Cabbage Head Weight Research Articles

Physiological Productivity of CABBAGE (Brassica oleracea var. capitata L.) in Response to Planting Distance and Rate of Nitrogen Application

Cabbage is one of the most important vegetables in the world, known for being a heavy nutrient feeder crop, especially nitrogen (N), and is influenced by planting distance, which plays a big role in production to attain a higher yield while producing the best quality cabbage suited to consumers’ preferences. A study aimed to determine the levels of nitrogen and planting distance that influence the growth parameters, yield attributes, and yield of cabbage, as well as the economic efficiency of the treatments. Results show that the yield of cabbage is significantly influenced by planting distances and rate of nitrogen application, wherein 30 cm x 30 cm spacing proved to be the most productive when applied with 150-200 kg N/ha, obtaining the same highest yield in tons per hectare. Moreover, the same treatment combinations influenced other key physiological parameters, e.g., polar and equatorial head sizes and cabbage head weight. Economic analysis revealed that planting cabbage at a closer distance (e.g., 30 cm x 30 cm) with 150 kg/ha N, which will eventually provide more plant population density per area, would lead to a highly profitable venture for cabbage production.

Evaluation of Furrow Irrigation System on Head Cabbage Yield and Water Use Efficiency in Arbegona Woreda, Ethiopia

Available fresh water resources are subjected to an ever-increasing pressure due to extensive agricultural water demand for irrigated lands. A long-term perspective in shortage of fresh water resources, especially in arid and semi-arid area, highlights an urgent solution for innovative irrigation strategies and agricultural water management. The experiment was conducted in Arbegona district, Sidama region of Ethiopia. This experiment was conducted to evaluate and demonstrate of Alternative, Fixed and Conventional furrow irrigations on Head Cabbage yield and water use efficiency. To achieve this objective the treatment were three furrow irrigation method (Conventional, Alternate and Fixed furrow) laid out in a random complete block design (RCBD) with three replications. The result shows that there is no significant difference between alternative and conventional furrow irrigation on Head cabbage yield. But, fixed furrow irrigation system reduces the yield significantly. The maximum yield (48407kg/ha and 43840kg/ha) was obtained from conventional and alternate furrow irrigation method, respectively. The minimum yield (35242kg/ha) was obtained under fixed furrow irrigation. Furrow irrigation method has no significant effect on plant height, head weight and head diameter of head cabbage. The highest water use efficiency was obtained from alternate furrow irrigation and shows significant difference between the other treatments. Therefore, to save water, labour and time without significant yield reduction alternate furrow irrigation is recommended in water scarce area of Ethiopia.

The Effect of Biochar Applied Alone and in Combination with Mineral and Organic Fertilisers on the Yield of White Cabbage and Soil Properties

The study aimed to investigate the effectiveness of biochar application on fertile soils in a temperate climate during the first year of application. The field trial was conducted on a nutrient-rich silt loam soil at two experimental sites in north-eastern Slovenia (Biš and Skorba). The effect of biochar applied alone or in combination with compost or mineral fertiliser on soil properties and yield of white cabbage was studied. In addition to the control (C), the soil received five treatments including biochar (B; 1.5 t/ha), compost (CO; 1.5 t/ha), biochar-mixed compost (BCO; 3.0 t/ha), standard mineral fertilisers (NPK; NPK 0.35 t/ha, potassium sulphate 0.25 t/ha and calcium ammonium nitrate 0.25 t/ha) and combined application of half the amountof NPK and BCO (NPK+BCO). The results showed that the applied treatments had no significant influence on the measured soil chemical parameters, except for the amount of total organic carbon, electrical conductivity and pH in Biš and total carbon in Skorba. All investigated parameters (cabbage head weight, head circumference, total and market yield) were higher at the experimental site Skorba. Statistically significant differences were found only at the experimental site Biš, where the treatment influenced all parameters (p < 0.01), except for the head circumference of the cabbage. The NPK and NPK+BCO treatments produced significantly higher total yields (66.7 t/ha and 65.8 t/ha, respectively) and marketable yields (53.2 t/ha and 51.8 t/ha, respectively) compared to the other treatments (41.3-52.6 t/ha and 30.5-42.4 t/ha, respectively). Although the differences between the other treatments were insignificant, a trend of decreasing cabbage yields towards CO > BCO > B was observed. Similar results were also obtained when analysing the average data of the two experimental sites.

Improvement of cabbage growth and yield by nanofertilizers and nanoparticles

Cabbage Brassica oleracea var. capitata L. is one of major winter leafy vegetable which belong to cruciferae family. The local seedlings of 30 days’ cabbage were implanted in 100 m2 land in the Abu Ghraib region, Baghdad, at the 1st of October 2019 and harvested after 75 days, as one agriculture season in Iraq. The plants divided into 6 groups, each includes 45 plants. One of the six groups do not receive any type of fertilizers, as control, while the last 5 groups received different types of nanofertilizers every 21 days. CeO2 prepared by laser ablation and commercial iron and zinc nanoparticles were characterized by field emission scanning electron microscope (FE-SEM), x-ray diffraction (XRD) and energy dispersive x–ray (EXD). The three metal nanoparticles were used as microelements to enhance NPK nanofertilizer. Cabbages that fertilized with nanofertilizers revealed higher circumferences (not less 49.42 cm) when compared with control (28.17 cm). High average of head circumference (56.22 cm) was observed when plant fertilized with NPK + Fe nano fertilizer. On the other hand, cabbages that did not receive any nano fertilizers, as control, show height head of 10.67 cm, while the height head average of 16.67 cm was observed when plant fertilized with NPK + Fe nano fertilizer. Moreover, the higher average of cabbage head weight increased three times more than than control to reach 1.88 Kg/plant when the cabbage fertilized with NPK + CeO2 NPs within 75 days. Furthermore, the higher chlorophyll content of 131.22 mg / 100 g plant leaves was observed in cabbage that fertilized with NPK + CeO2 NPs. Significant differences were obtained between the higher values and others.

Response of Head Cabbage (<i>Brassica olearacea L.</i>) Yield to Application of Different Rates of Inorganic Nitrogen and Phosphorus Fertilizers at Bore, Southern Ethiopia

The field trial was conducted during 2017 and 2018 main cropping season at the Bore Agricultural Research Centre which is located in Gudji Zones, of Southern Ethiopia to determine the effect of different application rates of nitrogen and phosphorus fertilizers on growth, yield and yield components of head cabbage and to identify their economically appropriate rates that maximize yield of head cabbage. The experiment was carried out to study cabbage variety Olsen to added N and P nutrients in respect to growth, yield and yield related parameters of the crop. The longest head initiation (90 days) and longest (140) days to maturity was attained in 294 kg ha^-1 Nitrogen and 138 kg ha^-1 phosphorus treatment, while shortest head initiation (64.33 days) was obtained in control treatment. The maximum plant height (26.4 cm) was recorded for the treatment T3P4 (235 +138 kag ha^-1), while the lowest (16.9 cm) plant height was recorded from the T1P1 (control) treatment. Nutrient levels markedly influenced the diameter, height, head mass and yield of head cabbage. The maximum average head diameter (25.44 cm) and average height (27.33 cm) was recorded in treatment receiving 235 kg N and 82 kg P ha^-1. Combined application of 235 kg N ha^-1 with the 82 kg P ha^-1 produced the highest (2356.67 g) untrimmed head weight of cabbage followed by second maximum (2133.33 g) untrimmed head weight with the rate of 235 kg N ha^-1 with the 110 kg P ha^-1 while the least (1120.67 g) untrimmed head weight was recorded for the control treatment. Combined application of 235 kg nitrogen and 82 kg phosphorus ha^-1 (N3P2) recorded maximum (69.00 t) head yield without wrapper ha^-1 and the lowest (27.66 t ha^-1) was recorded by control treatment. The marginal rate of returns, which determines the acceptability of any treatments shows that treatments that received 235 kg N ha^-1 in combination with 82 kg ha^-1 of P yielded 43498% marginal revenue. Therefore, this combined nutrient application rates can be recommended in the research area and similar agro-ecologies since it is the most feasible rates for the producers because of its low cost of production and higher benefits.

Correlational Analysis between Growth and Yield Parameters of Cabbage (Brassica oleracea) as Affected by Organic Manure and Inorganic Fertilizer in Jos

Aim: To determine the correlation between the growth and yield parameters of cabbage grown with organic manure and inorganic fertilizer.
 Study Design: The experimental design consist of randomized complete block design with five treatments which were replicated four times.
 Location and Duration: The experiment was conducted at the experimental field of Federal College of Forestry, Jos, during the 2018/2019 raining season.
 Methods: Land clearing was done and the land was properly demarcated based on the different treatments and replicates. Cabbage seeds were first planted in a nursery bed and later transplanted onto the experimental plots. Data was taken on the plant height, leaf count, cabbage head diameter and head weight. The data collected were subjected to analysis of variance (ANOVA) using SPSS version 23 and Duncan Multiple Range Test, used to separate the means were significance occurred.
 Results: The result of the correlation coefficient of growth and yield showed that a strong correlation exist between plant height and cabbage head weight (r = 0.681 and 0.648) at P ≤ 0.01. Plant height was also positively correlated with head weight (r = 0.365, P ≤ 0.05) and head weight was as well and positively correlated with head diameter at (r = 0.501, P ≤ 0.05).
 Conclusion: Based on the results obtained, it can be concluded that application of organic manure and inorganic fertilizer has positive correlations between the growth and the yield parameters of cabbage.

Influence of Organic Manure and Inorganic Fertilizer on the Growth, Yield and Phytochemical Constituents of Cabbage (Brassica oleracea)

Organic farming is gaining attention and increasing globally because of its eco-friendly, safety and its health benefits to humans. A field experiment was conducted at Federal College of Forestry Jos, to determine the influence of organic manure and inorganic fertilizer on the growth, yield and phytochemical constituents of cabbage. Randomized Complete Block Design was used as experimental design involving five treatments with T0 as control (No application of manure), T1 (N.P.K fertilizer), T2 (Poultry droppings), T3 (Cow droppings) and T4 (Goat droppings). Data was taken on plant height, number of leaves, head diameter and head weight of cabbage. Qualitative phytochemical analysis on saponins, tannins, alkaloids, flavonoids, cardiac glycosides, anthocyanins, phenols, amino acids, steroids and terpenoids were carried out and quantitative analysis was done for phytochemicals present. The result obtained showed a significant difference for the plant height, leaf count, head diameter and head weight at p≤0.05. Flavonoids, alkaloids, amino acids, terpenoids, tannins and phenols were present in the qualitative analysis and at different rates. Cabbage cultivation with poultry droppings (T2) was observed to stand out from the other treatments for the yield parameters and the phytochemical analysis. Result of the quantitative phytochemicals revealed that more phenolics, alkaloids and flavonoids were present in cabbage grown with organic manure than in inorganic fertilizer.

Organic fertilizer amended with immobilized bacterial cells for extended shelf-life

Abstract One of the major constrains in the development of microbially-amended agricultural products is the incapability of upholding high microbial count in the commercial products and field soil. The efficiency of immobilization technique to retain high microbial population and extend the shelf-life in bio-organic fertilizer was corroborated in this study. Four Gram negative bacterial strains with beneficial traits such as phosphorus solubilization, indole acetic acid production, siderophore production and nitrogen fixation were immobilized in a modified alginate solution and incorporated with compost, organic fertilizer and mineral fertilizer. The bacterial count in compost and organic fertilizer (5:5:5) were 107 cfu/g and 106 cfu/g respectively after one year of shelf-life. Mineral fertilizer (15:15:15) and immobilized bacteria that were mixed in 1:50 ratio exhibited 105 cfu/g after 210 days. Pelleting was found to be more suitable for liquid bacterial cells + organic fertilizer mixture than immobilized bacterial cells + organic fertilizer mixture. Sterilization technique by autoclaving was proven to be more destructive in eliminating indigenous microbes and effective in retaining nutrient content and immobilized bacterial cells as compared to gamma irradiation technique. One part of immobilized bacterial cells was mixed to fifty parts of organic fertilizer to sustain at least 106 cfu/g for 348 days. Field study results exhibited the efficiency of immobilized bio-organic fertilizer in increasing cabbage head weight as compared to organic fertilizer. This is also a pioneer report on the shelf-life of immobilized bacterial cells incorporated with organic and mineral fertilizers.

Investigating tarps to facilitate organic no-till cabbage production with high-residue cover crops

AbstractHigh-residue cover crops can facilitate organic no-till vegetable production when cover crop biomass production is sufficient to suppress weeds (>8000 kg ha−1), and cash crop growth is not limited by soil temperature, nutrient availability, or cover crop regrowth. In cool climates, however, both cover crop biomass production and soil temperature can be limiting for organic no-till. In addition, successful termination of cover crops can be a challenge, particularly when cover crops are grown as mixtures. We tested whether reusable plastic tarps, an increasingly popular tool for small-scale vegetable farmers, could be used to augment organic no-till cover crop termination and weed suppression. We no-till transplanted cabbage into a winter rye (Secale cereale L.)-hairy vetch (Vicia villosa Roth) cover crop mulch that was terminated with either a roller-crimper alone or a roller-crimper plus black or clear tarps. Tarps were applied for durations of 2, 4 and 5 weeks. Across tarp durations, black tarps increased the mean cabbage head weight by 58% compared with the no tarp treatment. This was likely due to a combination of improved weed suppression and nutrient availability. Although soil nutrients and biological activity were not directly measured, remaining cover crop mulch in the black tarp treatments was reduced by more than 1100 kg ha−1 when tarps were removed compared with clear and no tarp treatments. We interpret this as an indirect measurement of biological activity perhaps accelerated by lower daily soil temperature fluctuations and more constant volumetric water content under black tarps. The edges of both tarp types were held down, rather than buried, but moisture losses from the clear tarps were greater and this may have affected the efficacy of clear tarps. Plastic tarps effectively killed the vetch cover crop, whereas it readily regrew in the crimped but uncovered plots. However, emergence of large and smooth crabgrass (Digitaria spp.) appeared to be enhanced in the clear tarp treatment. Although this experiment was limited to a single site-year in New Hampshire, it shows that use of black tarps can overcome some of the obstacles to implementing cover crop-based no-till vegetable productions in northern climates.

Effect of Urine, Poultry Manure, and Dewatered Faecal Sludge on Agronomic Characteristics of Cabbage in Accra, Ghana

The study was to assess the: (i) effect of human urine and other organic inputs on cabbage growth, yield, nutrient uptake, N-use efficiency, and soil chemical characteristics; (ii) economic returns of the use of urine and/or other organic inputs as a source of fertiliser for cabbage production. To meet these objectives, participatory field trials were conducted at Dzorwulu, Accra. Four different treatments (Urine alone, Urine + dewatered faecal sludge (DFS), Urine + poultry droppings (PD), NPK (15-15-15) + PD) were applied in a Randomised Complete Block Design (RCBD) with soil alone as control. Each treatment was applied at a rate of 121 kg·N·ha−1 corresponding to the Nitrogen requirement of cabbage in Ghana. Growth and yield parameters, plant nutrient uptake, and soil chemical characteristics were determined using standard protocols. There were no significant differences between treatments for cabbage head weight, or total and marketable yields. However, unmarketable yield from NPK + PD was 1 to 2 times higher (p < 0.05) than those from Urine + PD, Urine + DFS, and Urine alone. Seasonal effect on yields was also pronounced with higher (p < 0.001) cabbage head weight (0.95 kg) and marketable yields (12.7 kg·ha−1) in the dry season than the rainy season (0.42 kg and 6.27 kg·ha−1). There was higher (p < 0.005) phosphorous uptake in cabbage from Urine + PD treated soil than those from other treatments. Nitrogen (N), phosphorous (P), and potassium (K) uptake in the dry season was significantly higher than the rainy season. Soils treated with Urine + DFS and Urine + PD were high in total N content. Urine + PD and Urine + DFS treated soils gave fairly high yield than PD + NPK with a net gain of US$1452.0 and US$1663.5, respectively. The application of urine in combination with poultry droppings has the potential to improve cabbage yields, nutrient uptake, and soil nitrogen and phosphorous content.

Use of different organic fertilizers on soil fertility improvement, growth and head yield parameters of cabbage (Brassica oleraceae L)

Field experiment was carried out in Akure in the rainforest zone of Nigeria to determine the effect of poultry manure, wood ash and rice bran on the soil fertility improvement, growth and head yield of cabbage (Brassica oleraceae L) in 2011 and 2012 cropping seasons. The three organic fertilizer treatments were applied each at 6 t/ha with a reference treatment NPK 15-15-15 applied at 300 kg/ha and a control treatment arranged in a randomized complete block design with three replicates. The results showed significant increases (P < 0.05) in the growth and head yield parameters of cabbage crop under the different organic fertilizers compared to the control treatment. The application of poultry manure resulted in the highest values of cabbage plant height, stem girth, leaf number, leaf area, head weight, head length and head girth followed by NPK 15-15-15, wood ash and rice bran, respectively. Cabbage head weight, head girth, head length, plant height, stem girth, leaf number and leaf area increased by 17, 18, 8,17, 19, 10 and 16 %, respectively, with application of poultry manure compared to NPK fertilizer. Also, these parameters increased by 23, 21, 13 29, 25, 17 and 45 % compared to the wood ash treatment. The highest values of soil pH, Ca and Mg were obtained under wood ash application, while the highest values of soil O.M and moderate values of soil P, K, Ca and Mg were obtained under poultry manure application. Moderate values of soil pH, K, Ca and low % N were also recorded under rice bran treatment. However, the highest K/Ca, K/Mg and P/Mg ratios of 93.1, 74.1 and 572.1, respectively, were obtained under NPK 15-15-15 fertilizer application compared to 2:1 K/Ca, 2:1 K/Mg and 16:1 P/Mg in rice bran treatment. The poultry manure applied at 6 t/ha gave the best results in improving soil fertility, growth and head yield of cabbage, and this was because of its balanced nutrient composition and the least C/N ratio.

Onion thrips (Thrips tabaci (Thysanoptera: Thripidae)) in cabbage on Prince Edward Island: observations on planting date and variety choice.

Onion thrips (Thrips tabaci Lindeman (Thysanoptera: Thripidae)) can be a pest in organic onion production on Prince Edward Island. This study was to examine the effect of planting time and variety on infestation levels and damage by onion thrips on cabbage (Brassicae oleraceacapitala (L.)). A field site was planted with 2 main and 8 lesser varieties of cabbage over 4 planting dates. Some varieties were short season and harvested on July 31 with longer season varieties harvested on September 2. Blue sticky traps were used to capture thrips migrating into the field site from July 22–September 2. Traps were counted weekly and cabbage heads within the field site were visually surveyed for thrips. At harvest, heads were weighed and measured, thrips damage was assessed then the head was dissected and thrips counted on the first four layers of the head. Thrips exhibited a preference for Lennox over Bronco throughout the season although thrips populations were not high enough to effect economic damage in 2014. Planting date influenced cabbage head weight and size with later plantings yielding the largest heads. Use of planting date and variety to avoid thrips populations is discussed.

Impact of Vermicompost on Growth and Development of Cabbage, &lt;em&gt;Brassica oleracea &lt;/em&gt; Linn. and their Sucking Pest, &lt;em&gt;Brevicoryne brassicae &lt;/em&gt; Linn. (Homoptera: Aphididae)

Aim of the present study was to produce vermicompost from organic solid wastes by using red earth worm, <em>Eisenia fetida </em> and to check growth promoting and pest suppression properties on cabbage, <em>Brassica oleracea </em>. The mass of 100 kg of various organic waste sources were collected from Gondar and used to prepare vermicompost. The vermicompost was prepared in the month of June-August 2011 and tested on cabbage, <em>B. oleracea </em> from October 2011 to February 2012. Vermicompost was applied at the rate of 25, 50, 100 and 200 gm/plant individually. Each application 10 plants were selected and vermicompost application was continued on bimonthly basis. Totally 40 plants were used for control group in which 10 plants were selected randomly. Total number of leaves per plant; leaf length and width; plant stand height and root length; cabbage head round distance and weight and aphid population built-up were the parameters studied in experimental and control cabbage plants. Significant differences (p<0.05; LSD) were observed in the growth and development and pest infestation level between vermicompost applied and control plants. The number of plant stand height, cabbage head, leaves of cabbage were also significantly different (p<0.05; LSD) in experimental cabbage compared to control. Maximum number of cabbage plant was infested by aphid in control than experimental groups. In conclusion vermicompost have significant impact on cabbage growth promotion and reduce the aphid infestation. In future using vermicompost to all kinds of crops and adopting it as commercial fertilizer may create job opportunity to small scale farming society. Also, in this ever escalating cost of chemical fertilizers, the use of vermicompost seems to be quite reasonable in agro-management and should be inclusive as one of the elements of poverty alleviation strategies in such as Ethiopian context.

Differences in Tolerance of Broccoli and Cabbage Cultivars to Clomazone Herbicide

Clomazone herbicide is registered for cabbage (Brassica oleracea Capitata group) in the United States but not for other crop groups within the species. Greenhouse and field experiments were designed to compare the tolerance of broccoli (B. oleracea Italica group) and cabbage cultivars to clomazone to assess its potential for weed management in broccoli. Four broccoli cultivars (Captain, Green Magic, Legacy, and Patron) and four cabbage cultivars (Bravo, SC 100, Stone Head, and Vantage Point) were evaluated in all experiments. In a greenhouse experiment where seedlings were transplanted into potting medium containing clomazone at 0, 1.0, 2.0, and 4.0 parts per million (ppm), ‘Bravo’ cabbage was most susceptible. Its injury ratings and shoot weight reduction at 1.0 ppm were similar to ratings and shoot weight reduction for the other cabbage cultivars at 4.0 ppm. Among the broccoli cultivars, Patron was highly susceptible, exhibiting injury and shoot weight reduction similar to Bravo. Green Magic was the most tolerant broccoli cultivar, and it exhibited injury and growth reduction similar to the tolerant cabbage cultivars. In a field experiment where clomazone was applied pretransplanting at 0.25, 0.5, and 1.0 lb/acre, 0.25 lb/acre caused moderate chlorosis to the susceptible cultivars, Bravo and Patron. At 0.50 and 1.0 lb/acre, most cultivars exhibited chlorosis at 2 weeks after transplanting (WAT); however, tolerant cultivars recovered and injury was often not observed at 6 WAT. At 1.0 lb/acre, chlorosis persisted until maturity on ‘Bravo’ and ‘Patron’ foliage. Clomazone did not reduce mean broccoli head weight or the percentage of plants producing market-size heads. Mean cabbage head weight for ‘Bravo’ was reduced by clomazone at 1.0 lb/acre. This study indicates that the variability in clomazone tolerance among broccoli cultivars may be similar to that among cabbage cultivars and suggests that the herbicide can be used safely on tolerant broccoli cultivars at rates that are recommended for cabbage.

Sorghum sudangrass as a summer cover and hay crop for organic fall cabbage production

AbstractNo-tillage (NT) organic vegetable production presents several economic opportunities for growers in the southeastern United States while promoting natural resource conservation. This study was conducted to determine if removal of sorghum sudangrass (SS) cover crop biomass as hay, frequency at which the cover crop is mowed, and tillage affect weed suppression and head weight of transplanted organic cabbage. Sorghum sudangrass [Sorghum bicolor(L.) Moench×Sorgum sudanense(Piper) Staph.] was planted in May 2004 at Reidsville and Goldsboro, NC, preceding the planting of organic ‘Bravo’ cabbage (Brassica oleraceaL. Capitata group) in August and September 2004, respectively. SS management systems included: low-frequency mowing with hay removed following the first mowing operation (LFM-H), low-frequency mowing with hay not removed (LFM), high-frequency mowing with hay not removed (HFM) and a no cover crop control. Two tillage treatments were applied within each management system: conventional tillage (CT) and NT. Under NT conditions, SS mulch generated by LFM offered broadleaf weed control in cabbage similar to that achieved under CT, regardless of whether cover crop biomass was removed as hay. Mowing with higher frequency reduced SS cover crop biomass by 18–33% and reduced weed suppression in NT cabbage. Mowing frequency did not influence the quantity of SS that re-grew in the cabbage crop. SS re-growth contributed to lower head weight in NT compared to CT cabbage in Goldsboro, and crop failure of NT cabbage in Reidsville. Cabbage head weight was highest when the crop was not preceded by SS in both CT and NT systems (1.6 as opposed to 1.3–1.4 kg head−1). Our findings suggest that the potential for growers to manage a cover crop also as a hay crop does exist; however, SS may not be a compatible cover crop species for organic fall cabbage production due to high amounts of re-growth.

Estimating cabbage physical parameters using remote sensing technology

Remote sensing has long been used as a tool to extract plant growth and yield information for many crops, but little research has been conducted on cabbage ( Brassica oleracea var. capitata L.) with this technology. The objective of this study was to evaluate aerial photography and field reflectance spectra for estimating cabbage physical parameters. An experiment was conducted on a cabbage field with 81 experimental plots to which different insecticide treatments were applied. Aerial color-infrared (CIR) photographs were taken from the field shortly before harvest. Meanwhile, field reflectance spectra and four plant physical parameters, including plant diameter, head diameter, plant weight and head weight, were measured from a total of 243 plants (three plants per plot). Plant area and spectral digital values for the near-infrared, red and green bands for each of the 243 plants were extracted from a digitized aerial CIR photograph. Four different vegetation indices, including the normalized difference vegetation index (NDVI), were calculated. Correlation analysis showed that the cabbage physical parameters were significantly related to the photo-derived plant area and spectral variables. Regression analysis showed that head weight was linearly related to plant area with an r 2 value of 0.91 and quadratically related to NDVI with an r 2 value of 0.66. Stepwise regression performed on cabbage head weight and 601 bands from 400 to 1000 nm in the field reflectance spectra revealed that 71% of the variability in head weight could be explained by eight significant bands in the spectra. As an application example, cabbage yield estimated from photo-derived plant area in each plot was used to compare the differences among 16 treatments. These results indicate that remote sensing can be a useful tool for evaluating cabbage growth and yield variations.

Effect of s-metolachlor application timing on cabbage tolerance

There is limited information on the effect of s-metolachlor application timing on cabbage tolerance in Ontario. A total of five field trials (1999–2004) were established near Ridgetown Ontario, Canada to evaluate tolerance of cabbage to s-metolachlor applied pre-transplant incorporated, pre-transplant and post-transplant at 800, 1600 and 2400 g a.i./ha. s-Metolachlor applied pre-transplant incorporated, pre-transplant and post-transplant at 800, 1600 and 2400 g a.i./ha did not have any effect on visual injury, marketable head production, marketable head weight and yield of cabbage. There was also no difference among s-metolachlor application timings (pre-transplant incorporated, pre-transplant and post-transplant) in respect to cabbage tolerance. Based on these results s-metolachlor applied pre-transplant incorporated, pre-transplant and post-transplant at 800, 1600 and 2400 g a.i./ha has an acceptable level of crop safety in cabbage.

キャベツの品種，作型および栽植距離が収穫時の生育の斉一性に及ぼす影響

キャベツ収穫時の生育の斉一性に及ぼす品種および作型の影響について，異なる栽植密度条件下で検討した． 1．株張りの小さい小型品種‘ダンディーボール’では個体間競合の生じる期間が短いうえ，地上部全重に占める結球重の割合が大きく，密植栽培条件下でも生育の斉一性が高かった． 2．冬まき初夏どり作型（気温上昇型の作型）では，夏まき冬どり作型（気温下降型の作型）と比較して生育初期の株張りが抑えられることで，比較的高密度栽培条件でも生育の斉一性が高く維持された． 3．以上の結果から，一斉収穫は気温上昇型の作型で導入が容易であること．また，気温下降型の作型では，株張りの小さい品種を用いるのが有効であることが明らかとなった．

Comparison ofTrichogramma brassicae(Hymenoptera: Trichogrammatidae) Augmentation with Organic and Synthetic Pesticides for Control of Cruciferous Lepidoptera

We monitored egg parasitism and larval populations of Pieris rapae (L.) and Trichoplusia ni (Hubner) in cabbage plots treated with point and broadcast releases of Trichogramma brassicae Bezdenko, and we investigated whether weekly sugar sprays improved egg parasitism rates. We also compared yield and pest densities in cabbage treated with Bacillus thuringiensis (Dipel), methomyl (Lannate), or point releases of T. brassicae to an untreated control, and investigated the economics of these control strategies. Egg parasitism was highest in the point release treatment (46%), and parasitism in the broadcast and the broadcast + sugar spray treatments (31 and 24%, respectively) did not differ from the control. Weekly applications of sucrose did not increase egg parasitism or decrease larval pest populations. Releases of T. brassicae did not significantly reduce P. rapae and T. ni larval populations, and plant damage and cabbage head weight were unaffected in the T. brassicae treatments relative to the control. In addition, the cost of applying the T. brassicae wasps was not recouped with significant yield improvements relative to the control. Methomyl and Bt consistently suppressed P. rapae and T. ni populations below action thresholds in a cost-effective manner.

Pest Evaluation in Sustainable Cabbage Production Systems

Conservation tillage systems provide optimum conditions to reduce soil erosion and increase surface soil organic matter. This experiment was established with the long-term goal of developing conservation tillage systems that use either chemical inputs to produce vegetables and control pests, or legume cover crops, biological pesticides, and tillage to provide plant nutrition and control pests. The experiment consisted of cabbage (Brassica oleracea var. L. Capitata Group) grown by traditional-tillage (TT) or strip-tillage (ST) culture using either chemical or organic production methods for pest control. Cabbage heads were heavier with TT than with ST for the chemical production system. Although weed biomass was significantly higher with organic methods, there was a poor relationship between weed biomass at harvest and cabbage head weight. The lack of differences in lepidopterous pest damage suggests that the conservation tillage systems examined likely would not affect lepidopterous pest management systems using biological insecticides. Within tillage treatments, the organic production system resulted in less Alternaria infection than did the chemical production system. Since no fungicides were applied on any treatment, lower disease ratings in the organic production system may have been the result of reduced soil contact of the cabbage leaves from the increased soil coverage by the weed and intercropped legume canopy.