Capillary Mat Research Articles

WATER RETENTION IN SOILLESS POTTING MEDIA

Water retention was measured in soilless potting media irrigated by capillary mat, flood and drain, drip or overhead sprinkler. Media were amended with wetting agent or hydrophilic polymeric gel. Pots 12 cm high with a volume of 465 cm3 were loose-filled to the top with media. Potted media were wetted overhead with 120 ml water, then pots were randomly assigned to irrigation treatments. Capillary mat irrigation was continuous; other irrigation treatments were applied daily. Water retention was measured by weighing. Irrigation was continued until no further retention was measured. Water retention was significantly affected by irrigation method and medium amendments. Irrigation method followed the order overhead >= drip > flood and drain >= mat. Hydrophilic gel increased water retention, but in contrast to previous results, wetting agent did not, nor was any interaction of gel and wetting agent observed. Retention of water at container capacity, measured in situ at the end of each experiment, was significantly larger than actual retention.

WATER RETENTION IN SOILLESS POTTING MEDIA

Water retention was measured in soilless potting media irrigated by capillary mat, flood and drain, drip or overhead sprinkler. Media were amended with wetting agent or hydrophilic polymeric gel. Pots 12 cm high with a volume of 465 cm3 were loose-filled to the top with media. Potted media were wetted overhead with 120 ml water, then pots were randomly assigned to irrigation treatments. Capillary mat irrigation was continuous; other irrigation treatments were applied daily. Water retention was measured by weighing. Irrigation was continued until no further retention was measured. Water retention was significantly affected by irrigation method and medium amendments. Irrigation method followed the order overhead >= drip > flood and drain >= mat. Hydrophilic gel increased water retention, but in contrast to previous results, wetting agent did not, nor was any interaction of gel and wetting agent observed. Retention of water at container capacity, measured in situ at the end of each experiment, was significantly larger than actual retention.

Poinsettia Irrigation Based on Evaporative Demand and Plant Growth Characteristics

Abstract An easy method to estimate water requirements for poinsettia (Euphorbia pulcherrima Willd. ex Kl.) production with practical applications to commercial operations was developed to promote water conservation. A water-requirement prediction equation (P ≥ 0.01, R2 = 0.78) that used pan evaporation along with plant-canopy height and width as input variables was generated. Equation verification was carried out by comparing plant quality of crops irrigated according to the generated water-requirement prediction equation to crops irrigated “on-demand” or with capillary-mat irrigation. Plants irrigated with the prediction equation were smaller than plants grown with capillary mat, but plant quality ratings for ‘Annette Hegg Diva’ and ‘Dark Red Annette Hegg’ were not significantly different. ‘Gutbier V-10 Amy’ plants grown with irrigation on-demand were of higher quality than plants grown using either the capillary mat or the prediction equation. Applied water was significantly lower for plants irrigated with the prediction equation than would normally be applied in a commercial operation using a conservative fixed daily irrigation rate.

Utilization of Recycled Irrigation Water on Marigolds Fertilized with Osmocote and Constant Liquid Fertilization

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.

Influence of Controlled-release Fertilizer on Exacum affine Balf. F. ‘Elfin’ during Production and Subsequent Simulated Home Conditions1

Abstract High quality Exacum plants suited for use as flowering house plants were produced in 10-cm pots using a 3 or 5 kg/m3 rate of a 3- to 4-month controlled-release fertilizer (Osmocote 14N-6.1P-11.6K) or an 8- to 9-month release Osmocote (18-2.6-10) with either capillary mat or overhead irrigation. Flowering plants placed in simulated home conditions had more foliar chlorosis at lower Osmocote rates while floral display decreased with higher Osmocote rates.

Soil temperature and moisture control in relation to screeningSolanum spp. for resistance to the potato cyst nematode (Globodera spp.) in greenhouses

Recent improvements in screeningSolanum populations for resistance to the potato cyst nematode are described. Soil temperature control within the required optimum range is obtained in greenhouse by cooling the bench. The use of a cotton blanket (capillary matting) on the bench under the pots reduced the frequency of watering to once or twice a week. The system is reliable, and provides a large capacity/low cost facility for large-scale resistance screening.

A technique for determining potassium release from a slow‐release fertilizer

Abstract A new technique was utilized to determine the rate of potassium release from a slow‐release fertilizer. The technique is based on diffusion of the potassium ion into a saturated capillary mat followed by extraction and analysis of the solution pressed from the capillary mat. The technique demonstrated that K was released at a rate similar to that reported by another researcher. The major advantage of this technique is the simple readily available equipment needed for solution extraction.

Influence of Watering Methods and Ancymidol on Two Tropical Foliage Species Held in a Simulated Interior Environment1

Abstract Epipremnum aureum (Linden & Andre) and Pilea depressa (Swartz) Blume were grown under different watering methods (a capillary mat and controlled volume of 250 ml/15 cm pot twice a week) and treated with the growth retardant alpha-cyclopropyl-alpha-(p-methoxyphenyl)-5-pyrimidinemethanol (ancymidol) as a soil drench at concentrations of 0, 0.25, 0.50 and 0.75 mg/15 cm pot and later held for 6 weeks in a simulated interior environment (SIE) with a controlled temperature of 18 ± 1°C and light intensity of 1080 lux. Ancymidol treatments retarded internode length and stem length of E. aureum regardless of watering methods. Fresh weight was not influenced by ancymidol but was affected by type of watering. Ancymidol retarded internode length and stem length of P. depressa and reduced fresh weight regardless of watering methods.

Influence of Rate and Placement of Slow-release Fertilizer on Pot Plants of African Violet Grown with Capillary Mat Watering1

Abstract Ballet African violets (Saintpaulia ionantha Wend. cvs. Ulli and Lisa) were grown in a peat-vermiculite-perlite mix using capillary mat subirrigation in the summer and winter. Rates of 0.9, 1.8, 2.7, and 3.6 kg of Osmocote 14-14-14 (14N-6.1P-11.6K) per m3 of growing medium were either top-dressed, incorporated, or placed in the bottom of the pot. In the summer, maximum dry weight of ‘Lisa’ was produced at the 3.6 kg/m3 rate and for ‘Ulli’ at the 2.7 kg/m3 rate (over all fertilizer placement methods). In winter, the 2.7 kg/m3 rate produced greatest dry weight in both cultivars. Placement method was significant for ‘Lisa’ dry weight and plant quality in summer, with top-dressing or incorporation generally being better than bottom-of-pot placement. Placement method was not significant for ‘Ulli’ in summer or winter for dry weight or quality.

Production Costs for 10 cm and 15 cm Potted Chrysanthemums1

Abstract Costs for growing 10 cm and 15 cm potted chrysanthemums (Chrysanthemum morifolium Ramet.) under shade cloth on capillary mats in Florida were estimated to be $0.42 and $1.52 per plant, respectively. If 10 cm and 15 cm potted chrysanthemums wholesale at $0.60 and $2.00 per plant, respectively, annual return above growing costs from a 2 ha structure would be $37, 514 and $13, 667 for 10 cm and 15 cm plants, respectively. Growers would need to wholesale 15 cm pot chrysanthemums at about $2.25 to equal annual return from 10 cm plants.