Marketable Fruit Quality Research Articles

Responses of interspecific hybrid eggplant f4 inbred lines to drought and heat stress

Eggplant is grown in and near the tropic and sub-tropic zones where climate change effects can be seen dramatically in agricultural production. As a vegetable, it is considered has tolerance to some abiotic stresses compared to others. However, significant reductions in yield and marketable fruit quality were observed under stress conditions that exceeded the tolerance level. Eggplant has wild relatives which are known as tolerant to stresses. As a part of the comprehensive project this research includes drought-tolerant line development from the F4 population obtained by interspecific crossing between Solanum incanum L., a wild relative of eggplant naturally distributed in the Sub-Saharan zone, and a pure line with superior characteristics developed in BATEM. Qualified 50 inbred lines were selected as drought tolerant among F3 progenies in previous studies. In this experiment, 12 plants from each 50 genotypes at F4 level were exposed to drought stress, which was created by 25% watering of full irrigation. On the 25th day of treatment, tolerant plants were distinguished by using 0-5 scale. From each genotype, 4 plants were selected as drought tolerant, and they were transferred to greenhouse to identify their heat tolerance. Among the drought-tolerant group 42 F4 lines were found as heat tolerant.

Boron Applications and Bee Pollinators Increase Strawberry Yields

ABSTRACT Several factors influence fruit set and yield in strawberry production. Bees play an important role in pollinating strawberry flowers; however, bee populations are decreasing due to air pollution and high usage of pesticides. Boron (B) can increase fruit set by improving pollen viability, germination, and pollen tube growth. This study aimed to assess how the application of honey bees and B fertilizer affects yields and marketable fruit quality of Fortuna strawberry cultivar. The experiment used two strawberry growing tunnels. One was open, thus allowing bee activity, and the other was closed, which meant that bees could not access the strawberry flowers. Each tunnel had different B applications. The presence of bees increased the total fruit yield per plant by 54% compared to the results of plants that were not pollinated by bees. Plants treated with bees yielded bigger fruit than those without bee treatment, which is likely a result of more achenes having been fertilized. Fruit formation, however, did not depend directly on pollinator activity. Both in the presence and absence of bees, applying B to the soil increased yields and decreased misshapen fruit rates. Applying B to the soil was more effective than B foliar applications. As a result of this study, it is demonstrated that strawberry plants perform at a higher rate with the application of B and the presence of bee activity.

COMMODITY EVALUATION OF APPLES TREATED WITH 1–METHYLCYCLOPROPENE AFTER HARVEST

The thesis being presented is study on marketable quality of early winter apple fruits cultivars ‘Calville’ and ‘Spartan’ during refrigerated storage under the condition of their post-harvest treatment with 1-methylcyclopropene (1-MCP). The suppression of apple’s ripening after harvest is necessary to reduce the losses of marketable fruit quality during storage and receive a high economic effect from the sale of product. SmartFresh technology, based on inhibition of ethylene due to the effect of 1-methylcyclopropene (1-MCP), use to improve the quality of the majority of apple’s cultivars. The post–harvest application of 1-MCP effectively restrains the development of physiological disorders such as superficial scald and fruit rot, but sometimes may increase susceptibility to flesh browning, especially stored during 6 or more months. Research objects were early-winter apple cultivars ‘Calville’ and ‘Spartan’, treated after harvest with 1-MCP (‘SmartFreshTM’ 0,068 g·m-3) for 24 h at 5 °C, during storage at 3±1 °C and relative humidity 85–90 % for two, three, four, five and six months (non-treated fruits – control). The value of weight loss, superficial scald, fruit rot and core browning damage carried by weighing of respective factions of fruits. Data are means of three replicates and expressed as a percentage of fruit’s weight before storage. There was a significant increase in more than two times, compared to the control, the yield of standard products and, in particular, higher and first grades of 1-MCP treated fruits after six months of storage in combination with a significant decrease in technical defect, which has a decisive impact on expected proceeds and the level of profitability of storage. The weight losses of both early-winter apple cultivars increased during storage with not-substantial difference between the both treated with 1-MCP and control fruits. During storage standard product fraction of 1-MCP treated fruits both cultivars decreased quadratically with high correlation coefficients. After six months of storage control apples cv. ‘Calville’ had most fruits with superficial scald, core browning and rot, and cv. ‘Spartan’ – with core browning and rot, while the damage product of 1-MCP treated apples consisted mainly of rotting fruits. Consequently, post-harvest treatment of apple fruits with ethylene inhibitor 1-MCP increased the marketable quality and efficiency of the storing of early–winter apple cultivars ‘Calville’ and ‘Spartan’, reducing the intensity of physiological disorder’s and rot’s damage.

Yield response of seedless watermelon to different drip irrigation strategies under Mediterranean conditions

Water is an essential resource for food production, as agriculture consumes close to 70% of the total freshwater, and its shortage is becoming critical in arid and semiarid areas of the world. Therefore, it is important to use water more efficiently. The objectives of this project are to determine the productive response and the irrigation water use efficiency of seedless watermelon to three irrigation management strategies over two growing seasons. This was done by applying 100, 75 and 50% of the irrigation water requirements (IWR) the first year, in the second year added six additional treatments, of which three treatments were regulated deficit irrigation with 75% IWR during the vegetative growth, fruit development and fruit ripening stages, and the other three treatments were with 50% IWR during the same stages. The exposure of watermelon plants to severe deficit irrigation resulted in a reduction in dry biomass, total and marketable yield, average fruit weight, fruit number and harvest index, and without improvement of marketable fruit quality. The fruit ripening was the less sensitive stage to water deficits. Relative water content and cell membrane stability index decreased as the water deficit increased. Irrigation water use efficiency decreased to a lesser extend during the fruit ripening stage than when water restriction were applied during different growth stages. If water is readily available, irrigating with 100% of water requirements is recommended, but in the case of water scarcity, applying water shortage during fruit ripening stage would be advisable.

Insect pollination as a key factor for strawberry physiology and marketable fruit quality

About 35% of global crop production arises from crop species that benefit from animal pollination, especially by insects. Animal pollination can enhance yields and increase fruit quality, but the effects of insect pollination on pre- and post-harvest fruit physiology and quality are largely unknown. For the first time, we analysed in much detail the physiological responses of fruit development and marketable quality improvements to different pollination treatments such as self-pollination, open-pollination and hand-pollination. In strawberries, self-pollination led to reduced seed set (fertilized achenes), reduced concentration of the phytohormone auxin, highest share of deformed fruits (>90%), smallest and lightest fruits, considerably lower commercial value (8% of the value of open- or hand-pollinated fruits), and reduced shelf life of fruits. Overall, insect pollination increased the average commercial value of marketable fruits by 92%. The commercial value of hand-pollinated and open-pollinated strawberries did not differ. We conclude that pollination services are not merely important for yield, but also vital for physiological processes that result in better marketable quality (e.g. fruit appearance, flavour-enhancing constituents, prolonged shelf life) and commercial value of many pollinator-dependent crops.

Effects of Global Warming Simulated Temperature and Water Stress on Fruit Quality of Tomato (<em>Lycopersicum esculantum</em>) Var. Rajitha

Experiments were conducted in the temperature regulated poly-tunnels for five consecutive growing seasons at the Open University of Sri Lanka to evaluate the impact of the enhanced temperature and water stress due to Global warming on marketable fruit quality. Split plot experiment based on complete randomized design with 10 replicates was applied as experimental design. The plants were grown in pots, and the main plot included two moisture levels (No water stress, 50% water stress from the field capacity) and sub plots contained 3 different temperature regimes (34°C maximum temperature / 32°C maximum temperature / ambient temperature). Experiments were repeated for 3 seasons to replicate temperature effect. The combination effect of water stress and temperature stress proved to be a significant drawback for tomato yield and marketable fruit quality such as colour, shape, soluble solids content, pH and sugar acid ratio. Mealy bug attack too was very significant in high temperature poly tunnel experiment which affected the marketable fruit quality. Therefore, tomato variety Rajitha could not be a successful open field crop in the dry zone of Sri Lanka if temperature is increased due to global warming. But tomato could be cultivated under green houses by providing adequate water and required soil temperature.

Evaluation of cultivars of strawberry, a temperate fruit for its adaptability as well as productivity in sub-tropical agro-climatic condition of Supaul district in Bihar

HIND AGRICULTURAL RESEARCH AND TRAINING INSTITUTE ABSTRACT : The findings of a field trial conducted in 2012-13 and 2013-14 to assess different cultivars of strawberry in Supaul district of Bihar revealed that short day cultivars were more tolerant to insect pests than day neutral cultivars, particularly in later stage of fruit development leading to record higher yield. It was also revealed that a suitable micro-climate was required for optimum plant growth, higher crop yield and the best quality fruits. Festival was found to be the best performing variety in respect of weight per fruit, yield and marketable fruit quality having maximum growth, plant height (21.34cm), flowering duration (60.09 days), fruiting duration (55.62 days) and yield (15.26 tons/ha).

Apple tree growth and overall fruit quality under organic and conventional orchard management

Two apple ( Malus × domestica Borkh.) orchards, a conventional and an organic one, were compared in terms of plant growth, marketable fruit quality attributes (fruit weight, shape, color, phenolic compound concentration, nutrients) and yield. The two orchards were located nearby, in order to exclude possible pedoclimatic influences on the measured variables. The two management systems resulted in similar new season's shoot growth and similar fruit quality attributes, in terms of total soluble solids, juice pH, titratable acidity and color indexes, while the conventionally grown trees produced almost twice the yield of the organically managed ones. The flesh plus peel portion of the conventionally produced fruits exhibited higher total flavonoid and o-diphenols concentration, while the flesh portion presented higher flavonoid concentration. Nitrogen concentration was higher in all portions of conventionally grown fruits, while potassium, calcium, sodium and manganese concentrations were higher in the flesh portion of organically produced fruits. Significant differences were observed between management systems concerning fruit nutrient ratios, but their values were within the desired ranges, under both conventional and organic management systems.