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Harvest Date (harvest + date)
Selected AbstractsThe effect of harvest date and inoculation on the yield, fermentation characteristics and feeding value of forage pea and field bean silagesGRASS & FORAGE SCIENCE, Issue 3 2001M. D. Fraser Two experiments describe the ensiling potential of whole-crop forage peas (Pisum sativum) and field beans (Vicia faba). In Experiment 1, forage peas (cv. Magnus) and field beans (cv. Mayo) were harvested at 10, 12 and 14 weeks after sowing, and ensiled in 10 kg mini-silos either untreated or treated with an inoculant (Lactobacillus plantarum). In terms of yield and ensiling potential, the optimum growth stage for harvesting forage peas occurred at 12 weeks of growth. In contrast, delaying the harvest of field beans until 14 weeks gave the highest yields of dry matter (DM) and crude protein (CP). Changes in crop maturity had little effect on the chemical composition of the fresh forages, but between-harvest date differences were observed in the DM, ammonia-N, CP, water-soluble carbohydrates (WSC), acid-detergent fibre (ADF), neutral-detergent fibre (NDF), lactic acid and volatile fatty acids (VFA) concentrations and pH of the corresponding silages. Fermentation was improved by applying an inoculant. In Experiment 2, forage peas and field beans were harvested at 14 weeks after sowing and ensiled as round-bale silage, either untreated or treated with an inoculant. The yields of the crops were similar, and the only difference in the chemical composition of the wilted forages was a higher CP concentration in the field beans. However, after the ensiling process was complete, the forage pea silages were found to have significantly higher DM, WSC, starch and butyric acid concentrations compared with the field bean silages, and lower ammonia-N, CP, ADF, acetic acid and lactic acid concentrations. Inoculation was found to increase the lactic acid concentration and reduce the pH and ammonia-N and acetic acid concentrations of the silages. Each of the silages produced in Experiment 2 was offered to six Suffolk crossbred wether lambs, aged 10 months. Voluntary DM intakes were similar on all treatments, despite the apparent digestibility of the forage pea silages being significantly higher than that of the field bean silages. Nitrogen retention was higher for lambs offered forage pea silage. Application of an inoculant was found to have a negative effect on the amount of N retained, indicating the necessity for more detailed investigations into proteolytic activity within these crops during the fermentation process. [source] The effect of accumulation period and harvest date in spring on dry-matter yield and forage quality in mixed swards containing Lolium spp. and Trifolium subterraneum in Western AustraliaGRASS & FORAGE SCIENCE, Issue 1 2001M. N. Callow The object of this study was to determine the effect of closing date and date of harvest for conservation (accumulation period), on dry-matter (DM) yield and forage quality of annual pasture in Western Australia. The field study comprised 48 plots, 2 m × 2 m, sown with either annual ryegrass (Lolium rigidum Gaud.) or Italian ryegrass (L. multiflorum Lam.), and mixed with subterranean clover (Trifolium subterraneum L.). Defoliation of swards until the end of winter was at the three leaves tiller,1 stage. In spring, once stem nodal development had commenced, swards were defoliated every 3,4 weeks. Swards were defoliated either twice with three leaves tiller,1 (accumulation period 1 commenced on 15 August); twice with three leaves tiller,1 and then once after 4 weeks (accumulation period 2 commenced on 11 September); twice with three leaves tiller,1 and then twice after 4-week intervals (accumulation period 3 commenced on 9 October) or; twice with 3 leaves tiller,1 and then twice after 4-week intervals and then once after 3 weeks (accumulation period 4 commenced on 30 October). From the commencement of the accumulation period, tiller density, DM yield and forage quality were determined weekly for up to 10 weeks. There was a positive quadratic association between DM yield and days after the commencement of the accumulation period. Yields were maximized from accumulation period 1 with 5·3, 6·6 and 9·5 t DM ha,1, and growth rates were 140, 128 and 145 kg DM ha,1 d,1, for Wimmera annual ryegrass and Richmond and Concord cultivars of Italian ryegrass respectively. In contrast, in vitro dry-matter digestibility (IVDMD) and crude protein (CP) content were negatively associated with days after the commencement of the accumulation period, and initial values were greater than 0·80 and 180 g kg DM,1 for IVDMD and CP content respectively. The rate of decline in IVDMD d,1 for Wimmera annual ryegrass was 0·005, 0·019 and 0·012 d,1 for accumulation periods 1, 2 and 3, respectively, while for Italian ryegrass cultivars Richmond was 0·015, 0·011, 0·02 and 0·012 d,1 and Concord was 0·014, 0·009, 0·013 and 0·01 d,1, for the 4 accumulation periods respectively. It is recommended that annual and Italian ryegrass pastures be harvested between 10% and 20% inflorescence emergence when IVDMD will exceed 0·70 regardless of cultivar and/or defoliation practice prior to the commencement of the accumulation period. [source] Seasonal patterns of sucrose concentration in relation to other quality parameters of sugar beet (Beta vulgaris L.)JOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE, Issue 1 2006Christine Kenter Abstract The chemical composition of sugar beet is the most important parameter affecting its processing. Sugar factories require beet with high concentrations of sucrose and low concentrations of melassigenic substances to maximise the amount of extractable sugar. In order to plan the processing campaign, forecasts of root and sugar yield by prediction models are possible but there are no means to predict the technical quality of the beet. In the present study, the seasonal development and physiological relationships of different parameters of sugar beet quality were analysed. In order to estimate possibilities for quality forecasts, the concentrations of beet quality variables in October were correlated with corresponding quality measurements in late summer and to weather variables during the growing season by linear regressions. In 2000 and 2001, 27 field trials were conducted on commercial farm fields in all sugar beet growing areas in Germany. From June to October, sequential samples were taken every 4 weeks and the concentrations of sucrose, potassium, sodium, total soluble nitrogen, ,-amino nitrogen, nitrate, betaine, reducing sugars and marc in the beet were determined. The sucrose concentration increased progressively until the final harvest date in autumn, whereas the concentrations of the melassigenic substances decreased markedly until late summer and remained fairly constant as the season progressed. Marc concentration was the most stable of the parameters analysed. The sucrose concentration was positively correlated with the concentrations of dry matter, betaine and marc, but negatively with nitrate concentration and leaf yield throughout the season. The correlation between the concentrations of sucrose and nitrogenous compounds measured in summer and their final concentrations in autumn was rather weak. However, it was close for potassium, sodium and marc and a satisfactory prediction of their final concentrations was possible by the end of August. Based on weather data, beet quality was not predictable. Therefore, it seems to be difficult to integrate beet quality parameters into prediction models. Copyright © 2005 Society of Chemical Industry [source] Development changes of anthocyanins in Vitis vinifera grapes grown in the Douro Valley and concentration in respective winesJOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE, Issue 14 2002Nuno Mateus Abstract Grapes of Touriga Nacional and Touriga Francesa red Vitis vinifera varieties have been sampled from two vineyard sites at different altitudes during three consecutive vintage years (1997, 1998 and 1999) in the Douro Valley. The total anthocyanidin monoglucosides (AMGs) detected by HPLC/DAD and the red colour of grape skin extracts were monitored during the last month of maturation. Microvinifications were performed with the grapes studied and the resulting Port wines were analysed. Malvidin 3-glucoside and its acylated esters were the major AMGs irrespective of cultivar at harvest date. Vineyard altitude, together with other variables, was found to be an important factor contributing to the amount of anthocyanin compounds found in grapes of Touriga Nacional and Touriga Francesa. Overall, the climatic conditions observed at higher vineyard sites appeared to be advantageous, resulting in larger amounts of AMGs in grapes. The same outcome was obtained in the resulting wines, which showed higher levels of AMGs when made from grapes grown at higher altitude, especially for Touriga Francesa. © 2002 Society of Chemical Industry [source] Relationships between wine phenolic composition and wine sensory properties for Cabernet Sauvignon (Vitis vinifera L.)AUSTRALIAN JOURNAL OF GRAPE AND WINE RESEARCH, Issue 3 2008H.E. HOLT Abstract Background and Aims:, Winemakers from a commercial winery observed sensory differences in Cabernet Sauvignon wines made from three pruning treatments in a single vineyard, particularly in mouthfeel characteristics. This study examined the relationships between wine composition and wine sensory characteristics, then related these to berry weight and composition and wine quality scores. Methods and Results:, Cabernet Sauvignon from three pruning treatments , Machine, Cane and Spur , was harvested at commercial harvest date, and replicate wines were made from each for three vintages. The composition of the wines from all three pruning systems was generally similar. Differences in individual descriptive attributes did not separate the wines from the three treatments, or across vintages, despite differences in overall quality scores. Principal component analysis (PCA) could separate the wines by pruning and by vintage using wine composition or sensory parameters. Higher concentrations of anthocyanins, tannins and phenolics in berries did not always result in higher concentrations in wines. Conclusions:, In this study, higher wine tannin or wine phenolic concentrations did not result in higher wine astringency, and wine colour measures and phenolic composition were not good indicators of individual wine sensory properties or wine quality. Wine composition was not necessarily directly influenced by berry composition. Significance of the Study:, Few studies focus on the berry to wine to sensory continuum, particularly over more than one vintage or in a commercial context. This study highlighted how complex the relationships among berries, wine sensory properties and wine quality can be, particularly within a single vineyard. [source] Browning reactions during storage of low-moisture Australian sultanas: Further evidence for arginine-mediated Maillard reactions during storage, and some effects of vine-shading and harvest dateAUSTRALIAN JOURNAL OF GRAPE AND WINE RESEARCH, Issue 3 2004DAMIAN FRANK Abstract Sultana grapevines (Vitis Vinifera L. cv. Sultana syn. Thompson Seedless) were subjected to four shading regimes: 50% shading (1), 25% shading (2), fully exposed-top of canopy (3) and beneath canopy (4) and harvested early (21 February) and late (13 March) in the 1996/1997 sultana season. Grapes from each of the eight field-treatment combinations represented a range of maturities (14.4 to 23.50oBrix). Grape samples from each of the treatments were dipped and dried to 18% moisture, with half of each of the sultana samples further reduced in moisture by sunfinishing on plastic sheets in direct sun. These field treatments resulted in sixteen unique dried sultana bulk samples with a range of initial chemico-physical properties; aw (0.481,0.691), skin-polyphenoloxidase (PPO) activity (4.40,9.05 ,mol O2/g.minute) free arginine in skin tissues (1.0,5.10 mg/g) and protein (16.40,27.18 mg/g). Sultanas were stored at 10oC and 30oC in either the presence or absence of oxygen for 10 months, and changes in CIE L*a*b* tristimulus values, hue-angle (hab*) and chroma (Cab*) were monitored. Significant changes in sultana colour occurred in samples stored at 30oC, especially in higher aw non-sunfinished sultanas. Although browning was more intense in the presence of oxygen, significant browning also occurred in the absence of oxygen. Lower concentrations of 5-hydroxy methylfurfural, a key marker of Maillard browning in samples stored at 30oC in the presence of oxygen, indicated that the non-enzymatic reactions were sensitive to oxygen. Changes in the concentration of trans -caftaric acid, the main substrate of grape PPO, were also measured during sultana drying. Storage browning (changes in L*, b*, hab*, Cab*)in dried sultanas could be predicted by regression models using pre-storage aw, free-skin arginine or Kjeldahl protein after 10 months' storage between 10oC and 30oC. Non-enzymatic and Maillard-type reactions (sensitive to both oxygen and aw), made an important contribution to sultana storage browning. We provide only weak evidence that either shaded (immature) or green fruit was more susceptible to storage browning. [source] The biology and management of wireworms (Agriotes spp.) on potato with particular reference to the U.K.AGRICULTURAL AND FOREST ENTOMOLOGY, Issue 2 2001William E. Parker Summary 1 This paper reviews and interprets relevant work on the biology and management of wireworms (Agriotes spp.) within the context of potato production in Europe, with particular reference to the U.K. Although the review concentrates on Agriotes spp., the extensive world literature on other Elateridae of economic importance is also drawn upon. 2 Possible reasons for the apparent increase in the importance of wireworms on the potato crop are discussed, followed by a review of wireworm biology, risk assessment techniques (soil sampling, bait trapping and adult pheromone trapping), crop damage, and cultural, biological and chemical control methods. 3 It is clear that the process of site risk assessment followed by appropriate control measures (usually insecticide use) will remain the mainstay of wireworm management programmes. However, there is considerable scope for adopting new risk assessment techniques, such as pheromone trapping of adult beetles. 4 These control measures will need to be underpinned by a greater understanding of wireworm biology, particularly adult dispersal. Factors affecting the initiation and maintenance of wireworm populations in individual fields also require further study. The current use of insecticides could also be optimized by a better appreciation of the interactions between insecticide use, potato variety choice and harvest dates. [source] Influence of delayed cooling on storability and postharvest quality of European plumsJOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE, Issue 6 2009Marcos Guerra Abstract BACKGROUND: Delayed cooling has been tested to delay the development of internal breakdown (IB) in other stone fruits, but the influence of delayed cooling on IB has not been studied to date in European plums. A controlled delayed treatment of 48 h at 20 °C was applied in order to study the storability and postharvest quality of European plum (Prunus domestica L.) cv. ,Green Gage'. RESULTS: Market life of ,Green Gage' plums after shelf life was 10 days shorter in delayed fruits than in control fruits at earlier harvest dates. Sensory attributes affected by delayed cooling treatment at harvest were astringency and aroma. Prompt cooling was essential to lower the rate of physiological deterioration of plums, helping to maintain fruit quality and prolong market life. CONCLUSION: Delayed cooling increased IB symptoms in ,Green Gage' plums, so, when storability is needed, rapid cooling of fruits is necessary in order to extend their market life. Delayed cooling modified the total soluble solids/titratable acidity (TSS/TA) ratio and the sensory properties aroma and astringency at harvest, so it is desirable to deliver fruits directly to market in order to improve TSS/TA, the instrumental property best correlated with sensory characteristics. Copyright © 2009 Society of Chemical Industry [source] Effects of plant phenology, nutrients and herbivory on growth and defensive chemistry of plantain, Plantago lanceolataOIKOS, Issue 2 2000C. M. Jarzomski To assess the combined effect of herbivory, nutrient availability and plant phenology on plant mass and defensive chemistry, we conducted a field experiment with plantain (Plantago lanceolata: Plantaginaceae) using three levels of herbivory, three levels of fertilizer and two harvest dates. Shoot mass of the no-herbivory plants showed a nonlinear response to increased fertilizer such that mass with high fertilizer was no greater than that with low fertilizer. In contrast, shoot mass of the low-herbivory plants (12% damage) was not influenced by fertilizer, but for high-herbivory plants (23% damage), there was a positive linear response to increased fertilizer. Increasing nutrient levels caused a decrease in iridoid glycoside concentration. Herbivory did not induce higher iridoid glycoside concentration in leaves of any age. But increasing herbivory resulted in a decrease in the concentration of catalpol in new leaves. Another experiment assessed how leaf age and plant age affected plant defensive chemistry. Total iridoid glycosides increased over 5 weeks, but catalpol only increased in new leaves. Overall, the order of importance in determining variation in iridoid glycoside concentration was plant phenology, nutrient availability and, to a much lesser extent, herbivory. [source] Tomato spotted wilt virus in peanut tissue types and physiological effects related to disease incidence and severity,PLANT PATHOLOGY, Issue 4 2005D. Rowland Three peanut cultivars, Georgia Green, NC-V11, and ANorden, were grown using production practices that encouraged the development of Tomato spotted wilt virus (TSWV). The progression of TSWV infection was examined through the season using enzyme-linked immunosorbent assay (ELISA) tests on different tissue types [roots, leaves, pegs (pod attachment stem structures) and pods] and the effect of TSWV infection on physiological functions was examined at three harvest dates. Plants were classed into three severity categories: (i) no TSWV symptoms or previous positive ELISA tests; (ii) less than 50% of leaf tissue exhibiting TSWV symptoms; and (iii) greater than 50% of leaf tissue affected. TSWV showed a slow rate of infection at the beginning of the season and a greater percentage of infection of the roots than in the leaves. Photosynthesis was reduced in virus-affected infected plants by an average of 30% at the mid-season harvest and 51% at the late season harvest compared with virus-free plants across all three cultivars. Leaf tissue with symptoms had lower photosynthetic rates than healthy leaves. There were small differences among cultivars, with cv. ANorden maintaining higher average photosynthetic levels than cv. Georgia Green and higher transpirational levels than cv. NC-V11. The ability to maintain high assimilation physiology in the presence of the virus may help cultivars withstand TSWV infection and maintain final yields. [source] | ||||||||||||||||