Harvest Interval Research Articles

Agronomic Evaluation of the Results of Selection within Early Maturing Dactylis glomerata Germplasm

Selection from novel orchardgrass (Dactylis glomerata L.) germplasm sources resulted in the development of an early maturing orchardgrass population. Fifty-eight families comprise this population and were evaluated under frequent and infrequent harvest intervals at Lewiston and Millville, UT, field locations during 2013 and 2014. The objective of this study was to characterize the performance of the individual families when compared with the check cultivars ‘Icon’, ‘Paiute’, and ‘Potomac’. Across the locations and harvest intervals, individual families produced greater herbage dry mass and nutritive value than the check cultivars. Only for maturity (cv. Paiute) did one of the included commercial checks possess a trait value among the statistically greatest for all families. Twenty-two half-sib families were among the families with the statistically earliest maturity, and between three and eight families were among the families with the statistically greatest trait values for herbage dry mass, crude protein, in vitro true digestibility, neutral detergent fiber, and water soluble carbohydrate concentration. Overall, based on the performance of its component families, this early maturing orchardgrass population exhibited potential for developing improved cultivars for both frequent and infrequent harvest management.

Effect of Plant Spacing and Harvest Interval on the Growth Parameters of Moringa oleifera Lam (Periyakulam-1) in Sokoto (Semi-Arid Environment)

Moringa is a typical representative of multi-purpose tropical tree crop due to the high nutritional value, it is an important source for food to many communities and provides raw materials for animal feed industries. This study investigates the influence of plant densities (15 x 15 cm, 15 x 20 cm, 20 x 20 cm, and 20 x 30 cm) and four (4) harvesting intervals (HI) of 2, 4, 6 and 8 weeks was laid out using Randomized Complete Block Design (RCBD) replicated three times. Data on silvicultural practices were collected and six (6) plants were randomly selected for harvest from each plot which were subsequently separated into leaves, stems and twigs. Fresh and air-dried weights were recorded for analysis. Analysis of Variance (ANOVA) was used for data analysis Duncan’s Multiple Range Test was used to separate the means. Results of the present study show non-significant effects of plant density (p>0.05) between treatments. However, greater number of branches, leaves, height and biomass accumulation was recorded at 8 weeks harvesting interval. A significant interaction effects were recorded between spacing and HI.

Does harvesting Urochloa and Megathyrsus forages at short intervals confer an advantage on cumulative dry matter yields and quality?

BACKGROUNDDue to increasing demand for livestock products in sub‐Saharan Africa, increasing livestock productivity is a priority. The core constraint is limited availability of feed of good quality. We assessed optimal harvesting time of three improved grasses, two Urochloa lines (Basilisk a selection from wild population, Cayman – a hybrid, a product of breeding) plus Mombasa, a Megathyrsus selection. All are released in Latin America and Kenya or in the registration in other regional countries. We assessed dry matter (DM) yields and quality at 4, 6, 8 and 12 weeks of age in two sites.RESULTSDM yields (in t ha−1) were of the order Cayman (9.6–14.3) > Mombasa (8.0–11.3) > Basilisk (5.5–10.2) in one site, and Cayman (6.4–9.7) > Basilisk (4.9–7.6) > Mombasa (3.3–5.9) at site two. The harvesting regimes produced DM largely similar for weeks 4 and 6, 6 and 8, 8 and 12. Across the sites quality was of the order Cayman > Mombasa > Basilisk for neutral detergent fiber (NDF), metabolizable energy (ME) and crude protein (CP). With increasing harvesting interval, MJ ME ha−1 and kg CP ha−1 were inconsistent across both sites, but significant differences returned for MJ ME ha−1 unlike kg CP ha−1.CONCLUSIONSHarvesting at either 8 or 12 weeks is not recommendable as quality drops without an increase in DM yield that can compensate despite doubling and tripling time respectively, compared to 4 weeks. We recommend harvesting at 4 through 6 weeks for any of the three grasses based on yield against time, and demand at the intensified cut‐and‐carry smallholder systems. © 2021 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Plant Growth and Morphological Characters of Sonchus arvensis L. from Different Chicken Manure Rates and Harvest Intervals with Ratooning Practices

Sonchus arvensis L., commonly known as perennial sow thistle, field milk thistle, among other names, is a weedy species that has medicinal values. Belongs to the Daisy family (Asteraceae), S. arvensis has a rosette form and it can be harvested more than once. The determination of harvest interval for ratoon of S. arvensis is necessary because ratooning can save time to produce the consecutive plant biomass, but the second harvest must be conducted at the correct time as it will determine the quantity and quality of leaves. As source of herbal medicine, cultivation of S. arvensis with organic fertilizer is preferred, and determination of organic fertilizer rates is also important for ratooning. The purpose of the study was to evaluate the plant growth response and yield with different chicken manure rates and different harvest intervals. The field experiment was conducted at IPB experimental station in Cikarawang, Darmaga Bogor, Indonesia. The study used a randomized complete block design with different manure rates (0, 7, 14, 21 ton.ha-1) and various harvest intervals (6, 8, and 10 weeks after the first harvest) as treatments. The results showed that for the first harvest, the effect of chicken manure rates was linear almost on all variables. For the ratoon (second harvest), manure rate of 14 ton.ha-1 (for first harvest) added with 4 ton.ha-1 (after first harvest) was enough for leaf production. The results indicate that ratoon should be harvested at 10 weeks after the first harvest to obtain the highest yield. The interaction between manure rates and harvest interval was not significant for growth variables of the second harvest.

The Effects of Different Rates of Chicken Manure and Harvest Intervals on the Bioactive Compounds of Bitter Leaf (Vernonia amygdalina Del.)

Bitter leaf (Vernonia amygdalina Del.) is a valuable functional vegetable and traditional medicinal plant in many tropical countries including Indonesia. Bitter leaf is commonly used to remedy hypertension and diabetes among Indonesian people. The leaf extract comprises bioactive compounds such as sesquiterpene lactones, steroid glycosides, and flavonoids. Despite its growing market demand, there is insufficient data on agronomic practice in order to obtain optimum yield with high bioactive compounds. The experimental design used was a randomized complete block design with two factors namely chicken manure rates (0, 2.5, 5, and 7.5 kg per plant) and harvest intervals (2 and 3 months). There was a significant difference in fresh and dry weights of leaves, chlorophyll a and b, carotenoids, nitrogen concentration, anthocyanins, and flavonoids among different manure treatment. The highest concentration and production of bioactive compounds on the bitter leaf was found on the highest treatment of 7.5 kg chicken manure per plant. The harvest interval of three months significantly increased fresh and dry weights of leaves, concentration of anthocyanins, phosphorus, and potassium, uptake of phosphorus and potassium, and production of anthocyanins and flavonoids. Cultivation using chicken manure with frequent period of pruning can enhance the production of biomass as well as secondary metabolites in bitter leaf.

Agronomic Evaluation of the Results of Selection within Late-Maturing Dactylis glomerata Populations

Selection from novel orchardgrass (Dactylis glomerata L.) germplasm sources resulted in the development of a late-maturing orchardgrass population. This population comprises 58 families that were evaluated with 5 commercial cultivars under frequent and infrequent harvest intervals at two Cache County, UT, USA field locations during 2013 and 2014. The objective of this study was to characterize the performance of individual families when compared to check cultivars Intensive and Latar. Across locations and harvest intervals, individual families produced greater herbage dry mass and nutritive value than the check cultivars did, i.e., up to 12% greater herbage dry mass than that of the highest check, Intensive, and 1% (neutral-detergent-fiber digestibility) to 14% (water soluble carbohydrates) greater forage quality than that of the corresponding highest check cultivar. However, there were substantial genotype-by-environment interactions between families and locations, but not harvest intervals. Because of this, results were analyzed across harvest intervals but within locations. Within each location, there were families that possessed similar or greater maturity, herbage dry mass, in vitro true digestibility, and neutral-detergent-fiber digestibility at both locations. Overall, on the basis of the performance of its component families, this late-maturing orchardgrass population exhibited potential for developing improved cultivars.

Simulation modelling of greenhouse gas balance in continuous-cover forestry of Norway spruce stands on nutrient-rich drained peatlands

We used a simulation model to analyse the effect of continuous-cover forestry on the carbon dioxide (CO2) and methane (CH4) emissions from nutrient-rich drained peatland sites in southern Finland. The simulation scenarios were constructed by varying harvesting interval and post-harvest basal area in a typical mature Norway spruce (Picea abies (L.) H. Karst.) stand. A process-based model of soil organic matter dynamics supplied with some additional empirical routines was used for calculation of emission due to decomposition of fresh litter and peat. The amount and chemical properties of litter inputs, as well as the hydrothermal conditions and the water table depth in the peat layer were used as predictors. We estimated the net ecosystem production as a difference between carbon sequestration in stand biomass and carbon losses due to decomposition of dead organic matter, and the net biome production as the net primary production minus losses due to harvesting. Simulations showed that the peatland forest acted as a carbon sink with low and middle harvest intensity, while it turned into a carbon source with high harvesting intensities. This was mostly because intensive harvesting raised the water table level, thus decreasing tree production and increasing soil methane emission. Carbon dioxide emissions from peat and litter, in turn, correlated negatively with the intensity of harvesting. Correlation of site carbon balance with harvested roundwood indicated that there is a significant trade-off between maintaining carbon in drained peatland forests and providing harvest revenues. The simulations provide novel results and fill a gap of knowledge in ecosystem responses to alternative management regimes in continuous-cover forestry on drained peatlands.

Comparison of two in situ reference methods to estimate indigestible NDF by near infrared reflectance spectroscopy in alfalfa

Undigested forage neutral detergent fiber (uNDF) from long-term ruminal in situ incubations are used to estimate indigestible neutral detergent fiber (iNDF). Measurement of iNDF is important in forage evaluation because it defines the potentially digestible pool of neutral detergent fiber (NDF). Near-infrared reflectance spectroscopy (NIRS) can be calibrated to in situ reference sets to rapidly predict uNDF. Our objective was to compare uNDF estimates after 240 h of incubation when two types of bags were used in the in situ reference method. The bags compared were 4 cm × 5 cm Ankom F57 bags (25 micron pore size), and 5 cm × 10 cm Ankom in situ bags (50 micron pore size). Alfalfa samples from Pennsylvania and Wisconsin (n = 144) of different varieties and harvest intervals were used. One-half or two gram samples, respectively, were weighed into the small and large bags in triplicate. Mass to surface area was 0.05 and 0.02 g/cm2 for the small and large bags, respectively. The iNDF content after 240 h incubation was evaluated by two types bags in three rumen-cannulated Holstein cows. Each dried and ground forage was also scanned to determine the visible–near-infrared-reflectance spectra with a FOSS 6500 spectrophotometer. Prediction equations were developed for each bag type using modified partial least square regressions. The estimated iNDF fraction from small and large bags were 13.75% and 9.97%, respectively (SED = 0.39, P < 0.001). The coefficient of determination for calibration (R2), cross-validation (1 - VR), calibration standard deviation (SEC), and interactive authentication standard deviation (SECV) was 0.94, 0.92, 0.85 and 0.98 for values determined with the small bag and 0.88, 0.85, 1.12 and 1.27 for iNDF for values determined with the large bag, respectively. Results indicate that iNDF varies among alfalfa cultivars and NIRS can be used to quickly and quantitatively estimate iNDF content in alfalfa. Bag type influences 240h NDF residues. NIRS predictions of iNDF from the small bag calibration set had higher R2 and lower SEC and SECV than the large bag calibrations.

STUDIES ON SOME FACTORS AFFECTING ROYAL JELLY PRODUCTION OF HONEYBEE COLONIES, Apis mellifera L.

A study was conducted in a private apiary located at El Mahala Elkobra, Gharbia to assess the impact of bee hybrid, supplemental feeding and the strength of production unit (bee colony) on royal jelly production in addition, queen cup material, age of grafted bee larva and royal jelly harvest interval were also taken in consideration. The results clear that the highest royal jelly production was attained when grafting one day old larvae. However, the differences between Carniolan and Italian hybrids in royal jelly production was insignificant. In addition, stronger colonies yielded higher royal jelly production than weaker ones in both honeybee hybrids. Using queen cups of honeybee wax produced the highest royal jelly yield followed by bee wax coated plastic cups, whereas plastic cups came in the last class. Regarding the effect of supplemental feeding (AD3E, Vit.B complex, Amino) in syrup and in patty, it is clear that AD3E induced the highest effect on royal jelly production, follow by Amino then Vit. B complex. Offering the additives in syrup was more potent than in patty the highest royal jelly yield was gained when harvesting process was made at 3 days post grafting. Mean while severe reduction in royal jelly yield was dectected when harvesting was taken place at 4 days post grafting.

DETERMINATION OF PHYTOCHEMICALS FROM FRESH FRUITS OF FIG (Ficus carica L.) AT DIFFERENT MATURITY STAGES

The natural and ubiquitous production of figs throughout Turkey makes it one of the most important centers of fig genetic resources. The current study aims to determine the most important phytochemical ingredients of a local variety of fig (Ficus carica L.) collected from the natural habitats in the province of Kahramanmaras at different harvest intervals in 2018. The fruit samples were assayed for various metabolites such as phenolic compounds, total phenols (TP), total flavonoids (TF), total anthocyanins (TA) and total antioxidant capacity (TAC). The results showed that epicatechin (7.809 mg/100 g FW) was dominant phenolic compound in the fruits of this variety, followed by myricetin (2.632 mg/100 g FW), kaempferol (2.396 mg/100 g FW) and quercetin (0.655 mg/100 g FW). The average values obtained for TP, TF, TA, and TAC were found to be 135.71 mg GAE/100 g FW, 188.20 mg/100 g FW, 54.65 ml/L, and 14.34 DPPH%, respectively. There were also observed significant differences in total polyphenolic, flavonoid, anthocyanin content, and the antioxidant capacity at different harvest periods. The current findings indicate that the fig variety explored has a high antioxidant activity and is rich sources of anthocyanins and phenolic content. This study provides valuable information about the health benefits of figs endorsed by the phytochemical characteristics.

Dry matter yield of rhizoma perennial peanut (Arachis glabrata) harvested at six, nine and 12 weeks at two semiarid sites.

Rhizoma perennial peanut (RPP) is a forage legume of excellent adaptability and persistence «»nder subtropical and tropical conditions. Four accessions (USDA-TARS 17033,17050, 17052, and 17097, with PI nos. 276233, 262826, 262833, and 262839, respectively) and two cuitivars (Arbrook and Florigraze) of rhizoma perennial peanut (RPP) in Lajas, and two of the accessions (17033 and 17097) and cultivar Florigraze in Juana Díaz, Puerto Rico, were evaluated for dry matter yield (DMY) under irrigation during a full year.The RPPs were evaluated at six-, nine- and 12-wk harvest intervals (HI) in each of the four seasons of the year. At both sites, yield of accession 17033 was highest (P &lt; 0.01) and averaged 35,779 kg DM/ha/yr. In Lajas, yield of accession 17097 was second best with an average of 30,151 kg DM/ ha/yr, yields of the other four RPPs were similar, averaging 25,374 kg DM/haV yr. Cultivar Florigraze, which produced 16% less than accession 17097 in Lajas, had similar productivity in Juana Díaz. On average, the total yields of accessions 17033 and 17097 and cultivar Florigraze declined (P &lt; 0.01) by about 35 and 27% at the two locations, respectively, as HI increased from six to 12 weeks. Season of harvest had a strong influence on the DMY of RPP. At both locations, 69 and 64% of total yields were produced during spring and summer, respectively. Differences in height among RPPs were significant (P &lt; 0.01) at both locations. Height averaged 26.0,17.6, and 18.5 cm for accessions 17033 and 17097 and cultivar Florigraze, respectively. The great adaptability of RPP to the tropical environment, and its high yield when harvested for hay, make it a crop with the potential of becoming one of the most important forages in the tropics.

Modelling the Interactions of Soils, Climate, and Management for Grass Production in England and Wales

This study examines the effectiveness of a model called LINGRA-N-Plus to simulate the interaction of climate, soil and management on the green leaf and total dry matter yields of ryegrass in England and Wales. The LINGRA-N-Plus model includes modifications of the LINGRA-N model such as temperature- and moisture-dependent soil nitrogen mineralization and differential partitioning to leaves and stems with thermal time from the last harvest. The resulting model was calibrated against the green leaf and total grass yields from a harvest interval x nitrogen application experiment described by Wilman et al. (1976). When the LINGRA-N-Plus model was validated against total grass yields from nitrogen experiments at ten sites described by Morrison et al. (1980), its modelling efficiency improved greatly compared to the original LINGRA-N. High predicted yields, at zero nitrogen application, were related to soils with a high initial nitrogen content. The lowest predicted yields occurred at sites with low rainfall and shallow rooting depth; mitigating the effect of drought at such sites increased yields by up to 4 t ha−1. The results highlight the usefulness of grass models, such as LINGRA-N-Plus, to explore the combined effects of climate, soil, and management, like nitrogen application, and harvest intervals on grass productivity.

Immunization against gonadotropin-releasing factor (GnRF) in market gilts: Effect on growth and carcass parameters, and impact of immunization timing.

Reproductive cycling in fattening gilts can be associated with undesirable effects, such as estrus-related aggressive behavior, reduced feed intake and, in production systems where gilts are co-housed with entire males, unwanted pregnancy. Immunization against Gonadotrophin Releasing Factor (IM) can temporarily suppress ovarian activity, including related negative consequences on animal welfare and productivity. Feed intake has been shown to be higher after IM, resulting in both increased growth and increased carcass fat. A series of studies was conducted to confirm these effects on production and look at their dynamics over time. Three trials were performed to a similar design, each involving 240 gilts divided into 4 experimental groups at 12 weeks of age. One group remained untreated while the others had the two dose, IM course completed 8, 6 or 4 weeks before harvest, which was on a single day at 24, 25 or 26 weeks of age depending on the study. Feed intake was measured daily and bodyweight weekly, allowing growth parameters to be calculated on a weekly basis and for specific longer periods. Carcass weight, backfat depth and lean meat percentage were recorded at harvest. No effects were observed before the second application of the immunological product (V2) and completion of the IM course. Starting in the second week after V2 all IM groups showed a marked and consistent increase in Average Daily Feed Intake (ADFI), typically peaking at over 120% of the control group 3 to 4 weeks after V2 and then slowly declining, but still remaining elevated at 8 weeks. Weekly Average Daily Gain (ADG) showed a similar pattern but with a faster decline, resulting in the initially favorable impact on feed efficiency becoming less favorable as the V2 to harvest interval (V2H) progressed. Carcass weights were higher in IM gilts and backfat depths were greater, with the effects increasing with increasing V2H. Correspondingly, carcass lean meat percentage tended to decrease, although the higher carcass weights meant that the absolute weight of lean meat remained similar or higher. Carcass yield was generally unaffected by IM, but some between-group differences were statistically significant, and it is possible that different factors predominated at different times after V2, creating a complex relationship with V2H duration. The optimum IM protocol will depend on local conditions and production objectives but, as a generalization and assuming ad libitum feeding, a shorter V2H will favor efficient growth, while a longer duration will maximize carcass changes, such as increased fat coverage. It is suggested that the growth performance changes seen after IM in gilts might be viewed as a process of adjustment to a heavier and fatter target body type.

Marjoram phytomass at harvest intervals in summer and winter transplants

Abstract: The objective of this work was to determine the harvest interval for phytomass production of marjoram (Origanum majorana) in summer and winter transplants. Two independent experiments were performed in off-ground cultivation: one with a summer and another with a winter transplant, in a completely randomized design with five harvest intervals (30, 45, 60, 72, and 90 days) and four replicates. The fresh and dry masses of leaves, branches, and aerial part were determined. For each plant, the production accumulated in the harvests was calculated as affected by days after the transplant. The fresh matter mass of the leaves was higher at the intervals of 60 and 90 days, in the summer transplant, and of 72 and 90 days, in the winter transplant. Harvesting at intervals of 60 days in the summer transplant and of 72 days in the winter transplant are appropriate for marjoram phytomass production.

Effect of Zinc Fertilization on Physiological Parameters, Nutrient Uptake, Yield and Economics of Babycorn

A field experiment was conducted during late Kharif (September-November) of the year 2018 at Eastern Block Farm, Tamil Nadu Agricultural University, Coimbatore to find out the effect of agronomic bio-fortification with zinc on physiological parameters, nutrient uptake, yield and economics of babycorn under irrigated condition. The field experiment was laid in randomized complete block design with three replications. The treatments comprised of T1: No zinc (control), T2: Zinc Sulphate (ZnSO4) at 25 kgha-1 as soil application, T3: ZnSO4 at 37.5 kgha-1 as soil application, T4: Foliar spray of ZnSO4 at 0.5% on 20 and 40 DAS, T5: Foliar spray of ZnSO4 at 1.0% on 20 and 40 DAS, T6: ZnSO4 at 25 kgha-1 as soil application + foliar spray at 0.5% on 20 and 40 DAS, T7 : ZnSO4 at 25 kgha-1 as soil application + foliar spray at 1.0% on 20 and 40 DAS, T8: ZnSO4 at 37.5 kgha-1 as soil application + foliar spray at 0.5% on 20 and 40 DAS, T9: ZnSO4 at 37.5 kgha-1 as soil application + foliar spray at 1.0% on 20 and 40 DAS. Babycorn hybrid G-5414 was used to experiment with a plant spacing of 45 cm x 25 cm. The results showed that the combined application of zinc sulphate @ 37.5 kgha-1 with 0.5% foliar spray at 20 and 40 DAS recorded significantly higher Crop Growth Rate (CGR) (31.07, 30.83) gcm-2day-1, Relative Growth Rate (RGR) (110.25, 31.67) mgg-1day-1 and Net Assimilation Rate (NAR) (9.65, 4.54) mgcm-2day-1 at 25-45 DAS and 45 DAS - harvest intervals respectively. NPK uptake was recorded higher in (T8) and green cob yield was recorded higher in (T9) at harvest stage. Green fodder yield and higher benefit cost ratio was obtained higher with soil application of zinc sulphate @ 37.5 kgha-1 with 0.5% foliar spray at 20 and 40 DAS.

Corrigendum to: Optimisation of dry matter and nutrients in feed rations through use of a near-infrared spectroscopy system mounted on a self-propelled feed mixer

Context Knowledge of the nutrient requirements of dairy cows, and the nutritional composition and physical form of the feed resources used to prepare the total mixed ration (TMR) of basic and concentrated feeds, is essential to achieving high milk yields, health and welfare in modern commercial herds. Grass and maize silage components can vary widely in composition depending on harvesting intervals and weather; thus, the distribution of dry matter (DM) and nutrients in silos may vary greatly, resulting in serious errors during sampling and analysis. In addition, the flow of information from the stored silage stops once the forages are stored in the silo. Aims The objective of this study was to develop a practical approach for measuring variations in DM and silage quality parameters (crude protein, fibre, ash and fat) during the feed-extraction process from a bunker silo by a self-propelled feed mixer, which would ultimately help farmers to optimise the TMR. Methods Near-infrared spectroscopy (NIRS) technology was used to estimate fodder DM and nutrient contents in the material flow. Wet chemical analyses were used for preliminary evaluation of grass and maize silage samples. A portable NIRS was developed to record the spectra of various silage samples. Key results The spans of calibration of sample DM content were 21.3–59.2% for grass and 26–46.7% for maize. Crude protein content had span values of 11.4–18.3% for the grass silage and 5.4–10.8% for the maize silage models. Conclusions NIRS technology was used successfully to estimate the DM and nutrient contents of the fodder. The location for the functional unit on the self-propelled feed mixer may need to be modified for series production because it is not fully accessible. Implications NIRS is a suitable method for measuring DM and nutrient contents continuously during feed extraction from the bunker silo and can be used to help farmers to optimise the TMR.

Safety Evaluation of Lambda-cyhalothrin and Quinalphos in Mango (Mangifera indica L.)

Persistence of lambda-cyhalothrin and quinalphos in mango (cv. Dashehari) following their foliar application is reported. Lambda-cyhalothrin and quinalphos dissipated from 2.01 and 3.45 mg kg–1 and 1.52 and 2.78 mg kg–1 at 0 d to 0.07 and 0.11 mg kg–1 and 0.15 and 0.26 mg kg–1 at 15 and 22 d of their application at single and double doses, respectively. No residue of these insecticides was detected in mature fruit and its pulp at the time of harvest. The rate of dissipation followed first-order exponential kinetics with half-lives of 3 d for lambda-cyhalothrin and 7 d for quinalphos. Based on their MRL values of 0.5 and 0.02 mg kg–1, pre harvest intervals of 5.0 and 7.5 d for lambda-cyhalothrin and 42 and 48 d for quinalphos were suggested at the two respective rates of application. The theoretical maximum residue contribution (TMRC) values for both the insecticides were found below the maximum permissible intake (MPI) values on fruit. The residues of both the insecticides are harmless to consumers if sprayed at single dose and following the suggested PHI before consumption.

Effect of planting dates and sources of nitrogen on growth and yield of cauliflower at Rampur, Chitwan, Nepal

Appropriate time of planting and use of suitable sources of nitrogen are highly conducive for better growth and yield of cauliflower. A field experiment was conducted to study the effect of planting dates and sources of nitrogen on growth &amp; yield of cauliflower at horticulture research block of Agriculture and Forestry University, Rampur, Chitwan, Nepal from 1st Nov 2019 to 4th March 2020 using ‘Snow mystic’, a late season variety of cauliflower. The study was laid out in split-plot design with two dates of planting (Dec 1st &amp; Dec 16th) as main plot factors &amp; four sources of nitrogen viz. 100% biochar (BCH), 100% Urea(U), 50% urea+ 50% Poultry manure (U+PM) &amp; 50% Biochar+ 50% poultry manure (BCH+PM) against a control as sub-plot factors and were replicated thrice with 30 experimental units each of 9 m2 size containing 5 rows with 5 plants per row. The recommended dose of fertilizer used for the research was 108:92:60 kg N, P2O5, K2O ha-1 and P and K were supplied through SSP and MOP. The soil of experimental plot was sandy loam with slightly acidic with pH (5.6). The data regarding days to 90% curding, canopy area (cm2), leaf number per plant, above ground dry mater (g m-2) (AGDM), curd size (cm2) and curd weight per plant(g), days to curding to harvesting interval, yield, HI and B:C ratio were recorded and analysed using MS Excel and R studio. Significantly higher number of leaves per plant (16.03), bigger average canopy area (5089.93 cm2), higher AGDM (217.91 g m-2), bigger (1563.03 cm2) and heavier curds (1412.44 g) were recorded in 1st Dec. transplanted cauliflower with significantly higher harvest index (68.20). Regarding the sources of nitrogen, all the above parameters were seen better under BCH+ PM but were statistically at par with other nitrogen sources except control. The 1st Dec. planted crop had 4 more days of curding to harvesting interval than 16th Dec. planted one but the difference was not significant. December 1st planted cauliflower yielded 110% more yield and net returns than 16th Dec. planted crop whereas BCH incurred maximum cost (NRs 322145 ha-1) and U and U+PM were the most profitable in terms of B:C ratio (12.77 and 12.96 respectively).Hence, better crop yield and benefit could be obtained by planting the late season cauliflower (var. Snow mystic) at 1st Dec with the use of 100% urea or U+PM as nitrogen source in plains of Nepal having Chitwan like climate.

Changes in forage nutritive value of reduced‐lignin alfalfa during regrowth

AbstractGenetically engineered alfalfa (Medicago sativa L.) cultivars with reduced lignin (RL) concentration are commercially available but their change in nutritive value as the crop matures within a growth cycle has not been thoroughly documented and might differ from non‐RL cultivars. This research documents changes in forage nutritive value of a RL cultivar (HarvXtra‐008) and two non‐RL cultivars (54R02 and WL355RR) within five growth cycles across 2 yr in six states in the United States. A randomized complete block design with a split‐plot arrangement of treatment randomization was used, with harvest growth cycles assigned to whole plots and cultivars to subplots in field trials. Cultivars were sampled on 3‐ to 4‐d intervals between day 20 and 37 of regrowth. HarvXtra‐008 was consistently lower (P ≤ .05) in acid detergent lignin (ADL) by 7–10% and amylase‐treated neutral detergent fiber (aNDF) by 2–10% and 4–9% greater (P ≤ .05) in neutral detergent fiber digestibility (NDFD) than non‐RL cultivars across all sampling dates. Cultivar × regrowth duration interactions (P ≤ .05) were found only for ADL and aNDF in two of the five growth cycles sampled, when regression coefficients were always smaller for HarvXtra‐008 than 54R02. We calculated that the interval between harvests can be extended on average from 8 to 11 d for HarvXtra‐008 compared with non‐RL cultivars while maintaining adequate fiber digestibility for animals with high nutritional requirements; however, the extent of that longer harvest interval varied from 2 to 20 d depending on environmental conditions.

In Situ Digestibility of Cogon Grass (Imperata cylindrica L.) in Various Forms and Harvesting Intervals in Rumen-Fistulated Brahman Cattle

An experiment was conducted to determine the nutritive value and nutrient digestibility in situ of cogon grass as affected by harvesting intervals in fresh and silage forms. The experiment was set up in a completely randomized design with a 2 x 5 factorial treatment design: factor A with two forms of cogon grass (soilage and silage), and factor B with five harvesting intervals after the last cutting (20, 25, 30, 35 and 40 days). Nutrient digestibility was determined by incubating ground samples of cogon grass soilage and silage in rumen-fistulated Brahman bull for 24 hours. Results revealed that cogon grass was best utilized in terms of the in situ digestibility of organic matter (OM) and neutral detergent fiber (NDF) at 20-day old after the last cutting and in silage form. Digestibility of dry matter (DM), OM and NDF of cogon grass in silage form were high at 25-30 days harvesting interval but these were significantly lower than that of 20 days interval. Therefore, the silage form of cogon grass is superior over fresh form, and the best utilization of cogon grass as feed is at 20 days after the last cutting to capitalize on high digestibility.