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.
Plant Nutrition
Mohmmad Hossein Aminifard; Hassan Bayat
Abstract
Purpose: Vegetables are important sources of carbohydrates, proteins, vitamins and minerals. Bell peppers, the fruit of Capsicum annuum L. is one of the most important commercial crops in the world. This study was conducted to determine the effects of nitrogen (N) doses on growth and yield of sweet pepper ...
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Purpose: Vegetables are important sources of carbohydrates, proteins, vitamins and minerals. Bell peppers, the fruit of Capsicum annuum L. is one of the most important commercial crops in the world. This study was conducted to determine the effects of nitrogen (N) doses on growth and yield of sweet pepper under field conditions. Research Method: Treatments consisted of 0, 50, 100 and 150 kg N ha−1. Plant height, Leaf chlorophyll index, flower number, yield, fruit seed number, 1000 seed weight and vitamin C were assessed at immature and mature. Findings: Nitrogen rate increasing affected significantly plant vegetative growth (plant height, lateral stem number, and leaf chlorophyll). The highest length and number of lateral stem and leaf number were obtained in plants treated with100 kg N ha-1.The results indicated that reproductive factors (weight and volume of fruit, plant yield, and 1000 seed weight) were influenced by nitrogen fertilizer. It was observed that fertilization with 150 kg N ha-1 resulted to the highest fruit weight and fruit yield. Although there were no significant differences in vitamin C content among treated plants with different nitrogen levels at a mature stage, it was shown significant differences between treated plants and control. Research limitations: If we could use several sources of nitrogen fertilizer such as ammonium nitrate and ammonium sulphate, then it was compared themو it seemed that we got better results about sweet pepper. Originality/value: Results showed that nitrogen fertilization has a strong impact on the vegetative, flowering and reproductive growth of pepper plants.
