Effects of Thidiazuron (Tdz) on Fruiting of Temperate Tree Fruits

Abstract

RESUMO -Thidiazuron (TDZ) é uma feniluréia que mostra uma atividade de citocinina, atuando na divisão celular, e conseqüentemente no crescimento e na forma das frutas em algumas fruteiras de clima temperado. A aplicação de Thidiazuron durante o período de floração em macieira, cv. Gala e Fuji, foi avaliada por um período de sete anos, nas mesmas plantas, quantificando seu efeito na frutificação efetiva, retorno de floração, tamanho e forma da fruta, maturação e outras variáveis. Também foi avaliado o TDZ em pereira e Kiwi. Em macieira, na cv. Gala, o TDZ aumentou significativamente, em todos os anos, a frutificação efetiva e o peso médio das frutas. Na média de sete anos, TDZ 10 mg.L -1 teve 112,7% de frutificação efetiva, contra 51,3% no controle. O número de cachos florais não foi afetado. O peso médio das frutas, em média, aumentou 7,0% e 18,3% para TDZ 10 mg.L -1 e 5 mg.L -1 , respectivamente. A produção por planta sempre foi superior quando aplicado TDZ, aumentando 28,7% e 41,8% para 10 mg.L -1 e 5 mg.L -1 respectivamente. O TDZ reduziu não só o número de sementes por fruta, como também o teor de cálcio na polpa das frutas e aumentou a resistência da polpa. Em pêra, o TDZ aumentou significativamente a frutificação efetiva na cv. Packam's Thiumph, e diminuiu o número de sementes por fruta. Em kiwi, TDZ 12,5 mg.L -1 aumentou o tamanho das frutas em 47,4% na cv. Monty. Termos para indexação:Thidiazuron, cálcio, TDZ, frutificação efetiva, macieira, pereira, Kiwi. EFFECTS OF THIDIAZURON (TDZ) ON FRUITING OF TEMPERATE TREE FRUITSABSTRACT -Thidiazuron (TDZ) is a phenylurea like citokinin on cell division fruit growth and fruit shape in some deciduous fruit trees. The effects of TDZ applied during flowering on apple cultivars 'Gala' and 'Fuji" were evaluated during seven growing seasons with annual applications on the same trees. The effects on pear and kiwi fruit trees were also evaluated. Every year, TDZ significantly increased fruit set and fruit weight on apple trees. The seven-year average of the fruit set from TDZ at 10 mg.L -1 was 112.7% while the control was only 51.3%. TDZ did not affect the number of clusters. The fruit weight increased 7.0% and 18.3% when the trees were sprayed with TDZ at 10 mg.L -1 and 5 mg.L -1 , respectively. TDZ also increased fruit yield per tree by 28.7% and 41.8% for the 10 mg.L -1 and 5 mg.L -1 treatments, respectively. TDZ reduced the seed number per fruit and the calcium content in the flesh fruit, but increased the fruit firmness. The fruit set increased significantly on pear cultivar Packm's Triumph treated with TDZ, and reduced the seed numbers per fruit. TDZ applied at 12.5 mg.L -1 increased fruit weight by 47,4% on "Monty" kiwi.

Study of the Consequences of Global Warming in Water Dynamics During Dormancy Phase in Temperate Zone Fruit Crops

“…In such artificial conditions of 80% of chilling fulfillment, a prolonged flowering period, with low number of opened flowers was observed, regarding of necrosis incidence in floral primordia. It was possible to reproduce, in this experiment, similar phenology observed in a warm winter conditions of Southern Brazil and described by several authors as "flower bud abortion" (Marafon et al, 2011;Petri & Herter, 2002;Petri et al, 2001;Trevisan et al, 2005;Veríssimo et al, 2002).…”

“…A great demand of this fruit in local market occurs in Brazil, but it is observed a technological lack available for growers, such as development of cultivars of both rootstock and scion adapted to mild winter conditions, crop management adapted to such environmental conditions, appropriate logistic systems, among other factors (Faoro, 2001). Low rates of fruit set (Petri, 2008) and high incidence of physiological disorder called locally "flower bud abortion" (Marafon et al, 2011;Petri & Herter, 2002;Petri et al, 2001;Trevisan et al, 2005) are cited as factors of low yield in pear crops. In mild winter conditions of Southern Brazil, over 60% of "flower bud abortion" was found in 2001 and more than 90% in 1999, resulting in low numbers of opened flowers at the bud break and consequently low production (Veríssimo et al, 2002).…”

Phytoregulators in the Reproductive and Productive Characteristics of Plants and Physicochemical Characteristics of ‘Packham’s Triumph’ European Pears

“…All other treatments differed from the NAA 200 mg L -1 concentration, which presented the lowest mean (11 °Brix). Gala apple plants treated with doses of 5 and 10 mg L -1 of Thiadizuron (phenylurea with cytokinetic effect) did not present a significant difference between the doses, and the averages were 12 and 11.8% of soluble solids respectively (Petri et al, 2001). In the 'Abate Fetel' pear tree, Luz (2016), there was also no difference between vigor control treatments, observing a mean of 13.3 °Brix for the plant growth regulator, Moddus (1,600 mg L -1 ).…”

Study on exogenous application of thidiazuron on seed size of Brassica napus L.

“…Application of TDZ during flowering significantly increased fruit setting and fruit weight in apple trees “Gala” and “Fuji” over seven growing seasons. The 7-year average fruit setting ratio for TDZ 10 mg L –1 was 112.7% compared to 51.3% for the control ( Petri et al, 2001 ). These results indicated that TDZ treatment increased yield traits such as the silique number per plant, thousand-seed weight, seed volume weight, the yield and seed setting ratio, thereby greatly improving the yield of B. napus.…”