Search Results
Abstract
At the highest concentration, sodium 2,3-dichloroisobutyrate (DCIB), 2-(chloroethyl)phosphonic acid (ethephon) and N-dimethylaminosuccinamic acid (SADH) produced abscission (flowers + floral buds) of approximately 90, 66, and 32%, respectively. DPA, at the rates used, produced no abscission. Only DCIB at 6000 ppm caused significant fruit drop. Ethephon and SADH were more effective for the abscission of buds than flowers, the reverse was true for DCIB. At the highest concentration, ethephon and DCIB produced approximately 35% abscission within 2 days, whereas with SADH abscission did not begin until 8 days after application. The chemicals × cluster-age interaction was highly significant.
Abstract
Deblossoming of ‘Summit’, a determinate cultivar of tomato (Lycopersicon esculentum Mill.) after the 4, 5 and 6 cluster stages significantly increased mean fruit wt and yield. Removal of late formed flowers tended to delay maturation of fruits.
Abstract
Ringing plants of the determinate tomato (Lycopersicon esculentum Mill cv. Summit) with copper wire when fruit had set on 3, 7 and 12 clusters increased early and total yield. Earlier ringing did not produce such increments. Ringing had no effect on fruit size and percent marketable yields.
Abstract
Infra-red light induced stem elongation of several species of plants. Tomato plants also had reduced fruit yield. Geraniums had wider leaves and longer internodes and flower stalks, but the no. of flower stalks was unaffected by infra-red treatment. These effects should be taken into consideration if infra-red heating is to be used in greenhouse operations.
Performance of `Kerman' pistachio (Pistacia vera L.) trees on three rootstocks (P. atlantica Desf., P. integerrima Stewart and `UCB-1', a P. atlantica × P. integerrima hybrid) was evaluated with 2-year-old trees grown in sand-tank lysimeters under combined SO4 2- and Cl- salinity and boron (B) stress for 6 months. Four salinity treatments were imposed by irrigating the plants with water at electrical conductivity (ECiw) of 3.5, 8.7,12, or 16 dS·m-1 each containing B at 10 mg·L-1. Growth of `Kerman' was evaluated based on increase in total leaf area, increase in trunk diameter, and total above-ground biomass production. All growth parameters decreased as salinity increased, but were not significant until ECiw exceeded 12 dS·m-1. However, growth of `Kerman' on P. atlantica and `UCB-1' was considerably better than on P. integerrima at 16 dS·m-1. The onset and severity of foliar injury differed among scions and treatments and was attributed primarily to B toxicity, rather than the effects of salinity. Concentrations of B in injured leaf tissue ranged from 1000 to 2500 mg·kg-1. Leaf injury decreased with increasing salinity, although leaf B was not significantly reduced suggesting an internal synergistic interaction between B and other mineral nutrients. However for P. vera on P. integerrima, the highest level of salinity produced the greatest injury, possibly as a combination of B plus Cl- and/or Na+ toxicity. Leaf transpiration, stomatal conductance, and chlorophyll concentration of P. vera, determined by steady-state porometry, were also reduced to a greater degree by combined salinity and B when budded on P. integerrima than on the other two rootstocks.