Abstract
Seed leachate conductivity (SLC) has been evaluated as a possible method of measuring seedling vigor in sweet corn (Zea mays L.) and other crops. It is known that genotypes leak solutes at different rates. Thus, it is important to determine if the different rates of leakage result in different SLC determinations when SLC is measured after various lengths of imbibition. A study was conducted using near-isogenic lines of three inbreds (C68, P39M94, and Ia5125a) in combination with five endosperm types, sugary dull (su du), sugary sugary-2 (su su2), sugary dull waxy (su du wx), shrunken-2 (sh2), and sugary (su), to evaluate the effect of length of imbibition and the interaction of imbibition length and endosperm type and inbred background on conductivity. Readings were taken at 0, 2, 4, 6, 8, 10, 12, 14, and 24 hr after the start of imbibition. Conductivity was affected by length of imbibition, inbred background, and endosperm-type main effects and interactions of these effects. Conductivity increased with increasing time after imbibition. Ranking of endosperm types within each inbred was stable by 2 hr after imbibition, although differences were not always significant. Thus, the interaction effects were due to an increasing separation over time and not to a change in ranking of the genotypes. However, means separation was greatest at 24 hr after imbibition.
The effects of overhead pulse irrigation versus conventional overhead irrigation on growth of Ageratum houstonianum `Blue Puff' in 2 media, container leachate volumes and leachate NO3-N and NH4-N levels were evaluated. Container leachate volumes, and NO3-N and NH4-N levels were higher with pinebark:sand medium. Container leachate volumes tended to be lower with pulse irrigation compared to conventional irrigation. Shoot dry weights of plants grown in pinebark:peat were greater under conventional irrigation compared to pulse irrigation; however, growth indices, flower number, and NO3-N and NH4-N levels were not affected by irrigation method in either medium.
Abstract
Nitrate and K ions did not accumulate significantly in the irrigation reservoir when the leachate from Osmocote 14N-6.1P-11.6K or constant liquid fertilization (CLF) was utilized. No accumulation of salts occurred whether ‘Scarlet Sophia’ marigolds (Tagetes patula L.) were irrigated by capillary mat or trickle tube. With one exception, plants fertilized with Osmocote 14N-6.1P-11.6K at the recommended rate (lx) or twice (2x) the recommended rate produced plants equal to or better than CLF at 100 ppm N. Except for recycled CLF, macronutrient content of plant tissues was within acceptable ranges. Fertilizer treatments did not affect the number of days to flower. The combination of Osmocote fertilization and capillary mat irrigation was more effective in producing high-quality plants than Osmocote fertilization and trickle-tube irrigation. Tap-water utilization was reduced substantially by using recycled water.
Leachates were collected at 3-month intervals over 12 months to determine the influence of bark, controlled-release fertilizer, and dolomitic lime sources and dolomitic lime application rates on pH of nursery media. The randomized complete-block design was arranged as a factorial and included three bark sources (pinebark, hardwood, and pinebark + hardwood), two fertilizer sources (Nutricote 17-7-8 and SierraBlen 18-7-10), and two dolomitic lime sources (microencapsulated granular and pulverized). Dolomitic lime application rates were 0, 5, 10, and 15 pounds per cubic yard. Leachate pH was influenced over the one-year evaluation period by fertilizer source, bark source, and application rate of dolomitic lime. Dolomitic lime source was not a significant factor in adjustment of leachate pH. Pinebark medium had lower leachate pHs than hardwood medium and the medium containing hardwood and pinebark. Dolomitic lime influenced leachate pH of pinebark medium more than the other bark sources. SierraBlen was more acid-forming than Nutricote.
Abstract
Of various controlled-release fertilizer materials, tested on African violet (Saintpaulia ionantha H. Wendl) at 300, 600, and 900 kg/ha for leachate soluble salts, Ca, P, K, and Mg and plant injury, Scott 25.0–4.4–8.3 gave the best result and Scott 15.0–8.7–4.2 gave the poorest result. Precise 8.0–4.8–4.2 leachate generally contained more Ca and Mg and lower leachate soluble salts, but was lower in P and K than the other fertilizers. With the exception of Precise, the leachate soluble salts of most of the fertilizers was initially (10th irrigation) too high. The 900 kg/ha rates for some fertilizers caused high leachate soluble salts and plant injury.
Seeds of jute (Chorchorus olitorius L.) undergo a period of dormancy, which hitherto has been broken with the conventional method of steeping in boiling water. Another seed treatment procedure, which involves soaking seeds in earthworm cast leachate, was found superior to the conventional method of breaking dormancy. Furthermore, radicle growth was enhanced when seeds were irrigated with water that contained earthworm cast leachate instead of water without earthworm cast leachate. This possibly suggests that earthworms excrete substances that contain hormones or biochemically active ingredients that are capable of stimulating root growth.
Leachates of living Cynodon dactylon (L.) Pers. and Amaranthus sp. were applied to Carya illinoinensis (Wangenh.) C. Koch. seedlings to compare effects on growth and elemental absorption. Water applied to the weed pot or control pot (no weeds present) leached through the pot and into a funnel with a tube attached, then directly into the corresponding pecan seedling pot. After 4 months of growth, pecan seedlings receiving weed leachates had less leaf area and were shorter than those watered through control pots. These results suggest that leachates from these two weed species inhibit pecan growth, independent of any competition effects.
Abstract
Excessive fertilization produces high soluble salts, resulting in root damage and poor quality foliage. Although usually determined by mixing soil with water, conductivity also can be determined by mixing with leachate obtained by pouring water through the potting medium.
Abstract
Leachates from asexual embryos of cacao (Theobroma cacao L.) inhibited seed germination of lettuce (Lactuca sativa L. ‘Ruby’), and inhibitor activity increased with concentration and duration of soaking. The amount of inhibitor was greatest in very small asexual embryos and was detected in immature but not mature zygotic embryos. The capability of cacao embryo leachate to inhibit lettuce seed germination was destroyed by heat (100°C for 20 min). When the leachate was separated into 15 fractions with high pressure liquid chromatography (HPLC), 5 significantly promoted and 2 significantly inhibited lettuce seed germination. Abscisic acid was not detected in the leachate. Fraction 10 co-chromatographed with p-coumaric acid, but p-coumaric acid is heat stable and its presence was not confirmed by mass spectrometry.
Soil Moist, acrylic polymer, was incorporated into a soil, peat compost, pinebark, and perlite medium at 0, 5, 10, and 20 g per 10 cm (500 ml) pot. One rooted cutting of Dendranthema grandiflora (Ramat) Kitamura was planted into the pot. Prior to planting, each pot received 0.25 mg of ancymidol in a 80 ml drench. Leachate was collected at drenching for foxtail millet bioassay. Chrysanthemum height, dry weight, area, flower number, and date of flowering were recorded at flowering. In a second experiment, Soil Moist, Supersorb C, Agrosoake and Broadleaf brand polymers were evaluated at the manufacturer's recommended rate. Height of millet seedlings grown in ancymidol leachate from polymer-treated media was greater than seedlings grown in ancymidol drench solution. Height of millet seedlings grown with ancymidol leachate from the various polymer media did not differ in height from seedlings which received tap water lechate. Growth parameters were unaffected by polymer rate or brand.