Search Results
Abstract
‘EarliGrande’ peach (Prunus persica (L.) Batsch) was released in 1979 for mild winter areas such as the Rio Grande valley of Texas. It is the earliest maturing peach in Texas with commercial potential. ‘EarliGrande’ has been the best adapted cultivar to the meadow orchard system in Israel (A. Erez, Personal communication).
Abstract
‘Morris’ was released to fill the need for a high-quality fresh-dessert plum adapted to the Coastal Plains, where accumulated chilling is at least 750 hr. Winter cold tolerance has not been determined. ‘Morris’ fruits (Fig. 1) mature with those of Ozark Premier’ or slightly earlier and are superior in flavor and color (Tables 1 and 2).
Abstract
‘Brison’, Rosborough’, and ‘Womack’ were released to replace the ‘Brazos’, blackberry cultivar. The fruits of the new cultivars (Fig. 1) although similar to ‘Brazos’, have improved flavor, smaller seed and firmer fruit (Tables 1, 2, 3).
Abstract
The peach as an item of commerce has developed primarily in the temperate regions of the world, the equatorial boundaries being limited by minimum accumulated chilling temperatures and the polar boundaries by minimum winter temperatures. Native temperate climate peaches contained combinations of desirable characteristics with which suitable cultivars could be developed with relative ease. Among such characteristics large fruit size, suitable acid-sugar ratio and flesh firmness are particularly important in commercial varieties.
Abstract
‘Milam’ peach (Prunus persica (L.) Batsch) has been released for public use to provide an alternative cultivar to ‘Loring’ especially in areas where ‘Loring’ is unadapted. Fruit of ‘Milam’ (Fig. 1) mature in about the same season at that of ‘Loring’ but ‘Milam’ is productive over a greater part of Texas than ‘Loring’.
Abstract
Concentrations of total abscisic acid (ABA) in flower buds from 7 clones of peach (Prunus persica (L.) Batsch) were measured on 4 sampling dates and compared with chilling requirements (CR) of these clones. In December the correlation coefficient between ABA content and CR was r = 0.89. ABA concentration increased with tree vigor. Fall-applied gibberellic acid (GA3) decreased ABA concentration in flower buds in December and delayed bloom the following spring.
Abstract
Soil applications of nitrogen in February and August delayed bloom of trees of ‘Redglobe’ peach (Prunus persica (L.) Batsch) the following spring. Applications of 67 to 134 kg N/ha delayed bloom progressively from 12 to 72 hours when compared to trees receiving no N. Buds from trees that received high levels of N contained higher levels of abscisic acid (ABA) and N and lower levels of carbohydrates (CHO) than did those from trees receiving no soil-applied N. ABA levels decreased sharply and CHO levels increased in buds from all treatments upon completion of the chilling requirement (850 hours). Delays in bloom of more than 24 hours prevented significant spring freeze damage in 1975.
Abstract
Generally, accumulative yields of peach (Prunus domestica (L.) Batsch) increased with increasing tree density. Training trees to a “Y” shape and to a hedgerow was promising as a management tool. Fruit size was not reduced significantly by increasing tree density.
Zinc supplied as a fulvic-based Zn compound was absorbed and retranslocated to unsprayed new growth as effectively as zinc sulphate in apple seedlings of low Zn status grown hydroponically in the greenhouse. Similarly, fulvic- and humic-based compounds were as effective as zinc sulphate at improving short-term growth and Zn uptake into new tissues in Zn-deficient apple seedlings, with the best growth occurring at spray concentrations of Zn at 500 mg·L-1. Under field conditions, Zn concentration of peeled and washed `Jonagold' apples at harvest was increased, without phytotoxicity, by two or four postbloom sprays of fulvic Zn. It is therefore possible to use this material safely as an effective Zn-source after bloom. However the mobility of the foliar-applied Zn is limited and any yield response by treated apple orchards of marginal Zn nutrition is unlikely to occur in the short term (within two growing seasons).
`Hass' avocados (Persea americana Mill.) were heated in air at 25 to 46C for 0.5 to 24 hours and stored at 0, 2, or 6C. After storage, fruit were ripened at 20C and their quality was evaluated. In unheated fruit, external chilling injury occurred in fruit stored at 0 or 2C, hut not 6C. Chilling injury was also evident after storage at 2C in fruit heated at 34C, and to a lesser extent in fruit heated at 36C. A heat treatment (HT) of 38C for 3, 6, or 10 hours and 40C for 0.5 hour further reduced external chilling injury induced by storage at 2C. These HTs did not reduce internal fruit quality and resulted in more marketable fruit than unheated fruit stored at 6C. Low-temperature storage and HT slowed avocado ripening, resulting in longer shelf life after storage. In flesh tissue sampled directly after selected HTs, the levels of mRNA homologous to cDNA probes for two plant heat-shock protein (HSP) genes (HSP17 and HSP70) increased to a maximum at 40C and declined at higher temperatures. These increases in gene expression coincided with the extent to which HTs prevented chilling injury. Hot-air HTs confer significant protection against low-temperature damage to avocados.