Effect of Nano Iron and Manganese Fertilizers on Mung Bean Growth and Yield in Water Deficit Stress Condition

Pulse crops have a huge role in Agriculture and daily life. The mung bean (Vigna radiate L. Wilczek) is one of the most important pulse crops in the world. It is a protein rich staple food and contains about 25 percent protein. Producing higher potential yield in comparison with other crops, is one of the greatest feature of the mung bean crop. Also, it improves the soil fertility by fixing the atmospheric nitrogen. Water deficit affects different growth and development stages of mung bean. In this regard, choosing the landraces and suitable cultivars and nutrition and irrigation management, play an important role in increasing of quantity and quality of pulses and reduce of negative effects of various environmental stresses on plants. The present research aimed to study the effect of water deficit stress on quantity and quality mung bean traits, Parto variety under applied and non-applied of foliar application of nano-iron and manganese chelates.
In order to study the effects of water deficit stress on reduction of quality traits of Vigna Radiata (Parto variety) under iron and manganese nano-chelate foliar application, an experiment was conducted as split-plot management in randomized complete block design with three replications during 2013-2014 in the research farm of agricultural college, Tarbiat Modares University. To determine the nature of soil, the amount of mineral elements (nitrogen, iron and manganese), the percent of organic carbon and soil acidity were sampled from zero depth to 30 centimeter and from 30 to 60 centimeters of soil in the zigzag pattern. Experimental treatments in main plots were three levels of irrigation regime (optimum irrigation, water deficit at reproductive stage and water deficit at vegetative stage) and in subplots were 10 levels of foliar application (without foliar application, foliar application pure water, one in a thousand a nano-Fe chelate, three in thousand a nano-Fe chelate, 1.5 in thousand a nano-Mn chelate, three in thousand a nano-Mn chelate, one in thousand a nano-Fe 1.5 in thousand a nano-Mn chelate, one in thousand a nano-Fe three in thousand a nano-Mn chelate, three in thousand a nano-Fe 1.5 in thousand a nano-Mn chelate, three in thousand a nano-Fe three in thousand a nano-Mn chelate) at withholding irrigation stage. SAS software has been used to analysis data, the analyses parameters were including variance and means comparison have been compared by using the LSD Test at probability level of 5%.
The results showed that water deficit stress and iron and manganese nano-chelate foliar application were significant for the most of plant traits at 1% probability level. Among of water deficit stress levels, the lowest yield and yield components for most traits, stress at reproductive stage and the highest amount in control (optimum irrigation). Also, the highest yield and yield component was achieved from different levels of iron and manganese nano-chelate spraying at the vegetative and reproductive stage, especially in the vegetative growth stage, while control spraying (no spray) led to decreasing yield and yield components in plant. Also, interaction between two main treatments were significant for the most of the traits at 1% probability level.
It can be concluded that water deficit stress at the reproductive stage had the most effect on reducing grain yield, protein yield and yield components, and using nanoparticles had the highest rates of grain yield, yield component and protein yield. The effects of water deficit can be reduced by spraying of nano-Fe and nano-Mn chelated. Also, it was observed that reproductive stage is the most vulnerable stage of the plant to the water deficit stress. Stress in this stage causes protein reduction by the plant and seed filling period. Regarding the effects resulted from water deficit stress, it is possible that spraying nano-chelated iron and manganese can make the seed a rich source by stimulating growth and cell division and as a result, more amount of dry material is preserved within the seed by adopting more photosynthetic materials. Among nano-chelated elements, iron and also mixed with manganese had the most effect on the seed yield and other studied traits in this test. Thus, it is suggested that these elements can be utilized as a factor for removing or decreasing stress and also increasing the production efficiency in the plants.