Redução da poda hibernal e aumento da produção de pereiras 'Hosui' pelo uso de prohexadiona cálcio

Abstract

Resumo -O objetivo deste trabalho foi avaliar o controle do desenvolvimento vegetativo e a capacidade produtiva de pereiras 'Hosui', em resposta ao uso de prohexadiona cálcio, nas condições climáticas do Sul do Brasil. Foram aplicadas diferentes doses de prohexadiona cálcio (0, 275, 550, e 825 g ha -1 ) em pereiras com 11 anos de idade, enxertadas sobre Pyrus calleryana. O uso de prohexadiona cálcio foi efetivo no controle do desenvolvimento vegetativo das pereiras 'Hosui' e reduziu a necessidade de poda hibernal, pela redução da massa total e do número de ramos podados. O controle do desenvolvimento vegetativo, pelo uso de prohexadiona cálcio, favorece o aumento da capacidade produtiva de pereiras 'Hosui', principalmente à concentração de 550 g ha -1. Termos para indexação: Pyrus pyrifolia, desenvolvimento vegetativo, fitorregulador, frutificação. Reduction of winter pruning and fruit production increase in 'Hosui' pears by prohexadione calcium useAbstract -The objective of this work was to evaluate the vegetative growth control and fruit production capacity of 'Hosui' pear, in response to prohexadione calcium use in Southern Brazil climate conditions. Different concentrations of prohexadione calcium (0, 275, 550, and 825 g ha -1 ) were applied on eleven-year-old 'Hosui' pear trees grafted on Pyrus calleryana rootstock. The use of prohexadione calcium was effective in controlling the vegetative growth of 'Hosui' pears and decreased winter pruning, by reducing total weight and number of pruned shoots. The control of vegetative growth, by prohexadione calcium use, favors the increase of fruit production capacity of 'Hosui' pears, mainly at 550 g ha -1 concentration.

Prohexadione calcium controls shoot growth of pear trees

“…to 250 mg L -1 a.i. Similar results were also observed by Hawerroth et al (2012), who obtained shoot growth reduction in 'Hosui' pear trees grafted to vigorous rootstocks by application of 600 g ha -1 a.i., split in two applications (first when shoots were ~5-10 cm long and the second 30 DAFA). Even though single applications of ProCa control shoot growth of some cultivars (Smit et al, 2005), split applications, such as used in the present study, are preferred since this would enable the relatively short-lived ProCa to control flushes of shoot growth, which may occur later in the season (Rademacher et al, 2004).…”

“…Similarly, the pruning weight of 'D'Anjou' and 'William's' pears treated with ProCa was reduced in comparison to control trees, and this reduction was correlated to the amount of ProCa applied (Elfving et al, 2003). In 'Hosui' pears, pruning weight was also reduced as ProCa dose increased (Hawerroth et al, 2012). The reduction in pruning weight associated with ProCa indicates a potential decrease in the need for pruning, which is an important component, approximately 14%, of production cost in pear orchards (Seavert et al 2005).…”

“…Previous studies have demonstrated that ProCa controls shoot growth of different pear (Elfving et al, 2003;Smit et al, 2005;Asín et al, 2007;Hawerroth et al, 2012;Einhorn et al, 2014;Pasa and Einhorn, 2014) and apple (Duyvelshoff and Cline, 2013) cultivars with varied influences on other horticultural traits. Sugar et al (2004) reported smaller fruit size of 'William's', but not 'Bosc', and 'Red Anjou' in the year of ProCa application, while 'D'Anjou' fruit size was affected in just one trial; 'Bosc' return bloom and yields were markedly reduced the year following application, but 'William's' and 'D'Anjou' were not similarly affected.…”

Prohexadione-calcium isolado ou em associação com herbicidas e outros produtos no manejo em pré-colheita do algodão

“…That happened due to the form of action of this product, which acts in the inhibition of the hormone that stimulates the plant growth (Kofidis et al, 2008). That is, the results from Hawerroth et al (2012a) and the ones found in this paper prove that PR may control the vegetative development of plants, and it has potential to be used for such end. Hawerroth et al (2012b) saw a reduction in the development of vegetative branches in the 'Imperial gala' apple tree, through the application of 330 g ha -1 of PR carried out at 20 and 28 days after flowering.…”

“…This means that, the closer to the maturation final phase, the higher the plant defoliation percentage. Regarding regrowth, regrown branches were not seen in the evaluations carried out at 0, 3 and 6 DAA (Table 5) Hawerroth et al (2012a) affirmed that the use of PR was efficient in the control of vegetative growth of pear trees from the 'Hosui' variety, and the highest doses (550 e 825 g ha -1 ) provided a better vegetative control, generating an increase in the reproductive capacity of those fruits. That happened due to the form of action of this product, which acts in the inhibition of the hormone that stimulates the plant growth (Kofidis et al, 2008).…”