Ethyl hydrogen l-propylphosphate (EHPP) was compared with ethephon and ethylene as a ripening agent of tomato fruit. EHPP increased the ripeness level of tomato fruit treated either in the field or under lab conditions and advanced the respiratory climacteric of the ripening fruit. Both EHPP and (2-chloroethyl)phosphonic acid (ethephon) compared favorably with ethylene as ripening agents.
Total sugar concentrations in leaves increased from 22 mg/g fresh weight to 50 mg/g fresh weight on day 8 in boxwood and from 44 mg/g fresh weight to 77 mg/g fresh weight on day 6 in cranberry leaves after being exposed to temperature treatment of 7°C with 8 hour light. Similarly, reducing sugar concentrations increased from 6.5 mg/g fresh weight prior to treatment to 10.5 mg/g fresh weight on day 8 in boxwood and from 22 to 33 mg/g fresh weight in cranberry.
‘Russet Burbank’ and ‘Nampa’ seed potatoes (Solanum tuberosum L.) were irradiated with gamma rays at 328 rads/minute for ¾, 1½ and 3 minutes for greenhouse studies and 167 rads/minute for 2, 4, and 7 minutes for Geld trials. The higher rates of irradiation delayed plant emergence and decreased tuber yield and tended to increase reducing sugar content of tubers. Total sugar content was variable depending on cultivar and culture. Number of stems and tubers, tuber size, and soluble protein of tubers produced by plants from irradiated seed pieces were unaffected by irradiation.
Seedling apple trees of the ‘Rome Beauty’ variety were treated with 20 ppm abscisic acid and 100 ppm gibberellic acid and compared with controls during predormancy and dormancy for killing point, soluble protein and content of specific amino acids. Amino acid and soluble protein content were statistically correlated with killing point. A relationship exists between cold hardiness and certain amino acids. Soluble protein content was correlated with killing point in the gibberellic acid and control treatments. Treatment with abscisic acid showed no correlation between soluble protein and killing point indicating that soluble protein may not be an index of hardiness in apple trees.
Apple seedlings, Malus sylvestris var. Rome Beauty, were treated with abscisic acid 20 ppm, gibberellic acid 100 ppm, and compared with controls during pre-dormancy and dormancy for killing point, total nitrogen, soluble protein, per cent dry matter, total ash, photosynthesis rate, respiration rate and growth. The seedlings were treated under a specific regime of decreasing temperature and day length. Analyses were made after 7 days at 21° and 16 hr light, 7 days at 7.2° and 10 hr light, and 7 days at 0° and 8 hr light.
Abscisic acid increased the hardiness of apple seedlings. Low temperature and short day treatments increased the hardiness in both the pre-dormant and dormant tests. Both N and soluble protein increased as the seedlings passed from the pre-dormant to the dormant period. The same trend was true for total ash, whereas per cent dry matter decreased during this period. Abscisic acid treatment decreased the photosynthesis rate of the seedlings.
‘Bonner’ tomato is a compact, ultra early tomato (Lycopersicon esculentum Mill.) intended for use in cool and short growing season areas (Fig. 1). It was named for Bonner County, Idaho, where it was selected.
The number of cracks in cotyledon pairs from 16 snapbean (Phaseolus vulgaris L.) cultivars varied from 0 to 4. Two resistant and 2 susceptible cultivars were sampled from different locations to determine field to field variation in cracking. ‘Earliwax’ was consistently resistant and other cultivars varied with environment. Ca, Mg and N content were higher in the two resistant cultivars than in the susceptible cultivars. No relationship was apparent between Zn, B and cotyledonal cracking. Calcium concentration was not correlated while Mg was negatively correlated with cracking index when 16 snapbean cultivars were analyzed.
Shoot tip explants of 12 woody species and cultivars of Rosaceae were cultured in vitro on Linsmaier and Skoog nutrient medium containing benzylamino purine (BA). Greatest shoot proliferation occurred in the presence of 0.1 to 2.5 mg/liter BA and was species-dependent. Root initiation was promoted when 1 to 10 mg/liter indolebutyric acid (IBA) was added to the medium. Rooting increased when cultures were incubated in the dark for 1 week prior to illuminated incubation.
Rapid in vitro propagation of Mailing (M) 7 apple rootstock (Malus sylvestris Mill.) was obtained on a modified Murashige and Skoog (MS) medium using shoot tips as primary expiants. Shoot regeneration was induced on a half-strength MS medium supplemented with 0.5 mg/liter benzylamino purine (BA). Rooting was induced by subculturing plantlets on a one-third strength MS medium containing 0.27% agar and supplemented with either 1.0, 2.0 or 3.0 mg/liter indolebutyric acid (IBA). Shoots subcultured on medium containing 2.0 mg/liter IBA rooted within 28 days.