Melhoramento da cana-de-açúcar IIa: experimentos regionais com clones obtidos em 1967 Sugarcane breeding: IIª experiments with clones obtained in 1967

• Main Authors: Raphael Alvarez, Candido Ricardo Bastos, Antonio Lazzarini Segalla, Helcio de Oliveira, Gentil Godoy Jr., Celso Valdevino Pommer, Oswaldo Brinholi, Antônio Ernesto Dalben
• Format: Article
• Language: English
• Published: Instituto Agronômico de Campinas 1983-01-01
• Series: Bragantia
• Online Access: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0006-87051983000100003
• ISSN: 0006-8705; 1678-4499

Uma série de clones obtidos em programas de melhoramento iniciado em 1967, no Instituto Agronômico, foi testada em quatro experimentos conduzidos em terras das diversas regiões canavieiras paulistas. No trabalho, iniciado em 1974, usando como testemunhas as variedades comerciais 'IAC 52-150', 'IAC 52-326', 'IAC 58-480', 'CB 41-76' e 'NA 56-79', foram feitas três colheitas em cada experimento: cana-planta, soca e ressoca, sendo as análises estatísticas executadas com as médias das três. Os clones 67-112, 67-48, 67-145 e 67-122 tiveram produção de cana superior à das testemunhas; os clones 67-19, 67-6, 67-14, 67-28, 67-21 e 67-7 não diferiram da melhor testemunha, a 'IAC 58-480', nessa característica. O clone 67-139 apresentou teor de açúcar superior ao de todos os tratamentos; o 67-55 teve teor de açúcar semelhante ao das três melhores testemunhas. Em produção de açúcar por área, o clone 67-112 foi superior a todos os outros tratamentos, com exceção do 67-122. Este último, juntamente com o 67-48, 67-12, 67-47 e 67-145, não diferiu das três melhores testemunhas nessa característica. Os clones 67-12, 67-47, 67-48, 67-55, 67-112, 67-122 e 67-139 foram considerados novas variedades, recebendo o prefixo IAC.<br>A lot of sugarcane clones obtained out of a breeding program started in 1967 was tested in a series of experiments. The experiments were carried out at the IAC Experiment Station, at Piracicaba, on a Ortho Dark Red Latosol soil, and in the property of the mills: Santa Elisa (Sertãozinho, Dusky Red Latosol), Itaiquara (Tapiratiba, Humic Red-Yellow Latosol soil) and Catanduva (Ariranha, Podzolized soils on calcareous sandstone, Marilia variation). The field trials started in 1974, and the commercial varieties 'IAC 52-150', 'IAC 52-326', 'IAC 58-480', 'CB. 41-76' and 'NA 56-79' were used as controls, as they represent about 70% of the sugarcane area in the São Paulo State, Brazil. Three harvests were done consecutively in plant cane (18 months), first ratoon (12 months after) and second ratoon (12 months). Statistical analysis were made in a three harvest mean for all experiments. It was found out that clones 67-112, 67-48, 67-145 and 67-122 had a cane yield superior to that of the controls. Clones 67-19, 67-6, 67-14, 67-28, 67-21 and 67-7 were not statistically different from the best control, 'IAC 58-480'. Clone 67-139 had a sugar content superior to the all the other treatments. On the other hand, clone 67-55 had a sugar content similar to that of the three best controls. In sugar yield, clone 67-112 was superior to all the other treatments, except 67-122. This one, as well as clones 67-48, 67-12, 67-47 and 67-145 were not different from the three best controls. Clones 67-12, 67-47, 67-48, 67-55, 67-112, 67-122 and 67-139 were considered as new varieties, receiving the prefix IAC.