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- Author or Editor: Martin L. Kaps x
Fourteen highbush blueberry cultivars are being evaluated in south central Missouri mineral soil. This soil is often not ideal for culture of highbush blueberry. The planting site was initially pH 6.3 with a 92% base saturation on the cation exchange capacity. Sulfur additions, and summer and fall cover cropping were done for 2 years prior to planting to lower soil pH (5.3) and increase organic matter content. Four replications of three plants were set in a randomized complete block in early Apr. 1998. Plant spacing is 1.2 × 3.0 m on bermed rows that are mulched with chipped hardwood. Acidified irrigation water is supplied through drip lines. Fertilizer is applied annually both as dry ammonium sulfate and soluble nitrogen through drip lines at 84 kg·ha-1 N. Cumulative yield per bush after the first five harvest seasons showed `Bluecrop', `Brigitta Blue', `Chandler', `Darrow', `Legacy', `Nelson', and `Reka' at 17 to 21 kg; `Duke', `Nui', `Ozarkblue', and `Sierra' at 14 to 15 kg; and `Collins', `Summit', and `Toro' at 9 to 10 kg. Berry weight averaged 2 g with a low of 1.4 g (`Reka') to a high of 3.3 g (`Chandler'). Plant height averaged 155 cm with a low of 117 cm (`Nui') to a high of 188 cm (`Legacy', `Nelson'). Cultivars in the two higher yield groups were recommended to Missouri growers for planting.
The grape cultivars Vidal blanc, a French-American hybrid, and Norton, primarily Vitis aestivalis, were transplanted to 19-L pots with soil amended to pH 4.5, 5.9, 7.2, and 8.5. The soil was a mixture of coarse sand and a silty clay loam in the proportion 2 to 1. The experiment was a randomized complete block with two treatments (cultivar, soil pH) and six replications. The objectives of the experiment were to determine vegetative growth and nutrient content of the two cultivars at varying soil pH, and the soil pH within those tested that optimized growth. Vidal blanc was superior to Norton in all growth measurements after 94 days. At pH 7.2 and 8.5, significant reductions in shoot length; leaf area; and leaf, shoot and root dry weights occurred for Norton but not for Vidal blanc. Trends toward lower P, Mg, Fe, and MN and higher B occurred at pH 8.5. Foliar symptoms of Mg and Fe deficiency were noticed for Norton at this elevated pH but not for Vidal blanc. The pH range 5.9 to 7.2 for Norton and 7.2 to 8.5 for Vidal blanc appeared to optimize growth for these two cultivars.
Preemergent herbicides were applied to vineyards in the southcentral Missouri Ozark region. These were applied at full label rate in the fall or in the spring, at half rate in the fall and again in the spring, and as tank-mixes in the spring. Days of acceptable annual weed control (30% or less cover) beyond the untreated control were determined for these application methods over three years. The fall applications were effective at controlling winter annual weeds and early summer annual weed growth the following season. By mid summer the fall applied preemergents lost residual activity. Splitting the label rate between fall and spring was no better than a full rate spring application at increasing the days of acceptable summer annual weed control. Single preemergent spring application performed as well as tank-mixes.
Nine preemergent herbicides were applied at maximum label rate in Fall 1986, 1987, and 1988 to a `Catawba' grape (Vitis labrusca L.) vineyard in the Missouri Ozark region. The untreated controls showed 30% total weed cover by 28 Apr. 1987, 21 May 1988, and 18 Apr. 1989. In 1988, less rain fell early in the growing season; thus, weed cover in the untreated controls was delayed until late in the season. The herbicides norflurazon, oryzalin, and oxadiazon gave the longest period of acceptable grass control. Dichlobenil, diuron, oxyfluorfen, and simazine gave the longest period of acceptable broadleaf control. Most of the herbicides lost residual activity by early summer. For this reason, fall preemergent herbicide application cannot be relied on to give season-long control the following year in southern Missouri. Chemical names used: 2,6-dichlorobenzonitrile (dichlobenil); N' -(3,4-dichlorophenyl) - N,N -dimethylurea (diuron); N,N -diethyl-2-(1-napthalenyloxy)-propanamide (napropamide); 4-chloro-5-(methylamino)-2-(3-(trifluoromethyl)phenyl)-3(2H)-pyrdazinone (norflurazon); 4-(dipropylamino)-3,5-dinitrobenzenesulfonamide (oryzalin); 3-[2,4-dichloro-5-(1-methylethoxy)phenyl]-5 -(l,l-dimethylethyl) -l,3,4-oxadiazol-2- (3H)-one (oxadiazon); 2-chloro-l-(3-ethoxy-4-nitrophenoxy) -4-(trifluoromethyl) benzene (oxyfluorfen); 3,5-dichloro-N-(l,l-dimethyl-2-propynyl)benzamide (pronamide); and 6-chloro- N,N' -diethyl-1,3,5-triazine-2,4-diamine (simazine).
`Seyval blanc' and `Vidal blanc' grapevines were planted in 1983 at in-row spacings of 1.8, 2.4, 3.0, 3.6 and 4.8 m. Vineyard location is in the southcentral Missouri Ozark region, an area characterized by shallow soil and fluctuating winter temperature. A temperature of -28°C in January 1985 severely damaged the vines, which required retraining from the roots. Less time was needed to retrain close spaced vines to a single curtain cordon. Close spaced vines also yielded more in their first production year (1987). Wide spaced vines had increasingly higher pruning weight, yield, and cluster number per vine in later years. Juice soluble solids, pH and titratable acidity showed few differences among the spacing treatments. Close spaced vines were the most productive on a per meter of cordon basis. Competition between these vines has not yet reduced their productivity.
The recommendation for planting highbush blueberry (Vaccinium corymbosum L.) in Missouri includes the incorporation of sphagnum peat in the planting hole. This experiment compared the use of fresh and aged pine bark to sphagnum peat as soil amendments at planting. One-year-old highbush blueberry `Blueray' plants were planted in 1983 at Mountain Grove, Mo. Plant height, spread, and number of new canes were recorded from 1983 through 1987. Yield and berry size were recorded from 1985 through 1988. There were no significant differences in these measurements among soil amendment treatments (P = 0.05).
Spring vs. fall plus spring (split) herbicide application times and single vs. tank-mix spring herbicide applications were compared as a means of extending summer annual weed control in vineyards. About 30% of the nontreated control areas were weed-covered by April or May of each of 3 years. Most treatments gave 60 or more days of acceptable annual weed control (≤ 30% cover) beyond the nontreated control. Fall plus spring application of diuron, norflurazon, or simazine at the half-label rate did not increase the days of control over spring application alone at the full-label rate. The tank-mixed herbicides diuron, norflurazon, and oryzalin in combinations of any two at the half-label rate were as effective as the full-label rate of these herbicides used alone. Weed control by oxyflurofen or simazine was extended by tank-mixing with oryzalin (half-label rates). Chemical names used: N -(3,4-dichlorophenyl) -N,N -dimethylurea (diuron); 4-chloro-5-(methylamino)-2-(a,a,a-trifluoro-m-tolyl)-3(2 H) -pyridazinone (norflurazon); 3,5-dinitro-N4,N4-dipropyl-sulfanilamide (oryzalin); 2-chloro-l-(3-ethoxy -4-nitrophenoxy)-4-(trifluoromethyl) benzene (oxyfluorfen); and 2-chloro-4,6-bis(ethylamino)-s-triazine (simazine).
The Japanese beetle (Popillia japonica Newman) is one of the most widespread and destructive invasive insect pests in the eastern United States. Blackberry (Rubus sp.) production in the United States has increased significantly in recent years. With the introduction of new blackberry cultivars, insect resistance should become the focus of further breeding efforts. The objective of the current study was to evaluate the susceptibility of 13 blackberry cultivars to the Japanese beetle. The seasonal population dynamics of this insect, beetle damage to blackberry foliage, and beetle preference of blackberry cultivars were monitored from 2016 to 2018 on a blackberry plantation in Mountain Grove, MO. Japanese beetles feeding on blackberries occurred between 814 to 1251 cumulative degree-days (CDD; base, 10 °C) after 1 Jan. The following cultivars were evaluated: Apache, APF-40, Arapaho, Chester, Chickasaw, Kiowa, Natchez, Osage, Ouachita, Prime-Ark 45, Prime-Jan, Prime-Jim, and Triple Crown. Foliage damage incidence, defined as average percentage of leaves damaged by beetles on a given cane, did not differ among the cultivars. However, average severity of damage, estimated by rating on a scale from 0 (least) to 5 (most) of all damaged leaves on a given cane was different among cultivars. Ouachita and APF-40 exhibited the lowest damage severity rating among floricanes and primocanes, respectively. Apache (a floricane) and Prim-Jan (a primocane) were the most susceptible cultivars. Japanese beetle preferences for cultivars correlated with the degree of foliage damage. Because all blackberry cultivars exhibited similar foliage feeding incidence, but different feeding severity, we suggest the Japanese beetle does not differentiate among blackberry cultivars from a distance, but does upon contact with the foliage of a given plant.
Wine and table grape vineyards were planted at Mountain Grove in 1985. Twenty-seven wine and 10 table grape cultivars were evaluated in respective 12 and 18 vine plots, replicated five times. Vineyard management practices were single curtain cordon training, dormant season balance pruning, protective spray program according to Missouri recommendations, grass sod row middles with preemergence herbicide applied underneath the trellis, and fertilization according to soil and petiole analysis. Cluster thinning and shoot positioning were done as needed. Productivity data was measured yearly and included: pruning weight, yield, cluster and berry weights, and juice °Brix, titratable acidity, and pH. Disease evaluation data was also taken on these cultivars. Based on these data and current market trends, two wine grape cultivar groups were identified: recommended, `Catawba', `Cayuga White', `Chambourcin', `Norton', `Seyval blanc', `Vidal blanc', and `Vignoles'; not recommended, `Aurore', `Baco noir', `Bellandais', `Chancellor', `Chelois', `Couderc noir', `DeChaunac', `Delaware', `Horizon', `LaCrosse', `Leon Millot', `Marechal Foch', `Melody', `Missouri Riesling', `Niagara', `Rayon d'Or', `Rougeon', `Ventura', `Villard noir', and `Vivant'. Three table grape cultivar groups were identified: recommended, `Mars' and `Reliance'; recommended for limited planting, `Canadice', `Vanessa', and `Vinered'; and not recommended, `Challenger', `Einset', `Festivee', `Himrod' and `Venus'. This information is used by growers to make cultivar decisions and also serves as a benchmark for comparing new grape germplasm coming into the state.
Crop reduction on single-shoot ‘Seyval blanc’ grapevines by either berry or cluster thinning resulted in a decrease in total fruit weight and an accompanying increase in berry weight, °Brix, and vegetative growth. Titratable acidity and pH of the juice were not consistently affected by either berry or cluster thinning. Net leaf photosynthesis at 43 days past full bloom increased with higher cluster number per plant. Berry weight was greatest when the crop of berries were borne in three clusters per shoot rather than in a single cluster. Berry thinning appears to be an acceptable substitute to cluster thinning for crop reduction of ‘Seyval blanc’ grapes.