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Lily species are considered one of the most important cut flowers worldwide. With annual production of 282 million flowers and total value of $200 million, lily is among the top five cut flower species auctioned in the international flower stock markets. The objective of this study was to assess the effect of different planting depths on morphology, physiology, root growth and flower quality of lilies. Three hybrid lilies [Lilium × elegans; Orienpet (‘Maytime’, white) and L.A. (‘Fangio’, pink and ‘Pavia’, yellow)] were used. Deep planting at 25 cm significantly improved total and stem root systems, stem diameter and leaf area. No significant differences were noticed between planting depths for plant height, chlorophyll content, and gas exchange (photosynthesis, stomatal conductance and transpiration). Flower quality variables, specifically, vase life from deep planting were higher in 25-cm compared to 5 and 15. The ‘Maytime’ cultivar had higher leaf area, total and stem roots, flower diameter, number of days to flowering, and brighter color (L*) while the ‘Fangio’ had higher leaf number per plant, more basal roots, flower number per plant, vase life, and red color coordinate (a*). Overall, our results revealed that lily growers can increase their lily flower quality by adopting the deep planting at 25 cm. RESUMO As espécies de lírio são consideradas uma das flores de corte mais importantes do mundo. Com produção anual de 282 milhões de flores e valor total de US$ 200 milhões, o lírio está entre as cinco principais espécies de flores de corte leiloadas nas bolsas internacionais de flores. O objetivo deste trabalho foi avaliar o efeito de diferentes profundidades de plantio na morfologia, fisiologia, crescimento radicular e qualidade floral de lírios. Três lírios híbridos foram avaliados [Lilium × elegans; Orienpet (‘Maytime’, branco) e L.A. (‘Fangio’, rosa e ‘Pavia’, amarelo)]. O plantio profundo a 25 cm melhorou significativamente o sistema radicular total e do caule, o diâmetro do caule e a área foliar. Não foram observadas diferenças significativas entre as profundidades de plantio para altura de planta, teor de clorofila e trocas gasosas (fotossíntese, condutância estomática e transpiração). As variáveis de qualidade da flor, especificamente, a vida de vaso do plantio profundo foi maior em 25 cm comparado a 5 e 15. A cultivar ‘Maytime’ apresentou maior área foliar, quantidade de raízes totais e do caule, diâmetro da flor, número de dias para floração e cor mais brilhante (L*) enquanto a ‘Fangio’ apresentou maior número de folhas por planta, raízes basais, número de flores por planta, vida de vaso e coordenada de cor vermelha (a*). No geral, nossos resultados revelaram que os produtores de lírio podem melhorar a qualidade da flor de lírio adotando o plantio profundo a 25 cm.

Polyethylene mulch is widely used for vegetable production in the United States as a tool to conserve water, control weeds, and produce earlier and cleaner products (i.e., less attached soil). However, the increasing labor costs for mulch removal and disposal after harvest and soil environmental pollution are major concerns. The objective of this study was to assess fruit yield and quality, mulch deterioration, soil microbial activity, and nutrient changes in ‘Stargazer’ watermelon (Citrullus lanatus) grown with degradable plastic mulch. The deterioration rates of degradable mulch were 7%, 37%, 57%, and 92% after 120, 210, 300, and 365 days, respectively, of placing the mulch in the field. However, the extra difference in using degradable mulch was calculated as $58.6/acre (polyethylene $600.9/acre vs. degradable $659.5/acre), including all costs associated with laying and disposing. One year after placing mulch in the field, the nitrate content and total and active fungi numerically increased (P = 0.08) in soils with the degradable mulch compared with polyethylene mulch. However, there were no statistical differences in soil phosphorus, potassium, organic carbon, and total and active bacteria. Extra-large fruit size yield (category >24.0 lb) from the polyethylene mulch treatment was higher than that from degradable mulch, whereas the 18.0- to 24.0-lb category was lower than that with degradable mulch. However, total yield and total soluble solids from both mulches were statistically similar. Considering the complete deterioration (less waste), mulch removal cost (not required), microbial associations (higher fungi abundance and activity), and similar yield and fruit quality of degradable mulch compared with polyethylene, the implementation of degradable mulches in commercial watermelon field practices is promising.

The objective of this two-year study was to assess the effect of N source on plant physiology, yield and fruit quality of apricot (Prunus armeniaca ‘Mogador’) trees. Parameters evaluated included: ...

Nitrogen (N) status in olive trees is critical to develop several developmental mechanisms that control shoot, root and nutrient uptake capacity. The objective of this field study was to assess the effect of N level and form on root growth dynamics, shoot growth, leaf-level gas exchange [photosynthesis (Pn), transpiration (E), and stomatal conductance (gs)] and leaf nutrient content of young olive (Olea europaea cv. Arbequina) trees. Olive cuttings were planted in the field and grown for two years (2015, 2016). In both years, cuttings were subjected to 7 N treatments: control (no N), nitrate (NO3−) form applied as calcium nitrate (CN) at 20, 40 and 60 kg ha-1, and ammonium (NH4+) applied as urea at 20, 40 and 60 kg ha-1. Minirhizotron image analysis showed that the application of N significantly reduced root length intensity (La, mm cm-2) compared to control olives in both years. No significant difference was noticed between N forms for La in 2015. However, CN treatment had higher La than urea in April and June 2016. In addition, the overall mean of La across the study period (2015–2016) showed that La in the lower soil depths, 40–60 and 60–80 cm was significantly higher than those from the top layers, 0–20 and 20–40 cm. Unfertilized (control) cuttings had also higher tree height, stem diameter and branch number than olives that received 40 or 60 kg ha-1-N across the study period (2015-2016). In both years, leaf N% in control olives was above the N deficiency thresholds; i.e. 2.1% in 2015 and 2.57% in 2016. However, leaf mineral concentrations were inconsistent (P, Ca+2, Na, Zn, Fe, Cu) or not significant (Mn, S and B). In addition, no significant difference was noticed between treatments in gas exchange (Pn, gs and E). Overall, untreated-control young olive trees showed consistently higher La and shoot growth than N-treated trees (CN and urea) over the study period 2015-2016. Therefore, N application is not needed if leaf N levels are normal during the previous season. In fact, high rates of N in the soil during establishment of young olive trees can negatively affect root and shoot growth.

This study investigated the influence of treated greywater on growth and protein content of multipurpose (forage and ornamental) transplants, Prosopis juliflora L., Prosopis tamarugo L., and Albizia lebbeck L. Transplants of tested species were irrigated with treated greywater, diluted greywater (grey + distilled water, 1:1/by volume), and distilled water (control) for seven months. Water quality analysis showed that the concentrations of nutrients and heavy metals found in the greywater were within the acceptable range compared with Jordan Institution for Standard and Metrology (JISM) and the World Health Organization (WHO) thresholds for safe use of greywater. Escherichia coli found in the greywater were lower compared to JISM and WHO guidelines for the safe use of greywater. Irrigation with treated greywater increased shoot fresh weight by 24–39% and dry weight by 34–40% compared to diluted greywater and control. No significant difference in crude protein was noticed between water treatments. Prosopis species (P. juliflora Albizia lebbeck L. and P. tamarugo Albizia lebbeck L.) had higher shoot fresh (35%) and dry weight the same species had lower crude protein (44%) when compared to Albizia lebbeck Albizia lebbeck L. The reuse of treated greywater for landscaping or forage production alleviates the demand for water resources and reduces the pressure on wastewater treatment plants. However, considering the controversial findings of previous studies on greywater quality (especially, long-term reuse), the reuse of treated greywater needs to be considered with caution and periodic quality analyses and economic assessments are required.

The objectives of this research were to assess the physical properties of six different growing substrate mixtures destined for roof gardens and determine the influence of these substrates on the morphology, physiology, growth and flower quality of pansy (Viola × wittrockiana), Madagascar periwinkle (Catharanthus roseus), and Pavia lily (Longiflorum×Asiatic lilies (Lilium) ‘Pavia’). Six green roof growing substrate mixtures (by volume) were used [T1: coarse tuff+fine tuff+cocopeat (5:1:4), T2:coarse tuff+medium tuff+fine tuff+cocopeat (5:5:2:8), T3: medium tuff+fine tuff+cocopeat (5:1:4), T4:medium tuff+fine tuff + peat moss (5:1:4), T5: perlite+medium tuff+fine tuff+cocopeat (5:5:2:8), and T6: lightweight expandable clay aggregates+fine tuff+cocopeat (5:1:4)]. The T6 (LECA-cocopeat) had the lowest weight at field capacity and good aeration and WHC to sustain optimal plant growth. Medium tuff-peat moss (T4) produced the highest pansy flowers number per plants. However, peat moss (T4) has been identified by environmentalists as an unsustainable media. LECA-cocopeat (T6) had a higher number of lily flowers and leaf area than T1-T4. The cost of the LECA substrate ($US 215 m−3, T6) is extremely higher than that of volcanic tuff ($US 36 m−3, T1-T4), and perlite ($US 100 m−3, T5). Overall, T6 can be an ideal option in terms of physical properties of growing substrate and flower quality but it might not be the best option for green roofs when cost is the primary concern. In addition, certain growing substrates could be used to satisfy specific growing requirements without sacrificing performance. For example, the combination of medium tuff and peat moss (T4) produced the highest pansy flower numbers per plant but required a longer period to flower (95 days). So, this growing substrate could be used where plentiful blooms are desired and the time to bloom is not a concern.

The ethylene inhibitor 1-methylcyclopropene (1-MCP) is commonly used to increase the shelf life of fruits. However, the application of 1-MCP to modulate the shoot growth of vegetable transplants is unknown. The objective of this study was to assess the influence of 1-MCP on improving the growth and quality of tomato transplants. Eight tomato cultivars ('Florida 47', 'Shanty', 'Volante', 'Tycoon', 'TAMU-Hot', 'Felicity', 'Charger', and 'BHN685') were grown in greenhouse conditions for seven weeks and then 1-MCP (50 mg L-1) was applied to transplants using a boom fertigation system. After treatments, both the 1-MCP and untreated plants were transferred to 0.5-L pots and placed in three growth chamber environments differing in day/night temperature regimes, 30/20°C (optimum), 34/24°C constant (stress) and 34/24°C ramping (stress). The plant morphology and physiology variables were collected during the study period. 1-MCP application significantly increased the leaf area, stem diameter and plant height of 'Florida 47' across all temperature regimes. 'TAMU-Hot', which was grown only in the 34/24 environment (ramping) also positively responded to 1-MCP. However, the leaf gas exchange (photosynthetic rate and stomatal conductance) and SPAD measurements were inconsistent across cultivars. 1-MCP had no negative effect on the transplant growth across all cultivars in the 30/20 environment but reduced growth components in Felicity and Tycoon in the 34/24 environment. Our results showed that the application of 1-MCP to improve the transplant quality is promising. Since genetics and environment may influence the sensitivity of tomato plants to 1-MCP, future studies should aim to identify the optimal microclimate growth conditions for specific cultivars.

The objective of this study was to assess the influence of plant- and animal-based soil amendments on soil nutrient availability, CO2 respiration, yield and phytochemicals of artichoke (Cynara cardunculus cv. 179) heads. Four certified organic fertilisers: fish meal, blood meal, alfalfa meal and chicken manure, were used as experimental treatments. After two years of organic soil amended with the plant-based fertiliser (alfalfa meal), soil respiration and content of organic matter (OM) was higher than that in soil amended with animal-based fertilisers (fish meal, blood meal, and chicken manure), though the difference in OM between alfalfa and chicken manure was not statistically significant. The marketable yield from soil amended with chicken manure was higher than that amended with alfalfa meal and in the first year (2015) yields from both chicken manure and fish meal treatments were higher than that of the alfalfa treatment. Concentrations of phytochemicals in artichoke heads grown in soil amend...

Soilless substrates enhance growing environment, nutrient content, and water quality in the growing medium. The objective of this study was to assess the influence of substrate particle size on growth and flower quality (flower number and length per plant) of two asiatic hybrid lily (Lilium ×elegans) cultivars Fangio and Ercolano. Plants were grown in 12-L pot under greenhouse conditions. Five grades of particle-size substrate, consisting of granulated volcanic material (tuff) were used as treatments. These sizes were 0 to 2, 0 to 4, 0 to 8, 2 to 4, and 4 to 8 mm. Fertigation was applied daily. Plant morphology, physiology, and flower quality were determined during flowering stage. Treatments of 2 to 4- and 4 to 8-mm tuff had lower water holding capacity (WHC), bulk density, electrical conductivity (EC), and pH compared with 0 to 2- and 0 to 4-mm tuff. In addition, plant height, leaf area, and flower quality of ‘Fangio’ were higher compared with ‘Ercolano’. Chlorophyll content and fluorescence were similar among all treatments. Leaf fresh weight, leaf area, shoot dry weight, root dry weight, and flower quality were higher in sizes of 0 to 4-, 2 to 4-, and 4 to 8-mm than 0 to 2-mm tuff, especially those from ‘Fangio’. The 0 to 4-mm substrate had an optimal and consistent flower quality results in both cultivars when compared with other tuff sizes. Overall, the results presented here suggest that using 0 to 4-mm tuff substrate holds promise for improving growth and flower quality of asiatic hybrid lily grown under soilless culture.

Tillage practices are critical for sustaining soil quality necessary for successful crop growth and productivity. A three-year study (2012–2014) was carried out to evaluate the influence of strip and conventional tillage practices and three water status levels [T1 = 100% of evapotranspiration (ET) demands, T2 = 0.75T1and T3 = 0.5T1] on plant morphology, physiology, yield and quality of triploid (seedless) watermelon (Citrullus lanatus cv. Magestic). Soil chemical and biological properties were also assessed at the end of the experimental study. Tillage practices (strip or ST and conventional or CT) started in 2009 and are being carried out to the present date of 2016. Irrigation was established using a center pivot system. Photosynthesis rate (Pn), stomatal conductance (gs), and chlorophyll content index (SPAD) were measured at flowering, fruit development and harvest stage and vine length measured at the harvest stage. Total marketable yield and fruit quality (firmness and sugar content) were determined during the harvest period. Soil chemical and microbial analysis were conducted at the end of the experimental period (March 2015). No significant differences (P = 0.05) were found between water deficit treatments in vine length, SPAD, Pn, gs, fruit firmness, and sugar content during the three-year study, except for vine length in 2013. But, marketable yield from T1 treatment was significantly higher (P = 0.03) than T3 in 2013. Vine length and SPAD measured from the ST plots were higher than CT, especially in 2012. Interestingly, marketable yield from ST was 8.6, 9.7 and 14.9 t ha−1 higher than CT in 2012, 2013 and 2014, respectively. Additionally, fruit sugar content under ST was statistically higher (P = 0.05) than those from CT. After 6 years of tillage practices (2009–2015) in the same site, ST increased total bacteria by 49%, active bacteria by 27%, active and total fungi by 37%, nematodes by 275%, and electrical conductivity by 14% compared to CT. However, ST significantly increased root-feeding nematodes (harmful to plant roots) and reduced phosphorus and nitrate-N compared to CT. Although long-term studies aimed at assessing soil quality and cumulative yield are required to further validate our results, yield and fruit quality (sugar content) responses were consistent across three years and with promising abundance of soil microbial activities.

Effective nutrition and irrigation are important nursery strategies to produce high-quality seedlings able to withstand heat and drought stress in the field. The objectives of this study were 2-fold, first to identify the influence of two nitrogen (N) levels (75 and 150 mg·L−1) and two fertigation (FR) methods, overhead (OH) and flotation (FL) of artichoke (Cynara cardunculus cv. Green Globe Improved) transplants on root/shoot growth and leaf physiology during the nursery period. A repeated greenhouse experiment was conducted and morphophysiological measurements were determined at 4 and 7 weeks after seeding (WAS). The second objective was to determine the impact of the nursery treatments (FR method and N level) on the subsequent crop growth and yield under three field irrigation methods [surface drip, subsurface drip, and overhead-linear system (OH-L)]. Field measurements were conducted at 50 and 150 days after field transplanting (DAT) during Fall–Winter 2015. Transplants fertilized with 75 mg·L−1 N (low N) had improved root components as compared to those with 150 mg·L−1 N (high N), especially at 4 WAS. The low N transplants had higher root surface area, root length, root branching, thinner root diameter, and less shoot area than the high N transplants. Wilting for low N transplants was 13.5% less than that for high N at 5 DAT, with a total yield similar or slightly higher than those of high N. Although growth of OH and FL transplants was statistically similar at transplanting, those irrigated with OH (greenhouse) had a 10% higher yield than FL irrigated transplants, regardless of the field irrigation method evaluated. Overall, low N level (75 mg·L−1 N) applied with OH irrigation in the nursery positively improved the transplant root system and transplant quality of artichoke seedlings.

For large fields, remote sensing might permit plant low moisture status to be detected early, and this may improve drought detection and monitoring. The objective of this study was to determine whether canopy and soil surface reflectance data derived from a handheld spectroradiometer can detect moisture status assessed using midday stem water potential (ψsmd) in pecan (Carya illinoinensis) during cyclic flood irrigations. We conducted the study simultaneously on two mature pecan orchards, one in a sandy loam (La Mancha) and the other in a clay loam (Leyendecker) soil. We were particularly interested in detecting moisture status in the −0.90 to −1.5 MPa ψsmd range because our previous studies indicated this was the critical range for irrigating pecan. Midday stem water potential, photosynthesis (A) and canopy and soil surface reflectance measurements were taken over the course of irrigation dry-down cycles at ψsmd levels of −0.40 to −0.85 MPa (well watered) and −0.9 to −1.5 MPa (water deficit). The decline in A averaged 34% in La Mancha and 25% in Leyendecker orchard when ψsmd ranged from −0.9 to −1.5 MPa. Average canopy surface reflectance of well-watered trees (ψsmd −0.4 to −0.85 MPa) was significantly higher than the same trees experiencing water deficits (ψsmd −0.9 to −1.5 MPa) within the 350- to 2500-nm bands range. Conversely, soil surface reflectance of well-watered trees was lower than water deficit trees over all bands. At both orchards, coefficient of determinations between ψsmd and all soil and canopy bands and surface reflectance indices were less than 0.62. But discriminant analysis models derived from combining soil and canopy reflectance data of well-watered and water-deficit trees had high classification accuracy (overall and cross-validation classification accuracy >80%). A discriminant model that included triangular vegetation index (TVI), photochemical reflectance index (PRI), and normalized soil moisture index (NSMI) had 85% overall accuracy and 82% cross-validation accuracy at La Mancha orchard. At Leyendecker, either a discriminant model weighted with two soil bands (690 and 2430 nm) or a discriminant model that used PRI and soil band 2430 nm had an overall classification and cross-validation accuracy of 99%. In summary, the results presented here suggest that canopy and soil hyperspectral data derived from a handheld spectroradiometer hold promise for discerning the ψsmd of pecan orchards subjected to flood irrigation.

Demand for New Mexico's limited water resources coupled with periodic drought has increased the necessity for tree water status monitoring to guide irrigation scheduling of pecan (Carya illinoinensis) orchards. The objectives of this study were to assess the impact of water status developed during the flood irrigation dry-down cycles on photosynthesis (Pn), and gas exchange (stomatal conductance (gS )t o H 2 O( gH2O), transpiration (E), and intercellular CO2 (ci)) and to establish values of midday stem water potential (Csmd) that are needed to maintain Pn and gas exchange of pecan. We conducted the study simultaneously on two southern New Mexico mature pecan orchards from 2011 through 2013. Flood irrigation as determined by grower practice was used on both orchards and Pn, gH2O, E, and ci were assessed at Csmd of -0.4 to -2.0 MPa. Photosynthesis and gas exchange were higher in pecan trees shortly after irrigation than trees exhibiting water deficit near the end of a flood irrigation dry-down cycle. The decline in Pn was markedly noticeable when Csmd dropped below -0.9 MPa. We attributed the reduction in Pn mostly to stomatal limitation. The decline in Pn and gH2O exceeded 50% when Csmd ranged from -1.5 to -2.0 MPa. For those reasons, we recommended that pecan orchards be maintained at Csmd higher than -0.90 MPa to prevent significant reductions in carbon assimilation and gas exchange. With the prediction of rising global air temperatures, drought may become more frequent and severe in areas where problems with water resources already exist (Wujeska et al., 2013). New Mexico has an arid to semiarid climate. Mean annual precipitation is 200 mm and average annual temperature is 20 � C. Pecan is one of the most important agricultural crops in New Mexico. In 2012, New Mexico produced 31.3 million kilograms of pecan nuts (in-shell basis), which accounted for 23% of the U.S. production (U.S. Department of Agriculture (USDA), 2012). However, the extreme demand for water coupled with periods of drought and increasing pecan acreage has reduced the available water for irrigating pecan (Johnson, 2004; Samani et al., 2011). Because of ongoing drought in the Rio Grande Basin, irrigation districts have allocated much less water to farmers than in the past. Farmers in the region recently have been forced to rely heavily on water pumped from wells to irrigate orchards. Orchards without available well water have not been irrigated adequately and typically have died. Pecan requires adequate water for development of the nut. Pecan nut development can be divided into two stages: nut