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A mixed modes solar dryer was modified from a Horticultural Innovation Laboratory design and its performance compared to a direct mode solar dryer to process horticultural crops. The mixed modes and the direct mode solar dryers dried vegetables at different rates with the mixed modes being faster for all products (p ≤ .001). Leaves and flowers of the spider plant (Cleome gynandra) had the shortest drying time (270 ± 6 min) while the fruit of the African bird's eye chili (Capsicum frutescens) took the longest time (3,866 ± 31 min). Moisture content of the dried vegetables met the industry standard for dehydrated fruits and vegetables (≤8.4%) and of chilies which had a moisture content of (9.5 ± 0.15%). This low cost mixed modes dryer is suitable for small‐scale vegetable processors and farmers as it does not require grid electricity to operate. Practical applications Fruits and vegetable production is a key economic activity in Kenya. To preserve such produce, farmers practice open sun drying which not only takes longer to dry produce than solar dryers but is also prone to contamination from flies and dust. Prolonged drying times result in products with inconsistent colors and lower nutritional value. Yet, there are simple low cost mixed modes dryers that can be used to dry fruits and vegetables faster than open‐air solar drying. The study aimed at providing local farmers with a modified mixed modes solar dryer to quickly dry fresh produce with a minimal loss of nutrients and color retention in the final product. Globally, such a dryer can be used as one of the simplest innovations toward reduction of postharvest food losses of fruits and vegetables.

An estimated 20% of the world's land surface is underlain by lithologies favorable for karst formation. Karst features (e.g., sinkholes) and soils coevolve, likely influencing local pedogenesis, soil carbon storage, and hydrologic patterns. While karst is widespread, our understanding of the influence of karst geomorphology on pedogenesis remains limited. To better estimate the impact of karst geomorphology on pedogenesis, we characterized nine pedons as a function of landscape position (i.e., toposequence) in two subsidence sinkholes located in the Inner Bluegrass physiographic region of central Kentucky; we characterized a suite of soil physical, chemical, and mineralogical properties. The Inner Bluegrass is underlain by a phosphatic limestone and is susceptible to karst formation. Expectedly, total carbon was greater in lowland positions relative to upland landscape positions. However, inverse relationships between elevation and clay content, selective iron, aluminum, and silicon extracts contradicted previous toposequence trends. Clay mineralogy differences between toeslope and summit positions suggested sediment transport from summit to toeslope positions. Karst geomorphology may limit pedogenesis and facilitate more rapid material export through karst conduits compared to other lithologies. Given the extent of karst terrains and lithologies susceptible to karst formation, future work is needed to understand the magnitude of the impact of karst on pedogenesis and other earth system processes. INTRODUCTIONKarst topography is complex; the rapid dissolution of carbonates leads to unique landscape features such as disappearing streams, abundant springs, extensive cave systems, lack of surface drainage, and sinkholes (Ford and Williams, 2007;Palmer, 2007). Karst hydrology is highly interconnected with rapid flowpaths that connect the soil surface to deeper groundwater (Chen et al.,

Vitamin C is an important micronutrient because of its antioxidant and health promoting properties. With the introduction and commercialization of improved African indigenous plants, few studies have examined the impact of leaf age or the nutrient status of the plants by fertilizer. This study sought to determine amounts of vitamin C using redox titration in mature and immature leaves of spider plant (Cleome gynandra) and black nightshade (Solanum ssp) grown in fields and subjected to various sources of fertilizers which were chicken manure to provide an organic source, Mavuno fertilizer to provide a conventional synthetic source and no fertilizer to serve as a control. Chicken manure led to the highest (167 mg/100 g) vitamin C content which was however not statistically significant from Mavuno fertilizer (150 mg/100 g) at P≤ 0.05 in the nightshade variety. The highest vitamin C with no fertilizer application was 105/100 g and 79 mg/100 g in SS-49 and UG-SF varieties respectively. Moreover, vitamin C content was highest in mature leaves than in immature ones whatever the kind of fertilization treatment applied. By recognizing the impact of leaf age and importance of providing adequate fertilization, farmers can produce higher yielding and more nutritious leafy greens.