Okra Crop Response Under Subsurface Drip and Conventional Furrow Irrigation with Varying N Fertilization

ABSTRACT

There is a growing concern about excessive use of nitrogen (N) and water in agricultural system with unscientific management in Indian and developing countries of the world. Field experiments were conducted on the lateritic sandy loam soils of Kharagpur, West Bengal, India, during spring–summer (February-June) seasons for three years (2015–2017) to evaluate okra crop response under subsurface drip and conventional furrow irrigation with varying amount of nitrogen treatments. Irrigation treatments had three levels of soil water depletion from field capacity (i.e., 20%, 35%, and 50%) under subsurface drip system. There was no soil water depletion under conventional furrow irrigation system. There were four levels of nitrogen fertilizer treatments (i.e., 0, 80, 100, and 120 kg ha^?1). This was supplied using urea as a nitrogenous fertilizer. The yield response of okra crop under subsurface drip was found to be 56.4% higher than that of the furrow irrigation treatment. Best yield response and maximum water use efficiency and nitrogen use efficiency were recorded under 20% soil water depletion with 100 kg ha^?1 of nitrogen fertigation. Among the various soil moisture depletions, subsurface drip at 20% soil water depletion treatment responded least quantity of water lost through deep drainage and nitrogen loss beyond the root zone as compared to other irrigation treatments. The water loss through subsurface drainage was observed as 33.11 mm lesser under subsurface drip as compared to that of the furrow irrigation, and this may due to low-volume and frequent irrigation water application with subsurface drip. Hence, irrigation through subsurface drip should be used for improving water and nitrogen fertilizer use efficiency of okra crop cultivation.     

秋葵黄酮的稳定性研究

以秋葵为原料,采用超声波辅助法提取秋葵黄酮,研究温度、pH值、食品添加剂及金属离子对秋葵黄酮化合物稳定性的影响。结果表明,秋葵黄酮溶液的耐热性较好,在80℃以下其化学结构保持不变;在酸性条件下,秋葵黄酮的稳定性良好;在常用的食品添加剂安全使用浓度范围内,葡萄糖、蔗糖和柠檬酸对秋葵黄酮的稳定性无明显影响,而抗坏血酸、山梨酸钾和偏重亚硫酸钠对其稳定性有明显的影响;金属离子Na+,K+,Ca2+对秋葵黄酮的稳定性无显著影响,而Al3+,Fe3+,Cu2+对其稳定性有明显的影响。     

北疆乌昌地区黄秋葵高产栽培技术

介绍了黄秋葵对环境条件的要求,并且结合新疆北部乌昌地区气候条件从栽培季节、整地施肥、播种育苗、适时中耕、施肥浇水、植株调整及摘叶、病虫害防治、适时采收等环节总结了黄秋葵高产栽培技术,旨在为北疆乌昌地区种植发展黄秋葵提供技术参考,以期达到提高产量、增加效益的目的。     

Impact of boron fertilization on boron fractions at different crop growth stages in cauliflower_cowpea_okra sequence in an inceptisols of North East India

Abstract

A field experiment was conducted at Horticultural Experimental Farm, Assam Agricultural University, Jorhat during the year 2015–17 to assess the impact of boron fertilization on dynamics of boron fractions in soil and crop yields in cauliflower–cowpea–okra cropping sequence. Five levels of boron (0, 0.5, 1.0, 1.5 and 2.0?kg ha^?1) along with the recommended dose of NPK fertilizer were applied in soil in cauliflower once in each 2 years (2015–17) of experimentation to assess the direct effect of boron fertilization, while cowpea and okra were grown as a suceeding test crop to study the residual effects of boron fertilization in the cropping sequence. Among the different levels of boron, the highest content of all the boron fractions in soil was recorded at rate of 2?kg B ha^?1 at different crop growth stages for all the three crops. Progressive decrease in content of all the boron fractions with crop ageing was noticed. The content of different boron fractions in soil follows the order readily soluble boron (RSB)<oxide bound boron (OXB)<organic bound boron (ORBB)<specifically adsorbed boron (SAB) <residual boron, respectively. The boron level of 2?kg B ha^?1 was found to prominent in increasing the yield in all the crops. In respect of contributions of different boron fractions to yield of crops, oxide bound boron(2.10) was found to be the highest contributor of cauliflower yield, while the residual boron (1.10), contributed the highest to cowpea yield and organic bound boron fraction (1.24) was found to be most prominent contributor of boron in leveraging okra yield.     

黄秋葵速冻保鲜研究

采用速冻方法对黄秋葵果实进行冷藏(-18℃)保鲜,研究其对果实主要品质的影响及其贮藏保鲜期.结果表明:黄秋葵经漂烫处理后进行速冻保鲜其保鲜期可达9个月,其中,漂烫时间以0.5～1min的处理效果显著.先用20%CaCl2溶液浸泡果实20min,再经漂烫后进行速冻处理,可较好地使产品保持其色泽和爽脆度;速冻后对果实进行真空包装,在贮藏过程中营养损失最小.     

棉大卷叶螟在黄秋葵上的发生与防治

分析棉大卷叶螟在建阳市城郊黄秋葵上的为害特点、形态特征及其发生规律，并提出农业防治、物理防治、化学防治等综合防治措施。     

酸解盐析法提取黄秋葵中的果胶研究

以黄秋葵为原料,采用酸解盐析法提取其果胶,对提取条件进行优化。通过对无机酸类型、料液比、酸解pH值、酸解温度、加热酸解时间5个因素进行研究,先进行单因素确定,再通过L9(34)正交试验来确定pH值、酸解温度、酸解时间、料液比4个因素的最佳工艺条件和影响果胶提取率的主次因素。试验结果表明,黄秋葵果胶提取的最佳工艺条件院pH值为4,酸解温度为70℃,酸解时间为110 min,料液比为1:10,最优无机酸是硫酸,在此条件下,果胶的得率为29.10%。     

IMPROVING SEED GERMINATION AND GREEN POD YIELD IN OKRA (HIBISCUS ESCULENTUS L.) USING CALCIUM CARBIDE—A NEW SOURCE OF ETHYLENE

The ability to sense and respond to physical stimuli is of key importance to all living things. Among the common environmental stimuli detected by living organisms are light, temperature, and a variety of chemical signals. A number of these stimuli appear to be closely related and can be considered as physico-mechanical stimuli. Plant hormones like ethylene have a definite role in plant growth stages from seed germination to senescence and death of plants. Calcium carbide, a solid material, has been proven in recent years to be a new source of this hormone. Calcium carbide absorbs moisture from soil and releases acetylene gas which by the microbial activities are converted to plant hormone ethylene. The role of calcium carbide was studied, especially the effects of this material during the seed germination stage. Under closed conditions this material was applied to okra seeds and its physico-chemical changes in seed during germination were observed. It was concluded from the experiment that calcium carbide has a definite role in okra seed germination as there was early germination and root formation observed in treated seeds with a callus formation on the roots of germinating seeds which developed in to secondary roots in very short time as compare to control in the same period. It was also observed that in treated okra plants, early flowering and fruit formation was initiated which contributed about 27% green pod yield increase in okra.     

黄秋葵果胶低脂抹茶干酪的研制

以脱去50％原脂肪含量的新鲜牛乳为主要原料,使用黄秋葵果胶与低甲氧基果胶以质量比1∶2的比例复配后作为脂肪替代物加入主原料中并添加少量抹茶粉,制备黄秋葵果胶低脂抹茶干酪.在考察抹茶添加量、果胶添加量、凝乳酶添加量和凝乳时间的单因素试验基础上,利用正交试验,以干酪凝乳得率与感官评分为考察指标,优化黄秋葵果胶低脂抹茶干酪工艺,确定加入果胶和抹茶的低脂干酪生产的最佳配方和生产工艺.结果表明,最优工艺配方为:抹茶粉添加量(相对生牛乳,其他同)0.8％,果胶添加量0.01％,凝乳酶添加量0.4％,凝乳时间25 min.在此工艺下生产的产品感官接近全脂干酪,且有抹茶特有风味,质地均匀,软硬适中有光泽.