Integrated Pest Management (IPM) has been defined as an interdisciplinary science (3). IPM has become popular this past decade; however, integrated pest management has been practiced by farmers and growers for decades. As nonfarming agricultural professionals become more specialized they tend to become “reductionists” or ever-narrower in their perspective base. From this evolution into disciplines has arisen the necessity to redirect thought and effort to addressing the total or whole such as is commonly done by the farmer or grower. IPM has been considered an effort in this direction, although unanimity in definition of IPM has been notably absent. Some have considered it synonymous with integrated pest control; in contrast, others have viewed it as a means to reduce the use of pesticides. Nevertheless, IPM has received considerable attention in the pest-related disciplines. Its implementation has been addressed in Presidential messages to Congress in 1977 and 1979 (7, 8).

Field experiments were conducted over a 4-yr period to determine the influence of selected herbicides on ozone injury in tobacco (Nicotiana tabacum L.). Isopropalin (2,6-dinitro-N,N-dipropylcumidine), pebulate (S-propyl butylethylthiocarbamate), and diphenamid (N,N-dimethyl-2,2-diphenylacetamide) were applied at the recommended rates of 1.7, 4.5, and 4.5 kg/ha, respectively. Treatment of tobacco plants with isopropalin or diphenamid reduced oxidant injury for the first 2 to 4 weeks after transplanting, but not later in the season. Pebulate had no consistent affect on the sensitivity of tobacco to ozone.

A field study was conducted to develop systems using cultural and chemical methods for control of bermudagrass (Cynodon dactylon L.) in cotton (Gossypium hirsutum L.). Several control options were promising. On areas prepared either with a moldboard plow or a disk, the sodium and magnesium salts of dalapon (2,2-dichloropropionic acid) at 4.7 kg/ha directed to 25-cm-high cotton and repeated at the 40-cm height or the ethyl ester of difenopenten {4-[4-[4-(trifluoromethyl)phenoxy] phenoxy]-2-pentenoic acid} directed to 15-cm-high cotton and repeated at the 30-cm height, with either standard or close cultivation as needed, provided good bermudagrass control. On areas prepared with a moldboard plow, the isopropyl amine salt of glyphosate [N-(phosphonomethyl)glycine] at 4.4 kg/ha over-the-top as a fall application with cultivation as needed was promising.

A considerable amount of scientific time has been spent defining Integrated Pest Management (IPM). The following is quoted from an Extension Committee on Organization and Policy publication (4): “Integrated Pest Management (IPM) is a system that utilizes all suitable pest control techniques and methods to keep pest populations below economically injurious levels. Each pest control technique must be environmentally sound and compatible with production and user objectives. Integrated Pest Management is more than chemical pesticide management. In many cases it includes biological, cultural, and sanitary control practices for all pest complexes.”

Soybean [Glycine max (L.) Merr.] cultivars ‘UFV1’ and ‘UFV2’ grown at Viçosa and Florestal, Brazil, and ‘Bonus' and ‘Wells' at Urbana, Illinois, were sprayed at growth stages R5.5 to R6 (full-pod) or R7 (50% defoliation) with the desiccant/herbicides glyphosate [N-(phosphonomethyl)glycine], paraquat (1,1′-dimethyl-4,4′-bipyridinium ion), or sodium chlorate:sodium borate (50:50, w/v). Desiccation of plants by paraquat significantly reduced seed weight and germination at all locations and increased the incidence of Alternaria and Phomopsis spp. at Urbana. Analysis of the combined data from the Brazilian locations showed a significant decrease in seed germination for all treatments except paraquat sprayed on the UFV2 at R7 and sodium chlorate: sodium borate sprayed on UFV1 at R7. Herbicide application at R7 did not result in consistent increases in seedborne Fusarium or Phomopsis spp. at any Brazilian location. Rainfall and temperature at seed maturation were more important variables in pod-to-seed infection by these fungi than increased rates of tissue senescence caused by the desiccants.

Plants started with seed, 'seedlings', and established plants of silverleaf nightshade (Solanum elaeagnifolium Cav.) were grown in the field under shade levels of 0, 47, 63, and 92% of full sunlight to determine vegetative, reproductive, and physiological responses to shade. Dry-matter production of both 'seedling’ and established plants declined markedly with increasing shade levels. Established plants did not bear fruit under 92% shade, and 63% shade prevented fruit production by 'seedlings'. Taproots of plants grown in full sunlight contained 16% more total non-structural carbohydrate (TNC) per gram dry weight than taproots of plants grown under 92% shade. Leaves of established plants grown under moderate shade had significantly more chlorophyll per unit leaf fresh weight than plants grown in full sunlight; however, plants under heavy (92%) shade had 35% less chlorophyll per unit leaf area than unshaded plants. The chlorophyll a/b ratio of the 92%-shaded plants was significantly less than with other treatments. Leaf area increased, with increasing shade; however, leaf weight per unit area decreased because of thinner leaves. Photosynthetic rates of recently expanded leaves were 10.4, 4.6, 3.3, and 0.9 mg CO2 · dm−2 · h−1 for the 0, 47, 63, and 92% shade treatments, respectively.

In the field, soybeans [Glycine max (L.) Merr. ‘Amsoy 71′] required 4 to 6 weeks free of sunflower (Helianthus annuus L.) competition for maximum yield. Competition studies suggested that more than one type of interference was involved when sunflowers grew with soybeans. In greenhouse studies, soybean height, fresh weight, and dry weight were significantly reduced at certain sunflower and soybean densities and levels of competition. Sunflower height was not reduced by any level of competition, but sunflower fresh and dry weights were reduced with high sunflower and soybean populations. Two percent (w/w) or greater amounts of ground, mature sunflower leaves mixed into the soil reduced emergence and growth of soybeans, sorghum [Sorghum bicolor (L.) Moench ‘G-625 GBR′], and sunflower. A mixture of powdered stems and branches of sunflower also reduced growth of the three species, although it was not as phytotoxic as ground leaves. Sunflower roots apparently released exudates into the nutrient solution and soil. Sunflower root exudates inhibited sunflower emergence, and reduced sorghum, soybean, and sunflower height, fresh weight, and dry weight.

Interference studies utilizing natural infestations of broadleaf signalgrass [Brachiaria platyphylla (Griseb.) Nash] in peanuts [Arachis hypogaea (L.) ‘Florigiant′] were conducted at two sites in 1978 and repeated at the same sites in 1979. Full-season interference from broadleaf signalgrass populations of 8, 16, and 1050 plants/10 m of row reduced seed yields 14, 28, and 69%, respectively. Linear regression analysis showed that slightly less than 4 plants/10 m of row significantly reduced yields. Broadleaf signalgrass interference with peanuts for 6 weeks or less after planting did not reduce seed yields; however, interference for 8 weeks or longer after planting did. Peanuts kept weed-free for 6 weeks or more after planting had seed yields equal to peanuts kept weed-free all season. Full-season broadleaf signalgrass interference reduced mature peanut forage yields 64%, but peanut interference only reduced broadleaf signalgrass forage yield 10%.

The fate of 3,4-dichloroaniline (DCA), a major metabolite of the herbicide propanil (3′,4′-dichloropropionanilide), in rice (Oryza sativa L.), soil, water, and aquatic organisms was determined in rice-paddy microecosystems. Soil, treated with 10 ppm DCA, was placed in glass chambers, planted to rice, then flooded when the rice reached the two-leaf stage. After flooding, four species of aquatic organisms were added. The concentration of DCA and metabolites in soil, rice, water, and aquatic organisms was determined over a period of time. A maximum of 2.8% of the total radioactivity applied to soil desorbed or leached into water. DCA recovered from water decreased from 12 to 1% of the total radioactivity in water between 1 and 30 days after flooding. Between 10.5 and 18.5% of the radioactivity remaining in soil at the end of the experiments was extractable. Of the radioactivity recovered, between 5 and 11% was DCA, and up to 6 to 19% was 3,3′,4,4′-tetrachloroazobenzene (TCAB), these percentages being dependent on exposure time. Rice accumulated 0.5% or less of the total radioactivity in soil. Only 35 to 55% of the accumulated radioactivity was extractable. Very small amounts of radioactivity were accumulated by aquatic organisms.

The persistence and effectiveness in pumpkin [Cucurbita moschata (Puch.) Poir.] weed control of several starch xanthide (SX) and commercial formulations of the ammonium (NH3) salt and methyl (CH3) ester of chloramben (3-amino-2,5-dichlorobenzoic acid) were studied in the laboratory and field. The soluble concentrate (SC) of chloramben NH3 salt and the emulsifiable concentrate (EC) of chloramben CH3 ester controlled weeds throughout the growing season on a silt loam soil. SC chloramben NH3 salt was not effective, and EC chloramben CH3 ester was inconsistent in weed control on sandy soil. Manipulation of the SX formulation produced products with slow, uniform release rates. The release rates (crosslinking reagent in parenthesis) rank as follows, from fastest to slowest: SX(Ca2+) CH3 ester = SX(H2O2) acid > SX(H2O2) CH3 ester > SX(Fe3+) acid > SX(Fe3+) CH3 ester. In trials on silt loam and sand, SX formulations did not control weeds better than EC chloramben CH3 ester.

Benazolin (4-chloro-2-oxobenzothiazolin-3-ylacetic acid) formulated as the dimethylamine salt was evaluated for common cocklebur (Xanthium pensylvanicum Wallr.) and prickly sida (Sida spinosa L.) control in soybeans [Glycine max (L.) Merr.] between 1977 and 1979. Benazolin was applied alone or in admixtures with acifluorfen {5-[2-chloro-4-(trifluoromethyl)phenoxy]-2-nitrobenzoic acid}, bentazon [3-isopropyl-1H-2,1,3-benzothiadiazin-4 (3H)-one 2,2-dioxide], dinoseb (2-sec-butyl-4,6-dinitrophenol) plus naptalam (N-1-naphthylphthalamic acid), and 2,4-DB [4-(2,4-dichlorophenoxy)butyric acid] over-the-top of soybeans {V3 to V12 [V(N); vegetative stage with “N” nodes on the main stem beginning with the unifoliolate node]}. Benazolin effectively controlled common cocklebur at rates of 0.2 and 0.4 kg/ha. Soybean tolerance was acceptable even with a repeat application of 0.4 kg/ha. Early-season (July) control was less than late season (August) because it took 2 to 3 weeks for benazolin to kill common cocklebur. Prickly sida control was poor with benazolin even at 0.6 kg/ha. Soybean tolerance and seed yields were higher when soybeans were treated with admixtures of benazolin plus bentazon than with benazolin alone. Antagonism was observed with this admixture for prickly sida and late-season common cocklebur control. Antagonism was eliminated with ratios of benazolin to bentazon of 1 to 3 applied in a single application or a 1 to 1.5 ratio repeated.

Use of R-25788 (N,N-diallyl-2,2-dichloroacetamide) eliminated early-season corn (Zea mays L. '501D′) injury, stand loss, and yield reduction caused by EPTC (S-ethyl dipropylthiocarbamate) at 3.4, 6.7, and 13.4 kg/ha. R-25788 also eliminated early-season corn injury from butylate (S-ethyl diisobutylthiocarbamate) at 9.0 kg/ha. R-25788 did not consistently prevent corn yield reduction from 2,4-D [(2,4-dichlorophenoxy)acetic acid] or EPTC + 2,4-D. R-25788 had no effect on weed control from any of the herbicides evaluated nor any effect by itself on corn injury or corn yield. No corn injury or yield reductions occurred from vernolate (S-propyl dipropylthiocarbamate) at rates up to 6.7 kg/ha or alachlor [2-chloro-2′, 6′-diethyl-N-(methoxymethyl)acetanilide] at rates up to 13.4 kg/ha. Early-season corn injury frequently did not result in reduced corn yield.

Laboratory and field studies were conducted to compare the degradation rate of EPTC (S-ethyl dipropylthiocarbamate) in soils with a previous history of EPTC application vs. soils with no prior EPTC application. Laboratory experiments showed a rapid breakdown of 14C-carbonyl EPTC to 14CO2 in Kennebec silt loam (sil) and Tripp very fine sandy loam (vfsl) with prior exposure to EPTC. A single prior application of EPTC to Tripp vfsl was sufficient to increase the rate of 14CO2 evolution. The rate of EPTC degradation in Tripp vfsl with a history of EPTC exposure was dependent on soil moisture from below 3% and independent of moisture above 3%. Patterns of degradation at 5, 15, and 25 C in the Kennebec sil with and without prior history were described by exponential decay. EPTC was degraded more rapidly at 15 and 25 C in the Kennebec sil with a prior EPTC history. Under field conditions the breakdown of EPTC in a Kennebec sil with and without prior exposure to EPTC was similar to laboratory results.

The effect of quackgrass [Agropyron repens (L.) Beauv.] density and duration of interference on soybeans [Glycine max (L.) Merr.] was investigated in two studies. In the density study, the average reduction in soybean yield by quackgrass densities of 520 and 910 shoots/m2 was 19 and 55%, respectively. Quackgrass densities of 95 and 160 shoots/m2 did not significantly reduce soybean yields. The number of branches that produced pods, the number of pods and seeds per plant, and soybean height were reduced by the two highest densities. In 1980, quackgrass densities of 265 and 595 shoots/m2 reduced soybean leaf area and plant dry weight. Leaf area partitioning (LAP), leaf weight partitioning (LWP), and net assimilation rate (NAR) of soybeans were reduced by a quackgrass density of 595 shoots/m2. In the duration study, interference by a natural stand of quackgrass for 6 weeks, 8 weeks, and full-season decreased soybean yield an average of 11, 23, and 33%, respectively. Results from the duration study suggest that a selective postemergence herbicide for the control of quackgrass in soybeans would be beneficial if available.

Soil-applied herbicides were evaluated for control of blackjack oak (Quercus marilandica Muenchh.), huisache [Acacia farnesiana (L.) Willd.], honey mesquite [Prosopis juliflora (Swartz) DC. var. glandulosa (Torr.) Cockerell], live oak (Quercus virginiana Mill.), Macartney rose (Rosa bracteata Wendl.), winged elm (Ulmus alata Michx.), and yaupon (Ilex vomitoria Ait.) in Texas. Various spacing of spot treatments of pelleted tebuthiuron {N-[5-(1,1-dimethylethyl)-1,3,4-thiadiazol-2-yl]-N,N′-dimethylurea} on huisache and live oak and picloram (4-amino-3,5,6-trichloropicolinic acid) on Macartney rose up to a 2.7-m square grid did not change herbicide effectiveness. Pelleted tebuthiuron at 2.2 kg/ha reduced the canopy of live oak and killed a significant percentage of plants; however, differences among herbicide formulations and distance of placement in a grid were small. On unburned plots, 2.2 kg/ha of tebuthiuron applied as pellets at 2.7-m centers and as a broadcast wettable-powder treatment killed fewer yaupon than pellets applied in most broadcast treatments. In individual-plant treatments, bromacil (5-bromo-3-sec-butyl-6-methyluracil) and picloram solutions at 2 g/plant killed 45% of the yaupon 1.5 to 2 m tall on a fine sandy loam, whereas 0.5 g/plant of either herbicide killed 70% or more of the yaupon plants 1 m tall on a loamy fine sand. Both bromacil and picloram at 1 g/plant killed all blackjack oak and winged elm sprouts 1 to 2 m tall. On a clay soil, 1 g of bromacil/plant killed 79% of the live oak and 88% of the winged elm plants, whereas picloram killed only 38 and 45%, respectively. Neither bromacil nor picloram was effective as soil treatments for killing honey mesquite.

Responses of Rhizoctonia solani Kuhn to napropamide [2-(α-naphthoxy)-N,N-diethylpropionamide], were evaluated by measuring whole-cell respiration, mitochondrial respiration, ATP synthesis, and membrane leakage. Whole-cell respiration, measured with an O2 electrode, was stimulated in the presence of napropamide at 1.1, 2.2, and 4.4 × 10−5 M. Mitochondrial respiration was stimulated at 1.1 × 10−11 M, but higher concentrations were inhibitory. The addition of 10−5 M napropamide to isolated mitochondria of R. solani resulted in reduced ATP synthesis, measured by the firefly luciferase assay, and in increased membrane permeability as measured by increases in electrical conductivity of filtrates from R. solani grown in culture medium containing napropamide. These results indicate that, under laboratory conditions, napropamide reduced ATP synthesis, caused membrane leakage, and stimulated respiration in R. solani.

Efficacy of atrazine [2-chloro-4-(ethylamino-6-(isopropylamino)-s-triazine] applied preemergence to no-tillage and conventional-tillage corn (Zea mays L.) was studied in the field for 2 yr at two locations. Other variables examined were lime treatments, atrazine rates, and acid-forming (NH4NO3) vs. nonacid-forming (NaNO3) nitrogen fertilizers. Mean surface soil pH levels during the growing season were higher with no-tillage than conventional tillage, because of the retention of lime in the surface in no-tillage vs. mixing it with the soil in conventional tillage, but there was no consistent increase in atrazine efficacy or longevity in one system over the other. Liming significantly increased atrazine efficacy and longevity in both no-tillage and conventional-tillage systems. Increased rates of atrazine increased weed control and longevity of the herbicide. Use of NaNO3 as a nitrogen source resulted in increased atrazine efficacy and longevity as compared with use of NH4NO3 during the first year, which was relatively dry, but had no effect during the second year, which was relatively wet.

The allelopathic potential of wheat [Triticum aestivum (L.) ‘Doublecrop′] straw residue was evaluated on weed-seed germination and seedling growth. The inhibition of weed-seed germination and seedling growth was extract-, species-, and temperature-dependent. The extracts prepared by agitating and soaking caused greater inhibition than those obtained by leaching. The descending order of species susceptibility was ivyleaf morningglory [Ipomoea hederacea (L.) Jacq.], velvetleaf (Abutilon theophrasti Medic.), pitted morningglory (Ipomoea lacunosa L.), hemp sesbania [Sesbania exaltata (Raf.) Cory], sicklepod (Cassia obtusifolia L.), and Japanese barnyard millet [Echinochloa crus-galli var. frumetaceae (Roxb.) Link]. Incubation at 35 C caused the greatest inhibition of germination and growth.

Of 15 pesticides evaluated in a screening test with respect to their effects on growth and nitrogen assimilation of the Azolla mexicana (Presl) – Anabaena azollae (Strasburger) symbiosis, the bipyridilium and phenolic herbicides at 0.1 ppmw were the most detrimental, causing up to a 75% reduction in nitrogen fixation and nitrate reduction with little or no effect on growth. Chloramben [3-amino-2,5-dichlorobenzoic acid] at 1.0 ppmw, and dicamba [3,6-dichloro-o-anisic acid], and benomyl [methyl-1-(butylcarbamoyl)-2-benzimidazolyl carbamate] at 10.0 ppmw caused an 84 to 99% reduction in nitrogen fixation without affecting nitrate reduction or growth. Simazine [2-chloro-4,6-bis(ethylamino)-s-triazine] at 10.0 ppmw stimulated nitrate reduction 20 fold, causing a 99% reduction in nitrogen fixation. Growth and nitrogen assimilation were reduced at similar concentrations between 0.1 and 10 ppmw for each of the other benzoic, triazine, dinitroanaline, and urea herbicides tested. Naptalam [N-1-naphthylphthalamic acid] was the only pesticide tested that had no effect on growth or nitrogen assimilation at 10.0 ppmw.