Monitoring grass swards using imaging spectroscopy

The potential of an imaging spectroscopy system with high spatial (0·16–1·45 mm²) and spectral resolution (5–13 nm) was explored for monitoring light interception and biomass of grass swards. Thirty‐six Lolium perenne L. mini‐swards were studied for a total of eleven consecutive growth periods. Hyperspectral images and light interception (LI) were recorded twice weekly. On two dates ground cover was scored visually (GC_v). At harvest, leaf area index (LAI), fresh‐matter yield and dry‐matter yield (DMY) were determined. Classification of images yielded several estimates of the image ground cover (GC_i) and the index of reflection intensity (IRI). The GC_i was highly correlated with GC_v ( = 0·94), LAI ( = 0·88) and LI ( = 0·95, for dense swards under cloudy skies). However, the relationship between GC_i and LI depended on sky conditions and sward structure. Under cloudy skies, LI was linearly related to GC_i, whereas under clear skies, this relation was logistic. Regression analysis of GC_i and yields showed correlations with of between 0·75 and 0·82. The mean error of DMY estimates was 340 kg. In conclusion, estimates of GC_i and IRI can be used to predict DMY, even for high yield levels (up to 3500 kg DM ha^?1), allowing accurate, non‐destructive monitoring of biomass and light interception of grass swards.     

In vitro fermentation patterns and methane production as influenced by cultivar and season of harvest of Lolium perenne L.

In some European countries, the majority of annual enteric methane (CH₄) emissions by ruminants occur at pasture – a direct result of the predominance of grazing within ruminant production systems. However, there are only limited data available as to the effect of perennial ryegrass cultivar and season of harvest on CH₄ production. Using the in vitro gas production technique, the effect of perennial ryegrass cultivar on fermentation characteristics and CH₄ production was determined (Experiment 1) and the persistence of these traits throughout the growing season for two cultivars, identified from Experiment 1 as having either a high or low methanogenic potential, was examined (Experiment 2). In Experiment 1, organic matter (OM) digestibility and cumulative total gas production profiles were unaffected by cultivar but, with regard to the kinetics of CH₄ production, the asymptote value (A), cumulative CH₄ yield at 72 h, and the fractional rate (μ) of CH₄ production at both time of 0·5A(T)(μCH₄T) and at 48 h (μCH₄48h) were significantly (P < 0·05) different. The amount of digested OM, as a proportion of cumulative CH₄ production (DigOM/CH₄) at 24 and 72 h after commencement of inoculation, revealed that the amount of substrate required to produce 1 ml of CH₄ also differed significantly between cultivars (P < 0·01). In Experiment 2, regrowth number significantly modified the majority of measured samples (P < 0·01); cultivar effects were limited to the lag phase of the cumulative CH₄ production curve and DigOM/CH₄ at 8 h only (P < 0·05). These results suggest that differences exist between cultivars in how OM is partitioned following microbial fermentation and that these differences demonstrate persistency throughout the growing season. In the course of time it may be possible to exploit these differences through cultivar selection and plant breeding programmes, and thereby reduce enteric CH₄ emissions within pastoral production systems.     

Influence of plant growth and root architecture of Italian ryegrass (Lolium multiflorum) and tall fescue (Festuca arundinacea) on N recovery during winter

Nitrate () leaching is an environmental and health concern. In grazed pasture systems, leaching primarily occurs beneath animal urine patch areas due to high nitrogen (N) loading and the inability of pasture plants to capture all of this N. This study investigated the relative importance of plant growth and root architecture to recover soil N. Herbage N recovery, dry matter (DM) yield and root architecture, following injections of ¹⁵N‐enriched urea at different soil depths (5, 25 and 45 cm), were measured for Italian ryegrass (Lolium multiflorum Lam.) and tall fescue (Festuca arundinacea Schreb.) grown in soil monolith lysimeters (18 cm diameter × 70 cm depth) under simulated South Island, New Zealand winter temperature and light levels. Total herbage N uptake and DM yield were on average 24 and 48% greater in L. multiflorum than F. arundinacea respectively. Root length density (cm cm^?3 soil) in the 5‐ to 25‐cm‐depth horizon was similar between species. In the 25‐ to 45‐cm‐depth horizon, F. arundinacea roots were found at higher densities than L. multiflorum. In the 45‐ to 65‐cm‐depth horizon, root length density was fourfold to ninefold higher for F. arundinacea than L. multiflorum, but N uptake efficiency was greater in L. multiflorum (0·48 mg ¹⁵N m^?1 root) than F. arundinacea (0·09 mg ¹⁵N m^?1 root). The results suggest that deep F. arundinacea roots are relatively inactive during the winter period and confirm that plant growth is more important than root architecture (e.g. deep roots) to recover soil N and ultimately reduce nitrate leaching losses.     

Thresholds of economic damage by clover seed weevil (Apion fulvipes Geoff.) and lesser clover leaf weevil (Hypera nigrirostris Fab.) on white clover (Trifolium repens L.) seed crops

Severe reductions in the seed yield of white clover can occur because of feeding by the white clover seed weevil Apion fulvipes and the lesser clover leaf weevil Hypera nigrirostris which together can reduce the seed yield by more than 0·50. From 2002 to 2006 five field experiments were carried out to investigate the relationship between the density of these two weevil species and seed yield of white clover. Damage caused by the weevils was calculated as the difference in the number of weevils and the difference in seed yield between the average of insecticide‐treated and untreated plots. Loss of seed yield was expressed as a proportion of the seed yield in insecticide‐treated plots, which allowed for a comparison between years as yields in insecticide‐treated plots varied. A multiple regression approach was chosen in which proportional loss in seed yield was the response variable and the weevils A. fulvipes and H. nigrirostris were the independent variables. Data obtained from the experiments were used to construct the following threshold model of economic damage:      

Nitrogen uptake and leaching loss of thirteen temperate grass species under high N loading

The intensification of grazed pasture systems in New Zealand has resulted in increased nitrate () leaching and associated significant reductions in water quality, resulting from high N loading in the cow urine patch. A glasshouse soil column experiment was conducted at Lincoln University examining the N uptake capacities and leaching losses of sixteen commercial and ‘weed’ pasture grasses, comprising thirteen species. Three dairy cow urine N treatments (N loading rates) were applied in May 2010: 0 (N0), 300 (N300) and 700 (N700) kg N ha^?1. Grass was harvested at 21‐d intervals, leachates collected to quantify N leaching losses and root mass measured. Shoot yield, root mass, N uptake and N leaching loss varied significantly between species (P < 0·001) and were strongly driven by N loading rate. The highest yielding species at N700 were Lolium multiflorum ‘Feast 2’ and ‘Tama’ (782 and 743 g DM m^?2), while Festuca arundinacea ‘Flecha’ and Lolium perenne ‘Alto' were lowest yielding (375 and 419 g DM m^?2). Plant N uptake and root mass followed a similar trend, and only moderate increases in total plant N uptake were observed for most species when urine N application rate was increased from N300 to N700. N leaching loss was highest at N700 for F. arundinacea ‘Flecha’ (378 kg N ha^?1) and lowest for L. multiflorum ‘Feast 2’ and ‘Tama’ (134 and 130 kg N ha^?1). Strong negative linear relationships were observed between N leaching loss, plant N uptake and root mass. The results indicate that species such as L. multiflorum may play a critical role in reducing pasture N leaching losses, while traditionally sown L. perenne, and also F. arundinacea, may be less suitable.     

Microbiological evaluation of tofu and tempeh during processing and storage

Tofu samples consisting of Fresh Tofu, Herb Tofu, Tofu Paste, Fried Tofu, Tofu Burger, Smoked Tofu and different types of herbs used for making Herb Tofu were analysed for their microbiological load. Tempeh samples consisted of cook water, inoculated beans and fresh tempeh. Fresh Tofu and Herb Tofu had high bacterial counts (10⁵ cfu/g). Tofu Burger and Smoked Tofu had counts around 10⁴ cfu/g. Tofu Paste and Fried Tofu had low counts (<10² cfu/g). Cutting board, knife and frequent hand contact with product were the major sources of contamination for tofu. Herbs used for making Herb Tofu were highly contaminated (>10⁵ cfu/g). Cook water and cooked beans for tempeh production had lower counts (10⁴ cfu/g). Initial count of fresh tempeh was high (about 10⁸ cfu/g). Most products had counts of >10⁶ cfu/g after 7 days of cold storage. The microbiological quality of the product may improve if producers avoid unnecessary contamination during processing.     

Beta-carotene content of postharvest orange-fleshed muskmelon fruit: Effect of cultivar,growing location and fruit size

The influence of two growing locations (soil types), six fruit sizes, and two years on the postharvestBeta-carotene content of muskmelon (Cucumis melo L. var. reticulatus Naud.) fruit was studied with two different cultivars. Fully abscised commercial size fruit: 9, 12, 15, 18, 23, and 30 (fruit/0.04 M³ shipping box) had highly variableBeta-carotene contents (5.3 to 33.8 µg/g fresh weight) that varied by size class, soil type and cultivar.Beta-carotene content increased with fruit size up to a maximum, though fruit size continued to increase. Find sandy loam soil produced fruit with lessBeta-carotene content than silty clay loam soil. The cultivar Primo contained higherBeta-carotene content levels than cultivar Cruiser. Mesocarp percent moisture content for both Cruiser and Primo at both locations by fruit size was not significantly correlated (r=0.40) withBeta-carotene content. Indicating fruit cell dilution may not contribute to the differences inBeta-carotene content in different fruit size classes.Beta-carotene content of size class 18 fruit from six cultivars grown on the silty clay loam soil for two consecutive years, showed a year, and year by cultivar effect for some cultivars. Whereas, some cultivars did not differ inBeta-carotene content between the two years. This indicates a potential for controllingBeta-carotene content of muskmelon fruit at a constant, high level by careful selection of production cultivar.Mention of a trademark of propriety does not constitute a guarantee or warranty of the product by the US Department of Agriculture or Texas A&M University and does not imply its approval to the exclusion of other products that also may be suitable.     

Reversed phase HPLC analysis of α- and β-carotene from selected raw and cooked vegetables

Traditional AOAC colorimetric procedures for carotenoid analysis are known to lack specificity and accuracy. Newer HPLC methods provide the investigator with a more precise tool for carotenoid quantification in foods and tissues. In the present studies, reverse phase HPLC was utilized to evaluate the - and -carotene content in raw and cooked leaves of lettuce, spinach and winged bean as well as in the carrot root. The vegetables were boiled or steamed and the true retention of - and -carotene in the cooked products was determined. Boiling for 30 minutes resulted in a 53 and 40% loss of -carotene from lettuce and carrots, respectively. Full retention or even an increase in -carotene content in boiled winged bean leaves and spinach was noted. Steaming resulted in very good retention of - and - carotene in all vegetables (83–139% retention). Thus, although cooking procedures (especially boiling) may result in oxidative loss of carotenoids in some vegetables, heat treatment increases the chemical extractability of - and -carotene in others. The presence of carotenoproteins in some vegetables may effect the heat stability of extractability of - and - carotene.     

Traditional production and chemical composition ofNdaleyi,a Nigerian fermented pearl millet food

Ndaleyi, a fermented, sun dried agglomerated powder produced from pearl millet or sorghum is one of the most popular foods consumed in Nigeria, mostly by the Kanuri people of Borno State. Its traditional production is described. The mean yields ofndaleyi (mainly starch),chir (millet gluten) and bran (overtail orbina) were 30.6, 22.5 and 21.5%, recpectively. A mean yield loss of 20% was observed. Chemical analysis revealed thatchir and bran have higher protein, fat and ash contents thanndaleyi. The titratable acidities (as percent lactic acid) ofndaleyi andchir were 0.9 and 0.3, while their pH values were 3.3 and 3.5, respectively.     

Evaluation of turmeric accessions for quality

One hundred and eighty four accessions ofCurcuma were analysed for curing percentage (dry recovery), essential oil, oleoresin and curcumin contents. Curing percentage varied from 13.5 to 32.4. The cultivar Konni had the maximum percentage of oleoresin (19.2). The volatile oil content was more inC. aromatica than inC. domestica. Curcumin content varied from 2.3% in cultivar Hahim to 10.9% in cultivar Edapalayam. However, curcumin content was comparatively lower in six exotic types as well as in 14 related species. The importance of quality aspects with respect to breeding is discussed.Contribution No. 493 of Central Plantation Crops Research Institute, Kasaragod-670 124, Kerala, India.     

Production,nutritional profiles and storability of ‘aadun’ and ‘kokoro’: Two corn products

Aadun and kokoro were produced from maize grains by processes involving roasting, kneading, spicing, and frying. Aadun with a moisture content (MC) of 12.5%, pH 5.3 had the following composition: crude protein, 7.49%; fat, 28.5%; total carbohydrate, 60.0%; ash, 3.0% and energy value, 3,600 kcal/kg whilst kokoro with a MC of 16% and pH 5.1 had, respectively: 6.42%; 22.9%; 66.6%; 2.84% and 3,550 kcal/kg. Whilst aadun and kokoro stored under ambient conditions (28±2°C; 75–80% RH) became mouldy within 7 days, samples treated with 1% butyl paraben did not develop off-colour and mouldiness.     

Vitamin C and quercetin modulate DNA-damaging effect of N-methyl-N′-nitro-N-nitrosoguanidine (MNNG)

The effects of natural compounds, vitamin C and quercetin, present in fruitsand vegetables, on the DNA damaging activity of a food carcinogen N-methyl-N-nitro-N-nitrosoguanidine (MNNG) were examinedusing the comet assay. Vitamin C, at a concentration of 50 M,inhibited MNNG-induced DNA damage in human lymphocytes. Quercetin,up to a concentration of 10 M, increased the extent of DNA damage,but at concentrations above 10 M decreased damage below controlvalues. Furthermore, quercetin had a strong antioxidant activity againstoxidative damage evoked by H₂O₂ at 10 M. The resultsobtained suggest that vitamin C and quercetin may have anti- orpro-oxidative properties depending on the state of the cell.     

Changes in carbohydrate and nitrogenous components and amylase activities during germination of grain amaranth

Grain amaranth (Amaranthus hypochondriacus), Yercaud local variety, was soaked overnight and germinated for 192 h taking the soaked grains as the zero time (0 h) sample. The changes in the activities of - and -amylases, starch, sugar, protein and lysine contents during germination are reported. Activity of -amylase was high in the 0 h soaked grains, while -amylase activity was high in 72 h germinated grains. The joint action of the amylases resulted in a decrease of starch content from 0 to 192 h in germinated grains and an increase in total sugars during the initial period of germination.Protein nitrogen was found to decrease from 48 h to 192 h accompanied by an increase in free amino acid and non-protein nitrogen contents. Total lysine content was found to be increased by 31% in 24 h germinated grain amaranth. Protein fractionation of raw, soaked and 24 h germinated grain amaranth showed that the distribution of different types of proteins varied during germination of the grains. An increase of water soluble protein content was noticed in 24 h germinated grains.     

Wide variation in nitrification activity in soil associated with different forage plant cultivars and genotypes

There is a growing interest in using plants to manipulate the nitrification rate in soils with the object of reducing losses of nitrogen from the soil–plant system – lower rates of nitrification being associated with reduced leaching of nitrate and reduced emissions of nitrous oxide. Here we screened the potential nitrification rate in soil associated with 126 cultivars from 26 species representing three functional groups used in temperate managed grassland. Plants were grown in pots, and the nitrification was measured using two approaches: (i) a measure of potential nitrification carried out in the laboratory on soil samples and (ii) a measure of nitrification in the presence of the growing plants using the ratio of nitrate to ammonium () measured on in situ ion exchange membranes after the application of urine. There was about a twofold difference among cultivars in nitrification measured using the potential assay and a 10‐fold difference using the ratio approach. The ranking of nitrification was different using the two approaches perhaps suggesting that the presence of plants in the ratio approach had an effect on the outcome although further work will be necessary to confirm this. Irrespective of the method used, the results demonstrate substantial differences between cultivars but also within cultivars offering the possibility of selection to enhance plant effects on nitrification.     

Development,acceptability and nutritional value of weaning mixtures

Low cost weaning mixtures were prepared by mixing (i) malted pearl millet (Penicitum typhidium L), roasted amaranth (Amaranthus sp.); roasted green gram (Vigna radiata); jaggery and (ii) malted barley (Dehusked barley); roasted amaranth grain; roasted green gram; jaggery in proportion 60204045 wt/wt and were nutritionally evaluated. Both the blends had a nutrient composition within the range prescribed by the Indian Standard Institute (ISI) for processed weaning foods. The processing of grains resulted in lower levels of phytic acid, polyphenols and saponins and higher in vitro protein digestibility than those of the raw grains used for preparing mixtures. Both the mixtures were acceptable to trained panelists and children.     

Commercial soybean starch blocker consumption: Impact on weight gain and on copper,lead and zinc status of rats

A commercial starch blocker was used to study the digestin of starch (potato) in mature female rates for four weeks. Two levels of starch blocker were used. The first level was calculated to inhibit starch digestion at 50%, the second was calculated to inhibit starch digestion at 100%. No significant effects on the body weights (271.10±29, 277.7±43, 259.1±25 g) were found among the groups of rats at 0%, 50% and 100% inhibition levels, respectively. Feed intakes were not affected. However, fecal copper and zinc excretions increased significantly (p<0.05) due to the inhibitors. Fecal copper excretions were 0.468±0.14, 0.578±0.09, 0.617±0.07 mg/rat/week, while fecal zinc values were 0.625±0.14, 0.859±0.32 and 0.778±0.26 mg/rat/week when no inhibitor was fed, at 50% inhibition and at 100% inhibition respectively. Thus, while use of starch blockers did not promote weight loss in the mature female rats, utilization of copper and zinc were negatively affected.Published as Nebraska Agricultural Research Division Project Journal Series No. 8791. Supported by funds from the Nebraska Agricultural Division Project No. 91-031 and U.S.D.A. C.S.R.S. Project No. W-143.     

Effect of cooking on protein solubility profiles of faba beans (Vicia faba L.) grown using different nutritional regimes

A field experiment was carried out to study the effect ofcooking on protein solubility profiles of mycorrhizal inoculated, phosphorusand sulphur fertilized faba beans under two water regimes. The resultsindicated that cooking significantly (p 0.05) increasedthe G₃-glutelin fraction as well as the insoluble protein butsignificantly (p 0.05) decreased the globulin and albuminfractions; prolamin, G₁-glutelin and G₂-glutelin fractionswere slightly increased. Mycorrhizal inoculation and mycorrhiza +phosphorus + sulphur fertilization significantly (p 0.05) increased albumin content. All fertilizer treatments significantly (p 0.05) decreased the insoluble protein.     

Nutritive characterization of purslane accessions as influenced by planting date

The uniqueness of purslane (Portulaca spp.) asthe richest vegetable source of omega-3 (-3)fatty acids is well documented. However, purslane hasnot been domesticated or fully evaluated for itsnutritive value. The objective of this study was todetermine the influence of planting date on chemicalcomposition of purslane accessions. Eight accessionsfrom different geographical locations were planted 12days apart, and whole plants harvested at full bloom. Chemical analysis (DM basis) of leaves showedsignificant differences among varieties for all thecharacteristics measured. Accession by planting dateinteraction influenced (p < 0.05) levels of crudeprotein, total lipids, and carbohydrate contents. Wild Greek accession had the highest, while aBeltsville (Maryland) wild type had the lowest crudeprotein content (27.1 vs 20.5%) at the secondplanting date. Crude protein, lipid and ash levelswere most influenced (p < 0.05) by planting date. Total lipids varied from 4.0–5.8% and 3.7–5.1% forthe first and second planting dates, respectively. Selected fatty acid content indicated significantly(p < 0.05) higher levels of 18: 26, and18: 33 in the Dutch Garden accession comparedwith other varieties. The Egyptian wild accession hadthe lowest level of 18: 33. The ratio of 3 to 6 acids, which ranged from 5.5 to22.3 indicated a highnutritive value of purslane compared to other oilcrops such as soybeans and perrilla. The high levelsof protein in purslane compete with those of othercommercially important vegetable crops. The studyshows that, in spite of its genetic diversity, purslaneremains one of the most abundant terrestrial vegetablesources of Omega-3 fatty acids and other essentialnutrients potentially beneficial for humans as well asanimals.     

Protein quality and digestibility of new high-lysine barley varieties in growing rats

Four new high-lysine barley mutants, the variety Lysimax, with the high-lysine genelys3a and the mutants mother variety Sultan were grown in a field trial in 1993 at Risø, Denmark. Mutants 609, 1242, 1385 and 1405 yielded in the range of 89 to 98 percent and cv Lysimax yielded 102 percent of cv Sultan (100 percent). One-thousand kernel weights for the mutants were in the range of 87 to 97 percent and cv Lysimax 83 percent of cv Sultan (100 percent). Protein contents of the mutants were slightly higher, in the range of 13.2 to 13.6 percent, than of cv Sultan (13.1 percent) and Lysimax which had a protein content of 12.6 percent. Fat content was higher in Lysimax and in the mutants except for mutant 1385 than in cv Sultan while dietary fibre contents of the barleys were similar. The levels of -glucans and starch were usually lower in Lysimax and in the mutants. The highest lysine levels: 4.6, 4.0 and 3.7 g/16 g N occurred in cv Lysimax and mutants 609 and 1405 compared to 3.3, 3.3 and 3.2 for cv Sultan and mutants 1242 and 1385, respectively. Mutants 609 and 1405 and cv Lysimax also had higher levels of threonine, histidine and valine. The increased lysine contents resulted in large, at most 20 percent, increases in biological value; 88.8, 81.7 and 78.3 percent for cv Lysimax and mutants 609 and 1405 compared to 74.2 percent for cv Sultan. True protein digestibilities and energy digestibilities were slightly lower in Lysimax than in Sultan, 5.3 and 4.3 percentage units, respectively. It is concluded that the development of high-lysine barley varieties is very beneficial for meeting the requirements of indispensable amino acids for humans and monogastric animals. In addition, nitrogen excretion into the environment is drastically reduced due to the higher biological values of the mutants.     

Forage peanut (Arachis spp.) genetic evaluation and selection

Forage peanut improvement for use in grass–legume mixtures is expected to have a great impact on the sustainability of Brazilian livestock production. Eighteen cloned Arachis spp. ecotypes were evaluated under clipping in a Brazilian Cerrado region and results analysed using a mixed model methodology. The objective was to estimate genetic and phenotypic parameters and to select the best ecotypes based on selection index applied on their predicted genotypic value. The traits of total dry‐matter (DM) and leaf DM yield presented moderate (0·30 <  < 0·50) to high (>0·50) broad‐sense heritability, in contrast to the low genetic variability in nutritional quality‐associated traits. Ecotypes of Arachis spp. contained average crude protein concentrations of 224 g kg^?1 DM in leaves and 138 g kg^?1 DM in stems, supporting the potential role of these species to overcome the low protein content in Cerrado pastures. The correlations between yield traits and traits associated with low nutritional value in leaves were consistently significant and positive. Genetic correlations among all the yield traits evaluated during the rainy or dry seasons were significant and positive. The ecotypes were ranked based on selection index. The next step is to validate long‐term selection of grass–Arachis in combination with pastures under competition and adjusted grazing in the Cerrado region.