TECHNOLOGICAL PARAMETERS OF SUGARCANE VARIETIES ATTACKED BY DIATRAEA SACCHARALIS

Wagner José Machado da Silva 1 , Flávia Aparecida Santos Matias Machado da Silva 1 , Renê Michel Ribeiro Pereira 1 , Guilherme Castanheiro de Souza 1 , Hiago Augusto Amaral Sacco 1 , Camila Regina Silva Baleroni Recco 2 , Jeruska Azevedo Moreira Brenha 2 and Lucas Aparecido Manzani Lisboa 2 . 1. Undergrade student, in Agronomy, at Educational Foundation of Andradina, state of São Paulo, Brazil. 2. Lecture, in Agronomy, at Educational Foundation of Andradina, state of São Paulo, Brazil. ...................................................................................................................... Manuscript Info Abstract ......................... ........................................................................ Manuscript History


ISSN: 2320-5407
Int. J. Adv. Res. 6(3), 562-568 563 Borer´s attack affects on the quality of the technological parameters of the sugarcane, mainly on its brix value, which measures the total reactive sugar and tons of sugarcane per hectare (Dinardo-Miranda, 2008).
An alternative to the control of sugarcane borer is the choice of more resistant varieties (Medeiros et al., 2016) or that have a higher fiber content in the stems making a physical barrier to the sugarcane borer. Elevation in fiber content is acceptable till the limit between 10,5 to 12,5% (Rodolfo Junior et al., 2016), since a greater value turns into a limitation factor in the milling process (Souza et al. 2005). Alongside the borer´s attack, biotic stresses and biotic can influence the technological parameters of sugarcane (Showler, 2016); such as chemical soil attributes (Zambrosi et al., 2017) and even the choice of the harvest method.
That way, this work aimed to evaluate technological parameters of sugarcane varieties attacked by Diatraea saccharalis.

Materials and methods:-
Installing the experiment:-The experiment was installed on August, 2015, at Usina Ipê, in Nova Independência, São Paulo State, Brazil; geographic coordinates 21 ° 9'58.739 "S and 51 ° 28'1.660" W; with altitude of 337 m. According to Koeppen the region´s climate is classified as Aw with rainy summers and dry winters.
During the conduction of the experiment, all the cultivars treatments were carried out when it was necessary. Figure  1 shows the average values of rain while the experiment was conducted.

Evaluation of parameters:-
The harvest were done on May, 2016 and April, 2017 by using mechanization in total plots, in which the values were converted in tons of sugarcane´s stem per hectare (TSH). Also, twenty-five longitudinally cut stems were randomly selected to determine of percents of attacked stems (%AS).

Statistical analysis:-
The data were submitted to analysis of variance by the F test (p <0.05) and their averages were compared by the Scott-Knott test at 5% probability (Banzatto and Kronka, 2013). The statistical program Assistat 7.7 (Silva and Azevedo, 2016) was used.

Results and discussion:-
On the parameter Pol percents in broth, it was not observed an interaction between the factors, as Chart 1 shows. Varieties CT046043; CTC25; CTC9003 and RB855453 showed lower average values as compared to the others, with a 14,92%-difference between them, being an important data in the choice of varieties. year; **significant at 1% level of probability (p<0.01); * significant at 5% level of probability (p<0.01) (0,01=<p<0.05); nsnon-significant (p>=0.05). Averages on columns followed by the same letter do not differ ecstatically. It was used Scott-Knott test at 5% probability.
As the cultivation cycle factor is considered, the first year of cultivation presented a higher average value, being this difference of 33.39% when compared to the second cycle. This result can be explained by the fact that the plant presents greater vigor, which allows a greater accumulation of sucrose in its stems. The variation of Pol can affect the sugar´s quality and even alcohol´s, Ekpélikpézé et al. (2016) stated that this variation is an important factor to choose the best variety, since they easily adapted to different production systems, their genetic potential is expressed (Tyagi and Naidu, 2016).
Due to the capacity of adaptation of sugarcane varieties to the ambient, their anatomic ultrastructures can be potentialized, mainly on quality and amount of lignin in the fibers, which is an important characteristic on resistance 565 to plagues´attack, even on the break of stems (Daniel et al. 2016). An interaction between the parameter percents of sugarcane´s fiber (%Fiber) was observed, as Chart 1 shows.
At the first cultivation cycle, varieties CT046043 and CTC7 displayed lower values on percents of sugarcane´s fiber (%Fiber), with a 10%-difference from the varieties that showed a higher value. However this variation was not observed at the second cultivation cycle. CT046043 and CTC7 are new varieties available on the sugarcane energy sector, it is recommended their use with low wind incidence, which can lead to the fall of its stems, as Chart 2 shows. The fiber content of less than 10.5% is an undesirable factor for the sugar and alcohol industry, as the boilers use sugarcane bagasse originated in milling of stems to generate steam, being recommended as ideal a fiber content between 10,5 and 12,5% (RODOLFO JUNIOR et al., 2016). That way, despite varieties CT046043 and CTC7 have show lower values as compared to other varieties, their fiber content is suitable.
According to Souza et al. (2005), a higher fiber content in stem can be considered an uneconomic factor to industry, thus mills are set to grind sugarcane with nearly 12,5 % fiber content., in case of an addition o between 0,5 and 1,0%, the milling process would be impaired, which could lead to 1,85 Kg of sugar per ton of grinded sugarcane.
It was observed a interaction between factors, as Chart 1 shows to the variable Purity%. Chart 3 shows average Values of %Purity (broth) of sugarcane varieties of sugarcane attacked by borer.  Souza et al. (2005) reported that values toward purity of broth must be over than 80% in the beginning of crop and 85% in its middle, most valued varieties are those ones which display greater values than 85%. Only variety CTC9001 showed values lower than the recommended, 83,65% of purity, as varieties RB975952 and RB966928 showed the highest values, 88,48 and 87,93%. In 2017, the second cultivation cycle, all the varieties were lower than recommended (80 -85%), however, among the studied varieties, only RB975952 ecstatically differed and showed a suitable purity value, 82%.

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This interaction between the cultivation cycle shows that even it occurs a suitable management, the reduction of technological parameters could has happened due to the decrease in force of new plants of regrowth in the following year. Other factors may influence on these parameters as soil fertility (Zambrosi et al., 2017), biotic and abiotic stress, which favors a higher attack of plagues; harvest method (Showler, 2016) and even the adaptation to production ambience of the chosen variety.
However, it was not observed an interaction between the factor in the parameter total-recoverable sugar per ton of sugarcane (TRS), as Chart 4 displays.  year; **significant at 1% level of probability (p<0.01); * significant at 5% level of probability (p<0.01) (0.01=<p<0.05); nsnon-significant (p>=0.05). Averages on columns followed by the same letter do not differ ecstatically. It was used Scott-Knott test at 5% probability.
The first cultivation cycle showed a higher average value of TRS with 133,58 kg t -1 of sugarcane, resulting in a 18,49% difference towards the second cultivation cycle. Varieties CT046043; CTC7; CTC25 and CTC9003 showed lower TRS values, this decrease coincides with varieties that displayed a greater incidence of sugarcane borer, as Chart 5 shows.

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It was observed an interaction between the factors, in which CT046043; CTC7; CTC22 and CTC25 displayed greater values of attacked stems on the first cultivation cycle, however, on the second one, only varieties CT046043 and CTC7 showed a higher plague´s influence as Chart 5 shows. This percentual variation reach 71,87% of attacked stems on the first cultivation cycle. This difference between the varieties with lower and higher borer attack index reach 71,48% on the second cultivation cycle.
Varieties CT046043 and CTC7 also showed lower values of fiber (Chart 2), which proves that borer´s attack can be decreased by using genetic modified varieties. That way, the 10-percent variation on the fiber content in sugarcane varieties can be favored plague´s incidence nearly 71% in varieties with lower fiber content. This characteristic is an important factor in the selection of plants to genetical enhancement programs. (Showler, 2016;Ekpélikpézé et al., 2016;Tyagi and Naidu, 2016).
Due to borer´s attack, an amount and quality reduction occurred in total-recoverable sugar (TRS), as observed in CT046043 and CTC7, which are among the varieties with the lowest TRS value (Chart 4). By decreasing sugar, sugarcane stems become lighter, consequently, a reduction in tons of sugarcane´s stem per hectare (TSH) occurs.
A significant interaction was observed between the studied cultivation cycles, as Chart 4 shows. Chart 6 displays Average values of percentual unfolding of sugarcane´s stem per hectare (TSH) attacked by borer. On the first cultivation cycle, only variety CTC9001 displayed higher average TSH values, with a 33,13% difference as compared to CTC25, which showed the lowest average value. This result shows a positive response of variety CTC9001 to the production ambient. These results agree with Souza et al. (2006), as they studied sugarcane varieties on initial stages and verified that variety CTC9001 showed better response on dry mass production. While, on the second cultivation cycle, varieties CTC25; RB975952; RB966928 and RB855453 had a lower TSH production.
According to Silva et al. (2007), the fast and uniform initial growth of sugarcane allows infer in a good tillering stand, leading to a fast closing of the empty lines, consequently, to a effective control of invasive plants, as well as an increase on TSH. As described by Silva et al. (2017), a greater cover of leaves is an important factor on soil conservation and elevation in biomass production.

Conclusion:-
The varieties CT046043 and CTC7 had lower values of fiber and higher incidence of borer. The presence of sugar cane drill reduced the quality and quantity of sugarcane stalks. The variation of 10% in fiber content in sugarcane caused a 71% difference in the incidence of Diatraea saccharalis.