Plastic mulches are routinely used in intensive horticulture for increasing yield and earliness, controlling weeds, and improving product quality. In Mediterranean horticulture, plastic mulches allow ...vegetable and fruit production along the year. However, the disposal of polyethylene-based plastics is an environmental concern, and causes costs and difficulties to users and managers. New biodegradable films have been recently made available for mulch applications, and their biodegradation in-soil requires to be analyzed in-depth. The aim of this research is to develop a laboratory respirometric system, working under controlled conditions, to evaluate the biodegradability of these materials in the soil. The designed respirometric analyzer was tested during 90 days at 25°C with commercial mulch films made from modified starch (Mater-Bi, Biofilm) or polylactic acid (Bioflex), and a cellulose film (Mimgreen Paper). Conventional low-density polyethylene was used as the reference mulch film. The unit determined the aerobic biodegradation rate as the CO2 generated by the different materials into the bioreactors. After incubation for 90 days, Mimgreen Paper biodegradated by ca. 14%, while biodegradation was similar for the three plastic films tested and ranked around 10%. The CO2 generated at the bioreactor containing the polyethylene was very low. The respirometric system developed proved to satisfactorily register the biodegradation of the materials tested. Mater-Bi, Biofilm, Bioflex and Mimgreen Paper demonstrated to start an in-soil biodegradation process.
In the Lower Elbe region of Northern Germany and in other Northern European fruit production areas, about 80 % of all storage rots of apples are caused by Neofabraea alba and N. perennans. Other ...pathogens include Colletotrichum acutatum, Monilinia fructigena, Phacidiopycnis washingtonensis, Neonectria galligena, Botrytis cinerea, Penicillium expansum and Fusarium avenaceum. Hot-water treatments of freshly harvested fruits for 3 min at 50–52 °C gave high efficacies against most of these storage rots except F. avenaceum. Substantial evidence supported a heat shock-induced antimicrobial response rather than a direct killing of fungal inoculum as the principal mode of action of hot-water treatments in apples. Shorter exposures for < 30 s at 55–60 °C also provided good control of fungal storage rots and thereby offer new possibilities for this technology in Northern European fruit production. These possibilities include the integration of a hot-water unit into existing grading lines and the option to treat fruits at different time points, e.g. at harvest, after short-term storage and/or after long-term storage.
Regulations governing the use of chemicals to control diseases and disorders of apples and pears in storage are becoming increasingly stringent, especially in European Union (EU) countries. The ...European Commission (EC) is currently conducting a review of the active ingredients (AI) of chemicals used in food production under EC Council Directive 91/414. DPA is under a review process and research is being conducting to address the concerns raised in the review. Ethoxyquin is also excluded from the list of AI in Annex I. Commercial supporters have recently come forward so this AI is also now under review. In light of the potential change in regulations, and the concern of fruit packers who market in EU, a survey of international researchers, suppliers and packers was conducted. The aim was to assess the situation in each fruit growing region, to determine which alternatives to antioxidants are being evaluated, gauge the perception about the acceptability of fruit treated with 1-methlycyclopropene (1-MCP) and learn how much packers of different regions are concerned about scald control. The respondents concerned about potential ban on antioxidants are from the countries that export to EU, especially from pear producing regions. Of all the alternatives mentioned by researchers consulted, the ones related to storage under controlled atmosphere (ultra-low oxygen, initial low oxygen stress, and dynamic controlled atmosphere) and 1-MCP are considered as the only sustainable technology to replace DPA. Other alternatives mentioned were ethylene removal, resistant cultivars, inhibition of phospholipase D and combined strategies. Regarding the use of 1-MCP, researchers report that it is a good alternative to current chemicals for control storage scald in apples. Although 1-MCP application to pears provides control of storage scald as well as the reduction in senescent scald, ripening may be inhibited after storage. Researchers are attempting to induce ripening in a number of ways including simultaneous application of 1-MCP and ethylene, conditioning through high temperatures, among others.
Eco-verified footprints are increasingly being used as criteria to secure shelf-access for products in large supermarket chains. The water footprint (WFP) of a product is the volume of water used ...along the supply chain to make that product. Green-water represents the store of soil water from rainfall that is transpired by the crop. Blue-water represents the store of ground and surface water that may be used for irrigation. Grey-water represents the amount of freshwater needed to assimilate a load of pollutants given natural background concentrations and existing water quality standards. We set up a field experiment in a commercial apple orchard to monitor the soil water balance and to measure nitrate leaching losses. Sap-flow data from apple trees and time-domain reflectometry (TDR) data from root-zone soil are used to quantify changes in the green-water store. Irrigation volumes are used to represent changes in the blue-water store. Passive-wick flux meters installed below the root-zone are used to monitor drainage and leaching losses of nitrate in order to quantify changes in the grey-water component. We demonstrate how this field data, along with mechanistic computer modelling, can be used quantify the water footprint of an apple orchard in the Hawke’s Bay, New Zealand. Model-measurement comparisons are very important to provide growers, industry and regulators with confidence in the quality of the data and appropriateness of the models used to determine footprints.
A model for predicting the response of apples (Malus x domestica) to chemical thinning treatments was evaluated on ‘Gala’/M.7 trees in 2008. The model assumes that fruit growing at a rate less than ...50% of the fastest growing fruit on the tree during the period between four and seven days after application of the thinner will abscise. The model accurately predicted fruit set in trees that did not receive a chemical thinner but slightly over-estimated fruit set following application of 100 mg/L 6-benzyladenine (6-BA) plus 1200 mg/L carbaryl when fruit were 10 mm in diameter. This overestimation was due to abscission of some fruit that were growing faster than the 50% threshold rather than to retention of fruit that were growing at a rate less than the threshold. These aberrant fruit were consistently among the largest at the first measurement date. Application of 600 mg/L carbaryl at petal fall resulted in aggressive early chemical thinning, but reduced the efficacy of a subsequent post bloom application of 100 mg/L 6-BA plus 1200 mg/L carbaryl applied when king fruit diameter was 10 mm. The aggressive early thinning resulting from application of 600 mg/L carbaryl at petal fall created many rapidly growing fruit that were presumably more resistant to the post bloom application of 6-BA plus carbaryl.
Thinning is a prerequisite in worldwide fruit production. The question arose as to its contribution to the carbon footprint in different production schemes. Carbon footprinting of thinning in fruit ...orchards is based on fossil fuel consumption, converted into greenhouse gas emission (GHG) and expressed as CO2 equivalents, which comprises carbon dioxide (CO2; factor 1), methane (CH4; factor 25) and nitrous oxides (N2O; factor 298), according to PAS 2050: Oct 2011 and PAS 2050-1 (hort). Flower thinning with ATS foliar nitrogen fertiliser emitted 25-37 kg CO2e/ha per treatment (without associated N2O emissions), while fruitlet thinning with 6-BA emitted ca. 13 kg CO2e/ha, Brevis 18.5 (single application) or 34 (double application) kg CO2e/ha and lime sulfur in organic orchards 27-42 kg CO2e/ha. Mechanical thinning with the Bonner machine at 6 km/h at 360 rpm produced 27.9 kg CO2e/ha emissions, while manual fruitlet thinning after June drop had a carbon footprint of only 3.1 kg CO2e/ha, since manual labour does not utilize fossil fuel.
Fruit picking is a tedious, time-consuming operation which accounts for the largest part of the labor employed in the production of fruit crops. Fruit picking requires decisions for selective ...harvesting (color, size and maturity) and maintaining high fruit quality throughout the picking process. Mechanization can reduce harvesting costs and dependence on seasonal labor so growers can stay competitive in the future by increasing harvest productivity in a timely fashion. However, fruit crops are affected by a diversity of factors such as climate, soil, market, utilization, fruit variety, tree or plant type and a lack of uniform maturity, all of which can slow the acceptance of substituted machines for human judgment and dexterity. This complexity has made commercial adoption of harvest machinery relatively slow. During the last 60 years of intensive R&D by industry, academia and the growers themselves, some significant implementation has occurred primarily with fruit destined for processing and/or fruit not sensitive to mechanical damage. Mechanical harvesting utilizes shaking of limbs, trunks and foliage of all nut crops, olives for oil, citrus for juice and grapes for wine, as well as deciduous fruit destined for processing that can tolerate a high level of mechanical stress including prunes, cling peaches and blueberries. A major hurdle to overcome in the future is the harvesting of soft, perishable fruit destined to the fresh market such as apple, pear and avocado. This will require a concerted effort and focused R&D on modifications of trees and orchard configuration along with further development of advanced technologies such as robotics, machine vision and artificial intelligence algorithms to facilitate selection of appropriate mechanization.
Many berry crops are managed by altering growth and environment in commercial production systems, to affect time of flowering and fruiting season. The effect of photoperiod, temperature, and ...production system on flower bud initiation and development is reviewed for strawberry, raspberry, blackberry and blueberry. While “flowering on command” is still a challenge, research and commercial production systems have been successful at scheduling fruit harvest for many of these crops. In strawberry and biennial cropping red raspberry, pre-conditioned plants, grown to maximize flower bud development, are commonly used along with staggered planting dates (often in tunnels) to time fruit harvest date. In primocane-fruiting raspberry, annual production systems with staggered planting dates, often in combination with pruning techniques, are used to target market windows. This system of production shows promise with primocane-fruiting blackberry. In southern highbush blueberry, cultivars are grown in warm regions using evergreening systems, pruning, and fertilization methods, to produce fruit at desired times. With a good understanding of plant physiology and the factors that affect flower bud initiation and development, bud break, and the production of high-quality fruit, it is possible to manipulate many berry crops to have fruit production target desirable market windows.
Dragon fruit (Hylocereus undulates) was planted in a large area of karst region in recent years. To understand whether karst drought may impact on its physiological process is important and useful ...for planning and management of this fruit. In this study, we contrasted with a relative species Hylocereus undatus, and set up experiment to study physiological and biochemical trait and its response to different karst soil water level deficiency, so as to understand the mechanism of H. undulates and H. undatus in adaptation to karst drought condition. The results showed that, trends of physiological and biochemical response to drought was similar between two species. With the intensive of soil water deficiency, such toxin substance as malonaldehyde (MDA) increased, but meanwhile, two protective enzymes superoxide dismutase (SOD) and peroxidases (POD) and osmotic adjustment Proline (Pro) increase as well. Under relative water content (RWC) >50% condition, the enzyme can effectively protect the cells from toxin MDA injure, and Pro can also maintain the water needs through osmotic adjustment. However, under RWC < 40% condition, protective enzymes were not enough for cleaning MDA. Biomass was largest under RWC=70%–80%, with low root shoot ratio and high aboveground biomass. Biomass significantly decreased under RWC 30%–40%, which decline by 73.28% and 73.56% in H. undulates and H. undatus respectively. Therefore, RWC=70%–80% would be an optimal soil moisture while developing dragon fruit in karst, which is favor to fruit production. Under moderate drought e.g. RWC=50%-60%, plants may regulate by metabolic process and balance unfavorable substance, but it allocated much more biomass to root, reduced the aboveground biomass, which is not advance for fruit production.
