Prohexadione-Ca and Ethephon Suppress Shoot Growth of Sweet Cherries (P. Avium)

Abstract

A 3-yr orchard study was conducted on Tehranivee, an advanced selection of sweet cherry [Prunus avium (L.) L.] on Mazzard and Gisela 6 rootstocks, to determine the efficacy of different prohexadione-calcium (P-Ca) and ethephon (ETH) treatments on vegetative growth. In experiment 1, cherry trees were treated with 123 or 246 mg L −1 P-Ca, which was sprayed on 16 and 30 d after full bloom (DAFB) or 16, 30, and 44 DAFB. In experiments 2 and 3, trees were treated before (−6 DAFB) and after (7 and 24 DAFB) bloom with P-Ca and rates similar to experiment 1, as well as with tank-mixed sprays of 123-246 mg L −1 P-Ca and 175 mg L −1 ETH applied at various timings. P-Ca alone or in combination with ETH decreased the vegetative shoot growth by up to 74% compared with the untreated control, but this varied by cultivar and year, as well as by plant growth regulator application rate, frequency, and timing. Lower rates of P-Ca at 123 mg L −1 were as effective as 246 mg L −1. No benefit was observed in applying P-Ca before bloom before active shoot growth had begun.

Effect of plant bio-regulators on photosynthesis, growth and yield efficiency of pear trained on Y-trellis system

“…Trunk circumference of the pear plants was measured at 10 cm above graft union. TCSA was calculated from trunk circumference as described by Cline (2017). Yield efficiency was expressed as the ratio of yield of a plant to its TCSA as suggested by Cares et al, (2014).…”

Reducing Preharvest Bolting in Open-field-grown Cilantro (Coriandrum sativum L. cv. Santo) through Use of Growth Regulators

“…Other PGRs, such as chlormequat chloride (CQC), paclobutrazol (PBZ), flurprimidol, and prohexadione calcium (PCa), directly inhibit GA biosynthesis (Rademacher, 2016). Currently, PCa has widespread use in controlling fire blight in apples (McGrath et al, 2009), reducing vegetative growth in peanuts (Beam et al, 2002), and decreasing shoot growth in apples and cherries (Cline, 2017). Although PBZ is mainly used in the ornamental plant industry, it has some efficacy in reducing shoot growth in tropical and subtropical tree crops (Rademacher, 2016).…”