ABSCISSION OF REPRODUCTIVE STRUCTURES IN PIGEONPEA (Caianus calan (L.) Millsp.)

The percentage abscission of reproductive structures in dwarf pigeonpea cultivars (UW 10, UW 17 and UW 26) was found to be high (83 - 87%) and was similar to those recorded for tall indeterminate cultivars. Variations in the percentage abscission were observed for inflorescences in different regions in the canopy. These variations differed with the cultivar. Higher abscission rates were recorded for flowers developing at the most proximal node and buds at the distal ends of the inflorescence. Flowers at the anthesis and the post-anthesis stages of development abscised in greatest quantities. Forty-eight percent of the flowers which abscised at either anthesis or post-anthesis stages of development from node three on the inflorescence had at least one of their ovules fertilized. These results are discussed in relation to proposed theories of abscission: inadequate supply of photosynthates, hormonal signals, incomplete development of translocatory tissues and unsuccessful fertilization of ovules

Synthesis and improved electrochemical performance of LiMn2-xGdxO4 based cathodes

LiMn2-xGdxO4 (x=0.00, 0.01 and x=0.04) spinel active material were prepared by sol-gel method. The morphology, crystal structure, thermal stability and electrochemical properties of the synthesized samples were evaluated. Gd-doping maintains the cubic spinel structure of LiMn2O4, leads to a decrease of the average particle size, and has a strong influence on the electrochemical properties of the cathodes. LiMn2-xGdxO4 cathode materials show two pairs of separated redox peaks, independently of the Gd-doping. After 40 charge-discharge cycles at C2, the discharge capacity was 55.9 mAh.g-1 and 33 mAh.g-1 for x=0.04 and x=0, respectively, corresponding to a capacity retention of 80% and 70%, respectively. The Gd-doped with x=0.04 showed improved cycling performance with respect to pristine LiMn2O4 due the smaller particle size and superior structural stability, showing its suitability for lithium-ion battery applications.The authors thank FEDER funds through the COMPETE 2020 Programme and National Funds through FCT - Portuguese Foundation for Science and Technology under Strategic Funding UID/FIS/04650/2013. A. G., C.M.C. and S. F. thank the FCT for grants SFRH/BD/90313/2012, SFRH/BPD/112547/2015 and IF/01516/2013, respectively. The authors thank funding from the FCT under the Indo-Portuguese program of cooperation in science and technology grant INT/Portugal/P-02/2013, 2014-2016. The authors are thankful for HRTEM and Raman characterization support from MRC, MNIT, Jairpur, INDIA. The fellowship from MHRD, Govt. of India was acknowledged for Pura Ram. SLM thanks financial support from the Basque Government Industry Department under the ELKARTEK Program