broccoli ( Brassica oleracea italica group), sweet corn ( Zea mays ), tomato [ Solanum lycopersicum (synonym Lycopersicon esculentum )], bell pepper ( Capsicum annuum ), winter squash ( Cucurbita sp.), and snap pea ( Pisum sativum var. macrocarpon
Sunn-hemp, Crotalaria juncea L. cv. Tropic Sun was developed in Hawaii in 1982 and recently introduced to the island of Guam by USDA Soil Conservation Service as a potential green manure crop. An evaluation of various legumes at three different soil regimes revealed that sunn-hemp produced greater biomass than other plants. In the study of the effects of sunn-hemp in subsequent vegetable production, slightly greater canopy was observed for potato, Solanum tuberosum cv. Kennebec, with green manuring with sunn-hemp than without. Yield of head cabbage, Brassica oleracea var. capita cv. KK Cross, was higher with green manuring (1085.5g/head) than without (725.4g/plant). Competition between indigenous rhizobia and introduced inoculant seems to exist at some locations. Major constraints in using sunn-hemp as green manure on the island are its limited seed sources and requirements of additional labor. Education and promotion of using this legume in a long term soil-improving system is needed.
Indian mustard (Brassica juncea) has been reported to be a preferred host for diamondhack moth (Plutella xylostellu) and other insect pests when interplanted with cabbage (Brasssica oleracea var. capitata). A cabbage-Indian mustard companion planting study was conducted to determine the seasonal occurrence of cabbage insects and the potential for using a trap-crop system to reduce insecticide applications to cabbage in West Texas. Three-row plots of cabbage 9 m long were transplanted with and without sequentially seeded borders of Indian mustard in three seasons. Harmful and beneficial insects were counted at roughly weekly intervals. Insecticides were applied when insect populations in individual plots reached predetermined thresholds. Indian mustard did not appear to be more attractive than cabbage to lepidopterous pests, but did preferentially attract hemipterans, particularly harlequin bugs (Margantia histrionica). The mustard trap crop eliminated two insecticide` applications in one trial by reducing harlequin bug pressure on the cabbage.
Correlation coefficients based on relative concentrations of 13 glucosinolates in the edible parts of 30 cultivars were determined. Brussels sprouts (Brassica oleracea L. gemmifera group), cauliflower (B. oleracea L. botrytis group), and either marrow-stem or smooth-leafed kale (B. oleracea L. acephala group) had similar glucosinolate patterns based on significant correlations (P < 0.01). The glucosinolates of ‘Morris Heading’ collards [(B. oleracea L. acephala group (var. sabellica)] were highly correlated with those of curly kale [B. oleracea L. acephala group (var. selensia)]. Mustard greens [B. juncea (L.) Czern. & Coss. var. rugosa Bailey] and the corresponding seeds were the most highly correlated of the 17 cultivars for which the edible parts and seeds were compared. Seed analyses indicated relationships among the cultivars somewhat similar to those seen for the edible portions.
We are evaluating the severity of apple replant disease (ARD)-characterized by stunted tree growth in replanted orchards, attributed to root pathogens and/or edaphic conditions-and testing preplant soil treatments for control of this wide-spread problem. Soil samples were collected during 1996–98 at 17 orchards in New York's major fruit growing regions and plant-parasitic nematodes and nutrient availability were quantified. Apple seedlings and potted trees on M.9 rootstocks were grown in fumigated and non-fumigated soil samples as a diagnostic bioassay for ARD severity. Factorial combinations of metam sodium, consecutive cover crops of Brassica juncea `Forge' and Sorghum sudanense `Trudan 8', and fertilizer/lime amendments were applied as preplant treatments at each orchard, 9 to 12 months before trees were replanted. Diagnostic bioassays indicated severe ARD at more than half the sites, and nematodes were not a major factor. Responses to preplant soil treatments were highly variable across the 17 farms. The best tree growth and yields followed preplant metam sodium at some sites, Brassica juncea and Sorghum sudanense at others, or fertilizer amendments at a few others. Tree responses to combined preplant soil treatments were often additive, and greater at irrigated sites. Comparisons of preplant diagnostic bioassay results with subsequent tree responses to metam sodium at the 17 orchards indicated that diagnostic tests predicted from 7% to 75% of tree growth response to soil fumigation, varying substantially across years and sites. It appeared that ARD was variable and site specific in New York orchards, and could not be controlled effectively with a uniform preplant soil treatment across our major fruit-growing regions.
, Z. Guo, S. Jiao, X. Liu, X. Gao, Y. 2013 Effects of different light quality on growth, chlorophyll concentration and chlorophyll biosynthesis precursors of non-heading chinese cabbage ( Brassica campestris L.) Acta Physiol. Plant. 35 2721 2726
Fifty-two germplasm accessions of Chinese vegetable Brassicas were analyzed using 112 random amplified polymorphic DNA (RAPD) markers. The array of material examined spanned a wide range of morphological, geographic, and genetic diversity, and included 30 accessions of Brassica rapa (Chinese cabbage, pakchoi, turnip, broccoletto), 18 accessions of B. juncea (leaf, stem, and root mustards), and 4 accessions of B. oleracea ssp.alboglabra (Chinese kale). The RAPD markers unambiguously identified all 52 accessions. Net and Li genetic similarities were computed and used in UPGMA cluster analyses. Accessions and subspecies clustered into groups corresponding to the three species, but some accessions of some subspecies were most closely related to accessions belonging to another subspecies. Using genetic similarities, it was found that Chinese cabbage is more. likely to have been produced by hybridization of turnip and pakchoi, than as a selection from either turnip or pakchoi alone. RAPD markers provide a fast, efficient technique for diversity assessment that complements methods currently in use in genetic resources collections.
A cultural system consisting of precision seeding on shaped beds, followed by cultivation using mechanically guided equipment, was developed and evaluated with several vegetable crops. The precision cultural system allowed for growing the crops at high plant populations by using precision planting and exact cultivation of multiple narrow rows of plants on wide beds. Eight field experiments were conducted from 1987 to 1989 on broccoli (Brassica oleracea var. botrytis L.), cabbage (Bra&a oleracea var. capitata L.), mustard (Brassica juncea var. crispfolia L.), and spinach (Spinacia oleracea L.) to evaluate production of these crops on single- and multiple-row configurations on narrow (1 -m) and wide (2-m) beds. The precision cultural system was assessed to be an excellent method for production of the small-seeded crops that were tested. Yield was highest for cabbage, mustard, and spinach planted in six rows on 2-m beds compared with four-, two-, or one-row beds. Multiple-row configurations did offer yield advantages over the single-row configuration for broccoli production.
Saline agricultural drainage water may be used as a resource to grow high value horticultural crops and reduce the volume of drainage for eventual disposal. To explore reuse options the effects of salinity and timing of application were tested on selected leafy vegetables grown in 24 sand culture plots in Riverside, Calif. The leafy winter vegetables included `Ruby Red Chard' Swiss chard [Beta vulgaris L. var. flavescens (Lam.) Lam.], `Space' spinach (Spinacia oleracea L.), `Vitamin Green' salad greens [Brassica rapa L. (Narinosa Group)], `Red Giant' mustard greens [Brassica juncea L. (Czerniak)], pac choi [Brassica rapa L. (Chinensis Group)], `Winterbor' kale [Brassica oleracea L. (Acephala Group)], tatsoi [Brassica rapa L. (Narinosa Group)], `Salad King' curly endive (Cichorium endivia L.), and `Red Preco No. 1' radicchio (Cichorium intybus L.). All vegetables were planted at the same time and irrigated initially with tap water and nutrients. At 3 and 7 weeks after seeding (application times), six salinity treatments were initiated by adding salts to the irrigation water to represent the chemical compositions of drainage waters found typically in the San Joaquin Valley, Calif. The six salinity treatments had electrical conductivities of 3 (control), 7, 11, 15, 19, or 23 dS·m-1. A randomized complete block design was used with (6 salinities × 2 application times × 2 replications). Within each plot a 1.5-m row of each of the nine vegetables was grown as split plots. Salinity reduced fresh weight (FW) yields of all species. Salt stress applied at 3 weeks after seeding reduced FWs for seven of the nine vegetables compared to salination at 7 weeks. Analyses of salt tolerance curves, maximum yields, and the point of 50% yield reduction (C50) were conducted. Greens produced the highest biomass at 874 g/plant, but was the most affected by application time. Swiss chard and radicchio were not significantly affected by timing of salinity application, and Swiss chard was the most salt tolerant overall. Greens, kale, pac choi, and to a lesser extent, tatsoi, have potential as winter-grown, leafy vegetables in drainage water reuse systems.
Biofumigation is an alternative to traditional methods of soil sterilization such as methyl bromide. Biofumigation utilizes volatile, pesticidal compounds in soil incorporated plant material from various Brassica species. Three experiments were conducted to study the degradation of allyl isothiocyanate (AITC) generated from the breakdown of glucosinolates present in Oriental mustard (Brassica juncea L. Czerniak). Mustard seed meal was incorporated into a sandy clay loam soil in all experiments. In the first experiment, samples were hydrated and then held in an incubator at 20 ± 0.2 °C. Samples were taken periodically for 7 days or until AITC was not detectable. For the second experiment, hydrated samples were removed from the incubator after 4 hours and 5 mL of ethyl acetate was added. The samples were then placed in a refrigerator at 4 ± 0.2 °C and samples were taken periodically over 77 days. For the third experiment, samples were taken from a strawberry plot experiment grown in a randomized complete block design. Samples were taken and 5 mL of ethyl acetate was added. Then samples were placed into a cooler until returning to the laboratory. The incubator experiment was repeated and showed that the highest concentration of AITC occurred between 2 and 8 hours after hydration. The storage experiment showed a stable relationship between time and AITC degradation. AITC was still present after 77 days. The strawberry plot experiment showed rapid AITC degradation similar to the incubator experiment. Future research will be done to confirm the effects of temperature and glucosinolate content on the amount of allyl isothiocyanate present.