Pink bollworm egg -larval survivorship in insecticide -treated fields averaged (± SE) 19.8% (± 2.3) for the F2 and F3 generations developing during the primary boll producing time of the year (July and August). These observations have been useful in developing a simulation model of pink bollworm population dynamics.

Growth and development was studied in the beet armyworm (BAW), Spodoptera exigua, reared on cotton seedlings at high (650 ppm) or ambient (325 ppm) carbon dioxide (CO₂) levels and at 2 fertilizer levels. Under high fertilization, female BAW reared on CO₂-enriched seedlings weighed significantly less (873 mg) than controls (101.0 mg) and had a significantly longer developmental time (14.2 vs. 12.4 days for controls). Male BAW followed the same pattern but the data were not statistically significant. Combined (male & female) survival rates for BAW reared on CO₂-enriched cotton seedlings on a high fertilizer level were 19.1 compared to 41.6 % for controls; more females survived than males by a significant ratio of 2:1.

Plant derived oils (cottonseed and soybean) in greenhouse and field studies were promising for sweet potato whitefly, Bemisia tabaci (Gennadius) control. Cotton seedlings treated with oil in the greenhouse repelled whiteflies up to 7 days and high mortality of treated larvae, pupae and adults occurred. In the field, application of crude cottonseed oil to cotton with high air-blast, ground spray equipment suppressed whitefly populations thoughout the season.

In 1987, seed samples from three cotton fields in Avra Valley, Arizona, grown with liquid sewage sludge and inorganic nitrogen fertilizer, were analyzed for five heavy metals. Concentrations of cadmium, copper, lead, nickel, and zinc were similar in cotton seeds fertilized with either sewage sludge or inorganic nitrogen fertilizer. The levels of all five metals were well below the allowable EPA limits.

No description available.

The effects of cotton leaf crumple disease on components of yield and on symptom expression were examined for cotton inoculated at five growth stages. As a result of virus infection, the total leaf area was reduced and significant reductions in yield were observed, regardless of plant age at time of inoculation. Yield reductions resulted from a smaller number of bolls set and/or a decrease in boll weight. Foliar symptoms were associated with plants inoculated at all five growth stages, but were observed sooner and were more severe for plants inoculated at the 2-3, 5-8, and 8-10 leaf stages than those inoculated at the 14-16 or 18-20 leaf stages.

No description available.

The sweet potato whitefly, Bemisia tabaci (Gennadius) continues to be a serious pest of cotton and an important vector of several virus diseases of fall vegetables. In our search for resistant germplasm, we counted adult whiteflies on cotton cultivars and breeding stocks in AZ and Israel. At Maricopa (MAC), seven of 19 cottons had significantly fewer whiteflies than the check, 'Stoneville 825'. Five of the seven were okra-leaf and two were normal-leaf cottons. In another experiment at MAC, an okra-leaf cotton did not have fewer whiteflies than a normal-leaf one. At several locations in Israel, the okraleaf cotton, BD-12, had significantly fewer whiteflies than a number of normal-leaf cottons.

The profitability of full and "50/92" participation in the 1988 upland cotton program is estimated for representative farms in Maricopa, Pinal, LaPaz and Yuma counties. Special attention is given to the effect on profitability of farm size, multiple partner ownership and changes in program provisions for harvesting alfalfa hay. In general, full participation is shown to be the most profitable, given the assumptions used here.

A survey of agricultural pest control professionals showed that certain compounds have consistently been recommended to control cotton pests for more than 40 years. Over that same period, the number of preferred materials available for recommendation has greatly increased. Other trends are toward greater use of compounds using lower application rates and biological insecticides.