Ibrahim G. Rubeiz

Yield Response of Greenhouse Cantaloup to Clear and Black Plastic Mulches

ABSTRACT Fruit yield of cantaloup (Cucumis melo l.cv. PSF 189) was not affected by the application of clear (C) or (B) plastic mulches, in comparison to unmulched soil (U), when grown inside an unheated greenhouse located in the Mediterranean mountains in a region with a cold early spring. Marketable yields of 30.5, 28.06 and 25.03 t/ha were achieved under the C, B and U treatments, respectively, during 1990. These yields were not significantly different (P>0.05). The mulches enhanced vegetative growth during the cold early spring; fully expanded leaves were 2.5 times more under C mulch, and 1.8 times more under the B mulch, than under the U treatment, by the fifth week after planting. Fruiting occurred later on when the weather warmed and thus no significant effect on yield occurred due to the mulches. Soil temperature at 10 cm depth under the C treatment was warmer by 1–2°C and 7–10°C than temperature under the B and U treatments respectively, when the plant canopy did not cover the mulches but became c...

Subsurface drip irrigation and urea phosphate fertigation for vegetables on calcareous soils

Abstract Drip irrigation lines installed at 5 cm (shallow) or 15 cm (deep) below the soil surface and furrow irrigation were compared for vegetables grown on calcareous desert soils. Urea phosphate (UP) fertilizer (17–44–0) was injected twice in the drip irrigation lines during the growing season. Yields were compared to preplant fertilized and unfertilized furrows. Fall cabbage (Brassica oleracea var. capitata L.) gave comparable yields under the different irrigation treatments with the drip treatments using half the water used by the furrow treatment. Cabbage yield increased in all fertilized treatments as compared to the unfertilized furrow. Petiole P and NO3‐N concentrations were higher from the drip than from the furrow treatments. Zucchini squash (Cucurbita pepo L.) had the highest yields under deep drip and fertilized furrow treatments, with the deep drip using half the water and P rate used by the furrow treatment. The deep drip increased squash yield by 34% over the shallow drip. The unfertilized...

Layer and broiler poultry manure as nitrogen fertilizer sources for cabbage production

Abstract Floor litter from one‐year‐old laying hens (LHM) and from eight‐week‐old broiler chickens (BCM) were incorporated in the soil of two fields and evaluated as nitrogen (N) sources for cabbage production on a non nutrient‐depleted soil. LHM had 3.4% moisture, 3.84% N and 3.41% phosphorus (P). BCM had 2.3% moisture, 4.46% N and 2.19% P. Field 1 recieved 2.4 t/ha BCM, 3.0 t/ha LHM, whereas Field 2 recieved 4.8 t/ha BCM and 6.1 t/ha LHM. Also, each field received ammonium sulfate [(NH4)2SO4] at a N rate of 100 kg/ha and an unfertilized control treatment. The manure was applied one week before cabbage transplanting on 18 May 1992. Ammonium sulfate was applied in two equal split applications during the growing season. Leaf nitrate‐nitrogen (NO3‐N) was higher at harvest in plants receiving the higher manure rate than in other treatments (P<0.05). Leaf phosphate (PO4‐P) was higher in early season in plants receiving LHM at both Tates than in other treatments. Soil BD, EC, NO3‐N, and P at harvest were not a...

Enhancing Late and Early Yield of Greenhouse Cucumber with Plastic Mulches

ABSTRACT Clear (C) plastic mulch installed inside unheated greenhouses, located in a temperate zone, increased late fall and early spring yield of greenhouse cucumber (Cucumis sativus L. cv. Lolita) in comparison with black (B) plastic mulch or unmulched (U) soil during 1986–1987. In the fall crop, yield during the last two weeks of harvest was 22.1% and 13.2% and total yield was 13.0% and 4.0% higher under the C and B mulches, respectively, in comparison with U soil. In the spring crop, yield during the first month of harvest was 29.0% and 6.7% and total yield was 18.8% and 4.4% higher under the C and B mulches respectively in comparison with U soil. It may be concluded that clear plastic mulch increased yield of greenhouse cucumber grown in unheated greenhouses located in a temperate zone.

Effect of irrigation methods on urea phosphate reactions in calcareous soils

Abstract Urea phosphate (17–44–0) (UP) was injected in surface placed drip irrigation lines, subsurface placed drip irrigation lines (15 cm below soil surface), or band under furrow irrigation on a calcareous soil. In drip irrigation, UP was split in two applications, two weeks apart, to give a total rate of 50 kg P2O5/ha. The furrow rate was 100 kg P2O5/ha in a single application. Soil analysis one month after the first injection of UP showed high levels of available P (NaHCO3 extractable) around the drip emitters. Considerable P mobility in the soil was detected within 20 cm from the emitters. Banding UP under the furrow did not leave any measurable levels of available P by the end of the experiment. Soil NO3‐N levels were comparable in all fertilized irrigation treatments, and were higher than the levels under an unfertilized furrow. Soil pH was reduced by 0.5 units around the drip emitters, but no change was measurable under furrow irrigation. Soluble salts (ECe) were concentrated in the top 10 cm of ...

Organic farming: economic efficiency approach of applying layer litter rates to greenhouse grown strawberries and lettuce.

Abstract The agricultural sector is becoming more and more concerned with implementing environmentally friendly practices in order to enhance environmental quality and lessen environmental degradation. The paper presented here is an identification of costs and benefits associated with applying ammonium nitrate, layer hen litter at 7 ton/ha, and layer hen litter at 14 ton/ha as fertilizers to greenhouse grown strawberry and lettuce, through the utilization of the Net Present Value (NPV) technique which compares benefits and costs. The results of this technique indicated that, after deducing costs from benefits, layer hen litter at 7 ton/ha or 14 ton/ha was found to be more profitable than ammonium nitrate. However, for environmental safety, the lower rate of layer hen litter (7 ton/ha) is preferred to the higher rate (14 ton/ha) because it is less than the critical 13 ton/ha, considered to cause water contamination by the United States Environmental Protection Agency (USEPA).

Comparative evaluation of broiler and layer poultry manure for greenhouse lettuce production

Abstract Disposing poultry manure from broiler and layer flocks by its incorporation into the soil was evaluated on greenhouse lettuce (Lactuca sativa L. cv. Paris Island cos). Floor litter that contains the manure mixed with sawdust and wood shaving, was 8 weeks old from broilers and one year old from layers. Broiler manure had 19% moisture and 5.5% N, while layer manure had 22% moisture and 3.7% N. Application of 27.5 ton/ha broiler manure and 18 ton/ha layer manure, on wet basis, gave comparable yield of lettuce as did an application of 100 kg N/ha from NH4NO3 in 2 split applications, and an unfertilized treatment. The manure was effective for lettuce growth 10 months after its incorporation in the soil. The highest yield was in manure treated plots, however, the lack of significant response in yield is due to the sufficient levels of soil NO3‐N and available P. There was no effect on soil EC, pH, and available P due to the treatments; however, soil NO3‐N was significantly increased under all fertilize...

Evaluation of layer litter rates as a fertilizer for greenhouse strawberry and lettuce

Abstract Laying hen litter [3.4% nitrogen (N), 0.86% phosphorus (P), 15% water (H2O)] as a fertilizer was evaluated in greenhouse production of strawberry (Fragaria ananassa Duch. cv. Oso Grande) and cos‐lettuce (Lactuca sativa L. cv. Amanthus). Litter was preplant soil incorporated at 7 (R1) and 14 (R2) ton ha‐1, and compared to ammonium nitrate (AN) (34–0–0) and an unfertilized (control) treatments. Rates of AN were at 150 kg N ha‐1 for strawberry, in eight split applications, and 100 kg N ha‐1 for lettuce, in two split applications. Preplant soil levels (mg kg‐1) of NO3‐N and P(H2O sol.) were 80 and 5.5, respectively (strawberry), and 91 and 6.8, respectively (lettuce). Strawberry yield was highest in R2 with all fertilized treatments yielding higher than the control. Leaf phosphorus (P) was comparable in all treatments, with R2 giving the highest P content. Lettuce yield was comparable in all treatments. Leaf NO3‐N was higher in all fertilized treatments than the control and leaf P was comparable amon...

Rowcover and Black Plastic Mulch Effects on Tomato Production

ABSTRACT Enhancing early crop production and yield by the use of rowcovers has achieved variable results depending on crop grown and climate. The performance of rowcovers, with or without plastic mulches, has not been evaluated in the Mediterranean region. Tomato plants (Lycopersicon esculentum Mill) were grown under floating rowcover, black plastic mulch, mulch plus rowcover, or no protection i.e. control, for studying the effect on yield in terms of earliness, total yield and average fruit size. Early yield was significantly increased by the mulch treatment while the rowcover treatment yielded the least (P<0.05). Total yield was increased by the mulch and mulch plus rowcover treatments, while the rowcover and control treatments yielded the least (P<0.05). Soil temperature at 10 cm depth varied between Io to 2°C only under the different treatments. Air temperature under the rowcover exceeded 35 to 40°C on many days, hence causing fruit setting problems and resulting in reduced early yield under the rowco...

Response of fall greenhouse COS lettuce to clear mulch and nitrogen fertilizer

Abstract Application of clear plastic mulch with or without N fertilizer did not significantly increase (P > 0.05) yield of cos lettuce (Lactuca sativa L. cv. Paris Island), grown in Fall in a greenhouse in the Mediterranean mountains. Yield ranged from 31 to 38 kg/50 heads. Leaf NO3‐N and total P levels were higher in mulched than unmulched plants, and in fertilized than in unfertilized plants, and always above the sufficiency level in all treatments. Soil levels of NO3‐N were higher under mulched than unmulched plots, and under fertilized than unfertilized plots, which had more than 50 ppm NO3‐N at harvest. This indicates ample supply of N and thus explains the lack of response to added N. It may be concluded that in mild climates and on soils with adequate N, lettuce will not respond to the use of clear mulch and N fertilizer.