Cauliflower Crops Research Articles

Chlorpyrifos soil and plant metabolisms in cauliflower crops grown on cow manure and composts soil fertilized fields

Several cauliflower crops were grown on fields located in different regions. Cauliflower plants were treated against the root fly by applying, some days after planting, chlorpyrifos onto the soil around the stem of the plant. Fields were divided into plots. Either one or 3.5 months before planting, one of the organic fertilizers city refuse compost, or mushroom cultivation compost, or cow manure was incorporated into the soil of each plot; there were also soil unamended control plots. The rates of chlorpyrifos soil metabolism were smaller in the organic fertilizers amended plots, than what they were in the unamended plots. In the summer cauliflower crop made on loamy sand soil, the chlorpyrifos soil half‐lives were 41, 44, 53 and 25 days, respectively in the plots amended either with the city refuse compost, or cow manure, or the mushroom cultivation compost, and in the unamended plots. The organic fertilizers effects were slightly greater when the amendments had been soil incorporated 3.5 months before planting, instead of 1 month before it. The chlorpyrifos transport from soil into the plant foliage was also greater in the soil organic fertilizers amended plots, than in the control plots. During the final crop period, the rates of chlorpyrifos soil metabolism increased; the organic fertilizers effects were levelled off, and the chlorpyrifos soil residues at harvest were similar in all the amended and unamended plots. During the first main crop period, to the greater chlorpyrifos soil residues—due to the soil organic fertilizers—should correspond a better insecticide protection efficiency against the soil insects, relative to the soil unamended plots. No chlorpyrifos, nor its metabolites were detected at harvest in the ‘flower’ of cauliflower of all the trials plots.

Effects of the soil organic fertilizers onto the carbofuran soil and plant metabolisms in field cauliflower crops

A spring cauliflower crop was made on the loamy sand soil of a field whose plots had been amended, one month before planting, with one of the organic fertilizers: city refuse compost, or mushroom cultivation compost, or cow manure; there were also unamended control plots. Some days after planting, an emulsion of carbofuran in water was applied onto soil, around the stem of the plant, for protection against the root fly. During growth of the crop, the rates of carbofuran soil biodegradation were smaller in the organic fertilizers amended plots, than in the unamended controls; the intensity of the effect was in the increasing order: city refuse compost < cow manure < mushroom cultivation compost. The organic fertilizers thus increased the insecticide soil concentrations; they thus should increase the insecticide protection efficiency against soil insects. During the final period of the crop, the rates of carbofuran soil biodegradation increased, and the organic fertilizers effects were levelled off; at harv...

Transport of the insecticides chlorpyrifos, chlorfenvinphos, carbofuran, carbosulfan, and furathiocarb from soil into the foliage of cauliflower and Brussels sprouts plants grown in the field

In several field assays made in different locations in 1988 and 1989, cauliflower and Brussels sprouts plants were treated some days after plantation by pouring onto soil around the stem of the plant one of the insecticides chlorpyrifos, chlorfenvinphos, carbofuran, carbosulfan, or furathiocarb, for protection against the root fly. During plant growth, each of the insecticides (and their soil metabolites) was transported from soil into the plant foliage, where it could give—during a certain period of time—a secondary plant protection against the foliage insects. The foliage concentrations of the non systemic chlorpyrifos and chlorfenvinphos were equal or greater than 1 mg/kg fresh weight during a period of about 44 days after soil treatment in Brussels sprouts crops, and 35 days in cauliflower crops. Comparison of 1988 and 1989 however showed that these periods of time changed according to the weather conditions, especially rainfall. These periods of time were greater when the insecticide soil concentrations were greater—and thus when the rates of insecticide soil metabolism were smaller— and when the rainfall were greater—water transporting the insecticides from soil to the foliage. Similar relationships were observed with the systemic insecticides carbofuran, carbosulfan and furathiocarb; the weights per plant of insecticide compounds transported from soil into the foliage however were greater with these systemic insecticides than they were with the non systemic chlorpyrifos and chlorfenvinphos. The extreme values observed for the periods of time of insecticide foliage concentrations equal or greater than 1 mg/kg fresh weight thus were: 1. in cauliflower crops: 21 to 36 days for chlorpyrifos, and 23 to 39 days for chlorpyrifos + oxon; 24 to 37 days for chlorfenvinphos; 20 to 48 days for carbofuran; 2. in Brussels sprouts crops: 43 to 49 days for chlorpyrifos; 47 to 53 days for chlorpyrifos + oxon; 41 to 45 days for chlorfenvinphos; between 2 to 3 months for carbofuran, carbofuran + carbosulfan, and carbofuran + furathiocarb in the fields treated respectively with either carbofuran, carbosulfan, or furathiocarb. Moreover, in the spring and summer cauliflower crops made on fields onto which continuous cauliflower crops—with their soil insecticide treatments—had been made since a greater number of years (greater soil “history”), the insecticide compounds soil and foliage concentrations generally were lower.

Effects of gibberellic acids on time of maturity and on yield and quality of cauliflower.

Gibberellic acid (GA4+7) was applied to cauliflower crops of the cultivars Delira and Elgon, grown in spring and summer of the years 1984, 1985 and 1986. Observations were made on the timing of the end of the juvenile phase and of curd initiation, the final number of leaves and the total length of growing period. In most crops the period between transplanting and harvest was shortened when GA4+7 was applied twice after the end of juvenility at a concentration of 80 mg/litre. The extent of shortening of the growing period increased with increasing difference between the number of leaves initiated at the time of application and the final number of leaves of the untreated crop. GA4+7 reduced the final number of leaves. Quality of the curds was unaffected by the treatment in most harvests, but the bracting incidence was reduced. In crops of cv. Delira with a low final number of leaves, size and quality of the curds was reduced. The results are discussed in relation to harvest planning of cauliflower. (Abstract retrieved from CAB Abstracts by CABI’s permission)

Residues of cypermethrin, fenvalerate and deltamethrin on cauliflower

Following the application of Cypermethrin, fenvalerate and deltamethrin to a cauliflower crop at rates of 50, 50 and 12 g a.i. ha-1, the maximum initial deposits of these insecticides on heads and leaves were 1.10 and 0.75, 1.14 and 0.60, and 0.32 and 0.12 mg kg-1, respectively. These residue values for fenvalerate were less than the maximum residue limit (MRL) of 2 mg kg-1 for this crop. While the maximum initial deposits of Cypermethrin and deltamethrin on cauliflower leaves were less than their respective MRL values of 1 and 0.2 mg kg-1 for brassica leafy vegetables, it took one day for their residues on cauliflower heads to decline below this level.

Relationships between the times of transplanting, curd initiation and maturity in cauliflower

SUMMARYIn order to determine the accuracy of controlling the time of maturity of a cauliflower crop by regulating the planting date, a series of transplantings of the variety White Fox was grown on a range of sites over 3 years and sampled throughout growth.The time from transplanting to maturity and the time from curd initiation to maturity were both quadratically related to the time of transplanting but there were marked differences in the relationships between years. Differences between years in the time taken to reach maturity tended to increase with later transplanting; for example, cauliflower crops transplanted in May took between 77 and 94 days to mature, while those transplanted in July matured in as few as 67 or as many as 106 days. These differences resulted from a combined effect of the time taken to satisfy the vernalization requirement and the duration of curd growth, both of which are temperature-mediated and therefore subject to seasonal and annual variation. Differences in the vernalization requirements of different cauliflower crops are illustrated by the number of leaves formed before curd initiation, which varied from 22·5 to 37·3.Variation in the time to maturity between crops transplanted at similar times of the year, in the same and different years, resulted in large deviations from planned production programmes and it is suggested that a complementary technique to aid crop marketing would be prediction of the time of crop maturity. However, the data collected in this study show that predictions based on the duration of crop growth from transplanting or curd initiation are unlikely to be sufficiently accurate and it is argued that predictions should be based on changes in curd dimensions with time.

Comparative soil and plant metabolism of carbosulfan, furathiocarb and carbofuran in Brussels sprouts, cauliflower and sugar beet crops

Brussels sprouts and cauliflower crops were soil treated at planting by one of the insecticides carbosulfan, furathiocarb, or carbofuran; moreover, a sugar beet crop was soil treated by carbofuran applied in the sowing furrow. In the soil, carbosulfan and furathiocarb were transformed into carbofuran, which then was transformed mainly into 3‐ketocarbofuran, carbofuran phenol, and 3‐ketocarbofuran phenol. In the soil of the carbosulfan treated crop, the carbosulfan and carbofuran concentrations were similar. In the carbosulfan treated soil, the concentrations of the sum carbosulfan‐+ carbofuran were higher than the carbofuran concentrations in the carbofuran treated soil. The chemical derivatization of the carbamate function which occurs in carbosulfan thus slowed down its soil biodegradation relative to the non derivatized carbamate function in carbofuran. The same occurred with furathiocarb, but with a lower intensity. When the soil microbial activity was exceptionally enhanced (by the climate and by a l...

Comparison of Fluid Drilling with Conventional Planting Methods for Stand Establishment and Yield of Spring and Fall Cauliflower Crops

Abstract Fluid drilling was compared with dry seeding and transplanting for effects on stand establishment and crop yields in spring and fall crops of cauliflower [Brassica oleracea L. (Botrytis Group)]. Two cultivars, at least two seeding dates, and one transplanting date were used in each experiment. Fluid drilling and dry seeding produced the desired post-thinning stand with March seeding dates. Fluid drilling usually failed to produce the desired post-thinning stand when planting occurred during the hot, dry weather of August. Fluid drilling was not superior to dry seeding or transplanting for earliness, uniformity of harvest, or total marketable yields in spring and fall cauliflower crops, with the exception of one spring planting date. Therefore, fluid drilling did not show benefits sufficient to justify the specialized techniques and equipment required. Cuitivar and planting date effects often were more important than effects of stand establishment methods in these studies.

Influence of field histories of continuous soil insecticide treatments on the rate of soil biodegradation of Carbofuran in cauliflower, Brussels sprouts, Chinese cabbage and sugar beet crops

In the soil of cauliflower, Brussels sprouts, Chinese cabbage and sugar beet crops, carbofuran was metabolized into the insecticide compounds 3‐hydroxycarbofuran and 3‐ketocarbofuran, and into the non insecticide carbofuran phenol and 3‐ketocarbofuran phenol. The rate of soil biodegradation of carbofuran and of the sum of insecticide carbamate compounds was multiplied by 3 when continuous monoculture and soil treatments with organophosphorus insecticides had been done previously during several years.

Dissipation of quinalphos (O, O, diethyl O‐quinaxalin‐2yl phosphorothioate) residues in and/or on cauliflower(Brassica oleracea Var. Botrytis)

Abstract A field trial was conducted to study the magnitude of quinalphos residues in and/or cauliflower (Brassica oleracea Var Botrytis. The cauliflower crop was sprayed once with quinalphos 25 e.c. at 0.25 and 0.5 kg a.i./ha 104 days after transplanting. The samples of cauliflower drawn at different time intervals were analysed colorimetrically. The initial deposits of quinalphos on cauliflower were found to be 5.79 and 9.52 ppm, an the half life values 1.61 and 2.12 days, respectively, at 0.25 and 0.5 kg a.i./ha. The waiting periods determined were 11 days at the higher and 7 days at the lower dose of quinalphos.

The effect of plant raising and cultural factors on the curd initiation and maturity characteristics of summer/autumn cauliflower crops

SummaryExperiments were conducted in 1986 and 1987 to determine the influences of plant raising temperature, transplant age, N top-dressing and irrigation regime on the curd initiation and maturity characteristics of the cauliflower variety White Fox. The prime objective of this work was to determine whether changes in crop production practice had an influence on the period between curd initiation and maturity, in order to aid the development of techniques predicting when curds will reach a specific size.The duration of the period from curd initiation to curd maturity was not significantly affected by any treatment in either year and treatment effects on curd size at maturity were of no practical importance provided that the recommended level of N top-dressing was achieved. It is therefore concluded that changes in production practices within the normal commercial range are unlikely to have any significant practical effect on the use of techniques to predict the timing of crop maturity.There were large differences between the experiments in the mean number of leaves formed at curd initiation, which ranged from 22·0 to 36·7. In order to interpret these data a relative vernalization stimulus was calculated from 12 leaves onwards. It had a maximum rate of vernalization between 5 and 17 °C and a reduced rate at lower and higher temperatures and adequately accounted for the differences in the number of leaves at curd initiation.

Fate of the insecticide chlorfenvinphos in the soil of cauliflower field crops

Fate of the insecticide chlorfenvinphos in the soil of cauliflower field crops

Inheritance of resistance to black rot (Xanthomonas campestris pv. Campestris) in cauliflower (Brassica oleracea var. Botrytis)

Black rot disease caused by Xanthomonas campestris pv. campestris is a limiting factor in the commercial production of the cauliflower crop. Crosses were attempted between SN 445, a mid season cultivar resistant to black rot and two highly susceptible commercial cultivars (Pusa Snowball-1 and K-1). Studies of the F1's, F2's and back crosses indicated that SN 445, carries a dominant gene imparting resistance to black rot.

The effects of living mulches and weed cover on the dynamics of foliage- and soil-arthropod communities in three crop systems

The effects of vegetation background in the form of living mulches and weed cover on the population dynamics of foliage and soil arthropods were studied in corn, tomato and cauliflower crop systems in California. In Davis (Central Valley site) herbivores (especially aphids and lygaeids) were more abundant in the weed cover than in the clover mulch, whereas leafhoppers were most common in the clover mulch. Higher numbers of natural enemies were observed in the clover plots. Significantly more ground predators (Carabidae, Staphylinidae, spiders) were caught in pitfalls placed in the weedy and clover plots, than in the clean cultivated plots. In Albany (Coastal area), specialized herbivore (cabbage aphids and flea-beetles) densities were significantly reduced in plots with additional vegetation cover. It is not clear if this reduction was due to plant diversity or density effects, to the effects of natural enemies or to the lower quality of plants in the weedy and mulched plots, as crop growth and yields were drastically reduced in these plots at both sites. Further agronomic work is warranted to minimize the competitive effects of legume covers on crops, so that the entomological advantages reported here can be used in a practical way.

Factors causing small curds in cauliflower crops

SummaryVigorous cauliflower plants sometimes bear abnormally small curds, yet this common problem has received little recognition or attention from research workers. Curd size is often reduced towards the end of the harvesting period of a crop, and this is more marked if environmental conditions reduce mean curd size and lengthen the time to maturity. Small late curds may be a consequence of their slow growth rather than their late initiation. Cultivars differ in their tendency to produce plants with late maturity and small curds. This may not be due to genetic differences within cultivars. Moreover, breeding to eliminate or reduce this condition may not be possible without affecting overall maturity time and curd size.

The Effect of Seaweed Extract Sprays Derived from Ascophyllum nodosum on Lettuce and Cauliflower Crops

Resultats d'essais sur laitues et choux-fleurs d'application d'un extrait d'A. nodosum obtenu par hydrolyse alcaline: effets sur le rendement, la formation du cœur chez la laitue et le diametre des influorescences chez le chou-fleur. Effet de l'addition de cytokinine a l'extrait d'algue

Growth and yield of high‐density cauliflower crops treated with pesticides to control weeds and cabbage root fly (Delia brassicae)

SUMMARYEffects of combinations of insecticides and herbicides on the growth and yield of cauliflower plants (cvs No. 110, Garant and Strong) were determined in two field experiments with seed drilled to give a stand of c. 300000 plants/ha. Granular formulations of chlorfenvinphos or fonofos were applied by the bow‐wave method at 2 kg a.i./ha to control cabbage root fly (Delia brassicae). Weeds were successfully controlled with combinations of trifluralin, incorporated into the soil at 0·6 or 1·2 kg a.i./ha before drilling, and propachlor, applied pre‐emergence at 2·2 or 4·4 kg a.i./ha. Fonofos, with and without herbicides, significantly lessened (P &lt; 0·01) numbers of seedlings that would survive to harvest. Herbicides and chlorfenvinphos generally did not significantly affect the emergence of healthy seedlings of any cultivar. Combinations of herbicides and chlorfenvinphos were compatible for control of target species. Chlorfenvinphos reduced root damage by at least 50% but did not significantly increase (P &gt; 0·05) the total or marketable weight of curds. Numbers of curds were not usually affected and consistent effects of treatments on maturation periods of the three cultivars were not detected.

Productivity Differences of Different Seasons for Cauliflower Crop of District Ranchi

The productivity of different seasons in couliflower crop in Ranchi district showed inanures and fertilizern in all the three seasons, marketing in Kharif season, irrigation and marketing in Rabi season and bullock labour days in Zaid season to have signifi- cant elasticities of production. Manures and fertilizers are the only input factors whose ratio of marginal value productivity to its factor cost was more than one in all the three seasons while that of human labour, plant protection measures and marketing in Rabi season and bullock labour in Zaid season were observed to be more than unity.

Quinalphos (0,0-diethyl-0-(2-quinoxalyl) phosphorothioate) residues on apples, tomatoes, and cauliflower

Abstract Quinalphos (0, 0-dielhyl-0- (2-quinoxalyl) phosphorothioate) residues have been monitored on tomato, apple, and cauliflower crops up to 2 weeks after a single application. Cauliflowers received 0.55 or 0.83 kg active ingredient (a.i.)/ha in 1285 1 water/ha, tomatoes 0.28, 0.57, or 0.85 kg a.i./ha in 1285 1 water/ha, and apples (cv. ‘Dunn's Favourite’) 1.0, 2.0 or 3.0 kg a.i./ha in 4500 1 water/ha or (cv. ‘Golden Delicious’) 0.25, 0.50, or 0.75 kg a.i./ha in 1100 1 water/ha. Residues on the apples and cauliflowers did not exceed 1.0 ppm fresh weight and after 2 weeks were below 0.1 ppm. Residues on the tomatoes at the highest rate were initially 2.5 ppm, but had declined to below 0.4 ppm after 2 weeks. An unidentified phosphorus-containing metabolite or degradation product was detected.

Studies on crop maturity in cauliflower: I. Relationship between the times of curd initiation and curd maturity of plants within a cauliflower crop

A study was made of the relationship between the times of curd initiation and curd maturity of plants of 32 crops of summer and autumn cauliflowers in 1965 and 60 crops in 1966. By the use of a dis...