Effect Of Harvest Date Research Articles

Profitability of dual‐purpose rye cover crop as influenced by harvesting date

AbstractHarvesting annual winter cereal rye (Secale cereale L.) (WCR) as an emergency forage could offset cover crop establishment costs, facilitate WCR adoption, and still provide multiple ecosystem benefits. A five site‐year trial was conducted in Colorado (CO) and Illinois (IL) to evaluate the effect of harvest date on WCR forage yield, quality, and its economic performance. From March to April, WCR dry matter (DM) yield increased exponentially in CO and linearly in IL. The DM yield at Julian day (DOY) 112–116 in CO was 6.9, 5.0, and 5.2 Mg ha–1 in 2018, 2019, and 2020, respectively, compared with 4.7 and 2.7 Mg ha–1 in IL in 2019 and 2020, respectively. Delayed harvesting increased acid detergent fiber and neutral detergent fiber concentrations and decreased crude, total digestible nutrients, and relative feed quality. Yield–quality trade‐off showed that forage yield increased rapidly but forage quality declined after DOY 105–108. Economic analysis, including cost of nutrient removal and 10% cash crop (corn [Zea mays L.]) yield penalty following WCR production revealed harvesting WCR biomass as forage was economically feasible in four out of five site‐years at hay price over $132 Mg–1. Eliminating corn yield penalty indicated profitability in four site‐years at hay price of ≥$110 Mg–1 and removing nutrient removal costs made all site‐years profitable at hay price of ≥$110 Mg–1. It was concluded that harvesting WCR biomass can be a profitable and effective strategy for sustainable intensification that can offer environmental stewardship and economic benefit.

Effect of Sugar Beet Harvest Date on Its Technological Quality Parameters by Exploratory Analysis

Choice of the harvest date is one of the foundations of vintage quality and good-yield sugar in sugar beet. However, it is difficult to define the harvest date and more precisely the date of maturity of beet roots, in an exact and absolute way. Indeed, maturity is divided into several stages and degrees depending on environmental and climatic conditions such as temperature, precipitation, geographic area, and others. The present study evoked the effect of three harvest dates (at esteemed maturity, 7 days after maturity, and 15 days after maturity) on the technological quality parameters, namely, sucrose, nitrogen, potassium, and sodium, using the most popular chemometric method, principal component analysis (PCA). To do this, samples from the Tadla irrigated perimeter were used. The results of exploratory analyses by the application of PCA clearly showed the influence of harvest date, in an important way, on the three quality parameters, composition of sucrose, potassium, and sodium. But, for nitrogen composition, there were negligible variations between samples.

The effect of harvest date on yield loss of long and short-grain rice cultivars (Oryza sativa L.) in Northeast China

Decisions regarding the harvest time of rice are of critical significance to labor management and agricultural machinery dispatching to avoid unnecessary losses. However, the comprehensive composition of harvest loss and its variation rules remain poorly understood. Our objectives were to optimize the harvesting date to improve the paddy rice yield (PRY) of long and short-grain rice (LG and SUI) by minimizing the grain dry matter loss (GDML) and four kinds of mechanical losses (ML), i.e., header loss (HL), cleaning loss (CL), entrainment loss (EL), as well as un-threshed loss (UTL). For this aim, field experiments were performed (2017–2020) to assess the GDML, HL, CL, EL and UTL of the respective cultivar from 45 to 59 days after heading (45 DAH-59 DAH, i.e., 15 days) in Northeast China. Rice harvested at the initial stage of maturity exhibited maximal GDML, whereas, the GDML of the two cultivars declined first and then rose with the prolonged harvest date. For the ML, the HL and CL increased, while the EL and the UTL decreased for both cultivars from 45 DAH to 59 DAH. By examining the correlation between straw moisture content (SMC) and ML, significant correlations between SMC and four kinds of ML were demonstrated, which revealed the main factor of the variations of HL, CL, EL, and UTL during the whole harvesting period. The GDML showed no significant difference between LG and SUI, whereas the ML were significantly different. Moreover, as indicated from the difference in the proportion of harvest loss showed that the GDML was the critical factor determining the total loss for two cultivars throughout the harvest season. Overall, the results demonstrated that the optimal harvest date for LG was from 52 DAH to 53 DAH, and from 53 DAH to 54 DAH for SUI. Harvesting on a suitable date was a more effective way to enhance paddy rice yield than machinery operation adjustment, which ensured both quality and quantity of the rice. Once the harvesting was advanced or delayed, the operating parameters of the machinery should be adjusted to reduce the ML.

Timeliness Harvesting Loss of Rice in Cold Region under Different Mechanical Harvesting Methods

The yield loss during the process of harvesting is a great challenge in rice production. A suitable harvesting time and harvesting method can help to reduce the yield losses of rice, and decisions about the harvest date have important implications for labor management as well as for agricultural machinery scheduling. Nonetheless, the comprehensive composition of timeliness harvesting loss (THL) and its changing rules for different harvesting methods remain poorly understood. The objective of this study was to determine the effect of harvest date and mechanical harvesting methods on grain dry matter timeliness loss (GDMTL) and mechanical timeliness losses (MTL) of rice in the cold region. To this end, the field experiment was conducted from 45 days after heading (45 DAH) to 59 days after heading (59 DAH), adopting a full-feeding and semi-feeding combine harvester (FCH and SCH) from 2019 to 2020. The results showed that harvest date had a significant effect on GDMTL and four kinds of MTL including header timeliness loss (HTL), cleaning timeliness loss (CTL), un-threshed timeliness loss (UTTL), and entrainment timeliness loss (ETL, only under FCH). With the prolonged harvest date, the HTL and CTL increased and the UTTL and ETL decreased, which ranged from 0.15–0.31%, 0.36–0.67%, 0.72–0.18%, and 0.69–0.31%, respectively for FCH. For SCH, the variation range of HTL, CTL, and UTTL was 0.41–0.59%, 0.66–0.98%, and 0.64–0.21%, respectively. The GDMTL increased first and then decreased, ranging from 2.84–0.87%. The mechanical harvesting methods had no significant effect on the GDMTL of rice, but the MTL could be large between FCH and SCH. In general, optimal harvest period was 52 DAH~53 DAH for both harvesting methods, which exhibited the highest yield and the lowest loss, i.e., 9269.3 kg/hm2 and 1.70%, respectively, and the mechanical operating mode on different harvest dates was recommended to minimize the mechanical loss. The optimal harvest date for rice in a cold region ensured both quality and quantity for mechanized harvesting, and provided a reference for the reasonable allocation of operating harvesters in the harvesting season.

Growth, yield and dormancy of aeroponically produced potato minitubers as a function of planting density and harvesting date

ABSTRACT Potato seed is one of the largest costs of a crop. This is mostly due to the incidence and spread of viruses that occurs when the crop is grown in the open field. Thus, it is necessary to obtain virus-free potato plantlets through meristem isolation, with subsequent cultivation in a protected environment, where it is easier to control virus-spreading insects. One way to increase greenhouse viability is by multiplicating potato seed using high technology systems, among them, aeroponics. The objective of this work was to determine the effect of planting density on the growth and yield of potato plants cv. Agata in aeroponic cultivation, and the effect of harvesting dates and planting densities on the dormancy of harvested minitubers. The number of stems, leaves, and the number and fresh weight of minitubers/plant reduced when planting density was increased from 60 to 180 plants/m2. However, the number of stems, leaves, initiated minitubers, and the number and fresh weight of minitubers/m2 increased when planting density was increased from 60 to 180 plants/m2. The maximum number of type III minitubers (>30 mm) was 613/m2, obtained at the density of 180 plants/m2. Plant density did not affect the dormancy of harvested minitubers, but harvesting date did. Minitubers obtained from latter harvesting dates had a shorter dormancy period. Minitubers harvested at 78 and 64 days after transplanting sprouted 21 and seven days earlier than those picked at 50 days after transplanting.

Introduction of four native legumes of the Canadian Prairies in monoculture and in mixtures with meadow bromegrass (Bromus riparius)

Many questions remain concerning the viability and productivity of seeding native legumes in the Canadian Prairies for forage production. Field research was conducted with four native legume species (Astragalus flexuosus, Dalea purpurea, Hedysarum boreale, and Vicia americana) to evaluate performance in Swift Current and Saskatoon, SK. The experimental design was a randomized complete block design with four replicates to evaluate legume–grass mixtures and monoculture performance, botanical composition, and effect of harvest dates (July and August) from 2016 to 2018. The native legume–grass mixtures performed differently at the sites, with greater foliar cover at Saskatoon but a greater proportion of legumes in mixtures at Swift Current. The mixtures had similar forage nutritive value as monoculture Bromus riparius, with legumes contributing 10% or less of the forage dry matter yield (DMY) at both sites. Astragalus flexuosus showed the greatest foliar cover and produced the greatest DMY in monoculture at both sites. Based on this study, native legumes would need to make up a larger proportion of forage dry matter yield to change the nutritional value of mixtures. In a subsequent seeding rate evaluation, the four legume species were planted at three seeding rates [300, 200, and 100 pure live seeds (PLS) per metre] and tested for DMY one year following establishment near Swift Current. Increasing seeding rates up to 300 PLS·m−1 corresponded with an increase in seedling density and foliar cover, but DMY was not affected. Additional research with A. flexuosus is needed to demonstrate its value as a forage.

Effects of harvest date and grass species on silage cell wall components and lactation performance of dairy cows

This study evaluated the effect of harvest date and forage species on the concentration of hydroxycinnamic acids in silage and its relationship to dairy cow performance. Tall fescue and timothy were harvested at a regular date on June 27 and July 8, respectively, or at a late date on July 8 and 25, respectively, in the first regrowth. Forage was treated with a salt-based additive and ensiled in hard-pressed round bales. Forty-seven lactating dairy cows were used in a block design. Cows received 1 of 4 treatments: (1) tall fescue harvested at regular date (RTF), (2) timothy harvested at regular date (RTI), (3) tall fescue harvested at late date (LTF), and (4) timothy harvested at late date (LTI). Diets were formulated to have the same forage-to-concentrate ratio (46:54 on a dry matter basis). Harvesting at late date increased fiber components, but only for timothy, where LTI contained greater neutral detergent fiber, acid detergent fiber, and acid detergent lignin concentrations than the other silages. Concentrations of hydroxycinnamic acids were affected by forage species, where concentrations of esterified ferulic acid and p-coumaric acid were greater for tall fescue silages than for timothy silages. Cows fed the RTI diet showed the greatest intakes of dry matter, organic matter, and crude protein. Feeding diets containing timothy silages increased milk yield and energy-corrected milk yield compared with tall fescue diets when averaged over harvest dates. Cows fed the RTI diet had greater milk protein yield than cows fed the RTF and LTF diets, and milk lactose yield was greater for cows fed diets containing timothy silage compared with tall fescue silage when averaged over harvest dates. Cows fed the LTF diet showed greater urinary N excretion compared with the LTI diet, but RTI showed the lowest urinary N and urea N excretions when calculated as percent of N intake. Cows fed diets containing timothy silage excreted more uric acid than cows fed tall fescue diets. Allantoin excretion was greater for cows eating the RTI and LTI diets compared with cows eating the RTF diet. Cows fed the RTI diet had a greater estimated microbial N flow and a greater excretion of hippuric acid than the RTF and LTF groups. In conclusion, besides the effect of harvest date on increasing the fiber components of timothy, concentrations of hydroxycinnamic acids were mainly affected by forage species; consequently, milk production was only affected by forage species. This indicates that hydroxycinnamic acids, such as ferulic acid, which cross-links to glucuronoarabinoxylans, was a major factor regulating milk production of cows fed tall fescue- and timothy silage-based diets, where lower hydroxycinnamic acid concentrations were responsible for greater milk yield.

Effect of harvest dates on β-carotene content and forage quality of rye (Secale cereale L.) silage and hay.

Limited data about the effects of various factors on forage quality and β-carotene content of rye produced in Korea are available, so this study investigated the effects of two preservation methods. Samples were collected from rye harvested every 5 days between April 25 and May 31, and comparisons were done among rye silage wilted for different periods of time and hay of three growth stages of rye. For the silage, dry matter (DM), acid detergent fiber (ADF), and neutral detergent fiber (NDF) contents increased with advanced maturity of rye, whereas crude protein, in vitro dry matter digestibility (IVDMD), total digestible nutrients (TDN), relative feed value (RFV), and DM loss decreased (p < 0.0001). Wilting increased the DM content and pH value significantly (p < 0.0001). Silage harvested at the heading stage had the lowest pH value (4.45), propionic acid (0.83 g/kg DM), butyric acid (0 g/kg DM), and fungi and yeast populations (3.70 Log CFU/g of fresh matter [FM]); conversely, it had the highest lactic acid (9.7 g/kg DM), lactic acid bacteria (LAB) (6.87 Log CFU/g of FM), total microorganisms (TM) (7.33 Log CFU/g of FM), and Flieg’s score (70) (p < 0.0001). Wilting elevated LAB and TM populations, but it had no consistent effect on other fermentation products. Both delayed harvest and prolonged wilting decreased β-carotene content. Rye silage harvested around May 9 (heading stage) with 24 h of wilting was preferred for highland, Pyeongchang. For rye hay, advanced maturity decreased DM loss, IVDMD, TDN, and RFV, but it increased DM, ADF, and NDF significantly (p < 0.05). β-carotene was decreased by delay of hay-making. Consequently, to attain lower DM loss and higher hay quality, the harvest date of May 9 (heading stage) is recommended.

Season and date of harvest effects on dry matter yield of sunn hemp (Crotalaria juncea L.) 'Tropic Sun' in northwestern Puerto Rico

An experiment to evaluate the effects of planting season and harvest dates on biomass production and nitrogen accumulation by sunn hemp was conducted at the Agricultural Research Station, Isabela, Puerto Rico. Sunn hemp Tropic Sun' was established in an Oxisol soil (Cotito series) at a seeding density of 10 kg/ha. Dry matter yield (DMY) was estimated at 71,92 and 121 days after planting (DAP) in June and November. Effects of both major variables were significant (P &gt; 0.05) for DMY, the June planting far surpassing that of November (15,831 vs. 5,665 kg/ha); DMY increased progressively for the three harvest dates (7,704; 11,141; and 13,398 kg/ha). Maximun biomass production (20,734 kg/ha) was obtained at 121 DAP in June, thus exceeding by threefold that of November at 121 DAP (6,062 kg/ha). Nitrogen accumulation followed a similar pattern, with that of June surpassing that of November (352 vs. 147 kg/ha) and values ascending for the successive harvest dates (193, 254, and 303 kg/ha). Differences (P &lt; 0.05) in N concentration were found by comparing the upper plant canopy with the lower. Expressed as crude protein (CP) the maximum value corresponded to that of the upper canopy at 92 DAP in November (19.0%), whereas the corresponding lower canopy value was only 4.72%. Based on its high biomass production and N accumulation, this legume could provide multiple beneficial effects when included in short crop rotations of sustainable production systems, taking advantage of the most favorable season and harvest stage. The present results suggest that 'Tropic Sun' planted in summer has good potential as a cover crop and green manure.

N-Alkanes and n-Alkenes in Virgin Olive Oil from Calabria (South Italy): The Effects of Cultivar and Harvest Date.

n-Alkanes and n-alkenes are components of the unsaponifiable fraction of an olive oil. These were analysed by GC on-column analysis and are here proposed as an additional tool to certify the origin, authenticity, traceability and chemical quality of olive oil produced in the Reggio Calabria province (South Italy). Nine cultivars were studied: Cassanese, Coratina, Itrana, Leccino, Nociara, Ottobratica, Pendolino, Picholine and Sinopolese grown in the region of Calabria (South Italy). n-Alkanes in the range from 21 to 35 chain carbon atoms and alkenes in the range from 23:1 to 25:1 chain carbon atoms were found with the following elution order: heneicosane (C21), docosane (C22), tricosene (C23:1), tricosane (C23), tetracosene (C24:1), tetracosane (C24), pentacosene (C25:1), pentacosane (C25), hexacosane (C26), eptacosane (C27), octacosane (C28), nonacosane (C29), triacontane (C30), entriacontane (C31), dotriacontane (C32), tritriacontane (C33), tetratriacontane (C34), pentatriacontane (C35). The oil of all cultivars showed a decreasing trend in total n-alkane and n-alkene content, with the oil of Sinopolese showing the highest content, varying from 328.50 to 214.00 mg/kg. Odd-chain alkanes predominated over even-chain n-alkanes, and tricosane, tetracosane and pentacosane were the most represented alkanes. Cultivar and harvest date significantly influenced the n-alkane and n-alkene content. These findings can be useful to distinguish different olive cultivars and to decide the fruit harvest date for the oil of the Reggio Calabria province (South Italy). A daily quantity of 30 g of olive oil of the Sinoplese cv (the one with the highest n-alkane and n-alkene content) was found to be in accordance with the suggestions of the European Agency for the evaluation of medicinal products Committee for veterinary medicinal products and biogenic hydrocarbons intake for the human diet.

Harvest date and variability in lipid bioactive compounds in Pistacia atlantica

BACKGROUND: The present work stands as an endeavor to uncover the ideal harvesting time of leaves in which they exhibits the maximum contents of bioactive molecules such as essential fatty acids, tocopherols and carotenoids. METHODS: A large scale investigation was carried out for the leaves of Pistacia atlantica involving a large number of populations collected over a period of four months during the growing season. The antioxidant activity was evaluated using both DPPH and β-carotene assays. The chemical percentage variability of the fatty acids was investigated using statistical analysis methods (Agglomerative Hierarchical Clustering “AHC”, also cited as CAH). OBJECTIVE: During the growth period, the effects of harvesting date on the total contents of lipids, tocopherols, carotenoids, fatty acids composition and also the antioxidant activities of the lipids were investigated. RESULTS: The content of myristic acid and other saturated fatty acids increased during leaf development, while linoleic, linolenic acids and unsaturated fatty acids decreased. The highest percentages of both linolenic C18:3 (27.25±5.92%) and linoleic acids C18:2 (17.68±3.80%) were obtained for the month of May at the first stage of leaves development (young leaves), but higher percentage levels of C18:1, were obtained for both consecutive months of August &amp; September (28.83±6.50%; 27.79±8.63%, respectively) at intermediate developing stage. The lipids, tocopherols, carotenoids contents and the saturated and unsaturated fatty acids were dependent on the harvest time. The antioxidant activity showed higher powers at the first developing stage (May). Two main clusters and two sub-clusters of the fatty acids were distinguished and were also depending clearly on the period of the collection. CONCLUSIONS: The results showed that the FA were dependent on the period of collection of the leaves. The main result of this study illustrate the nutritional potential (richness in MUFA such as C18:1, 2, 3) of the oil of P. atlantica leaves, which can provide opportunities for rational exploitation in the food industries or for medicinal purposes.

Improving Seed Retention and Germination Characteristics of North American Basin Wildrye by Marker-Assisted Gene Introgression

Basin wildrye [Leymus cinereus (Scribn. and Merr.) Á. Löve] and creeping wildrye [Leymus triticoides (Buckley) Pilg.] are native perennial grasses cultivated for seed used for fire rehabilitation and revegetation in western North America. Although L. cinereus produces large spike inflorescences with many seeds, it is prone to seed shattering. Seed can be harvested before shattering, but often displays poor germination and seedling vigor. Conversely, L. triticoides has fewer seeds per spike, but relatively strong seed retention. Both species are allotetraploid (2n = 4x = 28) and form fertile hybrids used for breeding and genetic research. A dominant, major-effect seed-shattering gene (SH6) from L. cinereus was previously identified in an L. triticoides backcross population. In this study, a DNA marker was used to select the recessive L. triticoides seed-retention allele (sh6) in cycle six (C6) of a L. cinereus × L. triticoides breeding population and evaluate gene × harvest date effects on seed yield and germination characteristics in a full-sib family derived from homozygous (sh6/sh6) and heterozygous (SH6/sh6) C6 parents. Although seed yields of shattering genotypes were 19.4% greater than non-shattering genotypes on the first harvest dates, yields of non-shattering genotypes were 167% greater on the last harvest dates. Seed harvested on the last harvest date reached 50% germination 4.2 days (26.4%) earlier and displayed 20.5% higher upper percentage germination limits than seed harvested on the first harvest date. Results indicate that the sh6 seed-retention gene will improve basin wildrye seed retention and indirectly improve seed germination by enabling later harvest dates.

Effects of harvest dates on microbial communities of ice grape skins from Xinjiang of China

Ice wine is a sweet dessert wine made from pressing grapes naturally frozen on the vines. The structure and metabolic characteristics of native microbial community dominated by organics and nutrients transformation in fermenting process of ice wine on the grape skin are likely to change due to climate events. Our objective was to evaluate the influence of harvest time on structure and metabolic characteristics of bacterial and fungal communities on Vidal ice grape surface. Vidal grape samples were picked between October and December in 2018; Harvest 1 (VG1): 14 October; Harvest 2 (VG2): 16 November; Harvest 3 (VG3): 18 December. Vishniacozyma, Alternaria, Cladosporium, Stenotrophomonas, unidentified_Cyanobacteria and Sphingomonas existed in all harvest dates and were the main genera widespread in most grape samples from the three harvest periods. Saprotrophic fungi and bacteria involved in metabolism were also dominant. For fungi, wood saprotrophs and unidentified saprotrophs were detected comprising Phoma, Didymella, Filobasidium and Clavaria. Delayed harvest of ice grapes has a distinct advantage for pathogen reduction compared with that of normally harvested grapes. Among bacteria, the most frequently occurring types in the metabolism category were energy metabolism, carbohydrate metabolism and lipid metabolism. In short, the harvest period can positively regulate the function of Vidal ice grape epidermal microorganisms.

Influence of Harvest Date and Postharvest Treatment on Carotenoid and Flavonoid Composition in French Marigold Flowers.

The aim of this study was to characterize carotenoids and flavonoids present in French marigold flowers (Tagetes patula "Durango Red") as well as to assess the effects of harvest dates and postharvest treatments on these compounds. Carotenoids and flavonoids were quantified using their respective standards or semiquantified using relevant related standards. Lutein and its derivatives largely dominated the flower carotenoids, while the flavonoids were diverse with patuletin leading the list. Of the different postharvest treatments, ensilage leads to the highest content of carotenoids (from 5.0 to 7.8 g kg-1 dw) and flavonoids (from 19 to 50 g kg-1 dw). The composition of individual flavonoids was greatly influenced by different postharvest treatments, while the influence of harvest dates was secondary. Ensilage and drying induced separate metabolic pathways leading to degradation of high-molecular glycosidic compounds, converting the compounds either to their aglycones or into the intermediate flavonoid glycosides. We conclude that according to the intended industrial application, different postharvest techniques can be employed to acquire desired flavonoids on a large scale.

Productivity of sugar sorghum as affected by the elements of the technology of cultivation in the zone of insufficient moisture in the Eastern Forest-Steppe of Ukraine

Purpose. To find out the dependence of sugar sorghum productivity on varietal characteristics, the sowing date and the harvesting date in the zone of insufficient moisture in the Eastern Forest-Steppe of Ukraine.Methods. The biological and statistical methods were used in the research. Biological methods included field experiments and monitoring of productivity indicators. The results were processed using the following statistical methods: descriptive statistics, ANOVA, and correlation analysis.Results. The degree of the effect of varietal characteristics, sowing date, harvesting date and weather conditions on the productivity and quality of sugar sorghum biomass have been established. The yield of green biomass, the sugar content of the juice and the dry matter content of sugar sorghum hybrid ‘Mamont’ exceeded the corresponding indicators of the variety ‘Sylosne 42’. Harvesting sugar sorghum of the ‘Sylosne 42’ variety and the ‘Mamont’ hybrid in the wax ripeness phase increased the yield of green biomass by 10.4 and 9.5 %, respectively, the sugar content of the juice by 1.8 times, and the dry matter content by 32.6 and 18.3 %, the crude ash content in this case decreased by 4.6 and 3.0 % compared with the phase of booting.Conclusions. The yield of green biomass depends on the varietal characteristics of sugar sorghum (36.5 %), the sowing date (12.1 %) and the harvesting date (12.2 %). A close relationship (R2=0.76) between the yield of green biomass and the length of the vegetation period of sugar sorghum had been established. To obtain a high yield of green biomass of sugar sorghum, its seeds should be sown in late April – early May, and the biomass should be collected no earlier than September in the phase of full ripeness of seeds. The dominant effect on the variation in the sugar content of the juice made the harvesting date (68.1 %). The effect of sowing dates, weather conditions and varietal characteristics on the sugar content in the juice was significantly less and amounted to 2.7, respectively; 2.3 and 1.0 %. Harvesting sugar sorghum in the wax ripeness phase provided a 1.8 times higher sugar content of the juice compared to the phase of booting, and further transfer of harvesting time to the full ripeness phase insignificantly increased the sugar content of the juice. The accumulation of dry matter in sugar sorghum plants was influenced by the harvesting date (54.5 %), the sowing date (5.2 %), weather conditions (3.3 %) and varietal characteristics (0.3 %). Delay in sowing date for every 10 days since the end of April leads to a decrease in the dry matter content in the biomass of sugar sorghum by an average of 1%. Extension of the vegetation by 1 day due to the later harvesting of biomass increases the dry matter content by 0,25 %. The influence of varietal characteristics (12.4 %), sowing date (1.9 %) and harvesting date (23.6 %) on the content of crude ash in the sugar sorghum was established. With an increase in the growing season, the content of ash elements in the biomass of sugar sorghum, both varieties and hybrids, decreased significantly. In terms of yield of green biomass (91.5 t/ha), sugar content of juice (12.7 %) and dry matter content (24.6 %), Sorghum sugar hybrid 'Mamont' exceeded the 'Sylosne 42' variety, the corresponding indices of which were 70,8 t/ha, 12 % and 24.0 %, while the content of ash elements in the biomass of the hybrid was lower than that of the variety.

Optimization of harvest date according to the volatile composition of Mediterranean aromatic herbs at different vegetative stages

Most of the studies concerning the optimal harvest date of aromatic herbs have dealt with different parts of plant such as flowers, leaves, stems, roots and seeds, but none have evaluated the effect of different harvest date at different vegetative stages on shoots (leaves and stems). Therefore, the main objective was to investigate the effects of harvest date of two consecutive seasons on the volatile composition of shoots of 4 aromatic herbs (dill, parsley, coriander and mint) widely cultivated worldwide. The impact of harvest date during the evolution of vegetative part of four aromatic herbs (parsley, dill, coriander and mint) was investigated. Volatile compounds of shoots of the four herbs were identified by GC–MS. The main compounds were 1,3,8-p-menthatriene, beta-phellandrene, myristicin and myrcene for parsley, alpha-phellandrene, dillether and beta-phellandrene for dill, decanal, E-2-dodecenal, 1-decanol and dodecanal for coriander, and carvone and limonene in case of mint. There was a significant effect of harvest date on the content of volatile compounds of the four species. The results showed that highest total concentration of volatiles and therefore the optimal harvest date of parsley was found 9 weeks after planting date with a total concentration of 2543 mg kg−1, for dill was 2619 mg kg−1 14 weeks after planting date, for coriander was 2191 mg kg−1 3 weeks after planting date, and 23329 mg kg−1 for mint 6 weeks after planting date.

Kemijske komponente kvalitete zrna sh2 genotipova kukuruza šećerca (Zea mays L. saccharata Sturt.) u ovisnosti o roku berbe

Kernel water (KW) and total soluble sugars (TSS) are major components of sweet corn taste, while total carotenoids (TC), total phenols (TP) and antioxidant activity (AA) contribute to its health benefits. Main objective was to determine the effect of genotype, harvest date and year on chemical components of kernel quality in shrunken (sh2) sweet corn. Nine sh2 genotypes were harvested at 3-day intervals from 20 to 32 days after pollination (DAP) over two years. Growing season significantly affected TC and TP only. Significant differences among genotypes were found for KW (75.3 - 77.4%), TTS (282.4 - 343.2 mg/g), TC (9.3 - 15.7 µg/g), TP (243.6 - 289.4 mg GEA/100 g) and AA (74.6 - 83.6 % inhibition). Effect of harvest date and genotype by harvest date interaction was significant for all traits. Compared to the 20 DAP, KW and TSS decreased, while TC, TP and AA tended to increase with later harvest dates. Based on KW, genotypes OS 5Esh and Overland extended harvest window up to 29 DAP. In contrast, optimum harvest window for genotype OS 244sh finished at 20 DAP. Extended harvest window for genotype Overland resulted in significant increase of TC (62.8%), TP (12.1%) and AA (12.4%).

Effect of Harvest Date on Technological Yield and Evolution of Hydrocyanic Acid Loss Rate after Transformation of Cassava Root (Manihot Esculenta CRANTZ) from Yacé Variety by Placali and Attiéké Consumed in Côte d'Ivoire

In order to contribute to their better utilization and valorization, tuberous roots of cassava (Manihot esculenta CRANTZ) of the yace variety consumed in Cote d’Ivoire have drawn our attention. Four different harvest periods of these tuberous roots were used in the study. Cassava tubers were harvested at 11th, 12th, 13th and 14th months after planting. The hydrocyanic acid loss rate and technological yield after the transformation of cassava roots (harvested at the 11th, 12th, 13th and 14th months after planting) into placali and attieke were investigated. The results showed that the products obtained with the 11 th month of harvest had the greatest losses. Peeling (29.59 % for attieke and 36.68 % for placali) and pressing (33.32 % for attieke and 34.56 % for placali) are the stages causing the most significant losses during the transformation of cassava roots into placali and attieke. The technological yield increases with the harvest period and falls after the twelfth month. The maximum corresponding to the 12th month of harvest is 81.65 % for attieke and 70.83 % for placali. Regarding the rate of loss of hydrocyanic acid, it was moreimportant at the eleventh month of harvest for placali and attieke with respective values of 95.85 % and 94.11 %. Cassava tubers harvested at the 12th month after planting are therefore ideal for the production of attieke and placali.

Production area and harvest date influence superficial scald incidence and ultra-structure of 'Suli' pear skin during long term storage

The effect of production area and harvest date on the superficial scald incidence, ultra-structure of the pericarp, core browning, and related physical qualities of ‘Suli’ pears during storage period at 0 °C were investigated. ‘Suli’ fruits were harvested at Taigu and Linyi in Shanxi province of China over five different dates and then stored at 0±0.5 °C with 85-90% relative humidity for 120 or 200 days. Superficial scald was detected after 120 and 200 days of storage. Harvest date and production area significantly affected the incidence of superficial scald and the quality of 'Suli' fruits. Earlier harvest time was associated with increased incidence of superficial scald. Fruits picked at Linyi developed more severe superficial scald than fruits harvested at Taigu. Scanning electron microscope (SEM) revealed that the cuticle and wax layer of fruits from Taigu were thicker than those from Linyi after storage. The surface of earlier harvested fruits had less wax and more extensive cracking, lower pectin content, and damaged skin organization structure. The incidence of superficial scald in ‘Suli’ pears is dependent on the ultra-structure of these superficial layers, and differences may be driven by harvest date and location. Keywords: Production area, Harvest date, Superficial scald incidence, Ultra-structure, ‘Suli’ pear

Polyphenols composition and anti-diabetic properties in vitro of haskap (Lonicera caerulea L.) berries in relation to cultivar and harvesting date

Haskap (Lonicera caerulea L.) is a recently commercialized fruit crop in Canada. Berries of four cultivars, Aurora, Rebecca, Larissa, and Evie, were harvested at five harvesting dates (H1-H5) and assessed for their polyphenol composition and anti-diabetic potential in vitro. The analyses revealed that the interaction effect of cultivar and harvesting date influenced the concentration of anthocyanins. Cyanidin-3-O-glucoside represents about 79 % of total anthocyanins present in ripened haskap berries. Total anthocyanins estimated by a non-destructive method showed a strong correlation for quantified anthocyanin by liquid chromatography-mass spectrometry (UPLC-ESI-MS), indicating the potential application of the non-destructive method for deciding the berry maturity for mechanical harvesting of haskap berry for value-added processing. Extracts derived from five maturity stages of four cultivars showed anti-diabetic properties including inhibition of activities of alpha-amylase (IC50 ranges from 2380 to 5080 μg/mL), alpha-glucosidase (IC50 ranges from 1130 to 2120 μg/mL), dipeptidyl peptidase-4 (DPP-4, IC50 ranges from 2150 to 11,600 μg/mL), and formation of advanced glycation end-products (AGE, IC50 ranges from 1200 to 4790 μg/mL) in vitro. Though the impact of harvesting date on polyphenol composition is very distinct, the extracts of late harvesting date (H5) reduced the anti-diabetic activities in vitro only in Aurora and Larisa cultivars. Inhibition of DPP-4 and AGE formation dependent on cultivar and harvesting date. Haskap berry warrants further investigation as a dietary therapeutic to manage type 2 diabetes.