Black Nets Research Articles

Colored Shade Nets Can Relieve Abnormal Fruit Softening and Premature Leaf Senescence of "Jumeigui" Grapes during Ripening under Greenhouse Conditions.

High temperature causes premature grape leaf senescence, abnormal berry softening, and shortening of the fruiting period. Furthermore, the fruit quality and yield are severely affected. Here, the “Jumeigui” grape quality and leaf senescence were evaluated under shading; green, blue, black, and gray nets were used for shading, and their spectra were measured. At the same density, the shade-net color significantly affected cooling and shading efficiencies, with gray nets showing the best light transmission and cooling effect. Shading significantly alleviated abnormal heat-induced grape softness. The total soluble solids (TSS) content and grape coloration were affected under gray, blue, and green shade nets. Nonetheless, TSS exceeded 18 °Brix under gray, blue, and green nets, as required of first-class high-quality fruit. The peel color was not significantly affected under gray or blue shade nets, whereas unshaded grapes showed clear heat-stress damage, especially on the edges of unshaded bottom leaves, in which the net photosynthesis rate was significantly lower than that under shading, indicating that high light intensity and heat caused premature leaf senescence. Colored shade nets reduced greenhouse temperature and light intensity, thereby alleviating the premature senescence of grape plants. Grape quality under black shade nets was poor, whereas superior quality was achieved using gray or blue shade nets.

Spectral light distribution affects photosynthesis, leaf reflective indices, antioxidant activity and growth of Vanilla planifolia

Vanilla planifolia is an obligate sciophyte (shade plant) with crassulacean acid metabolism (CAM) photosynthesis. Plants were grown for 12 months under black, blue, green, or red photoselective shade netting (PSN) to alter the spectral light distribution impacting the plants. Light wavelengths were measured in each treatment and plants were assessed for photosynthetic characteristics, leaf chlorophyll index (LCI), maximum quantum yield of photosystem II, leaf reflectance indices, leaf area, growth, antioxidant enzymes, lipid peroxidation, reactive oxygen species (ROS), and osmolyte content. Plants grown under red PSN had a higher quantity of red and far-red light and had greater nocturnal net CO2 assimilation (NocA), leaf area and leaf dry weight than plants in the other treatments. Plants grown under blue PSN had a higher quantity of blue light, resulting in a higher LCI and maximum quantum yield than plants in the other treatments. Plants grown under the red and blue PSN had increased leaf spectral reflectance indices compared to plants in the other treatments, which resulted in the highest levels of antioxidant scavenging enzymes, ascorbic acid (AsA), proline, and glycine betaine, and the lowest levels of H2O2. These findings demonstrate that increasing light in the red and far-red or blue portions of the spectrum by using PSN alters the photosynthetic and/or antioxidant responses of V. planifolia and increasing red and far-red light by using red PSN can also accelerate plant growth, possibly due to higher photosynthesis.

Abiotic stress in neotropical climate influences pigment production, antioxidant capacity and expression of physiological disorders in apples

Apple cultivation, which is labour-intensive and relevant in terms of food sovereignty, is experiencing a decrease in the number of producers. The fruit, of recognised organoleptic quality, often shows physiological disorders such as sun damage, scald, lenticellosis and bitter pit. These damages are associated with abiotic stresses and are expressed in the field or postharvest, reducing the economic sustainability of the crop in the neotropical climate. The objectives of the present work were: a) to determine climate factors that are limiting for adaptation under neotropical climate conditions, b) to evaluate physiological responses using spectroradiometry and analyse their potential for predicting disorders, and c) to evaluate management strategies capable of mitigating abiotic stress damage. Our results showed a high variability of predisposing conditions and damage development, with soil water availability being the condition most related to sun damage. Of the field treatments, 50% black netting was the one that reduced damage levels the most, reducing air and fruit temperature and presenting the least restrictive xylem potential (-0.54MPa), without affecting growth parameters. The treatments under netting always showed lower expressions of sunscald. Regarding damage prediction, water potential differences between fruit faces, proline concentration (destructive indicators) and PSRI480 spectroradiometry index (non-destructive indicator) showed the best characteristics.

Could black anti-hail net have an extra role as an amelioration agent against heat stress in kiwifruit?

BACKGROUND: Kiwifruit plants are extremely sensitive to hail storms. Black anti-hail nets are the most frequently used in kiwifruit culture, to protect both the plant and current as well as future production. OBJECTIVE: The present trial aimed to assess if the black hail net could also serve as an amelioration agent against high temperature and irradiance during the summer months. METHODS: The photosynthetic capacity, the yield, and fruit quality (carbohydrates, organic acids, phenolic compounds, and antioxidant capacity) of “Hayward” kiwifruit cultivar, both at harvest and after three months of storage were evaluated. RESULTS: Photosynthetic capacity under the net was slightly higher compared to control, while leaf temperature was always lower during the summer and autumn. The yield was significantly enhanced under the net, while the fruits exhibited higher titratable acidity, organic acids, and ascorbic acid concentration. After the storage, fruits produced from vines grown under net still had higher organic acid content, as well as total soluble solids but lower antioxidant capacity compared to control. CONCLUSIONS: Net installation above kiwifruit canopy seems to alleviate the effects of high temperature and heat load on kiwifruit vines, under saturating light intensity, inducing higher yields with good fruit quality.

Color Shade Nets Affect Plant Growth and Seasonal Leaf Quality of Camellia sinensis Grown in Mississippi, the United States.

Shading modifies the microenvironment and can provide plants with some protection from frequent heat, drought, frost, and hail induced by climate change and has the potential to improve plant growth, yield, and quality. Tea (Camellia sinensis) is an ancient plant originating from tropical and subtropical regions and prefers to grow in partial shade under the forest canopy. The emerging tea industry in the United States (US) requires research support on establishing tea fields in novel environmental conditions as well as on producing high-quality tea products. This study investigated the effects of black, blue, and red shade nets on tea plant growth and seasonal leaf qualities in the southeastern US with a humid subtropical climate. When compared to no-shade control, black, blue, and red shade nets increased plant growth index (PGI), net photosynthetic rate (Pn), and stomatal conductance (gs), decreased air and leaf surface temperatures in summer, and reduced cold damage in winter. No significant difference was found among the black, blue, and red shade nets on tea plant growth. Varying contents of total polyphenols, carbohydrates, free amino acids, L-theanine, gallic acid, caffeine, and catechins in fresh tea leaves were observed among different shade treatments and harvesting seasons. 69.58% of the variations were depicted in a biplot by principal component analysis. Red shade was considered helpful for improving green tea quality by increasing the content of L-theanine and free amino acids in tea leaves collected in spring and fall when compared to no-shade control.

Effect of Colored Shading Nets on the Growth and Water Use Efficiency of Sweet Pepper Grown under Semi-arid Conditions

Colored shading nets have been increasingly studied in semi-arid crop production systems, primarily because of their ability to reduce solar radiation with the attendant reductions in air, plant, and soil temperatures. However, there is a paucity of research concerning the impact of colored shading nets on various crops grown under semi-arid environments, particularly the sweet pepper (Capsicum annum) production system. This study aimed to investigate the effects of three colored shading net treatments (i.e., white, green, and black shading nets with 50% shading intensity and control with unshaded conditions) on the growth and instantaneous water use efficiency (WUE) of sweet pepper. The results showed that all colored shading nets exhibited significantly lower daytime air temperatures and light intensity (22 to 28 °C and 9992 lx, respectively) compared with the control (32 to 37 °C and 24,973 lx, respectively). There were significant differences in sweet pepper growth performance among treatments, including plant height, shoot dry weight, leaf area, leaf chlorophyll content, and vitamin C in ripened fruit. The enhanced photosynthetic rates were observed in sweet pepper plants under the colored shading nets compared with control plants. WUE increased among the colored shading net treatments in the following order: control ≤ white < black < green. Overall, the application of green and black shading nets to sweet pepper production systems under semi-arid environments significantly enhanced plant growth responses and WUE.

Grey and Black Anti-Hail Nets Ameliorated Apple (Malus × domestica Borkh. cv. Golden Delicious) Physiology under Mediterranean Climate.

The use of anti-hail nets on orchards changes the microclimate underneath the net. This might be of great importance in apple growing regions characterized by high radiation levels and hot and dry climates during the summer season. But, depending on the net colour and on the local climatic conditions, the shade promoted triggers different responses by the trees. Grey and black anti-hail nets were applied in an apple orchard (cv. ‘Golden Delicious’) located in Northeast Portugal. Under the nets a lower concentration of glomalin related-soil proteins was observed, along with an improvement on trees water status, stomatal conductance, net photosynthetic rate, total chlorophylls, N, Mg, Fe and Cu concentrations, as well as an increase in mean fruit weight. The major difference between nets was on the photosynthetic efficiency, being higher on black net in sunny days, while grey net performed better under cloudy conditions. The use of netting systems proved to be effective in improving “Golden Delicious” apple trees performance under a Mediterranean climate, mainly when the radiation reaching the plants surpass the tree saturation point for photosynthesis. Therefore, these findings anticipate solutions for current and forecasted negative effects of climate change.

Effect of Shading Nets on Yield, Leaf Biomass and Petiole Nutrients of a Muscat of Alexandria Vineyard Growing under Hyper-Arid Conditions

Background: Currently, viticulture is exposed to extreme weather fluctuations and global warming, thus the implementation of short-term adaptation strategies to mitigate climate change impacts will be of a wide importance for the sustainability and competitiveness of wine industry. This research aimed to study the effect of shading nets on the viticultural performance of a Muscat of Alexandria vineyard growing under hyper-arid conditions. Methods: Three treatments were randomly arranged in the vineyard: (i) a control (without shading), (ii) a white shading net (25% of shading), and (iii) a black shading net (40% of shading). Subsequently, yield, vine vigor, berry composition, leaf biomass and petiole nutrient content were assessed. Results: Both shading nets decreased the incidence of solar radiation in vines. The application of white shading nets induced a high bunch weight and a higher number of berries per bunch than the black shading nets. Black shading nets increased pruning weight, decreased Ravaz index and induced a considerably accumulation of soluble solids in grapes. This treatment also decreased bunch weight and the number of berries per bunch, and increased rachis length compared to control. Black shading nets decreased Mg petiole content, leaf dry weight and leaf biomass at flowering compared to uncovered vines. Conclusions: Shading considerably affected the viticultural performance of Muscat of Alexandria vines growing under hyper-arid conditions, modifying yield, leaf biomass and petiole nutrients.

Colored Anti-Hail Nets Modify the Ripening Parameters of Nebbiolo and a Smart NIRS can Predict the Polyphenol Features

In the cultivation of vines the risk of hail appears to be increasing with the ongoing climate change. The use of protective plastic nets is spreading, but there is little knowledge on the additional processing costs and on the phenological and qualitative consequences, moreover, as depending on different colors of the nets. Thus, a randomized trial was carried out in Nebbiolo, a wine of great aging, testing three plastic anti-hail nets colored in green, gray and black. Results showed that 24% more-time was necessary for the canopy management practices under the nets. The black nets advanced the ripening process, with a berry weight decrease of about 13%. A significant decrease in the seed number per berry was observed under the black nets (-45%), while a rise (+102%) was observed under the green and gray nets with a parallel increase in the pH of the juice (+13%) and in malic acid (+28%) under the green nets. The berry skin did not show any significant differences in polyphenol and anthocyanin profiles, while the plants that matured in the upper part of the vineyard showed higher level in the berry skin extractable flavan-reactive to vanillin, and total polyphenol. On the other hand, in the seeds grown under green nets an increase in the extractable polyphenol compounds was observed, sign of a delay in seed ripening, with a higher tannin polymerization ratio, preserving the malic acid, and decreasing the acidity of the berry. In conclusion, the use of colored green may be a useful tool against excessive microclimatic warming and / or irradiation. The field internal variability affects much more the ripening dynamics than the nets used. A second aim was to develop a smart NIR SCiOTM model for polyphenols and the results were in line with the favorable expectations, providing R2 predictions of about 0.74 from the skin and 0.81 from the seeds.

Early apple fruit development under photoselective nets

The objective of this 2-year study (2017, 2019) was to evaluate the influence of photoselective nets on apple fruit growth, focusing on the initial fruit growth stages of “Pink Lady”. Trees were subjected to four photoselective nets (Blue, Red, White and Yellow) and a standard black one (serving as Control), resulting in 5 light environments (LE), all shading at 20%. From 20 to 90 DAFB, 32 fruit and extension shoots, for each LE, were measured for a total of 11 times during the season. For each LE, fruit gauges were also installed to monitor fruit daily growth parameters, from 50 to 90 DAFB. At harvest, all fruit from each light environment were weighed and quality parameters were measured on 40 fruit per treatment. For each year, correlations were made to test the influence of LEs on final fruit weight and quality, and the impact that extension shoot growth had on fruit growth. In both years, white and control nets led to the production of fruits with higher weight compared to the other treatments (blue, red and yellow nets). In 2019, LEs did not appear to influence the relationship between shoot and fruit growth, probably due to the higher crop load and the massive pruning carried out the previous year. The higher vegetative outburst in this year might have unbalanced resources towards the shoots, than towards the fruit. Results show how weather and orchard management heavily influenced the trees responses. Yet, the consistent findings of final fruit weight, for both years, indicate that different wavelengths influence fruit and shoot behavior, even at early phenological stages. Hence, growers searching for bigger fruit should refer to white and black nets. Further studies approaching this technology can help improve apple production management and knowledge of the use of photoselective nets.

Effects of Light Intensity and Spectral Composition on the Transcriptome Profiles of Leaves in Shade Grown Tea Plants (Camellia sinensis L.) and Regulatory Network of Flavonoid Biosynthesis.

Black net shade treatment attenuates flavonoid biosynthesis in tea plants, while the effect of light quality is still unclear. We investigated the flavonoid and transcriptome profiles of tea leaves under different light conditions, using black nets with different shade percentages, blue, yellow and red nets to alter the light intensity and light spectral composition in the fields. Flavonol glycosides are more sensitive to light intensity than catechins, with a reduction percentage of total flavonol glycosides up to 79.6% compared with 38.7% of total catechins under shade treatment. A total of 29,292 unigenes were identified, and the KEGG result indicated that flavonoid biosynthesis was regulated by both light intensity and light spectral composition while phytohormone signal transduction was modulated under blue net shade treatment. PAL, CHS, and F3H were transcriptionally downregulated with light intensity. Co-expression analysis showed the expressions of key transcription factors MYB12, MYB86, C1, MYB4, KTN80.4, and light signal perception and signaling genes (UVR8, HY5) had correlations with the contents of certain flavonoids (p < 0.05). The level of abscisic acid in tea leaves was elevated under shade treatment, with a negative correlation with TFG content (p < 0.05). This work provides a potential route of changing light intensity and spectral composition in the field to alter the compositions of flavor substances in tea leaves and regulate plant growth, which is instructive to the production of summer/autumn tea and matcha.

Maintaining the Grape Quality on Organically Grown Vines (Vitis vinifera L.) at Vineyard Condition under Temperate Climate of Konya Province

Organically produced conventional products have gained great attention in accordance with the increasing awareness on healthy foods as well as improvements in living standards. Environment friendly strategies to extend the quality of grapes after commercial maturity provide healthy and profitable sustainability in market chain. In the present study, possibilities to maintain the quality of grape clusters on grapevines without any chemical treatments have been studied under vineyard conditions in temperate climate characteristics of Konya Province in Central Anatolia. Grape clusters of ‘Alphonse Lavallée’ and ‘Narince’, one of the most popular conventional grape cultivar in Turkey, were kept on the vines trained with bilateral cordon system. The vines were drip irrigated during the hot summer and the vine canopy was covered with black nets after veraison to protect from the birds, hail and climatic extremities. After commercial maturity, twelve cluster samples per cultivar were collected with monthly intervals to investigate the changes in quality. Up to the 3rd sampling date (at the end of November 2019), little losses in quality features were determined in both cultivars. At the end of the study, at 4th moth (December), significant decay incidences were observed with similar patterns in cultivars. General findings demonstrated that the grape clusters could be maintained on grapevines under intact condition of the cool autumn season in temperate zone by protecting them from the external damages using convenient protective materials up to three or four months depending on the response of cultivars to environmental variables.

Effect of spectral manipulation and seasonal variations on cut foliage production and quality of Philodendron (Philodendron ‘Xanadu’)

Influence of spectral manipulation of light using coloured nets and seasonal variation on cut foliage yield and quality of Philodendron ‘Xanadu’ was evaluated under red, green, white and black coloured shade nets permitting light intensities ranging from 240.50 to 370μ mol m-2 s-1 (75% shade net), for two consecutive years from 2014-16, at ICARIIHR, Bengaluru. The plants grown under white shade net (75% shade) resulted in higher foliage production plant-1month-1 (14.53) and were on par with those grown under green shade net. The quality of the cut foliage in plants grown under white shade net with respect to stalk length (24.91 cm) and width of the lamina (5.19 cm) was on par with those under green and black shade nets. Coloured shade nets did not influence the vase life of the cut foliage. Developmental stages of the foliage under the different coloured nets have indicated that leaves attained the harvestable maturity stage at 29.92 days post-emergence under white shade. Cultivation of Philodendron ‘Xanadu’ under white shade resulted in maximum cut foliage yield and quality.

Effect of spectral manipulation and seasonal variations on cut foliage production and quality of Philodendron (Philodendron ‘Xanadu’)

Influence of spectral manipulation of light using coloured nets and seasonal variation on cut foliage yield and quality of Philodendron ‘Xanadu’ was evaluated under red, green, white and black coloured shade nets permitting light intensities ranging from 240.50 to 370μ mol m-2 s-1 (75% shade net), for two consecutive years from 2014-16, at ICARIIHR, Bengaluru. The plants grown under white shade net (75% shade) resulted in higher foliage production plant-1month-1 (14.53) and were on par with those grown under green shade net. The quality of the cut foliage in plants grown under white shade net with respect to stalk length (24.91 cm) and width of the lamina (5.19 cm) was on par with those under green and black shade nets. Coloured shade nets did not influence the vase life of the cut foliage. Developmental stages of the foliage under the different coloured nets have indicated that leaves attained the harvestable maturity stage at 29.92 days post-emergence under white shade. Cultivation of Philodendron ‘Xanadu’ under white shade resulted in maximum cut foliage yield and quality.

Photo-Selective Nets and Pest Control: Searching Behavior of the Codling Moth Parasitoid Mastrus ridens (Hymenoptera: Ichneumonidae) under Varying Light Quantity and Quality Conditions.

Simple SummaryAlthough substantial studies exists evaluating the effects of photo-selective nets (PSN) on physiological and morphological aspects of crops in different parts of the world, there is a paucity of studies regarding the effects of PSN on the searching behavior of natural enemies of insect pests. Cydia pomonella is a major insect pest of apples worldwide and the parasitoid Mastrus ridens is an important natural enemy of this pest. We evaluated the effects of pearl and red PSN and black standard nets (SN) on the searching behavior of this parasitoid. The host localization ability of the parasitoid was significantly affected by the net color. The females found their hosts faster under the pearl and red PSN compared to the black SN. However, no effects were found in terms of parasitism or the initial behavior of the parasitoid. Even though parasitism was not affected, host localization was delayed under black SN compared to the other PSN. Therefore, it is necessary to carry out further studies in field conditions to verify whether parasitism or other parameters could be affected.Photo-selective nets (PSN) are used to manipulate the physiology of fruit crops. Besides their advantages to the crop, PSN potentially affect insect pests and their natural enemies. We aimed to assess the effects of these production systems on the searching behavior of the codling moth parasitoid, Mastrus ridens. We hypothesized that PSN and black standard nets (SN) affect the behavior of the parasitoid by delaying host localization and reducing parasitism. Laboratory experiments were carried out in closed cages under four treatment conditions: black SN, pearl PSN, red PSN, and no PSN as control (uncovered cages). Our results showed that the host localization of M. ridens was delayed under black SN and enhanced by pearl and red PSN. The PSN and the black SN did not affect the parasitism levels. In addition, the initial behavior of the parasitoid during the first 30 min of the bioassays was not affected by treatments. However, females spent most of the time walking around the arena, grooming, or resting, regardless of the color of the net. Parasitism was not affected under the PSN or the black SN; however, this must be verified in field conditions.

Physiological Responses of the Tetrastigma hemsleyanum Plant under Different Color Films

Tetrastigma hemsleyanum is a traditional Chinese medicine herb, commonly used for its anti-inflammatory and antitumor properties. Flavonoids are the main functional constituents of T. hemsleyanum, and their production in the herb is affected by light quality. T. hemsleyanum is a shade-loving plant and is usually covered by black shade nets during cultivation. However, there are only a few studies on the effects of using color films on growth and flavonoid synthesis in T. hemsleyanum. In this study, we measured the influence of five different color films on growth indexes—sugar, soluble amino acid, soluble protein, and flavonoid content—and flavonoid-synthesizing enzyme activities in T. hemsleyanum. The films used were colorless plastic film as the control group (CK-W), red film (RF), yellow film (YF), green film (GF), and blue film (BF). BF promoted plant growth and increased yield, as evidenced by the highest growth indexes, soluble amino acid content, and chalcone isomerase (CHI) enzyme activity. RF increased the content of secondary metabolites, thereby enhancing herb quality, as evidenced by the highest phenylalanine ammonia lyase (PAL) activity and increased flavonoid content.

Effectiveness of several commercial non-toxic antifouling technologies for aquaculture netting at reducing mussel biofouling

Biofouling causes a range of problems in aquaculture, and there is a need to validate the effectiveness of antifouling products marketed in the industry. We tested the antifouling performance of four commercial aquaculture netting options at a trout aquaculture operation in the Bras d'Or Lakes, Nova Scotia, Canada. This site has brackish water and a severe mussel (Mytilus edulis) biofouling problem – complete net occlusion can occur within four weeks of the onset of mussel larvae settlement. We tested white and black nylon netting as controls, and four products marketed as having non-toxic antifouling properties: white and black Finsulate®, white Netminder® coating on white nylon netting, and white Dyneema® netting. In 2017, using image analysis measurements of fouling, we found only Netminder® significantly delayed fouling by two weeks over controls. Nonetheless, biofouling on all netting treatments (a mixture of filamentous algae and mussels) reached saturation (i.e. complete net occlusion in the images) within six weeks. After 17 weeks, the Netminder® coated netting supported significantly greater mussel biomass (measured by shell masses). In 2018, a follow-up experiment found that Netminder® caused a one-week delay in exclusively mussel biofouling compared to the white nylon control netting. We conclude that none of the options tested are likely to reduce severe mussel biofouling substantially. However, the benefits of a one-to-two week delay in biofouling caused by Netminder® (including reduced cleaning costs and diminished influence of mussels on water properties and the benthos under the net pens) should be weighed against the cost of application and maintenance for the coating.

USING COLORED SHADE NETS AND ORGANIC MULCH TO IMPROVE MICROCLIMATE, GROWTH, AND YIELD OF YELLOW SWEET PEPPER

The study was carried out to investigate the effect of using color shade nets and organic mulch on improvement microclimate, growth, yield, and its components and fruit quality of yellow sweet pepper cv. Yellow Star F1 under high temperature. The study was conducted at El- Arish Agriculture Research Station, Agric. Res. Center, North Sinai Governorate, Egypt, during the summer seasons of 2018 and 2019. The results indicated that application of color shade nets modified microclimate around pepper plants where decreased average monthly of air temperature and light intensity; however, increased air relative humidity compared with unshaded. On the other hand, using black, green, and white shade nets combined with dry vegetable residues mulch followed by barley straw mulch reflected the lowest soil temperature at depths 10 and 20 cm in both growing seasons. Also, the results showed that using green shade nets followed by black shade nets combined with dry vegetable residues or barley straw mulches recorded the highest values for a fresh and dry weight of pepper plant organs. Besides, the highest contents of Chlorophyll b in leaves and vitamin C in fruit juice were obtained when covered by green nets combined with dry vegetable residues mulch in both seasons. Also, results revealed that the interaction between shading of yellow fruit pepper plants by black and green color nets with dry vegetable residues mulch significantly increase average fruit weight and total fruit yield for marketable yield compared to the open field without mulching in the first and second season. For that, it is recommended using of shade color nets (Black and green) with organic mulch (dry vegetable residues mulch and/or barley straw mulch) under high-temperature regions for modifying microclimate conditions of pepper plants and soil to improve growth, productivity, and fruit quality traits.

Maturation of 'Baigent' apples protected by anti-hail nets and sprayed with aminoethoxyvinylglycine and ethephon

Abstract The objective of this work was to evaluate the effect of pre-harvest spraying with aminoethoxyvinylglycine (AVG) and ethephon on fruit maturation of 'Baigent' apple (Malus domestica) trees grown under black anti-hail nets. The treatments were: control; 125 mg L-1 AVG, sprayed 30 days before anticipated harvest time (DBAH); 120 mg L-1 ethephon 7 DBAH; 62.5 mg L-1 + 62.5 mg L-1 AVG 30 and 20 DBAH; and 62.5 mg L-1 + 62.5 mg L-1 AVG 30 and 20 DBAH + 120 mg L-1 ethephon 7 DBAH. Fruit were harvested in the commercial harvest of the control treatment (harvest 1) and 14 days later (harvest 2). Yellowing and loss of firmness were delayed by the treatments with AVG and accelerated by that with ethephon. AVG application in a single rate of 125 mg L-1 30 DBAH or in two split rates of 62.5 mg L-1 30 and 20 DBAH delays fruit maturation. The pre-harvest application of AVG in a single rate reduces the red color of the fruits, which is not affected by application in split rates, combined or not with ethephon, regardless of the date of harvest.

Influence of coloured shade nets and seasons on production and quality of cut foliage of leather leaf fern (Rumohra adiantiformis)

Leather leaf fern [Rumohra adiantiformis (G forst) Ching.] was grown under red, green, white and black coloured shade nets permitting light intensities ranging from 240.50 to 370 μ mol m-2 s-1 (75% shade net), for two consecutive years from 2014-16, at ICAR-IIHR, Bengaluru. The influence of coloured nets and the season on cut foliage yield and quality were evaluated. Developmental stages of the fronds under the different coloured nets were also studied. Fronds attained the harvestable maturity stage at 33 days post emergence under red shade net, whereas it took 31.5 days under green shade net. The plants cultivated under red shade net (75% shade) resulted in higher foliage production/plant/ month (6.60) while it was on par with black shade nets in terms of quality of the foliage with respect to length of lamina (24.90 cm) and frond width (17.77 cm). The vase life of the cut foliage grown under red shade net was 47.6 days. Cultivation of leather leaf fern under red shade resulted in maximum cut foliage yield, quality and post harvest life.