Puffy Soundy

Bioactive Compounds and Fruit Quality of Green Sweet Pepper Grown under Different Colored Shade Netting during Postharvest Storage.

UNLABELLED In this study, influence of 3 types of photo-selective nets (pearl, red and yellow) and a standard black net on marketable yield, fruit quality and bioactive compounds after postharvest storage was investigated. Percentage marketable fruits were higher in green sweet peppers produced under the pearl nets. Fruits produced under the pearl nets showed higher fruit mass, firmness, chlorophyll content, ascorbic acid content, antioxidant scavenging activity after postharvest storage. Red/far red photon ratio under the pearl net could have improved the ascorbic acid content and the antioxidant scavenging activity in green peppers. Green sweet peppers grown under the pearl nets had higher hue values and maintained green color longer. Our results showed the impact of modified light quality on the bioactive compounds of green sweet pepper during postharvest storage. PRACTICAL APPLICATION Green sweet peppers are rich in phytochemicals. Marketability of green sweet peppers is affected partially due to ripening after postharvest storage and decay. Maintenance of green color, fruit mass, firmness, and nutritional composition are important parameters that attract consumers. This research shows the influence of light quality during production on the fruit quality parameters and bioactive compounds after postharvest storage.

Variety-specific responses of lettuce grown under the different-coloured shade nets on phytochemical quality after postharvest storage

ABSTRACT This study illustrates the effects of light quality as influenced by photo-selective shade nets (red, yellow, and pearl with 40% shade) and the widely used commercial black net (25% shade) on overall retail quality and phytochemical contents of three lettuce (Lactuca sativa L.) varieties (two green varieties, Ashbrook and Aquarell, and a red variety, Exbury) at after postharvest storage. Variety-specific responses were observed with respect to different coloured shade nets with regards to the accumulation of β-carotene, ascorbic acid, flavonoids (kaempferol, isorhamnetin, quercetin, myricetin, anthocyanin), and antioxidant activity at harvest. Growing var. Ashbrook under the pearl net improved the ascorbic acid and myricetin contents after postharvest storage. Var. Exbury (red) produced under the black net showed higher retention of ascorbic acid, and anthocyanin contents after postharvest storage. Also pearl net production improved the β-carotene content after postharvest storage in var. Aquarell. All lettuce types produced under the pearl nets showed less weight loss, and overall acceptance after postharvest storage. Spectral quality under the shade nets enabled us to improve the phytochemical content and antioxidant properties in light-sensitive varieties Ashbrook Aquarell and Exbury, during winter season.

Lettuce (Lactuca sativa L.) growth, yield and quality response to nitrogen fertilization in a non-circulating hydroponic system

ABSTRACT The objective of this study was to determine the effect of nitrogen fertilization rate on growth and quality of leafy lettuce grown during the winter season in non-circulating hydroponic system. Plants were subjected to seven nitrogen (N) concentrations, i.e. 0, 30, 60, 90, 120, 150 and 180 mg L−1 N using ammonium nitrate. Nitrogen treatments did not have a significant effect on leaf fresh and dry mass, root fresh and dry mass, number leaves and leaf area. Leaf ascorbic acid and total phenolic content, and antioxidant capacity peaked at 100 and 120 mg L−1 N, whereas leaf chlorophyll concentration linearly increased with increasing N application. The results indicate that a solution N concentration of 100 and 120 mg L−1 may be sufficient to improve growth, yield and quality parameters of leafy lettuce grown in non-circulating hydroponic system.

Influence of Postharvest Storage Temperature and Duration on Quality of Baby Spinach

S agriculture in most developing countries world-wide including South Africa is largely rain-fed. Changes occurring in the Extension environment include the climate, globalisation and technological improvements. Broad political and scientific consensus exist that climate change and variability is happening and will continue well into the future with negative effects on food production and food security. Extension professionals, therefore, need to constantly develop and improve their capabilities to remain useful and relevant to farming communities. The purpose of the paper is to determine the extension agents’ competencies regarding coping strategies they promote and their effectiveness in contributing tosmallholder crop farmers’ food production in light of climate variability. The study adopted a multi-stage random sampling approach to select districts, municipalities and respondents. Semistructured questionnaires were used to collect data from 194 smallholder crop farmersin 20 villages from four municipalities of Limpopo province, South Africa in January of 2014. Extension managers and field-level extension agents of the Limpopo Department of Agriculture Extension service took part in the survey. Findings show that only one-third of survey respondents receive public extension services including information on climate variability coping assistance; this group finds the information useful for farm production. The most popular climate variability coping strategies promoted by most extension agents were conservation agricultural practices. Small yield differences between extension service and non-extension service recipients indicate agents need new competencies in how to apply coping strategies with producers. Study recommends involvement of extension agents, scientists and farmers in adaptive, municipality-specific trials on the effective implementation of conservation agricultural practices to enhance crop yields. There is need for agents to use multiple channels for effective communication to improve adoption of climate variability coping innovations which have the potential to improve crop yields.Groundnut is one of the most important oilseed crops grown in Andhra Pradesh. The crop is affected by variety of diseases, of which stem rot caused by Sclerotium rolfsii is very important and has become one of the major constraints causing damage to the crop. Management of stem rot is difficult because of soil borne nature of the pathogen and its wide host range and the chemical methods are very expensive and will not provide complete protection from the pathogen. There is worldwide acceptance to the use of ecologically safe, environment friendly methods of protecting crops from the plant pathogens. Using plant produced allelochemicals in agricultural and horticultural practices could minimize synthetic pesticide use, reduce the associated potential for environmental contamination and contribute to a sustainable agricultural system. In vitro studies conducted to reduce the growth of S. rolfsii against mustard leaf discs (8 mm size) inoculated with S. rolfsii (5 mm size), un-inoculated leaf discs revealed at the end of the experiment i. e. at 72 hours, the growth of the pathogen exposed to S. rolfsii inoculated leaf discs was reduced by 15.68 per cent over control and in un-inoculated leaf discs it recorded 11.48 per cent over control. Similarly, the S. rolfsii exposed to mustard powder 2 mg, 5 mg, 10 mg and 20 mg after 24 hours of exposure to mustard powder, the growth of S. rolfsii was completely inhibited in all the concentrations. At the end of the experiment at 96 hours of exposure, mustard powder of 20 mg was found 63.2% inhibitory to the growth of S. rolfsii, while 2 mg of mustard powder did not show any effect on S. rolfsii, suggesting that the fungus may have the ability to adapt to volatiles at lower concentrations. In green house experiment, incorporation of the mustard plant parts into the soil reduced the infectivity of S. rolfsii at every date at which inoculum was added to soil over the 13 day period. The disease incidence was minimum 37.44% at 0 day application of S. rolfsii immediately after incorporation of mustard. The present results also showed that the persistence of Brassica residues was significantly shorter than the persistence of residue action. The results on the effect of incorporation of Brassica sp residues with other treatments on stem and pod rot of groundnut, indicated that the incorporation of mustard plant parts with conventional and non-conventional treatments highly influenced the incidence of stem rot and plant growth. Treatment FYM application @ 6 kg per plot + in situ application of Brassica residues + rhizobium seed treatment @ 20 g per kg seed (T9) showed highest plant height (25.63, 36.93, 42.50 cm), leaf area (272, 1040, 1348.58 cm) at 30, 60 and 90 DAS respectively, fresh weight and dry weight (70.91, 26.66 g plant) and pod yield (2.16 kg plot) at the time of harvest. Soil drenching with propiconazole @ 0.1% + in situ application of Brassica residues @ 4 kg per plot + rhizobium seed treatment @ 20 g per kg seed (62.55%, 67.95%) followed by soil solarization + in situ application of Brassica residues @ 4 kg per plot + rhizobium seed treatment @ 20 g per kg seed (57.10%, 66.70%) resulted in maximum reduction in stem rot and pod rot disease severity per cent over inoculated control respectively. Among all the treatments lowest fungal and bacterial population were recorded in soil drenching with propiconazole @ 0.1% + in situ application of Brassica residues @ 4 kg per plot + rhizobium seed treatment @ 20 g per kg seed (before sowing of groundnut as well as after harvest of groundnut (4.66 x 10, 5.00 x 10; 21.33 x10, 24.00 x 10 cfu g of soil) respectively. In vitro studies on the effect of dried leaf residues of mustard, cabbage and onion on soil microbial population showed that the population of bacteria was revealed more over the fungi in all the treatments. Minimum microbial population was noticed in the soil exposed to dried mustard leaf volatiles followed by onion and cabbage dried leaf residues.D from national typical matter spectral library of China, the featured crop spectral library in south China was built including litchi, banana, winter crop (potato, chili, etc). Spectral and remote sensing models and Applications were developed for inversion of land surface temperature, surface soil moisture. We built the spectral models (350-2500nm) of leave chlorophyll a, soil organic matter, N and P for precision fertilizing in litchi orchard. Besides, a new remote sensing method was developed for estimating the planting area of winter potato, combining the NDVI spectra and spectral angle method. The research achievements had been widely applied in crop planting area estimation, drought & cold disaster monitoring and litchi fertilizer application with notable economic and social benefits.Conservation of biodiversity on dryland agricultural farms, forests, and protected areas is likely to backup future livelihood options. The main objective of this research was to investigate the ethnobotanical importance of indigenous trees protected within agricultural farming system of Mutale local municipality. Tree layer of indigenous species were recorded and classified into families, parts used and their utilization purposes. Twenty two agricultural fields were visited and nineteen species were recorded. The 19 species were classified into sixteen families with Fabaceae, Combretaceae, Capparaceae being the dominating families. Sclerecarya birrea belonging to Anacardiaceae family was the plant species which was well represented in the agricultural farming fields, occurring in 21 farms, followed by Adansonia digitata (19 farms) which belongs to Malvaceae family, and Boscia albitrunca (16 farms), Maerua angolensis (15 farms) which both belong to the Capparaceae family. Shade use category amongst tree species protected within agricultural fields was the dominant category followed by medicine, food, demarcation fence, fodder, and firewood. Protection of these indigenous trees within agricultural fields will go a long way towards conservation of declared protected and endangered species.

Spectral quality of photo-selective shade nettings improves antioxidants and overall quality in selected fresh produce after postharvest storage

ABSTRACT Growing vegetables under shade nets is currently becoming popular in summer to provide protection from high intensities of light. High temperatures and light quality affect postharvest quality and storage life of vegetables. Photo-selective shade netting technology is an emerging agro-technological concept that aims at the improvement of crop quality by the modification of spectral light and provides physical protection of the crop. Incorporation of various light-dispersive and reflective chromatic additives in the photo-selective nets is responsible for the modification of spectral quality, especially in the UV 200–400 nm, visible (400–700 nm), or far-red (FR; also known as “near infrared”; 705–740 nm) in the infrared region of the spectral region. Altered light-quality changes under the photo-selective nets were shown to improve the accumulation of phytochemicals and aroma compounds, and ultimately, the growth, yield, and quality of the selected vegetables such as tomatoes, sweet peppers, lettuce, and aromatic herbs. The postharvest quality of fresh produce is also influenced by environmental conditions such as light, average temperature, minimum temperature, and day-night temperature differences. During production, light quality under the photo-selective shade nets had a positive effect on the quality parameters and phytochemical content in fresh produce after postharvest storage. The review includes the use of photo-selective netting in protected agriculture as a preharvest tool to improve aroma volatiles, antioxidants, and overall quality of fresh produce after postharvest storage.

Biofortification of common bean as a complementary approach to addressing zinc deficiency in South Africans

ABSTRACT Deficiencies of vitamin A, iodine, iron and zinc (Zn) in humans are caused partly by the consumption of food that has insufficient quantities of these. Their deficiency has a negative impact on the health, wellbeing, social and economic status of human beings. A national survey conducted in 2012 identified deficiencies of vitamin A, Fe, and Zn among other nutrients in South Africans and regarded the deficiencies of vitamin A and Fe as a moderate but not Zn. This review discusses causes of Zn prevalence in low-income South Africans and that it is largely caused by the low content of Zn in their diets. Initiatives to reduce Zn deficiency include fortification of wheat products and maize meal which has failed to address it successfully. Weaknesses of fortification include high cost of fortified food products to low-income populations, poor regulation in ensuring compliance in fortification, non-fortification of sorghum meal, and leaching of fortified nutrients during processing. This review suggests Zn-biofortification of locally-preferred common bean cultivars as an alternative strategy to compliment fortification. The review also discusses advantages of adopting biofortified Nutritional Andean common beans. Furthermore, the review suggests initiatives including evaluation of the common bean genotypes’ adaptation to different agro-ecologies.

Anti-proliferative properties of commercial Pelargonium sidoides tincture, with cell-cycle G0/G1 arrest and apoptosis in Jurkat leukaemia cells

Abstract Context Pelargonium sidoides DC (Geraniaceae) is an important medicinal plant indigenous to South Africa and Lesotho. Previous studies have shown that root extracts are rich in polyphenolic compounds with antibacterial, antiviral and immunomodulatory activities. Little is known regarding the anticancer properties of Pelargonium sidoides extracts. Objective This study evaluates the anti-proliferative effects of a Pelargonium sidoides radix mother tincture (PST). Materials and methods The PST was characterized by LC-MS/MS. Anti-proliferative activity was evaluated in the pre-screen panel of the National Cancer Institute (NCI-H460, MCF-7 and SF-268) and the Jurkat leukaemia cell line at concentrations of 0–150 μg/mL. The effect on cell growth was determined with sulphorhodamine B and 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assays after 72 h. The effect on cell cycle and apoptosis induction in Jurkat cells was determined by flow cytometry with propidium iodide and Annexin V: fluorescein isothiocyanate staining. Results Dihydroxycoumarin sulphates, gallic acid as well as gallocatechin dimers and trimers were characterized in PST by mass spectrometry. Moderate anti-proliferative effects with GI50 values between 40 and 80 μg/mL were observed in the NCI-pre-screen panel. Strong activity observed with Jurkat cells with a GI50 value of 6.2 μg/mL, significantly better than positive control 5-fluorouracil (GI50 value of 9.7 μg/mL). The PST arrested Jurkat cells at the G0/G1 phase of the cell cycle and increased the apoptotic cells from 9% to 21%, while the dead cells increased from 4% to 17%. Conclusion We present evidence that P. sidoides has cancer cell type-specific anti-proliferative effects and may be a source of novel anticancer molecules.

Cultivar-specific responses in red sweet peppers grown under shade nets and controlled-temperature plastic tunnel environment on antioxidant constituents at harvest

Antioxidant constituents such as carotenoids (capsanthin, phytoene, lutein, β-cryptoxanthin), polyphenols content (p-coumaric, ferulic, p-hydroxybenzoic, caffeic acid, sinapic acid, and quercetin-3-glucoside) and marketable yield were investigated in 11 sweet pepper cultivars grown under controlled temperature plastic tunnel and white shade net. Marketable yield was not affected by either of the environments, while the interaction between cultivar and growing environment significantly affected the accumulation of antioxidant constituents. The principal component analysis illustrated that controlled temperature plastic tunnel improved the accumulation of carotenoid components and ascorbic acid and vitamin C content in most cultivars. On the contrary, white shade nets favoured the accumulation of phenolic compounds and ORAC activity in most cultivars. A strong correlation was noted between phytoene and carotenoid components in this study (capsanthin r = 0.60; P < 0.001; lutein r = 0.75; P < 0.001; β-carotene r = 0.78; P < 0.001) while ORAC correlated with phenolic compounds. Based on this study, it is possible to refine the choice of environment and cultivar to enhance individual antioxidant constituent groups to improve health benefits for consumers.

Development, Yield, and Antioxidant Content in Red Cabbage As Affected by Plant Density and Nitrogen Rate

ABSTRACT Red Cabbages (Brassica spp.) are becoming popular as intact or fresh-cut products for consumers. Head size and yield are important quality parameters for marketing. These factors are influenced by N application and plant density, which can affect anthocyanin content, which is responsible for the red color and ascorbic acid content. The study was undertaken to determine the influence of nitrogen application rate and plant density on yield, head size, anthocyanin and ascorbic acid contents, and antioxidant activity in Red Cabbage (B. oleracea L. var. capitata f. rubra DC.), cv. Red Jewel. Cabbage plants were fertilized with 40, 80, 120, 160, or 200 kg∙ha−1 N using NH4NO3 at plant densities of 100,000, 125,000, or 166,700 plants∙ha−1, achieved by plant spacings of 20 × 25, 20 × 20, or 20 × 15 cm, respectively. Rates of N and plant density did not affect head size or yield. Anthocyanin and ascorbic acid content and antioxidant activity were higher at 80 kg∙ha−1 N and at 125,000 plants∙ha−1, which can be used without negatively affecting cabbage head size and yield.

Impact of transportation, storage, and retail shelf conditions on lettuce quality and phytonutrients losses in the supply chain

Abstract This study was initiated to investigate the impact of transportation, storage, and retail shelf conditions on lettuce quality and phytonutrients losses in the urban fresh produce market supply chain. Reducing postharvest losses is a priority to reduce the loss of the dietary‐based phytonutrients and to improve the health of the consumers. Limited information is available in South Africa related to the postharvest and nutrition loss in the urban fresh produce market supply chain. In this study, we quantified the postharvest losses, changes in phytochemicals, and loss of minerals in lettuce at different points of Tshwane Fresh Produce Market supply chain. Lettuce supply to the Tshwane Fresh Produce Market from two different provinces, Gauteng and North West, were included in this study for comparison. Lettuce from the two provinces was collected from five different farms. The loss of fresh weight, changes in visual quality, phytonutrition properties, and economic loss of lettuce at the supply chain points: (a) transport; (b) storage; (c) and at the retail shelf was investigated. Five boxes of lettuce per supply chain point from Gauteng and North West provinces were randomly selected. The results indicated that the high temperature (25°C) and low RH (40%) at the retail shelf affected the weight, overall quality, and phytonutrition properties of lettuce. Cumulative economic loss was higher at the retail shelf due to the inferior quality of lettuce. The study identified where major quality and phytonutrition losses occur during marketing. The study demonstrated to identify the where major food and nutritional loss losses occur during marketing. This information will significantly benefit food sustainability by introducing technologies to manage food and nutrition losses.