Reduced‐Lignin Alfalfa Can Extend Harvest Timing

CSA News ◽  
2021 ◽  
Vol 66 (3) ◽  
pp. 24-24 ◽  
Keyword(s):  
Harvest Timing

Linking mango infestation by fruit flies to fruit maturity and fly pressure: A prerequisite to improve fruit fly damage management via harvest timing optimization

2021 ◽  
Vol 146 ◽  
pp. 105663
Author(s):  
Isabelle Grechi ◽  
Anne-Laure Preterre ◽  
Aude Caillat ◽  
Frédéric Chiroleu ◽  
Alain Ratnadass
Keyword(s):  
Fruit Fly ◽  
Fruit Flies ◽  
Timing Optimization ◽  
Fruit Maturity ◽  
Harvest Timing

scholarly journals Effect of root and butt rot uncertainty on optimal harvest schedules and expected incomes at the stand level

2021 ◽  
Vol 78 (3) ◽  
Author(s):  
Ana Aza ◽  
Annika Kangas ◽  
Terje Gobakken ◽  
A. Maarit I. Kallio
Keyword(s):  
Decision Tree ◽  
Reliable Information ◽  
Heterobasidion Annosum ◽  
Risk Of Infection ◽  
Butt Rot ◽  
Rotation Length ◽  
Optimal Harvest ◽  
Harvest Timing ◽  
Spruce Stands ◽  
Timing Decisions

Abstract • Key message Root and rot (RBR) caused byHeterobasidion parviporumNiemelä & Korhonen andHeterobasidion annosum(Fr.) Bref. damages Fennoscandian spruce stands. In case the rot infection and its severity are unknown, the mere risk of infection should seldom affect the harvest timing. When it does, the gains by harvesting earlier are minimal. • Context It has been suggested that stands infected by RBR should be harvested earlier than the healthy ones. Yet, we must decide on harvest timing decisions without reliable information on the infection. • Aims We studied if harvesting earlier pays off under RBR uncertainty. • Methods We structured the uncertainty with a decision tree and calculated the optimal rotations based on expected net present values. We compared rotation lengths to those of healthy stands and calculated gains from earlier harvesting. • Results The inclusion of RBR-related uncertainty in the model changed the rotation length of only 14–23% of the stands. The average reduction was 1.3–4.7 years. Yet, the gain from harvesting earlier was too low to be considered. • Conclusion In the absence of information on the extent and severity of RBR, it seldom pays off to advance harvests. The value growth in healthy trees tends to compensate for the value reduction due to rot.

Absorption, Translocation, and Metabolism of14C-Glufosinate in Glufosinate-Resistant Corn, Goosegrass (Eleusine indica), Large Crabgrass (Digitaria sanguinalis), and Sicklepod (Senna obtusifolia)

Weed Science ◽  
2009 ◽  
Vol 57 (1) ◽  
pp. 1-5 ◽  
Author(s):  
Wesley J. Everman ◽  
Cassandra R. Mayhew ◽  
James D. Burton ◽  
Alan C. York ◽  
John W. Wilcut
Keyword(s):  
Weed Species ◽  
Digitaria Sanguinalis ◽  
Eleusine Indica ◽  
Leaf Stage ◽  
Senna Obtusifolia ◽  
Harvest Timing ◽  
Treated Leaf ◽  
Harvest Intervals ◽  
Corn Plants ◽  
Large Crabgrass

Greenhouse studies were conducted to evaluate14C-glufosinate absorption, translocation, and metabolism in glufosinate-resistant corn, goosegrass, large crabgrass, and sicklepod. Glufosinate-resistant corn plants were treated at the four-leaf stage, whereas goosegrass, large crabgrass, and sicklepod were treated at 5, 7.5, and 10 cm, respectively. All plants were harvested at 1, 6, 24, 48, and 72 h after treatment (HAT). Absorption was less than 20% at all harvest intervals for glufosinate-resistant corn, whereas absorption in goosegrass and large crabgrass increased from approximately 20% 1 HAT to 50 and 76%, respectively, 72 HAT. Absorption of14C-glufosinate was greater than 90% 24 HAT in sicklepod. Significant levels of translocation were observed in glufosinate-resistant corn, with14C-glufosinate translocated to the region above the treated leaf and the roots up to 41 and 27%, respectively. No significant translocation was detected in any of the weed species at any harvest timing. Metabolites of14C-glufosinate were detected in glufosinate-resistant corn and all weed species. Seventy percent of14C was attributed to glufosinate metabolites 72 HAT in large crabgrass. Less metabolism was observed for sicklepod, goosegrass, and glufosinate-resistant corn, with metabolites composing less than 45% of detectable radioactivity 72 HAT.

scholarly journals Fruit Ripening, Antioxidants and Oil Composition in Koroneiki Olives (Olea europea L.) at Different Maturity Indices

Agronomy ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 122
Author(s):  
Mina Kafkaletou ◽  
Georgia Ouzounidou ◽  
Eleni Tsantili
Keyword(s):  
Oil Quality ◽  
Tocopherol Content ◽  
Oil Composition ◽  
High Quality ◽  
Maturity Indices ◽  
Peel Color ◽  
Harvest Timing ◽  
Full Production ◽  
Total Antioxidant ◽  
Positive Correlations

Harvest timing of oil olives is important for oil quality. Concerning the specific features of each cultivar, physiological and quality characteristics during ripening of Koroneiki olives were investigated in two successive years, A and B, from trees on full production. In A, olives were harvested at maturity indices (MIs) 0.9, 1.4, 2.1 and 4, while in B at MIs 1.1, 3.8 and 6.9. MIs ~1, ~4 and ~7 corresponded to green, red and dark purple peel in olives, respectively. Peel color parameters (L*, h° and C*), respiration and ethylene production rates were evaluated along with phenolic compounds and total antioxidant capacity (TAC) in olives of both crop years. Additionally, oil composition and a-tocopherol content were examined in olives harvested in years A and B, respectively. During fruit development, respiration and ethylene productions rates, hydroxytyrosol concentration and linoleic acid increased, while TAC, oleuropein, luteolin-7-O-glucoside, linolenic acid and α-tocopherol values decreased. Positive correlations were found among the attributes determined in both crop years that had a similar course of change during ripening, and vice versa, which could be also related to harvest timing and to quality traits of olive products. At MI ~4, at least all determined variables corresponded to oil of high quality. Practically, an early harvest might result in an olive fruit rich in antioxidants and therefore in oil production of high quality, high stability during storage and long self-life.

scholarly journals Technologies for Forecasting Tree Fruit Load and Harvest Timing—From Ground, Sky and Time

Agronomy ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 1409
Author(s):  
Nicholas Todd Anderson ◽  
Kerry Brian Walsh ◽  
Dvoralai Wulfsohn
Keyword(s):  
Machine Vision ◽  
Structural Parameters ◽  
Qualitative Assessment ◽  
Sampling Strategies ◽  
Yield Data ◽  
Proximal Sensing ◽  
Fruit Number ◽  
Fruit Maturity ◽  
Harvest Timing ◽  
Fruit Load

The management and marketing of fruit requires data on expected numbers, size, quality and timing. Current practice estimates orchard fruit load based on the qualitative assessment of fruit number per tree and historical orchard yield, or manually counting a subsample of trees. This review considers technological aids assisting these estimates, in terms of: (i) improving sampling strategies by the number of units to be counted and their selection; (ii) machine vision for the direct measurement of fruit number and size on the canopy; (iii) aerial or satellite imagery for the acquisition of information on tree structural parameters and spectral indices, with the indirect assessment of fruit load; (iv) models extrapolating historical yield data with knowledge of tree management and climate parameters, and (v) technologies relevant to the estimation of harvest timing such as heat units and the proximal sensing of fruit maturity attributes. Machine vision is currently dominating research outputs on fruit load estimation, while the improvement of sampling strategies has potential for a widespread impact. Techniques based on tree parameters and modeling offer scalability, but tree crops are complicated (perennialism). The use of machine vision for flowering estimates, fruit sizing, external quality evaluation is also considered. The potential synergies between technologies are highlighted.

scholarly journals Nitrogen and harvest impact on warm-season grass biomass yield and feedstock quality

2017 ◽  
Author(s):  
◽  
Chamara Sandaruwan Weerasekara Imbulana Acharige
Keyword(s):  
Biomass Yield ◽  
Warm Season ◽  
Early Spring ◽  
Harvest Date ◽  
Feedstock Quality ◽  
Harvest Timing ◽  
Bioenergy Feedstocks ◽  
Partial Factor ◽  
The Impact ◽  
Warm Season Grasses

Perennial warm-season grasses including switchgrass (Panicum virgatum L.), big bluestem (Andropogon geradii Vitman), and Indiangrass (Sorghastrum nutans L.) have drawn interest as bioenergy feedstocks due to their high yielding capacity with minimal amounts of inputs under a wide range of environments, and their capability to produce multiple environmental benefits. Nitrogen (N) fertility and harvest timing are considered as critical management practices when optimizing biomass yield and the feedstock quality of these grasses. The objective of this investigation was to quantify the impact of N fertilizer rate, N timing and harvest date on warm season biomass dry matter yield. Research was conducted in 2014 and 2015 on a total of four field-plot locations situated in central and west-central Missouri. Nitrogen fertilizer was applied using dry ammonium nitrate at the rates of 0, 34, 67, and 101 kg ha-1 at two application times, all N early spring and split N (early spring and following 1st harvest). Harvest treatments were as follows: 1) one cut in September; 2) one cut in November; 3) one cut in June and a second in September; and 4) one cut in June and a second in November. Treatments were arranged in a split-plot design with N rate as the main plot and harvest as the sub-plot in arandomized complete block design. Both N and harvest date and their interactions impacted biomass yield at all four locations. Delaying harvesting until late fall or killing frost increased yield. November harvest in combination with N rates grater than or equal to 67 kg ha-1 year-1 produced higher yields compared to the control and 34 kg ha-1N treatments and other harvest timing strategies. Although N was needed to optimize yield, partial factor 24 productivity (PFP) of applied N was flat when N applied was greater than 34 kg ha-1. Nitrogen fertilization at 67 kg ha-1 per growing season provided an opportunity to maintain a balance between both yield and efficiency of N inputs. Results of this research highlight the interactions of N fertilization and harvest management have when optimizing yield of warm-season grasses grown as bioenergy feedstocks. List of acronyms: N, Nitrogen; PFP, partial factor productivity.

scholarly journals Comparative effects of grazing, herbicide or forage conservation on barley grass content in Trifolium subterraneum L. clover-based pasture

2019 ◽  
Vol 70 (9) ◽  
pp. 800
Author(s):  
John W. Piltz ◽  
Simon J. Flinn ◽  
Leslie A. Weston
Keyword(s):  
Subterranean Clover ◽  
Trifolium Subterraneum ◽  
Annual Ryegrass ◽  
Lolium Rigidum ◽  
Herbicide Application ◽  
High Quality ◽  
Harvest Timing

Barley grass (Hordeum spp.) is a relatively short lived annual that provides high quality grazing early in the season, but its seed heads cause contamination of wool and carcasses, and may irritate the mouth, eyes and nose of sheep. Treatments were imposed on established subterranean clover (Trifolium subterraneum L.) annual pasture in the same plots for three consecutive years (2015 to 2017) to evaluate changes in barley grass content. Treatments included: grazing alone (G), herbicide followed by grazing (HG), or a forage conservation harvest in early October, late October or early November consistent with an early silage harvest (ES), late silage harvest (LS) or hay cut (H). Grazing plus herbicide markedly reduced (P < 0.05) barley grass numbers compared with all other treatments, but increased (P < 0.05) the growth of annual ryegrass (Lolium rigidum L.). ES reduced (P < 0.05) barley grass and increased (P < 0.05) subterranean clover compared with H, but broadleaf weed content benefitted by LS in contrast to either ES or H. Although herbicide application was the most effective method for barley grass control, forage harvest timing could be used to beneficially manipulate pasture composition.

Effect of decision variable definition and data aggregation on a search process applied to a single-tree simulator

2001 ◽  
Vol 31 (6) ◽  
pp. 1057-1066 ◽  
Author(s):  
Peder Wikström
Keyword(s):  
Tabu Search ◽  
Data Aggregation ◽  
Net Present Value ◽  
Planning Horizon ◽  
Solution Technique ◽  
Search Process ◽  
Decision Variable ◽  
Stand Management ◽  
Harvest Timing ◽  
Execution Times

This paper focuses on how computer execution times and net present value (NPV) are affected by different groupings of tree-selection harvest controls, different procedures to determine harvest timing, and tree data aggregation. The problems related to stand management are viewed as a hierarchy, where the main problem is determining harvest periods and the subordinate problem is determining what trees to cut in a given set of harvest periods. The solution technique is a derivative-free search process, and the objective is to maximize the NPV of harvest revenues for a stand over a given planning horizon. The tree-selection harvest controls are based on diameter and species groupings. The procedure to determine harvest timing is based on Tabu search and fixed cutting cycles, respectively. Sensitivity analysis is performed for a selection of stands in southern Sweden, where each stand is represented by a set of inventoried plots. Both even-aged and uneven-aged management are considered. Solutions improved with the number of decision variables. The Tabu search procedure proved very efficient at determining harvest periods for the even-aged problems. For the uneven-aged problems, fixed cutting cycles approximated the harvest timing problem, but at considerably shorter execution times. It is suggested that aggregated data be used for determining harvest timing, after which, using the original nonaggregated data, the tree-selection problem for a given set of harvest periods can be resolved.

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