Efficacy study with the 8-month-old plants showed that the rate at 2.0 kg ae/ha triclopyr and fluroxypyr gave more injury to the internal tissue of pineapple stumps compared with the lower ones. Triclopyr induced more phytotoxic effects on the internal tissue compared with that of fluroxypyr at the same rates. In contrast, fluroxypyr resulted in more injury to the external tissue. Study on shoot cutting at days after application, the shoot cutting at 5 and 7 days slightly reduced the herbicide phytotoxicity. For spray volume requirement, the volumes at 2,000, 1,000 and 500 L/ha produced better efficacy than with 250 L/ha. Adding 1.25 kg ion/ha of paraquat to the spray mix of triclopyr and fluroxypyr was found to decrease the phytotoxicity especially with triclopyr. Fluroxypyr needed 2 hr of the simulated rainfall to provided the full efficacy whereas triclopyr required 4 hr. The experiment under field conditions was conducted with fluroxypyr 1.5 and 2.0, triclopyr 2.25 and 3.0 kg ae/ha and followed by heavy-dish ploughing at 5 and 45 days after application (DAA) in rainy season. At 90 DAA, the density of growing volunteer seedlings was about 15 to 20 % compared with those of the untreated control, and almost all were from the plant crop stumps. The land preparation by this technique could be used for the new planting in about 3 months after application, or 3 months earlier than the normal practice and with the less number of ploughing at least 2 rounds.

Application of nanofiltration membranes to processing sweet whey and skim milk ultrafiltration permeate increased lactose crystal yield by about 10 and 8%, respectively, at a concentration factor of 3.0. These increases were attributed to depletion of minerals, especially monovalent cations such as sodium and potassium, by the partial demineralization effect of the nanofiltration membrane. These membranes may be incorporated into current industrial processes for producing lactose from whey and milk permeates.

The effectiveness of uniconazole for height control of Hypoestes (Hypoestes phyllostachya Bak. 'Pink Splash') was determined, and the persistence of uniconazole with chlormequat and daminozide for limiting stem elongation in a low-light interior environment was compared. Spray and drench applications of uniconazole decreased plant height linearly with increased concentration. Two uniconazole sprays at 5.0 mg liter-1, 0.05 mg a.i./pot uniconazole drench, or two chlormequat sprays at 2500 mg liter-1 resulted in equally aesthetic plant size for 0.4-liter pots. Chlormequat was more effective than uniconazole for reducing rate of growth in the postharvest environment. No difference in postproduction rate of growth occurred between two sprays at 5.0 mg liter-1 and 0.05 or 0.10 mg a.i./pot drench treatments of uniconazole.

Mite (Tetranychus sp) and rust disease (Uromyces sp) are the important pest and disease of carnation in Indonesia. Information on effective pesticides to control those pest and disease is rarely found. An experiment on the efficacy, of several pesticides in controlling mite and rust had been conducted in Segunung Horticultural Research Station from May 1991 until March 1992. The result showed that the most effective fungicide of nine fungicides tested was propineb. The grade of effectivity of the rest of fungicides tested were respectively mancobe + carbendazim, mancozeb + metalaxyl, benomyl, captan and iprodione. Bioassay test on 9 acaricides resulted in dicofol as the most toxic contact acaricide followed by fosalon, oxytiokuinox, methomyl, fenpropatrin and metamidofos

The effectiveness of uniconazole for height control of Hypoestes (Hypoestes phyllostachya Bak. 'Pink Splash') was determined, and the persistence of uniconazole with chlormequat and daminozide for limiting stem elongation in a low-light interior environment was compared. Spray and drench applications of uniconazole decreased plant height linearly with increased concentration. Two uniconazole sprays at 5.0 mg liter-1, 0.05 mg a.i./pot uniconazole drench, or two chlormequat sprays at 2500 mg liter-1 resulted in equally aesthetic plant size for 0.4-liter pots. Chlormequat was more effective than uniconazole for reducing rate of growth in the postharvest environment. No difference in postproduction rate of growth occurred between two sprays at 5.0 mg liter-1 and 0.05 or 0.10 mg a.i./pot drench treatments of uniconazole.

Leafspot, a fungal disease which infects peanut plants, is commonly controlled with the chemical chlorothalonil. The effectiveness of the fungicide is dependent on several factors including time of application, weather, stage of leafspot development, and growth stage of the peanut plants. Because of the complex factors involved in the decision to spray, a simulation model was developed to assist the producer. Two models of fungicide persistence from the literature were studied; a model in which the fungicide residue decayed exponentially with time, and a model where the amount of fungicide residue was dependent on rainfall and temperature. The fungicide efficacy model was developed by the authors and assumes chlorothalonil slows disease progress by inhibiting germination of spores. A sigmoidal dose-response curve is assumed, with the 50% lethal dose at approximately 0.062 microgram chlorothalonil/cm2 leaf area. Simulations using both persistence models were compared to observed disease levels for 1982 and 1988, the only two years for which data were available. The persistence model which calculated fungicide decay as a function of rainfall and ambient temperature predicted disease levels that were in closer agreement with the observed values than the constant-rate exponential decay persistence model. It has been suggested by other authors that fungicide decay models which are driven only by time since fungicide application are acceptable, however our research suggests that rainfall and temperature are essential components of fungicide persistence models. Other environmental variables were not studied. The weather-driven fungicide persistence model and the sigmoidal dose-response curve efficacy model predicted disease levels and percent yield reductions which agreed well with the observed field data for 1982 and 1988. In 1982, the observed yield from the plots where no fungicide was applied was 46.7% less than the plot where chlorothalonil was applied conventionally, and the model predicted a 48.3% yield reduction. The yield reduction observed when half the recommended amount of fungicide was applied was 4.7%, and the model predicted 2.8% reduction in yield. The potential yield reduction from a predicted leafspot infection is the main driving force behind the decision of whether or not to spray the crop. Since the simulation model accurately predicted yield reductions and leafspot infections resulting from varying fungicide applications, the model could be a valuable tool for exploring alternative chlorothalonil application strategies for the control of leafspot.

Impatiens L. wallerana Hook., Salvia splendens Sello ex Nees, Tagetes erecta L., and Petunia hybrida Vilm. plants in 610-cm3 pots, were sprayed with either uniconazole or paclobutrazol at concentrations from 10 to 160 mg.liter-1. For all species, both chemicals reduced plant size compared with untreated control plants, and the effect increased with higher concentrations. Uniconazole produced smaller plants than did paclobutrazol at similar concentrations. For impatiens, salvia, and marigold, there was an interaction between chemical and concentration; the degree of difference between the effects of the chemicals was greater at higher concentrations. For these three species, uniconazole elicited a quadratic response and reached saturation within the concentrations used; however, these concentrations were still in the linear portion of the dose response curve for paclobutrazol.