Repeated applications of CPPU on highbush blueberry cv. Duke increase yield and enhance fruit quality at harvest and during postharvest

Abstract

Applications of N-(2-chloro-4-pyridyl)-N'-phenylurea (CPPU) can increase blueberry (Vaccinium corymbosum L.) yield and fruit size, but their impact on postharvest is unknown. We studied repeated CPPU applications effects on yield and quality (harvest, postharvest), over 2 yr on mature 'Duke' plants in South-Central Chile. The first year, 5 or 10 mL L -1 CPPU was applied at 3, 10, and/or 17 d after full bloom (DAFB) plus a non-sprayed control. The second year, 5 or 10 mL L -1 CPPU were sprayed 10 and 17 DAFB plus a control. The first year, only 10 mL L -1 CPPU sprayed 3+17 DAFB increased yield (32.5% > control); 10 mL L -1 CPPU applied 10 or 3+17 DAFB had highest fruit diameter; and 10 mL L -1 CPPU at 17 DAFB or at 3+10+17 DAFB had highest soluble solids. Overall, 10 mL L -1 CPPU applied 3+17 DAFB, was the best treatment for year one, since it increased fruit yield and diameter, while soluble solids and postharvest weight loss were similar to control. The second year, 10 mL L -1 CPPU reduced fruit coloration (blue color coverage index: BCCI) and soluble solids, but not firmness at harvest. This rate increased berry weight (24.2%) and fruit wax (59% > wax coverage index: WCI) at harvest. Harvest and postharvest WCI increased consistently as CPPU rate increased. CPPU reduced fruit rotting (15% at 45+5 evaluation). During storage, CPPU-treated-fruit had a slower decrease in firmness (30.5% < control at 30+1), but no difference at 30+5. CPPU-treated-fruit usually had higher post harvest soluble solids. Ten mL L -1 CPPU retarded color evolution at harvest and at 30+1, but not at 30+5, 40+1 or 40+5.

Effect of CPPU on Carbohydrate and Endogenous Hormone Levels in Young Macadamia Fruit

“…CPPU is a highly active synthetic cytokinin that promotes chlorophyll biosynthesis, cell division, and cell expansion [ 17 , 18 ]. This compound also increases fruit set and accelerates fruit enlargement, and has been tested extensively in fruit crops including apple [ 12 ], blueberry [ 19 , 20 ], citrus [ 21 ], Kiwifruit [ 17 ], persimmon [ 22 ] and pear [ 23 ]. There is evidence that CPPU promotes fruit development in kiwifruit by increasing endogenous cytokinins, gibberellins and auxins [ 24 , 25 ], which results in a greater sink strength in the fruit [ 26 , 27 ].…”

Impact of Cold-Storage and UV-C Irradiation Postharvest Treatments on Quality and Antioxidant Properties of Fruits from Blueberry Cultivars Grown in Southern Chile

“…Most of the blueberry fruits produced in Chile are sent as fresh fruits to the Northern Hemisphere (USA, Canada, Europe, and Asia), traveling 20-50 days depending on destination (Beaudry et al 1998;Retamales et al 2014). Thus, several preservation technologies have been proposed to improve fruit shelf life of blueberries, in order to reduce fruit deterioration and retain fruit quality and antioxidant properties, which includes modified atmosphere, cold-storage, and UV-irradiation pulses (Chiabrando et al 2004;Duan et al 2011;Wang et al 2019).…”

Nondestructive detection of kiwifruit treated with N ‐(2‐chloro‐4‐pyridyl)‐ N ′‐phenylurea by electrical method

“…Plant growth regulators (PGRs) are widely used in kiwifruit to increase the yield and quality. N ‐(2‐chloro‐4‐pyridyl)‐ N ′‐phenylurea (CPPU), a synthetic cytokine (Jáuregui‐Riquelme, Kremer‐Morales, Alcalde, & Pérez‐Donoso, 2017) that promotes cell division and seed germination, is applied to a variety of fruits, such as apple (Matsumoto, Fujita, & Sato, 2018), grape (Jáuregui‐Riquelme et al, 2017), mango (Pujari, Malshe, Shedge, Zagade, & Lawande, 2016), and blueberry (Retamales, Lobos, Romero, Godoy, & Moggia, 2014), and vegetables to increase their volume and yield. CPPU was initially used in the production of kiwifruit in the 1990s, and this treatment improved the fruit yields and brought about great economic benefits (Blank et al., 1992).…”

“…et al, 2017), mango (Pujari, Malshe, Shedge, Zagade, & Lawande, 2016), and blueberry (Retamales, Lobos, Romero, Godoy, & Moggia, 2014), and vegetables to increase their volume and yield.…”