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Sugar industry and sugar cane cropping is one of the main economic and social activities in the northwestern region of Argentina. The goal of this study was to analyze the growth dynamic and productivity of three varieties grown in two agro-ecological regions of Tucumán, Argentina. Two trials were established in different locations where EEAOC's sugar cane nurseries were established (plot 11-15 and Los Trejos). From the beginning of sprout emergence, periodic measurements of stalk population dynamics and stalk height were carried out. At the end of the cycle, cane and sugar yield per hectare (TSCH and TAH) was estimated. Plot 11-15 presented higher tiller population, between 44 and 40 stalks m-1 for LCP 85-384 and TUC 97-8 respectively. TUC 95-10 registered 30 stalks m-1 in both locations. Final number of stalks per linear meter (FN) did not evidence differences between locations, but a significant interaction location*variety was determined. In this case, LCP 85-384 registered 20 stems m-1 in Los Trejos. Individual variables stalk weight showed significant differences between locations and the highest value was observed in Los Trejos even though no significant interaction location*variety was determined. TSCH was significantly higher in Los Trejos where TUC 95-10 produced 113 t ha-1, presenting significant differences between the rests of the interactions. TUC 95-10 showed better adaptation to different agro-ecological conditions, presenting high sugar cane yields in both considered regions. [ABSTRACT FROM AUTHOR]

During the green harvesting system of sugarcane, a large amount of agricultural harvest residue is produced that can be left as mulch on the soil, removed from the field or incorporated into the profile, depending on the agroecological characteristics of each area. It is important to rapidly decompose the cover crop residue in areas where it is detrimental to sugarcane production. One of the alternatives to accelerate the natural decomposition of the residue is the use of lignocellulolytic fungi. The objective of this work was to isolate autochthonous fungal strains from sugarcane ARH, select and characterize culturally, morphologically and molecularly those with the greatest potential to accelerate the decomposition of the green harvest residue of the sugarcane field. Five autochthonous fungal strains were isolated from fragments of freshly harvested residue. Cellulolytic and ligninolytic activity was evaluated in vitro, using carboxymethylcellulose and guaiacol as substrates, respectively. Strain HR5E3 was the only strain able to decompose cellulose and lignin. This strain was culturally, morphologically and molecularly characterized as Trichocladium pyriforme and produced enzymes of the lignin peroxidase group, polyphenol oxidases and laccases. In solid substrate fermentation bioassays, this strain accelerated the decomposition of the residue by di-auxic growth with glucose. Trichocladium pyriforme HR5E3 could be used as a bioinoculant capable of degrading lignocellulose, and avoid the detrimental effects that the unaltered cover of the agricultural residue could have on the development of sugarcane. [ABSTRACT FROM AUTHOR]