Crop leaf disease management and control pose significant impact on enhancement in yield and quality to fulfill consumer needs. For smart agriculture, an intelligent leaf disease identification system is inevitable for efficient crop health monitoring. In this view, a novel approach is proposed for crop disease identification using feature fusion and PCA-LDA classification (FF-PCA-LDA). Handcrafted hybrid and deep features are extracted from RGB images. TL-ResNet50 is used to extract the deep features. Fused feature vector is obtained by combining handcrafted hybrid and deep features. After fusing the image features, PCA is employed to select most discriminant features for LDA model development. Potato crop leaf disease identification is used as a case study for the validation of the approach. The developed system is experimentally validated on a potato crop leaf benchmark dataset. It offers high accuracy of 98.20% on an unseen dataset which was not used during the model training process. Performance comparison of the proposed technique with other approaches shows its superiority. Owing to the better discrimination and learning ability, the proposed approach overcomes the leaf segmentation step. The developed approach may be used as an automated tool for crop monitoring, management control, and can be extended for other crop types.

Wide band gap semiconductors have many applications in photo luminescence devices and optoelectronic devices. We have investigated the structural, magnetic and optical properties of pure ZnS and Sm doped ZnS using density functional theory and implemented first principle linearized augmented plane wave (LAPW) method. For exchange correlation potential energy, generalized gradient approximation (GGA), GGA+U (where U is Hubbard potential) and Trans and Blaha modiefied Becke-Johnson (TB-mBJ) approximations are used. ZnS is a wide band gap semiconductor material having experimental band gap ~ 3.54eV. In this study band gap of pure ZnS was calculated as 1.963eV, 2.124eV and 3.574eV by using GGA, GGA+U and TB-mBJ approximations. GGA+U approximation was used for spin polarized calculations of ZnS: Sm shows ferromagnetic (FM) behaviour of doped semiconductor with band gap is 2.75eV. Pure ZnS is isotropic material while after doping with Sm it becomes anisotropic material. Ultraviolet and visible radiations are absorbed in these materials hence they can have potential applications in optoelectronic devices.