São apresentados resultados obtidos de uma série de experiências efetuadas em 1959/61, com a finalidade de determinar a melhor época de corte, considerando a riqueza em açúcar e a brotação das soqueiras, para diferentes variedades cultivadas no Estado de São Paulo. Para este estudo foram. plantadas, em fevereiro-março, em sete usinas, compreendendo vários tipos de solo, 17 variedades de cana. Foram estudadas quatro épocas de corte, a saber: 1.° de junho, 20 de julho, 10 de setembro e 30 de outubro, e cada bloco cortado em uma dessas épocas. Foram feitos dois cortes (cana-planta e soca), nas épocas determinadas, com intervalo de 12 meses do primeiro para o segundo corte. Os resultados obtidos demonstram que a época de corte não influiu na produção de cana. Notou-se diferença entre variedades e localidades. Quanto à riqueza em açúcar, houve diferença entre variedades e épocas de corte. Não se observou diferença entre localidades. A riqueza em açúcar das variedades aumentou até a terceira época, estabilizando-se ou decrescendo na quarta, com exceção das variedades Co 301 e CB 40/35, nas quais ainda aumentou. Em função da riqueza apresentada nas diferentes épocas pelas variedades, foram elas classificadas em três grupos, para serem cortadas no inicio, no meio e no fim da safra.
The present work reports the results obtained in a series of tests whose finality was to determine the best time of harvest for 17 sugar cane varieties that were planted in the State of São Paulo in the years 1958-1959,. The tests were carried out at the following localities: 1) Usina Junqueira, Igarapava, on "terra-roxa" soil type; 2) Usina Santa Elisa, Sertãozinho, and 3) Usina Tamoio, Araraquara, on "terra-roxa-misturada" soil; 4) Usina Ester, Cosmópolis, on "terra-roxa-misturada Glacial" soil; 5) Usina Monte Alegre, Piracicaba, on "Corumbatai" soil; 6) Usina Itaiquara, Tapiratiba, on "Massapê-salmourão" soil; 7) Usina Miranda, Presidente Alves, on sandy soil of "Arenito de Bauru". In four different times of harvest June 1st, July 20, September 10 and October 30, the following varieties were compared: CP 44/101, N:Co 293, Co 301, Co 413, Co 419, CB 36/14, CB 38/22, CB 40/13, CB 40/19, CB 40/35, CB 40/69, CB 41/14, CB 41/58, CB 41/70, CB 41/76, CB 47/15 and CB 49/260. Two harvests (plant and ratoon) were made in each of the tests. Statistical analyses were made of the cane and sugar yields of the two harvests and their sum. The results obtained permit to draw the following conclusions: 1) In cane yield there were differences between varieties and localities having still interaction varieties x localities, there being no inlluence of the time of harvest on the yield. The varieties which presented better production were: CB 40/13, CB 40/69, CB 49/26Q, Co 419, CB 41/14, CB 41/58, N:Co 293, CB 40/35, Co 301 and CP 44/101. CB 41/76 and Co 413 were lower than CB 40/13, the second being lower also than CB 40/69. 2) In sugar content there were differences between the varieties and the time of harvest; between localities no differences were found but there was interaction varieties x times. The sugar content increased at the third time of harvest, stabilizing or decreasing at the fourth time, except for the varieties Co 301 and CB 40/35, whose sugar content still increased. With regard to the sugar content presented by the varieties in the different times of harvest they may be separeted in three groups: a) Varieties for the beginning of the crop, June and July: CP 44/101, CB 40/13 and CB 41/70. b) Varieties for the middle of the crop i August and September: CB 47/15, CB 40/69, Co 419, Co 413, CB 40/19, CB 41/76, CB 49/260 and CB 41/58. c) Varieties for the end of the crop; October and afterwards: N:Co 293, CB 36/14, CB 41/14, CB 38/22, CB 40/35 and Co 301. 3) Considering the sugar yield by area, the following varieties are recommended, in accordance with the time of harvest: CB 40/13, CP 44/101, CB 40/69, Co 419, CB 49/260, CB 41/76, CB 41/58, N:Co 293, CB 40/35, CB 41/14 and Co 301. CB 41/76 except at the third time, presents lightly lower yields.
