Plant Stress
Rabeb El khaldi; Dhaouadi Latifa; Besser Houda
Abstract
Purpose: In Oasis areas, salinity becomes a real threat for sustainable agricultural production, and with the introduction of non-native varieties, salinity pressure is more expressed and has harmful outcomes to the local ecosystem and biodiversity. In this context the present study was conducted ...
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Purpose: In Oasis areas, salinity becomes a real threat for sustainable agricultural production, and with the introduction of non-native varieties, salinity pressure is more expressed and has harmful outcomes to the local ecosystem and biodiversity. In this context the present study was conducted to compare salt stress behavior of local oasian and introduced cultivars. Research method: Seeds of two local oasian cultivars namely Djerid (Dj) and Nefta (Ne) and one exotic cultivar namely Cayenne (Ca) were treated with four salt concentrations (0; 2.5; 5 and 7g/l NaCl). Salt stress responses were evaluated using germination parameters and early seedling growth. Findings: Results revealed that the increase of salinity level had negatively effect on germination and early seedling for the three cultivars. However oasian cultivars were found to be the most tolerant to salinity. Ne cultivar showed the highest germination percentage and germination index and the lowest mean germination time at 7g/l NaCl concentration. Also, “Ne” performs better on seedling traits as indicated by the less effect of the high salinity on radicle and plumule length as well as plumule fresh weight, compared to the other cultivars. The introduced cultivar “Ca” was identified to be the most sensitive to salt stress. Limitations: No limitations were founded. Originality/Value: This study valorized the autochthone chili pepper cultivars by highlighting their salt stress tolerance. Thus, oasian genotypes could be very useful as genetic resources for the development of chili pepper cultivars with improved germination and seedling growth under salt-stress conditions.
Olericulture
Flavien Shimira; Fabrice Afloukou; Festus Maniriho
Abstract
Purpose: Potato (Solanum tuberosum) is an important food and cash crop globally, particularly in Rwanda whereby it is ranked fourth most grown food crops after banana, sweet potato and cassava. The purpose of this review study is to analyze and understand potato yield production systems in Rwanda and ...
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Purpose: Potato (Solanum tuberosum) is an important food and cash crop globally, particularly in Rwanda whereby it is ranked fourth most grown food crops after banana, sweet potato and cassava. The purpose of this review study is to analyze and understand potato yield production systems in Rwanda and to find out related constraints. Main findings: After key informants and various research work, it was found that the low potato yield (with on average 11.6 t/ha compared to yield potential of 50.6 t/ha), pests and diseases are the main constraints for potato production in Rwanda. However, it was revealed that the later are highly related to an inadequate supply of good seed tubers. Indeed, it is was reported that the actual mini-tubers seed production systems can cover up to 30% of the national demand; and hence farmers recycle their own seeds or get them from informal sources. This situation is leading to persistent pests and diseases particularly potato bacterial wilt (PBW) and late blight disease hampering potato productivity. Limitations: Soil erosion exacerbated by land fragmentation and use of steep land, and poor fertilization practices both in quantity and quality are reportedly highlighted in this review as secondary bottlenecks for potato production in Rwanda. Directions for future research: Active involvement of the private sector in seed production in conjunction with aeroponic systems and integrated pest and disease management (IPDM) is the promising future research path and most effective approach to be adopted for sustainable potato production and food security in the country.
Olericulture
Gebremedhin Hailay; Awgchew Haymanot
Abstract
Purpose: Swiss chard (Beta vulgaris L.) is highly appreciated for its nutritional properties, year round availability, low cost and wide use. In central highlands of Ethiopia, Swiss chard has been producing in urban and peri-urban areas but limited information is available about its nutrition and planting ...
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Purpose: Swiss chard (Beta vulgaris L.) is highly appreciated for its nutritional properties, year round availability, low cost and wide use. In central highlands of Ethiopia, Swiss chard has been producing in urban and peri-urban areas but limited information is available about its nutrition and planting distance. Research method: An experiment was designed to study the effects of 50, 100 and 150 kg ha-1 and control (0 kg ha-1), and different spacing with row including 20 cm, 30 cm and 40 cm distance on growth, yield and nutritional composition of Swiss chard in Debre Berhan. Treatments were set in randomized complete block design with three replications making 45 treatment combinations. Findings: Results indicated that total plant fresh weight, total plant dry weight, above ground fresh weight, above ground dry weight, root fresh weight, root dry weight, plant height, leaf number per plant were significantly affect by the interaction effect of plant spacing and N levels. Leaf area index was significantly affected by intra-row spacing but not by N rate and their interaction. Remarkable difference was recorded on total nitrogen, nitrate contents and vitamin C of leaves due to varied N levels. Generally, growth attributes, yield performance and nutritional composition of Swiss chard obtained best at the combination of 100 kg N ha-1 N and 40 cm plant spacing. Research limitation: Intra-Row needs further study above the 40 cm planting distance. Originality/Value: combination of 100 kg N ha-1 and 40 cm in-row spacing can be used for Swiss chard production in Debre Berhan central highlands of Ethiopia.
Olericulture
Mohmmad Hossein Aminifard; Hassan Bayat; Mehdi Khayyat
Abstract
Purpose: The objective of this study was to establish equations to estimate leaf area (LA) using length (L), width (W), fresh weight (FW) and dry weight (DW), length × width (L×W), width/length (W/L) of cress leaves as a leafy vegetable and radish leaves as a root vegetable. Research ...
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Purpose: The objective of this study was to establish equations to estimate leaf area (LA) using length (L), width (W), fresh weight (FW) and dry weight (DW), length × width (L×W), width/length (W/L) of cress leaves as a leafy vegetable and radish leaves as a root vegetable. Research method: An experiment was carried out under greenhouse conditions to study the relationship between leaf dimension and weight with LA of these two vegetable plants. Observed LA was obtained by an automatic measuring device and leaf dimensions were measured by a ruler. Regression analyses of LA versus L, W, FW, DW, L×W and W/L led several models that could be used for estimating the area of individual cress and radish leaves. Findings: A linear model employing FW as an independent variable [LA=0.295 (Fresh W.)+ 1.430] resulted the most accurate estimate (R2 = 0.912, RMSE = 1.52) of cress LA. For radish, a linear model using W as an independent variable [LA=22.50 (W) + 7.46] showed the most accuracy (R2 = 0.874, RMSE = 11.26) for estimating LA. Validation of the regression models showed that the correlation between measured and simulated values using these equations was quite acceptable for radish and cress (R2 = 0.922, 0.876), respectively. Research limitations: Evaluation of more leafy vegetables possibly had better results. Originality/Value: The results showed that cress and radish LA could be monitored quickly, accurately, and non-destructively by using the leaf FW and leaf W models, respectively.
