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Several commercial formulations of Bacillus thuringiensis (Al) insecticides were applied on cabbage and lepidopterous pests including Tricoplusia it (cabbage looper, CL), Spodoptera exigua (beet armyworm, BAW), and Plutella xvlostella (diamondback moth, DBM) were effectively reduced in population. The ten commercial products did not appear to vary significantly in controlling CL, the dominant species present in the cabbage.

Proclaim® insecticide (emamectin benzoate, MK -244, Merck Research Laboratories) was applied two times during the broccoli growing season for lepidoperous insect control. The primary pest was cabbage looper (Trichoplusia ni CL) and very few beet armyworm (Spodoptera exigua). After the second application at 1, 2, and 3 weeks after treatment (WAT), Proclaim reduced the number of CL in the broccoli relative to the untreated check. The number of large larvae observed in the Proclaim treated broccoli was one-half of that found in the untreated broccoli. Proclaim efficacy to reduce CL was comparable to the standard treatment of Larvin® (thiodicarb) plus Asana® (esfenvalerate). At harvest, the Proclaim treated broccoli had 20% infested crowns compared to 28% for the standard treatment and 44% in the untreated.

Four experimental insecticides being developed for lepidopterous insect control in vegetable crops were applied on cabbage and demonstrated efficacy against cabbage looper (Trichoplusia ni, CL). Chlorfenapyr (Alert®), tebufenozide (Confirm®), spinosad (Success®), and emamectin- benzoate (Proclaim®) reduced the number of larger cabbage loopers following multiple applications. The experimental insecticides were comparable or superior to the commercially available standard treatments of thiodicarb (Larvin®), methomyl (Lannate®), or cryolite (Kryocide®). Evaluations at 7 days after treatment (DAT) showed that Success controlled CL so that no medium to large -sized larvae were observed. Alert, Confirm, and Proclaim were highly effective and less than 0.3 CL/plant were detected. The untreated cabbage had 0.5 to 1.1 CL/plant that were medium to large-sized at various observation dates.

In a small plot field study, diamondback moth (Plutella xylostella, DBM) in cabbage were not significantly reduced by various insecticide treatments when applied one time during the season. ABG -6406 (Abbott Laboratories), Success® (spinosad, DowElanco), and Kryocide® generally maintained larger -sized DBM larval numbers below or similar to the untreated check at most rating dates. Cabbage treated by Xentari®, Alert® (clorfenapyr, Cyanamid), Confirm® (tebufenozide, Rohm and Haas) and Proclaim® (emamectin benzoate, Novartis) exhibited numbers of larger -sized larvae that exceeded the untreated check at certain rating dates. DBM populations were not consistent during the testing period to allow assessment of treatment differences.

Includes bibliographical references (leaves 174-201) / xxii, 201, [20] leaves : ill., photos (col.) ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Thesis (Ph.D.)--University of Adelaide, School of Agriculture and Wine, Discipline of Wine and Horticulture, 2004

Thesis ((MSc. Agriculture (Agronomy)) -- University of Limpopo, 2015 / An experiment was conducted to evaluate the effect of vermicompost on cabbage growth and yield. Vermicompost (VC) was applied at 2500 kg/ha and was compared to one organic {vita grow (VG) [N:P:K 2:3:2 (16)] and one chemical fertiliser (CF) (N:P:K 2:3:2(22)]} which were both applied at 1500 kg/ha. The other treatments were prepared as mixtures of the three fertilisers (i.e. vermicompost and vita grow; vita grow and chemical fertiliser as well as vermicompost and chemical fertiliser) at 50% recommended rate, with no fertiliser treatment as a control. The trial was laid out in a randomised complete block design with three replicates. Chemical fertiliser achieved the highest chlorophyll content (80.6 nmol/mg) which was significantly higher than the other treatments. Vermicompost and the control had the least chlorophyll content at 58.6 and 55.8 nmol/mg, respectively. VC+VG, CF and CF+VC achieved the highest numbers of marketable heads while the control had the least. VC+VG, CF and CF+VC had more than 60% of the plants producing marketable heads whilst VC and VG had less than 40% of the plants producing marketable heads. The control only had 19.93% of the plants producing marketable heads. Range of marketable heads ranged from 2.82 t/ha for the control to 12.7 t/ha for CF. VC+VG, CF and CF+VC achieved marketable yields above 10.0 t/ha.VC and VG achieved 5.45 and 8.28 t/ha. The results thus show that use of chemical fertiliser or the combinations of VC and VG and that of CF and VC are the ones that can be recommended for cabbage production. Key words: vermicompost, growth, yield, cabbage, fertiliser

Three criteria, development, flight, and oviposition, were used to compare a laboratory-adapted and wild-type colony of Trichoolusia ni. The laboratory-adapted colony was further examined to determine the effect of larval crowding and starvation on the above criteria. The laboratory-adapted colony displayed a shorter development time and higher immature mortality than the wild-type colony. Differences in flight activity between and within the colonies were observed. Wild-type mated females were the most active group of tested moths. The oviposition rate of the laboratory-adapted colony was higher than the wild-type colony. Innate differences in parent populations and selective pressures during the rearing of the laboratory-adapted colony may explain differences between the colonies. Larval crowding resulted in prolonged development time, lower pupal weight, increased larval mortality, and increased adult longevity. Starvation during the larval stage produced similar changes. Flight activity declined with the degree of larval crowding and starvation. Larval crowding and starvation also resulted in a decline in adult fecundity and mating frequency. It is postulated that stress to the larvae resulted in a decline in energy sources to be used in the adult stage, producing docile adults. / M.S.

The structure of the cabbage looper ocellus was examined by light and electron microscopy. Rhabdoms were found in the distal region of the retinula cells. These were formed by the apposition of microvillar borders of adjacent cells, thus, an interrupted network of rhabdoms was found to exist in cross section. No convergence of first order neurons to second order neurons was found anywhere above the protocerebrum as is typical of insect photoreceptors in general. No synapses were found to exist anywhere above the brain. It is hypothesized that the cabbage looper ocellus plays a major role in determining the light intensity at which crepuscular flight is initiated. This hypothesis was tested in the following manner. Laboratory reared moths were divided into five groups each with a different or no treatment. These were: 1. Compound eyes and ocelli occluded. 2. Compound eyes occluded. 3. Ocelli occluded. 4. Controls. 5. Controls sham treated. All groups were placed in transparent flight chambers and submitted to a simulated sunset. Test results were compared using the Duncan Multi-Range Test and Standard errors. The results indicate that the cabbage looper ocellus plays a role in determining the light intensity at which crepuscular flight is initiated. / Master of Science

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