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Banana (Musa acuminata cv. 'Grand Nain') is prone to chilling injury (CI) during cold storage, which limits extended storage and shelf life. In this study, we investigated the postharvest application of chitosan (CS) and chitosan nanoparticles (CSNPs) on the CI and quality of unpacked banana fruits during and after cold storage. CSNPs were synthesized using sodium tripolyphosphate (STPP), and analyzed using a Fourier infrared spectrophotometer (FT-IR) and a scanning electron microscope (SEM) to assess the changes in the functional groups and surface morphology. Reacting CS with STPP did not result in changes in the functional groups present but the size and morphology of CS were altered. For the treatments, banana fruits were dip coated in 0.5% (wt/vol) CS and 1.5 g/L CSNPs separately for 2 min in the presence of 1% Tween 80. The fruits were stored at 10 ± 2 °C or the optimal storage temperature of 14 ± 2 °C with relative humidity 85–90% for a 20-day period but subsets were transferred from cold storage on 5-day intervals to a storage rack to ripen at 22 ± 2 °C. The CI index, firmness, hue angle (H°), weight loss, total antioxidant activity (TAA) and total phenolic contents (TPC) were measured at each interval. Untreated fruits were used as a control. Application of CS or CSNPs reduced CI and weight loss but increased firmness, hue angle, TAA and TPC relative to the control samples. These results affirm that CS and CSNP applications maintain banana fruit quality by alleviating CI symptoms throughout cold and ripening temperatures. [ABSTRACT FROM AUTHOR]

Fruit quality is preserved through cold storage, but climacteric fruits are prone to chilling injury (CI) which limits their shelf life and marketability. Two postharvest treatments, 1 mM methyl jasmonate (MeJA) and 4% (wt/vol) calcium chloride (Ca2+), were separately used to investigate their influences on chilling injury (CI) incidence and fruit quality in unpacked banana cultivar "Grand Nain" during cold storage and subsequent ripening. Banana fruits were dipped for 2 min in aqueous emulsions containing 1% Tween‐80—used here as a surfactant with untreated fruits being used as control. Fruits were stored at 10 ± 2 or optimal 14 ± 2°C temperature and relative humidity 85%–90% for a 20‐day cold storage period and then removed from cold storage at 5, 10, 15, and 20 days followed by ripening at 22 ± 2°C. Treatments with MeJA or Ca2+ significantly reduced CI in banana fruit during cold storage and subsequent ripening temperature. Untreated controls exhibited increased CI, weight loss, and decreased hue angle, as well as firmness. In contrast, the aforementioned changes were considerably delayed after treatments with MeJA or Ca2+. Application of MeJA or Ca2+ also increased total phenolic compound contents and maintenance of total antioxidant activity throughout cold storage and during ripening periods as compared to that of the control. These findings indicate that coating bananas with 1 mM MeJA or 4% (wt/vol) Ca2+ can improve the postharvest quality and shelf life of fruits, and it can ameliorate chilling injury during cold storage and at ripening temperature. [ABSTRACT FROM AUTHOR]

Local knowledge, attitudes, and practices (KAP) regarding African Indigenous Vegetables (AIVs) among local growers are required to design effective vegetable productivity-enhancing interventions. However, limited studies have been conducted in Kenya to assess the knowledge, attitudes, and practices on production performance of AIVs. A survey was conducted among 600 AIV growers in Busia, Nyamira and Machakos Counties of Kenya to assess the knowledge, attitudes and practices regarding AIVs and their contribution on output/yield. Primary data were collected using a semi-structured questionnaire supplemented with key informant interviews. Results showed significant knowledge and positive attitude of farmers regarding AIVs, but insignificant use of improved farming practices. The study used a binary logistic regression to identify the variables that are associated with yield increase in AIVs production. It was established that by employing a 5% criterion of statistical significance, ploughing tools, land proportion allotted to the cultivation of AIVs, and water irrigation in AIVs farming significantly influenced the output/yield. Whereas the agro-ecological zones, gender of the farmer, and the fact of being trained in AIVs farming were statistically significant at 10%. On the other hand, farmers' KAP was not statistically significant. An important implication of this result is that farmers' personal characteristics need to be taken into consideration when planning developmental programmes for them. We encourage further intervention studies to be done to complement these findings in order to enable effective methods of interventions to boost production of AIVs. [ABSTRACT FROM AUTHOR]

Western flower thrips (WFT), Frankliniella occidentalis (Pergande) (Thysanoptera: Thripidae), are one of the most serious pests of horticultural crops worldwide. Despite one third of its lifecycle being in the soil, the potential for biological control of WFT in the soil is poorly understood and requires further elucidation. A number of studies report that polyphagous predatory mites prey on pupal stages of WFT in the soil, but little has been done on consumption rates. Therefore, we designed a laboratory study to examine the rate of consumption of WFT pupae in potting media, by the soil-dwelling mite Hypoaspis sclerotarsa (Costa). Five predator densities were evaluated (0, 2, 4, 6 and 8) against four densities of WFT prey (5, 10, 15 and 20 pupae). Pupal consumption was assessed at 2 hourly intervals over a six-hour period. The study confirmed that H. sclerotarsa did consume WFT pupae and that the rate of consumption increased with increasing density of H. sclerotarsa. The rate of consumption also increased with the density of WFT pupae. However, this was not consistent because, as the numbers of WFT pupae increased, so did the ratio of WFT pupae remaining to those consumed, increase. This paper is the first report of H. sclerotarsa in Kenya, and of its potential as a biocontrol agent of WFT. Further studies are now needed to understand interaction of foliar and soil dwelling predatory mites (H. sclerotarsa) for control of WFT under field conditions. [ABSTRACT FROM AUTHOR]

African indigenous vegetables (AIVs) have the potential to contribute substantially to food and nutrition security in Kenya because of their high nutritious value. However, there is a limited pool of knowledge on how AIV innovations are disseminated along the value chain. The study uses the concept of innovation systems and attempts to explore social network analysis in the context of the ALV value chain organisations, using a graph-theoretic method for analysis. Data used in this study are from two counties and were collected using a semi-structured questionnaire. The focus was to identifying pathways of interactions between organisations. Information sharing, knowledge and resource flows were used as proxies to connote linkage. The findings show that the linkages between the organisations do exist and was found to be a top-down approach, the producer organisation did not demand for information, knowledge and resources. The role of policy is creating an enabling environment—in this study interpreted as access to information, knowledge and resources—which is critical in ensuring that the organisation along the value chain have access to the information and resources needed to promote the production and utilisation of these vegetables. Strengthening and empowering producers, extension service and marketing organisations is critical for the uptake and adaptation of inclusive innovations along the AIV value chains. This emphasises the need for further research on how to enhance participation among organisations in the development of innovations. [ABSTRACT FROM AUTHOR]