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The present paper has objective informer the compartment the Weeds Global Invasive in sugar cane crop Saccharum spp. L. (WWGIS) with climate change for Green House Effect. The WWGIS-Worst Weed Global Invasive in Latina American and Caribbean were selection in the I and II curse of weed biology and management in sugarcane, Tabasco sugarcane, 2010-2013. The results of the first course were highlighted by the participants and corroborated in the second. These plants growth in habitats worm and limited water available. The species selections are: 1) ROOEX-Rottboellia exaltata L.f.1782; 2) TRCYN- Digitaria insularis (L.) Fedde, 1904; 3) CYNDA-Cynodon dactylon (L.) Pers. 1805; 4) CYNPL-Cynodon plectostachyus (K. Schum.) Pilg.1907; 5) CHRPO-Chloris elata Desv, 1831; 6) PANPU-Brachiaria mutica (Forssk.) Stapf, 1919; 7) DIGNU-Digitaria nuda Schumach, 1827; 8) DIGAD-Digitaria ciliaris (Retz.) Koeler, 1802; 9) PANMA-Panicum maximum Jacq. 1781; 10) SORHA-Sorghum halepense (L.) Pers. 1805; 11) CYPRO-Cyperus rotundus L. 1753; 12) SYNPO-Syngonium podophyllum Schott, 1851. Ten plants per square meter of each species were height determined. The WWGIS excluded the total organisms in this habitat. With climate changes, there was an increase of 1.03 °C since 1981, alter their biological behavior, with difficult and onerous weed control. With appearance of dwarf plants and produced seeds in winter. After 2005 the biological comportment were graduates altered with normal seeds productions in spring, summer and winter, showed mini plants 0.10-1.30 m high. The behavior of PMIGS is directly linked to the highest minimum winter temperatures. [ABSTRACT FROM AUTHOR]

Biological nitrogen fixation is a process that occurs in nature and is the cheapest source of N for humid tropical acid soils. The aim of this study was to quantify the amount of N fixed by species of fabaceae through 15N isotopic techniques, in a savanna soil in Mexico. The treatments were established under a design of a randomized complete block, with four replicates. The variables evaluated were: fresh biomass (FB), dry matter (DM), nodule number (NN), nodule dry mass (NDM), total nitrogen (tN) and biologically fixed nitrogen (fN). Our results show that Mucuna deerengiana L. had higher production of FB and DM (17.50 and 5.47 Mg ha-1), NDM (58.79 mg plant-1) and higher content of tN and fN (526.94 and 522.11 kg ha-1) respectively, compared with Cajanus cajan L., Phaseolus lunatus L. and Sesbania emerus L., species that showed low values in these variables. We conclude that Mucuna deerengiana L. tolerates unfavorable factors prevailing in acid soils and therefore has efficiency greater than 500 kg ha-1 fN; we consider it appropriate to increase the level of nitrogen in savanna soils, without applying chemical fertilizers. [ABSTRACT FROM AUTHOR]