Articles, Conference and Workshop Papers Collection

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Browsing Articles, Conference and Workshop Papers Collection by Subject "African eggplant"

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    The feasibility of hand-held thermal and UAV-based multispectral imaging for canopy water status assessment and yield prediction of irrigated African eggplant (Solanum aethopicum L)
    (Elsevier, 2021) Mwinuka, Paul Reuben; Mbilinyi, Boniface P; Mbungu, Winfred B; Mourice, Sixbert K; Mahoo, H.F; Schmitter, Petra
    This study was conducted to evaluate the feasibility of a mobile phone-based thermal and UAV-based multi spectral imaging to assess the irrigation performance of African eggplant. The study used a randomized block design (RBD) with sub-plots being irrigated at 100% (I100), 80% (I80) and 60% (I60) of the calculated crop water requirements using drip. The leaf moisture content was monitored at different soil moisture conditions at early, vegetative and full vegetative stages. The results showed that, the crop water stress index (CWSI) derived from the mobile phone-based thermal images is sensitive to leaf moisture content (LMC) in I80 and I60 at all vegetative stages. The UAV-derived Normalized Difference Vegetation Index (NDVI) and Optimized Soil Adjusted Vegetation Index (OSAVI) correlated with LMC at the vegetative and full vegetative stages for all three irrigation treatments. In cases where eggplant is irrigated under normal conditions, the use of NDVI or OSAVI at full vegetative stages will be able to predict eggplant yields. In cases where, eggplant is grown under deficit irri gation, CWSI can be used at vegetative or full vegetative stages next to NDVI or OSAVI depending on available resources.
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    Optimizing water and nitrogen application for neglected horticultural species in tropical sub-humid climate areas: a case of African eggplant (Solanum aethiopicum L.)
    (Elsevier, 2021) Mwinuka, Paul Reuben; Mbilinyi, Boniface P; Mbungu, Winfred B; Mourice, Sixbert K; Mahoo, Henry F; Schmitter, Petra
    African eggplant, a traditional and important nutrient-dense crop to Tanzania’s nutrition and food security. However, yields remain low as a result of sub-optimal irrigation and fertilizer practices. To reduce the yield gap, a randomized split-plot design set up with irrigation as a main and nitrogen (N) treatments as a sub-factor. The irrigation regimes were 100 % (I100), 80 % (I80) and 60 % (I60) of crop water requirements whilst nitrogen levels were 250 kg N/ha (F100), 187 kg N/ha (F75), 125 kg N/ha (F50) and 0 kgN/ha (F0). The study evaluated the effect of irrigation water and N on crop growth variables and yield, fruit quality, WUE and NUE. The study showed the importance of combining different irrigation performance indicators which responds to different levels of water and nitrogen to evaluate and assess suitable irrigation and fertilizer strategies for African eggplant. The crop growth variables (plant height and LAI) had a good correlation with fruit yield (R2 = 0.6 and 0.8). The fruit quality was best performed by 100 % water in combination with 75 % N treatment. The best WUE and NUE was attained at 80 % and 100 % levels of water in combination with 75 % N. However, minimizing trade-offs between the various indicators, the optimal application for African eggplant would likely be around 80 % of the total irrigation requirement and 75 % of the N requirement in sandy clay loam soils under tropical sub humid conditions.
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    Viability and genetic integrity of African eggplant (Solanum spp.)seeds during natural ageing under cold dry storage
    (Sokoine University of Agriculture, 2024) Jonas Nickas; Sognigbé N'Danikou; Abdul J. Shango; Newton Kilasi
    Seed deterioration occurs gradually during long-term seed storage. Viability, vigour, and genetic integrity of African eggplant seeds were assessed under natural ageing during genebank storage. The percentage of tail DNA before and after seed imbibition was used to account for genotoxicity and DNA repair during cold dry storage at 10 °C using the comet assay. After 2, 5, and 12 years of storage in the genebank, a reduction of seed viability was observed in all studied African eggplant genotypes. However, seed viability was more significantly reduced in seed lots that had been stored for a longer period in the genebank (p < 0.05). Overall, higher viability loss was recorded in seeds regenerated 12 years before (p < 0.05). The molecular analysis by comet assay showed significant DNA damage during natural aging under genebank conditions, accompanied by important loss of viability and germination energy in older seeds translated into low DNA repair after seed imbibition. The seed lots which had better initial quality were able to maintain higher viability during genebank storage. The findings inform on the storage behaviour of African eggplant genotypes and are relevant for the proper handling of seed lots in genebanks. They are also relevant for future studies on seed longevity prediction in African eggplant.