‘Rio Oso Gem’ and ‘Loring’ Peach Flower Bud and Wood Hardiness as Affected By Different Rootstocks

Abstract

Fourth leaf ‘Rio Oso Gem’ and ‘Loring’ peach ( Prunus persica(L.) Batsch.) on their own roots or budded to nine rootstocks (Tzim Pee Tao, Harrow (H) 7141041, H7141049, H7338013, H7141064, H7338001, H7141137, Lovell, Halford, or Sinung Chumi) were evaluated for rootstock effects on flower bud hardiness after field exposure to −23°C in 1987 and −26°C in 1988. ‘Rio Oso Gem’ flower buds were hardier on H7141064 compared to H7141049 in 1987. ‘Loring’ flower buds were hardier on H7338001 compared to Tzim Pee Tao, H7141041, Sinung Chumi, self-rooted and H7141137 in 1988. In addition, ‘Loring’ flower buds on Lovell were hardier than on H7141137 or self-rooted ‘Loring’ trees. Pooled yearly data suggests that ‘Loring’ flower buds on H7338001 were hardier than ‘Loring’ on Tzim Pee Tao, H7141137 and self-rooted trees. No significant rootstock effect on ‘Rio Oso Gem’ flower bud hardiness was detected with pooled data. Controlled freezing tests indicated both a date and a rootstock effect on ‘Loring’ wood hardiness. Wood hardiness was low in November and increased to a maximum in January and March. ‘Loring’ wood hardiness on Tzim Pee Tao decreased in March compared to January. ‘Loring’ wood hardiness in January was lower in trees budded to Lovell compared to ‘Loring’ budded to H7338001, Sinung Chumi or Tzim Pee Tao.