM) and 2.7% supplement (SUPP). Whole plant particle size was estimated from three sub-samples per treatment. Whole cob fraction as a percent of total dry mass was 0.0% for PR and 6.4% for UP ( P<0.05). Undamaged kernels as a percent of the total dry kernel mass were 17.3 for UP and 1.8 for PR ( P<0.05). There was no difference in average daily gain (ADG; 0.96 kg per day versus 1.00 kg per day), DM intake (DMI; 7.55 kg per day versus 7.59 kg per day) or feed to gain ratio (8.12 versus 7.70) between heifers fed UP or PR silages, respectively. Processing of CS did not alter ruminal pH but total VFAs and acetate concentrations were higher in heifers fed the UP treatment ( P=0.04). Treatment had no affect on whole tract DM or acid detergent fiber (ADF) digestibility ( P>0.05) but neutral detergent fiber (NDF) digestibility was higher in heifers fed the PR treatment ( P<0.008). Processing substantially reduced the number of whole kernels in CS and increased NDF digestibility, but did not improve heifer performance on diets containing 55% of DM as CS.

Twenty-Four Cycles of Mass Selection for Prolificacy in the Golden Glow Maize Population

Maize (Zea mays L.) has the potential to produce an ear primordium at several nodes, and selection for increased prolificacy often increases grain yield. We have previously demonstrated the effectiveness of mass selection for increasing the number of active ear shoots in the ‘Golden Glow’ maize population. The objective of our research was to evaluate associated changes in ear and plant morphology after 24 cycles of mass selection for prolificacy in Golden Glow. Cycles 0, 6, 12, 18, 23, and 24 were grown in 1997 at two locations (Madison and Arlington, WI) at two planting densities (15 070 and 73 197 plants ha−1). At the lower planting density, the mean number of ears per plant increased from 1.61 at C0 to 4.93 at C24, and the response rate increased over the more recent cycles, mainly from C18 to C24. At C24, tiller number has increased, and lateral branches (terminating in ears) were located at approximately one node higher and two nodes lower on the main stalk compared with the original population. Total node number on the main stalk increased, and the internode length decreased over the 24 cycles, but the opposite occurred for lateral branches. At the lower planting density, ear diameter, ear length, and kernel size decreased by 0.03, 0.10, and 0.01 cm cycle−1, respectively, but total number of kernels per plant and dry kernel weight per plant increased significantly at a rate of 36.69 kernels cycle−1 and 5.60 g cycle−1 over the 24 cycles. Similar trends, but of lesser magnitude, were observed at the higher planting density. The changes in plant morphology observed across cycles of selection for prolificacy represent a general derepression of axillary meristematic growth in both main stalks and lateral branches.

Effects of Deficit Irrigation on Hull Rot Disease of Almond Trees Caused by Monilinia fructicola and Rhizopus stolonifer.

Almond trees were irrigated from March through November 1994 and 1995 with 70, 85, and 100% of potential evapotranspiration (ETc). Deficit irrigation was accomplished by delivering 70 or 85% of ETc at every irrigation (sustained) or 50% of ETc during 1 June to 31 July (70 regulated) or 1 to 15 July (85 regulated). The natural incidence of dead leaf clusters and dead spurs, twigs, and small branches, measured at harvest, lessened with decreasing amounts of water, and regulated deficits were more effective than sustained deficits in reducing disease. Fruit at early dehiscence on trees in each of the five irrigation treatments were inoculated with 0.1 ml of suspensions of 104 spores per ml of Monilinia fructicola or Rhizopus stolonifer. Monilinia fructicola caused more hull rot than R. stolonifer, and both pathogens responded similarly to the irrigation treatments. The rate of fruit maturation was monitored for approximately 4 weeks before harvest by scoring the percent abscission and dehiscence and measuring the hull moisture content of fruit on trees in each irrigation treatment. Dry kernel weight was determined at harvest. Maturation was slower and kernel weight greater in treatments receiving 85% of ETc than 70% or those under sustained compared with regulated irrigation regimes.

Effect of Measurement Method and Moisture Content on Wheat Kernel Density Measurement

Wheat kernel breakage is a critical factor in the flour milling process, and is affected by kernel density. Kernel density measurement is not routinely performed, and depends on the measurement technique used and the moisture content of the grains. This study compared currently available wet and dry methods based on gas displacement and liquid displacement (using water, water-ethanol mixtures and xylene) to determine the density of Hereward (hard) and Consort (soft) wheat kernels of different sizes and moisture contents. A gas pycnometer was used to measure the average density of a sample of wheat kernels, while a double cup system was used to measure individual kernel density by weighing kernels in air and immersed in liquid. The hard wheat variety, Hereward, had kernels of slightly higher average density, with a narrower distribution, than the soft variety, Consort. Kernel density was independent of kernel size, while increasing moisture content decreased the measured kernel density. The dry technique using the gas pycnometer gave the highest kernel densities, followed by xylene immersion, with water immersion giving the lowest density values, lower than the dry technique by 6.2% for Hereward and 9.9% for Consort. This was attributed to the effect of surface tension effectively increasing the kernel volume measured by the wet method. Further investigations with water-ethanol mixtures of varying surface tension supported this. The current trend in cereal quality testing is to measure distributions of single kernel physico-chemical parameters. The wet method allowed the measurement of the distribution of single kernel densities, but with poor accuracy due to surface tension; what is needed is a dry single kernel density method.

Physiological Maturity in Wheat Based on Kernel Water and Dry Matter

Estimation of the time of physiological maturity could be beneficial to avoid yield penalties due to lodging, sprouting, hail, and other harvest risks. The aim of our study was to evaluate a simple empirical relationship (model) to determine physiological maturity by simultaneously analyzing the water and dry matter dynamics of wheat kernels. An experiment was conducted in which two cultivars with different kernel mass potential were sown on four dates. Fresh and dry kernel mass from different positions in the spike were measured twice weekly. To validate the regression model, measured and calculated data from different cultivars, growing seasons, and kernel positions were compared. A negative linear relationship between kernel dry matter (relative to final kernel mass) and kernel water concentration was determined. This showed that in wheat, physiological maturity is reached at 37% of kernel water concentration. Validation of the regression model was done using data from field experiments in Argentina and Mexico, and from controlled‐conditions experiments reported in the literature. The regression model successfully simulated results from field experiments (.) In addition, data from controlled‐conditions experiments showed the same negative linear relationship between relative kernel dry matter and kernel water concentration (), and the model achieved a good fit for measured data (). This regression model is proposed for use by farmers and crop managers, who can simply measure grain humidity with grain moisture meters.

Diversity of the Sheanut tree (Vitellaria paradoxa C.F. Gaertn.) in Ghana

The Sheanut tree (Vitellaria paradoxa C.F. Gaertn.) is highly valued for oil obtained from its seeds and frequently maintained in the semi-arid parklands of sub-Saharan Africa from Senegal to Uganda. Although variation has been noted for V. paradoxa subsp. paradoxa, few studies have been undertaken on patterns of phenotypic or genotypic diversity. Results are presented from 294 accessions collected in Ghana, using easily quantifiable morphological parameters. Productive mature trees varied from shrubby multi-stemmed individuals (height <5 m) to 30-m straight-boled trees with high compact canopies. The leaf lamina (tree mean ±% coefficient of variation of total mean) varied from 9.2 to 22.5 cm (±15.0%); seed length from 1.74 to 3.74 cm (±11.7%); and fat content from 29.1 to 61.9% of dry kernel weight (±9.4%). Clinal trends significantly correlated with location parameters that in turn related to environmental variation. Population variation of seed characteristics increased to the Northeast, perpendicular to the annual movement of the inter-tropical convergence zone. It is proposed that this is a consequence of past climatic changes, coupled with a lack of methodical selection for seed type when trees are maintained on agricultural land. Isozyme analysis revealed moderate to high levels of heterozygosity (He 0.2142) and high geneflow (Fst = 0.0124, Nm = 19.9), supporting results obtained from morphological studies. Isozyme and multivariate morphology analyses showed similar but weak geographical separation patterns.

Effect of residual fertilizer N, lime and Bradyrhizobium inoculum on groundnut yield, N uptake and N2 Fixation

Groundnut (Arachis hypogaea L.) is known to be effective in symbiotic N2 fixation, but uncertainty remains concerning the magnitude of this process, especially when this crop is grown under acid conditions with different N management systems. This study was conducted to determine the effect of previously applied fertilizer N and previously applied lime rates on groundnut yield, 15N concentration, total N uptake and N2 fixation. Previously applied N rates were 0, 80, 160 and 240 kg N ha‐1 as NH4NO3 to main plots or labelled‐N rates of 0, 40, 80 and 120 kg NO3‐N ha‐1 to microplots as NH4 I5NO3. The lime was previously applied at the rates of 0 and 2 Mg ha‐1 to the preceding maize (Zea mays L.) crop. The effect of inoculum was also investigated. Nodulating isoline, groundnut cv Chalimbana seed was treated with Bradyrhizobium peat inoculum containing Bradyrhizobium sp. (inoculant strain TAL 1000) 105 cells per seed. Non‐nodulating isoline PI 109839/NC AC17090 (NFN‐43) and nodulating isoline Chalimbana were grown in the field during the 1989/90 cropping season on a Misamfu red sandy loam soil at Kasama, Zambia. Whole‐plant dry matter production or kernel yield and total N uptake of non‐nodulating plants were lower than those of the nodulating plants. Total N uptake by whole‐plant dry matter in all plants was higher in a treatment previously supplemented with 160 kg N ha‐1 than in 80 kg N ha‐1. Residual lime increased kernel yield and N2 fixation in nodulating plants. The amounts of fertilizer 15N uptake by plants increased with labelled previously applied fertilizer N rates. The higher recovery of previously applied labelled N fertilizer in nodulated than in non‐nodulated plants was due to differences in dry matter production. Previously applied higher N fertilization rates (greater than 160 kg N ha‐1) with previously applied lime reduced N2 fixation. Lime enhanced N2fixation by the isotope dilution (ID) method. Groundnut inoculation seems to be a viable technology, since it increases in plant dry matter production and grain yield.

98/00426 Energetic approach of waste water processing using dry kernel as a fuel

98/00426 Energetic approach of waste water processing using dry kernel as a fuel

Energetic approach of waste water processing using dry kernel as a fuel

The aim of this paper is to identify a suitable usage of the enormous amount of dry kernel, a biomass derived from olive-oil processing, as a combustible fuel in the disposal process of waste water. The method recommended besides the disposal of waste water, allows the recovery of the diluted substances with a remarkable reduction of functional costs. The method is supported by a two-year long experimental campaign during which more than 13,000 tons of waste water were processed.

Variation in sweet corn kernel characteristics associated with stand establishment and eating quality

A better understanding of the relationships between kernel characteristics associated with eating quality and stand establishment could be helpful in selection of superior genotypes by the sweet corn industry. A set of sweet corn (Zea mays L.) inbred lines with different endosperm mutations (su1, su1 se1 and sh2) were evaluated for field emergence and seedling growth rate at two locations over two years. Kernel characteristics associated with eating quality (kernel moisture concentration, kernel tenderness, sugars, phytoglycogen and dimethyl sulfide (DMS) concentrations were determined for the same inbreds by laboratory analysis from ears harvested at 18 and 22 days after pollination (DAP). Amounts of sugars, phytoglycogen and starch were also measured in mature dry kernel samples of the same inbreds. Extensive genetic variability was found among endosperm mutations and among genetic backgrounds within the different endosperm groups for most of the characteristics under study. Most of the kernel attributes associated with eating quality were uncorrelated indicating that selection to improve specific eating quality characteristics can be conducted simultaneously. A negative correlation between field emergence and sugar concentrations in immature kernels suggests that in breeding programs designed to develop germplasm with improved germination and stand establishment, concurrent attention must be given to the fresh quality of the harvested product. This information is of value to breeders and commercial growers for selection of sh2 and su1 se1 lines with superior field emergence and eating quality.

In search of a new vegetable oil

Terminalia bellirica Roxb., commonly known as Bahera in India and commercially as belliric myrobalan, may become the olive of the East and is a fairly abundant plant in the tropical Indian subcontinent. The raw flesh of the fruit can be converted to fodder. The seed oil content (about 47% by weight of dry kernel) appears very promising as a vegetable oil for edible purpose and can be hydrogenated or used for soap production

Feasibility of biomass-fuelled steam turbine cogeneration for olive oil pressing plants

SYNOPSIS The adoption of a cogeneration integrated system is described in this paper. The dry kernel, a woody residue of olive pressing, is produced in very large quantities and could therefore be used in high pressure condensing-extraction team turbines to supply on-site electricity and steam needs. This system is becoming more and more interesting since it produces an excess of electricity which could be sold, e.g. to the electric utility. Such a cogeneration system will be discussed in terms of efficiency, capital cost, near-time commercial viability and power-to-fuel costs. The economical analysis is presented here for olive press-cake processing plants and can be extrapolated to biomass-based industries having the same characteristics. An energy audit has been carried out on 16 plants.

Lipid composition of melon ( Cucumis melo) kernel

Total kernel lipids extracted from musk melon ( Cucumis melo, cucurbitaceae) amounted to 49.4% of the dry kernel. The total lipids contained 91.5% neutral lipids, 6.4% glycolipids, and 2.1 % phospholipids. Neutral lipids consisted mostly of triacylglycerols (90.7%) with small amounts of diacylglycerols, monoacylglycerols, free fatty acids, sterols, sterolesters, and hydrocarbons. At least four glycolipids and eight phospholipids were detected. Monogalactosyldiacylglycerol, digalactosyldiacylglycerol, and acylmonogalactosyldiacylglyceroI were the major glycolipids, while acylated sterylglucoside was present in small amounts. The major phospholipids were phosphatidylcholine and phosphatidylethanolamine, while phosphatidic acid, phosphatidylserine, phosphatidylglycerol, lysophosphatidylcholine, lysophosphatidylethanolamine, and phosphatidylinositol were present in small amounts. The fatty acid compositions of the neutral lipid, glycolipid, and phospholipid fractions were determined.

Evaluation of date kernel oils and their effects on wheat flour characteristics

Date kernels constitute about 13% of the whole date fruit, and cotain moderate amounts of oils with relatively high caloric values. Agwa soft and Aprimi dry date kernel oils were used in this work. Results showed that Aprimi date kernel oils have high levels of both caproic acid and stearic acid of 23.04 and 18.40% respectively, while Agwa kernel oils have high levels of caprylic acid and capric acid of 22.31 and 12.20%. Moreover Agwa oils achieved higher amounts of unsaponifiable matters, sterols and tocopherols. The addition of soft and dry date kernel oils did not improve the wheat flour strength but raised its resistance to extensibility.

Yield comparison of Australian selections of almond cv. Nonpareil

Eight Nonpareil almond clones on Nemaguard rootstock were yield-tested in a field trial at Irymple, Victoria, for 4 cropping seasons (1986-89). Although few significant differences in yield were recorded in any year, the results showed that the Nonpareil clones differed in total yield and in total yield per unit of butt cross-sectional area by as much as 50%. For example, clone L54/3 produced a total dry kernel yield per tree per unit of butt crosssectional area of 51.2 kglcm2, while the high yielding clone G11/16 produced a yield of 77.6 kg/cm2. The 3 top-yielding clones (GI 1/16, P7/29 and K5/7) produced total dry kernel yields (1986-89) per tree per unit of butt cross-sectional area of 77.6, 73.6 and 71.7 g/cm2. However, clone K5/7 proved to be subject to non-infectious bud failure, and it is concluded that clones G11/16 and P7/29 could be useful, high-yielding clones for the Australian almond industry.

Lipid composition ofCalophyllum inophyllum kernel

Total kernel lipids extracted fromCalophyllum inophyllum, Guttifereae amounted to 60.1% of the dry kernel. The total lipids consisted of 92.0% of neutral lipids, 6.4% glycolipids and 1.6% phospholipids. Neutral lipids consisted of triacylglycerols (82.3%), free fatty acids (7.4%) and small amounts of diacylglycerols, monoacylglycerols and sterols. At least four glycolipids and five phospholipids were identified. Acylmonogalactosyldiacylglycerol and monogalactosylmonoacylglycerol were major glycolipids; while monogalactosyldiacylglycerol and an acylated sterolglucoside were present in small amounts. The phospholipids consisted of phosphatidylethanolamine and phosphatidylcholine as major phospholipids, and minor amounts of phosphatidic acid, phosphatidylserine and lysophosphatidylcholine. The fatty acid composition of these different neutral lipids, glycolipids and phospholipids was determined.

Macadamia cultivar evaluation in Natal

Vegetatively propagated macadamia cultivars were grown in six ecologically different areas in Natal. Nut quality was tested over a number of years. The warm, moist north coast area is best for most cultivars tested with Keaau, Ka'u, Kakea and Beaumont giving nuts of best quality. The relatively newer Hawaiian cultivars Keaau and Ka'u produce nuts of reasonably acceptable quality in the cooler subtropical areas where the quality of the older cultivars Keauhou, Ikaika and Kakea is more limiting. The most recently released higher quality Hawaiian cultivars have yet to produce nuts. Hybrid cultivars are best for the cooler areas but their kernels and those of some other cultivars are more suitable for the dry kernel trade. Breeding of locally adapted M. integrifolia cultivars is an urgent priority. Sound management practices are essential to produce good quality kernels.