Pertumbuhan Cabai Merah (Capsicum annuum L.) pada Tanah Masam yang Diinokulasi Mikoriza Vesikula Arbuskula (MVA) Campuran dan Pupuk Fosfat

This research aimed to find out the interaction effect between mixed Vesicular Arbuscular Mycorrhiza (VAM) and phosphate fertilizer to the growth of red chili (C. annuum) in acid soil, and to fnd out the best combination of mixed VAM and phosphate fertilizer to the growth of red chili (C. annuum) in acid soil. This research used an experimental method with Completely Randomized Design (CRD) in a factorial pattern with two factors. The first factor was mixed VAM dosages consisted of four levels: 0; 10; 15; 20 g/plant. The second factor was phosphate fertilizer dosages consisted of four levels: 0; 0,2; 0,4; 0,6 g/plant. Each combination treatment had three replication. The parameters were observed in the form of plant height, stem diameter, plant top dry weight, degree of VAM infection, and P content of plant tissue. Data obtained from the observation was analyzed with Analysis of Variance (ANOVA) at an error rate of 5% and 1%, treatment that showed significant or very significant result, then followed with Honestly Significant Difference (HSD) test. The result showed that interaction between mixed Vesicular Arbuscular Mycorrhiza (VAM) and phosphate fertilizer did not increase the plant height, stem diameter, and plant top dry weight, but each factor increased the plant height, stem diameter, and plant top dry weight. VAM dosage inoculation of 20 g/plant without phosphate fertilizer is the most effective combination in increasing the degree of VAM infection.

Effects of Meloidogyne incognita and Thielaviopsis basicola on Cotton Growth and Root Morphology

Effects of the root-knot nematode Meloidogyne incognita and the fungal pathogen Thielaviopsis basicola on cotton seedling growth and root morphology were evaluated in controlled environmental experiments. Four pathogen treatments, including noninfested soil, soil infested with M. incognita, soil infested with T. basicola, and soil infested with both pathogens were evaluated at soil bulk densities (BDs) of 1.25 and 1.50 g/cm3. Plant growth and the morphology of the root systems were evaluated 44 days after planting. Infestation with M. incognita and T. basicola together significantly reduced seedling emergence, number of stem nodes, and root system volume compared with either pathogen alone. Either M. incognita or T. basicola reduced plant height, root fresh weight, top dry weight; root parameters total root length, surface area, and links; and root topological parameters magnitude, altitude, and exterior path length. M. incognita infection increased root radius. Root colonization by T. basicola increased with the presence of M. incognita at the lower soil BD. In contrast to previous research with Pythium spp., root topological indices (TIs) were similar with all of the treatments. Root TIs were near 1.92, indicating a herringbone (less branching) root architectural structure. Studying root architecture using a topological model offers an additional approach to evaluating fungi and nematodes and their interactions for soilborne-pathogen systems.

Gibberellin A3 Treatment of Seeds, Container Volume, Substrate pH, and Nitrogen Source and Rate Influence Growth of Containerized Seabeach Amaranth (Amaranthus pumilus)

Seeds of seabeach amaranth (Amaranthus pumilus Raf.), a species federally listed as ‘threatened,’ were stratified (moist-chilled) for 90 days at 4C (39F) or treated with a solution of the potassium (K) salt (K-salt) of gibberellin A3 (K-GA3) at 1000 mg·liter−1 (ppm) for 24 hr. After treatment, both groups of seeds were sown in containers of two volumes, 139 or 635 cm3 (9 or 39 in3) with a substrate of peat:pine bark (1:1, v/v) amended with one of two rates of pulverized dolomitic lime [2.24 or 4.48 kg·m−3 (3.8 or 7.6 lb·yd−3)]. Containers were maintained in a greenhouse. After seedling emergence, seedlings were fertilized with a 20N-4.4P-16.6K (20N-10P205-20K20) acidic, water soluble fertilizer or a 15N-2.2P-12.5K (15N-5P205-15K20) basic, water soluble fertilizer applied thrice weekly at nitrogen (N) application rates (NARs) of 75, 150, 225, or 300 mg·liter−1. The study was terminated 8 weeks after seeds were sown and data recorded. Regardless of fertilizer, acidic or basic, top dry weight and leaf area of seabeach amaranth increased linearly with increasing NAR. Maximum top dry weight and leaf area occurred with N at 300 mg·liter−1, whereas root dry weight was unaffected by NAR. Both fertilizers increased electrical conductivity (EC) linearly with increasing NAR, and EC values of 1.15 to 1.18 dS·m−1 were adequate for maximum top growth or leaf area. Substrate pH decreased linearly with increasing NAR 21, 43, and 57 days after initiation. Top and root dry weights and leaf area were greatest for seedlings derived from seeds treated with K-GA3. Large containers yielded top and root dry weights and leaf area 61, 33, and 57% greater, respectively, than smaller containers. Top N concentration increased linearly with increasing NAR for acidic and basic fertilizers with N concentrations of 58.4 and 50.4 mg·g−1, respectively, at maximum top dry weight. Although top nutrient content of N increased linearly with NAR, top N content was unaffected by either rate of lime or type of fertilizer.

Day/Night Temperatures Influence Growth and Photosynthesis During Containerized Production of Selected Species of Helleborus (Hellebores)

Containerized seedlings of Helleborus foetidus L. (stinking hellebore), H. niger L. (Christmas rose), and H. ×hybridus L. (Lenten rose) were grown under long-day conditions in controlled-environment chambers for 95 days with 9-hr days of 14, 18, 22, 26, or 30C (57, 64, 72, 79, or 86F) in factorial combination with 15-hr nights of 10, 14, 18, 22, or 26C (50, 57, 64, 72, or 79F). Long-day conditions were provided by a 3-hr night interruption. Growth of each species responded differently to day and night temperatures. Calculated maximum root, top, and total dry weight, and leaf area of H. foetidus occurred with days/nights of 20/15, 18/13, 19/14, and 18/15C (68/59, 65/55, 66/57, and 65/59F), respectively. While night temperature (NT) had no effect on root:top ratio [RTR (root dry weight ÷ top dry weight)], RTR was greatest (0.65) with days of 22C (72F). Helleborus niger had calculated maximum root dry weight and total dry weight with days of 14C (57F) and nights of 16 and 13C (60 and 55F), respectively. Top growth of H. niger decreased linearly as NTs increased for days of 14 or 22C (57 or 72F). Day temperatures (DTs) had no effect on RTR, whereas RTR responded quadratically as NT increased with a calculated maximum RTR at nights of 19C (66F). Leaf area was maximized at days/nights of 14/10C (57/50F). At days of 22 or 26C (72 or 79F), top growth of H. ×hybridus responded quadratically as NT increased with maxima occurring at nights of 18 or 17C (64 or 63F). Root dry weight responded quadratically at days of 14, 22, or 26C (57, 72, or 79F) and calculated maxima occurred with nights of 18C (64F). At days of 22 or 26C (72 or 79F), there were quadratic responses in total dry weight with calculated maximum growth of H. ×hybridus at nights of 18 or 17C (64 or 63F), respectively. For days of 14, 22, or 30C (57, 72, or 86F), there were quadratic responses in RTR with greatest RTR calculated at nights of 15, 18, or 16C (59, 64, or 60F), respectively. There were quadratic responses at days of 22 or 26C (72 or 79F) for leaf area with calculated maxima at nights of 18 or 17C (64 or 63F), respectively. As DTs increased from 14 to 30C (57 to 86F) net CO2 assimilation (PN) of H. ×hybridus also increased linearly whereas increased NTs had no effect on PN. In contrast, stomatal conductance was not impacted by DT or NT.

Nursery Production of Helleborus x hybridus: Management of Nitrogen and Substrate pH

One-year-old seedlings of Helleborus x hybridus Hort. Ex Vilmorin (Lenten rose) were potted into 3.8 liter (#1) containers filled with a pine bark substrate amended with one of five rates of dolomitic limestone [0, 1.4, 2.7, 4.1, or 5.4 kg/m3 (0, 3, 6, 9, or 12 lb/yd3)]. Substrate pH responded quadratically with increasing rate of dolomitic limestone (DL) producing a range of substrate pH from 4.5 to 6.9. Nitrogen application rates (NARs) ranging from 10, 20, 40, 80, and 160 mg/liter were applied with every irrigation. Top dry weight was affected by NAR, DL, and NAR × DL rate interaction. When no DL was added to the substrate, top dry weight increased quadratically with increasing NARs with maximum dry weight occurring with N at 124 mg/liter. However, when the substrate was amended with DL at 1.4, 2.7, 4.1, or 5.4 kg/m3 (3, 6, 9, and 12 lb/yd3) top dry weight increased linearly with increasing NARs with maximum top dry weight of 15 g to 16 g (0.53 oz and 0.56 oz) occurring with N at 160 mg/liter. Contrast analysis comparing DL rates within each NAR revealed DL rates of 1.4, 2.7, 4.1, and 5.4 kg/m3 (3, 6, 9, and 12 lb/yd3) produced greater top growth compared to growth at the DL rate of 0 kg/m3 (0 lb/yd3) at NARs of 40, 80, and 160 mg/liter. Furthermore, when fertilized with N at 40, 80 or 160 mg/liter, top dry weight produced with DL rates of 1.4, 2.7, 4.1, and 5.4 kg/m3 (3, 6, 9, and 12 lb/yd3) did not differ within each NAR. Root dry weight was unaffected by NARs and NAR × DL rate interaction. Rate of DL affected root dry weight with the largest increase in root growth occurring with DL between 0 kg/m3 and 1.4 kg/m3 (0 lb/yd3 and 3 lb/yd3). Root-to-top ratio (RTR) responded quadratically with increasing NAR with the lowest RTR occurring with N at 140 mg/liter. Foliar N, P, K, Ca, Mg, S, and Fe concentrations were unaffected by rate of DL and NAR × DL rate, whereas foliar N, P, K, Ca, Mg, and S were affected by NARs. Foliar N, P, K, and S concentrations responded quadratically to increasing NARs; foliar Ca and Mg concentrations were linear; and foliar Fe concentration was unaffected by NARs.

(37) Irrigation and Fertilizer Placement Affects Plant and Weed Growth In Container Tree Production

On 24 Apr. 2003, 3-gallon (11.4-liter) Quercus shumardii were potted into 13.2-gallon (50-liter) containers using a standard nursery mix. Treatment design was a 3 × 2 × 2 factorial with two fertilizer placements, three irrigation methods, and two herbicide rates. Controlled-release fertilizer 17N–2.9P–9.8K was dibbled (placed 10.2 cm below the surface of the container media at potting) or top-dressed at a rate of 280 grams per container. Irrigation was applied using one of three methods: 1) a spray stake attached to a 3-gallon- (11.4-L-) per-hour pressure compensating drip emitter; 2) a surface-applied pressure-compensating drip ring delivering water at a rate of 2.3 gallons (8.9-L) per hour; and 3) the same drip ring placed 4 inches (10.2 cm) below the container substrate surface. A granular preemergent herbicide (oxyfluorfen + oryzalin) was applied at 2.0 + 1.0 lb/acre (2.24 + 1.12 kg·ha-1). At 75 days after treatment (DAT), containers with no herbicide and top-dressed fertilizer had a percent weed coverage of 46% compared to 18% for dibbled containers with no herbicide. At 180 DAT weed top dry weight was greater for top-dressed containers compared to dibbled. None of the treatments in the study had any effect on height increase. At 240 DAT, trees irrigated with drip rings at the surface had a 28% greater caliper increase among the dibbled fertilizer-treated containers. Trees irrigated with the drip ring placed below the surface and fertilizer top-dressed had the smallest caliper increase. Irrigation method had no effect on weed control in this study; however, a repeat fall application showed a significantly greater weed control with the drip ring below surface compared to the spray stake.

The Effect of Pythium ultimum and Soil Flooding on Two Soybean Cultivars

The effect of flooding and Pythium ultimum on soybean, Glycine max, was determined in a series of greenhouse experiments using the cultivars Hutcheson and Archer. Seeds were planted into pasteurized soil either not infested or infested with sand-cornmeal inoculum of P. ultimum and either flooded at emergence for 2 days or at the four leaf node stage (V4) for 5 days. A nonflooded control was included in each experiment. Seeds placed directly into infested soil resulted in little or no stand for Hutcheson regardless of flood treatment, whereas stand was reduced for Archer only in the flooded infested soil treatment. Additional experiments were conducted by placing seed onto a 2- to 5-mm layer of pathogen-free soil on top of the infested soil. Flooding at emergence reduced plant height, growth stage, and top dry weight for Hutcheson and root fresh weight for both cultivars. Greater reductions for Hutcheson in root weight, and top dry weight in P. ultimum-infested soil in the soil layer experiments, also indicated that Hutcheson was more susceptible than Archer. Flooding alone decreased root weights, and infestation with P. ultimum reduced weights further resulting in an additive effect. This also was the case for plant height, growth stage, and top dry weight for Hutcheson for flooding at emergence. Root discoloration was greatly increased for both cultivars in infested soil flooded at emergence. Similar results were found when plants were flooded at V4; however, the effect was not as great as with flooding at emergence. These studies indicate that Pythium damping-off and root rot may account for a portion of the negative response of soybean to flooding. The results also indicate that Archer has some resistance to P. ultimum.

Raw and Composted Paper Mill Sludges and Municipal Compost in Nursery Substrates

Silverleaf dogwood (Cornus alba L. `Argenteo-marginata'), forsythia (Forsythia × intermedia Zab. `Lynwood Gold'), and weigela (Weigela florida Bunge A.DC. `Red Prince') were grown in #2 (6-L) containers filled with 100% bark or bark mixed with 20%, 40%, or 60% (by vol.) each of raw paper mill sludge (RB group), composted paper mill sludge (CB group), a proprietory paper mill sludge-derived compost (PB group), and municipal compost (MB group). A fifth substrate group (MH) consisted of 100% hemp chips or hemp chips mixed with the same rates of municipal compost. The containers were trickle-irrigated and fertilized with a controlled-release fertilizer. Among the bark-amended groups, growth was highest for dogwood and forsythia with PB, increasing dramatically and peaking at ca. 40% rate (68 and 94 g/plant top dry weight, respectively). Growth of these species was intermediate with MB and CB and least with RB, increasing to rates ≥ 50% in these groups, except for a nonsignificant response of dogwood to RB. Growth of weigela increased equally with PB and MB substrates up to ca. 40% (117 g/plant), but was unresponsive to rates of RB and CB. With the hemp-amended MH group, growth of all three species increased to rates ≥ 50% (62, 93, and 116 g/plant for dogwood, forsythia, and weigela, respectively). Growth of the three species over most rates of all substrate groups was similar to, or exceeded, that in 80% bark: 15% peat: 5% topsoil, a proven nursery mix. Top dry weight of all three species was positively correlated with soluble salts concentrations in the substrates at planting after first irrigation (0.23-1.72 dS·m-1, range over all substrates) and at various intervals during the season.

Effect of population densities of Heterodera glycines race 3 on leaf area, photosynthesis and yield of soybean

The effect of Heterodera glycines on photosynthesis, leaf area and yield of soybean (Glycine max) was studied in two experiments carried out under greenhouse condition. Soybean seeds were sown in 1.5 l (Experiment 1) or 5.0 l (Experiment 2) clay pots filled with a mixture of field soil + sand (1:1) sterilized with methyl bromide. Eight days after sowing, seedlings were thinned to one per pot, and one day later inoculated with 0; 1.200; 3.600; 10.800; 32.400 or 97.200 J2 juveniles of H. glycines. Experiment 1 was carried out during the first 45 days of the inoculation while Experiment 2 was conducted during the whole cycle of the crop. Measurements of photosynthetic rate, stomatic conductance, chlorophyll fluorescence, leaf color, leaf area, and chlorophyll leaf content were taken at ten-day intervals throughout the experiments. Data on fresh root weight, top dry weight, grain yield, number of eggs/gram of roots, and nematode reproduction factor were obtained at the end of the trials. Each treatment was replicated ten times. There was a marked reduction in both photosynthetic rate and chlorophyll content, as well as an evident yellowing of the leaves of the infected plants. Even at the lowest Pi, the effects of H. glycines on the top dry weight or grain yield were quite severe. Despite the parasitism, soybean yield was highly correlated with the integrated leaf area and, accordingly, the use of this parameter was suggested for the design of potential damage prediction models that include physiological aspects of nematode-diseased plants.

Nitrogen Nutrition of Containerized Anemone x hybrida

Uniform single crown plantlets of Anemone x hybrida Paxton ‘Margarete’ were grown in 3.8-liter (#1) containers filled with a substrate of composted pine bark:sand (8:1 by vol). Plants were fertilized three times weekly for 15 weeks with a complete nutrient solution at nitrogen application rates (NARs) of 10, 40, 80, 150 or 300 mg/liter (ppm) nitrogen (N), in a constant ratio of 1 ammonium:2 nitrate. All other nutrients were held constant. Leaf area, top dry weight, and root dry weight increased with increasing NAR until reaching a plateau at a NAR of 144 ± 21 mg/liter (ppm), 158 ± 28 mg/liter (ppm), and 119 ± 30 mg/liter (ppm), respectively. The proportion of fine roots to thick roots was unaffected, and production of propagation material (root cuttings) reached a plateau at a NAR of 108 ± 28 mg/liter (ppm). Leaf concentrations of N, P, and K at maximum leaf area were 4.7%, 0.5%, and 3.5%, respectively.